Forecast Discussions mentioning "ACARS", "MDCRS", "AIRCRAFT", "TAMDAR", or "AMDAR" received at FSL on 06/14/08

AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
200 AM PDT THU JUN 12 2008 .SYNOPSIS...HIGH PRESSURE ALOFT WILL INCREASE TODAY THROUGH SATURDAY. LITTLE CHANGE SUNDAY...THEN A TROUGH WILL GRADUALLY DEEPEN TO THE NORTH NEXT WEEK. WARMER AND HOTTER THROUGH SATURDAY. MARINE LAYER WILL BEGIN TO DECREASE AFTER THIS MORNING AND BECOME LOWER...THEN INCREASE NEXT WEEK. SOME DENSE FOG MAY DEVELOP MAINLY NEAR THE COAST FRIDAY NIGHT AND SATURDAY MORNING. NO SIGNIFICANT WINDS EXCEPT BREEZY IN THE UPPER DESERTS SATURDAY AFTERNOON. && .DISCUSSION...FOR SOUTHWEST CALIFORNIA INCLUDING SAN DIEGO... ORANGE...SOUTHWEST SAN BERNARDINO AND WEST RIVERSIDE COUNTIES. COASTAL EDDY CONTINUES TO PLAGUE SOCAL BUT MODELS SHOW EDDY BECOMES MORE ELONGATED WITH A BROAD SOUTH FLOW OVER THE COASTAL WATERS TODAY THROUGH TONIGHT. NAM MODEL SHOWS EDDY FALLING APART LATE FRIDAY INTO SATURDAY BUT STILL KEEPS SOME HIGH RELATIVE HUMIDITY AT THE COAST. HIGH PRESSURE ALOFT INCREASES THROUGH SATURDAY. MARINE LAYER MAY BE SQUASHED OUT OF EXISTENCE BY SATURDAY MORNING BUT MODELS KEEP MOISTURE INTACT ALONG THE COAST AND ALONG WITH THE STRONG INVERSION...MAY BE SOME DENSE FOG LATE FRIDAY NIGHT INTO SATURDAY MORNING. LITTLE CHANGE FOR SUNDAY. A LARGE AREA OF MAINLY HIGH CLOUDS IS FORECAST TO MOVE OVER SOCAL FRIDAY NIGHT THROUGH SUNDAY... DECREASING SUNDAY AFTERNOON. WILL KEEP IT MOSTLY SUNNY FOR NOW BUT COULD BE A BIT DENSE WITH MORE LIKE PARTLY CLOUDY SKIES THEN. MOISTURE ALSO COMES DOWN TO ABOUT 700 MB WHICH MAY CONTRIBUTE TO PARTLY TO MOSTLY CLOUDY SKIES. HIGH PRESSURE WEAKENS SLIGHTLY SUNDAY. A TROUGH SLOWLY DEEPENS INTO THE PACIFIC NORTHWEST THROUGH THE MIDDLE OF NEXT WEEK...INCREASING THE MARINE LAYER WITH A COASTAL EDDY POSSIBLY WINDING UP AGAIN. WARMER IN THE COASTAL AREAS TO HOTTER INLAND THROUGH SATURDAY...THEN LITTLE CHANGE SUNDAY OR NOT AS HOT...THEN GRADUAL COOLING THROUGH THE MIDDLE OF NEXT WEEK. VERY WEAK OFFSHORE FLOW FOR THE MORNINGS THROUGH SATURDAY WILL CAUSE SOME LIGHT NORTHEAST WINDS OVER THE MOUNTAINS AND INLAND DURING THE MORNINGS...OTHERWISE NO SIGNIFICANT WINDS WITH ONSHORE BREEZES IN THE AFTERNOONS AND WINDS TO 25 MPH IN THE UPPER DESERTS SATURDAY AFTERNOON. && .AVIATION... 120800Z...MDCRS SOUNDINGS AND TOP REPORTS SHOW THE MARINE LAYER DEPTH TO BE AROUND 2000 FEET. THE MARINE LAYER SHOULD LOWER TO AROUND 1500 FEET TONIGHT. STRATUS WITH BASES AROUND 1600 FEET MSL EXTENDS INLAND OVER THE INLAND VALLEY AREAS. EXPECT THE STRATUS TO BEGIN TO BREAK UP ALONG THE EASTERN EDGES AROUND 15Z AND CLEAR BACK TO THE COASTAL WATERS BETWEEN 16Z AND 17Z. STRATUS SHOULD PUSH BACK ONTO THE COAST AROUND SUNSET AND INLAND DURING THE EVENING. WITH THE LOWER MARINE LAYER EXPECTED TONIGHT...STRATUS SHOULD NOT GET AS FAR INLAND. ABOVE THE MARINE LAYER...A MOSTLY CLEAR SKY WITH UNRESTRICTED VISIBILITIES WILL CONTINUE THROUGH FRIDAY. && .SGX WATCHES/WARNINGS/ADVISORIES... HIGH RIP CURRENT RISK AT ORANGE COUNTY BEACHES TODAY. && $$ PUBLIC......WHITLOW AVIATION....HORTON NWS ON THE WEB AT WEATHER.GOV/SANDIEGO
AREA FORECAST DISCUSSION
NWS UPTON NY
1030 AM EDT THU JUN 12 2008 .SYNOPSIS... HIGH PRESSURE WILL BUILD IN BOTH ALOFT AND AT THE SURFACE THROUGH THE END OF THE WEEK. A COLD FRONT WILL MOVE ACROSS THE REGION LATE ON SATURDAY...THEN ANOTHER WEAK SYSTEM WILL AFFECT THE REGION MONDAY. AN UPPER LEVEL LOW WILL THEN PARK ITSELF OVER THE NORTHEAST EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... SFC HIGH PRESSURE JUST NORTH OF NY STATE WILL CONTINUE TO BUILD ACROSS THE NORTHEAST THE NEXT 24 HOURS. SUBSIDENCE AND A DEEP-LAYERED NORTHERLY FLOW WILL ALLOW THE AIRMASS TO HEAT UP THIS AFTERNOON INTO THE LOWER AND MIDDLE 80S MOST EVERYWHERE...EVEN COASTAL AREAS AS THE FLOW REMAINS OFFSHORE. THIS SUPPORTED BY LATEST LAV NUMBERS. A LARGE AREA OF CONVECTION UPSTREAM ACROSS THE UPPER MS VLY... ASSOCIATED WITH AN ANOMALOUSLY STRONG UPPER LOW (NEGATIVE HEIGHT ANOMALY OF 3-4 STANDARD DEVIATIONS)...MAY SEND SOME HIGH CLOUDS THIS WAY THE NEXT 24 HOURS. HOWEVER...BUILDING HEIGHTS ALOFT SHOULD HELP TO DISSIPATE THE CLOUDS ENOUGH SO FOR MOSTLY SUNNY/MOSTLY CLEAR SKIES. A COMBINATION OF A DRY AIRMASS AND LIGHT WINDS TONIGHT WILL ALLOW THE OUTLYING SUBURBS TO RADIATE WELL...WITH MORNING LOWS FORECAST TO BE BELOW NORMAL BY SEVERAL DEGREES. METRO NY ON THE OTHER HAND WILL BE A FEW DEGREES ABOVE NORMAL. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... HIGH PRESSURE BUILDS OFFSHORE ON FRI WITH A RETURN FLOW BECOMING ESTABLISHED. VERTICAL TEMP PROFILE WILL BE SIMILAR TO THU...BUT THE ONSHORE FLOW WILL KEEP COASTAL LOCATIONS SEVERAL DEGREES COOLER. INLAND...TEMPS WILL BE AT OR SLIGHTLY HIGHER THAN ON THU. A HIGH AMPLITUDE RIDGE ALOFT WILL TRANSLATE SLOWLY EASTWARD THROUGH SAT. THIS WILL RESULT IN MOSTLY SUNNY SKIES FRI AND FOR MUCH OF SAT. HEIGHT FALLS ACROSS CENTRAL CAN AND THE GREAT LAKES...ASSOCIATED WITH A STRONG UPPER LOW...WILL SEND THE UPPER HIGH OFFSHORE AND A WEAKENING COLD FRONT INTO THE AREA SAT EVE. MODERATE INSTABILITY AND WEAK SHEAR MAY LEAD TO SCT STRONG THUNDERSTORMS WITH A PERHAPS AN ISOLATED PULSE SEVERE STORM. HOWEVER...THE TIMING OF THE FRONT AND LACK OF SHEAR DOES NOT FAVOR ORGANIZED CONVECTION. DAYTIME HIGHS WILL BE SIMILAR TO FRI...LOWER TO MIDDLE 80S INLAND AND IN THE 70S ALONG THE IMMEDIATE COAST. COLD FRONT MOVES THROUGH EAST OF THE AREA BY AROUND DAYBREAK SUN. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... A SECOND FRONT WILL LIKELY MOVE ACROSS THE AREA THE BEGINNING OF NEXT WEEK. THEREFORE...ANOTHER ROUND OF SHOWERS AND POSSIBLY THUNDER IS POSSIBLE LATER MONDAY THROUGH TUESDAY. HIGH PRESSURE BUILDS BACK IN ON WEDNESDAY. OVERALL...TEMPERATURES DURING THE LONG TERM FORECAST LOOK TO BE NEAR SEASONAL LEVELS. && .AVIATION /14Z THURSDAY THROUGH MONDAY/... VFR FOR THE NEXT 24 HOURS. WINDS RECENTLY SHIFTED NNW TO N WITH RECENT PASSAGE OF WEAKENING COLD FRONT. THE QUESTION WILL BE IF A SEA BREEZE CAN INITIATE AND MOVE THROUGH SOME OF THE TERMINALS THIS AFTERNOON/EVENING. IT WAS HELD IN CHECK YESTERDAY BY A DEEP NW FLOW. NAM FORECAST SOUNDINGS SHOW AN OPPOSING NORTHERLY FLOW UP TO A COUPLE THOUSAND FEET TOMORROW AFTERNOON/EVENING AT A MAGNITUDE AT OR STRONGER THAN YESTERDAY`S (BASED ON ACARS SOUNDINGS). GFS IS WEAKER...AND THUS OFFERS A BETTER CHANCE OF A SEA BREEZE INITIATION LATE IN THE AFTERNOON. THINK THAT THERE`S A BETTER CHANCE THAT A SEA BREEZE DOES NOT DEVELOP...AND IF IT WERE TO...IT PROBABLY WOULDN`T MAKE MUCH NORTHERN ADVANCEMENT. WILL THEREFORE NOT HAVE SEA BREEZE IN THE FORECAST. WINDS GO LIGHT AND VARIABLE AFTER DARK AS HIGH PRESSURE RIDGE AXIS MOVES INTO THE REGION. OUTLOOK FOR 12Z THURSDAY THROUGH MONDAY...VFR THROUGH AT LEAST FRIDAY. SUB VFR CONDITIONS POSSIBLE IN SHOWERS ON SATURDAY WITH THE APPROACH OF A COLD FRONT. VFR CONDITIONS WILL RETURN ON SUNDAY. ANOTHER COLD FRONT MAY BRING SUB VFR CONDITIONS ON MONDAY. && .MARINE... HIGH PRESSURE WILL SLOWLY BUILD ACROSS THE WATERS THROUGH FRIDAY. A WEAK COLD FRONT MOVES ACROSS THE WATERS ON SATURDAY NIGHT... TOUCHING OFF SCATTERED SHOWERS AND TSTMS SATURDAY AFTERNOON AND NIGHT. WEAK HIGH PRESSURE MOVES INTO THE WATERS ON SUNDAY...BUT ANOTHER WEAK COLD FRONT WILL AFFECT THE WATERS MONDAY NIGHT INTO TUESDAY. SUSTAINED WINDS THROUGH THE ENTIRE PERIOD ARE NOT FORECAST TO GO ABOVE 15 KT...SO WINDS AND SEAS ARE EXPECTED REMAIN BELOW SCA CRITERIA. && .HYDROLOGY... DRY THROUGH FRI. NEXT CHANCE OF RAIN IS WITH A COLD FRONTAL PASSAGE SAT NIGHT. RAINFALL AMOUNTS LOOK TO BE LESS THAN ONE HALF INCH...BUT LOCALLY HIGHER AMOUNTS POSSIBLE IN ANY THUNDERSTORMS. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$
AREA FORECAST DISCUSSION
NWS UPTON NY
737 AM EDT THU JUN 12 2008 .SYNOPSIS... HIGH PRESSURE WILL BUILD IN BOTH ALOFT AND AT THE SURFACE THROUGH THE END OF THE WEEK. A COLD FRONT WILL MOVE ACROSS THE REGION LATE ON SATURDAY...THEN ANOTHER WEAK SYSTEM WILL AFFECT THE REGION MONDAY. AN UPPER LEVEL LOW WILL THEN PARK ITSELF OVER THE NORTHEAST EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... A WEAKENING COLD FRONT HAS NOW DROPPED SOUTH OF THE AREA...BRINGING A REINFORCING SHOT OF DRY...MILD AIR INTO THE REGION. HEIGHTS WILL BUILD ALOFT...WHILE SFC HIGH PRESSURE OVER EASTERN CANADA BUILDS ACROSS THE NORTHEAST THE NEXT 24 HOURS. SUBSIDENCE AND A DEEP- LAYERED NORTHERLY FLOW WILL ALLOW THE AIRMASS TO HEAT UP THIS AFTERNOON INTO THE LOWER AND MIDDLE 80S MOST EVERYWHERE...EVEN COASTAL AREAS AS THE FLOW REMAINS OFFSHORE. A LARGE AREA OF CONVECTION UPSTREAM ACROSS THE UPPER MS VLY... ASSOCIATED WITH AN ANOMALOUSLY STRONG UPPER LOW (NEGATIVE HEIGHT ANOMALY OF 3-4 STANDARD DEVIATIONS)...MAY SEND SOME HIGH CLOUDS THIS WAY THE NEXT 24 HOURS. HOWEVER...BUILDING HEIGHTS ALOFT SHOULD HELP TO DISSIPATE THE CLOUDS ENOUGH SO FOR MOSTLY SUNNY/MOSTLY CLEAR SKIES. DAYTIME HIGHS TODAY WILL RUN 5 TO 10 DEGREES ABOVE NORMAL. A COMBINATION OF A DRY AIRMASS AND LIGHT WINDS TONIGHT WILL ALLOW THE OUTLYING SUBURBS TO RADIATE WELL...WITH MORNING LOWS FORECAST TO BE BELOW NORMAL BY SEVERAL DEGREES. METRO NY ON THE OTHER HAND WILL BE A FEW DEGREES ABOVE NORMAL. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... HIGH PRESSURE BUILDS OFFSHORE ON FRI WITH A RETURN FLOW BECOMING ESTABLISHED. VERTICAL TEMP PROFILE WILL BE SIMILAR TO THU...BUT THE ONSHORE FLOW WILL KEEP COASTAL LOCATIONS SEVERAL DEGREES COOLER. INLAND...TEMPS WILL BE AT OR SLIGHTLY HIGHER THAN ON THU. A HIGH AMPLITUDE RIDGE ALOFT WILL TRANSLATE SLOWLY EASTWARD THROUGH SAT. THIS WILL RESULT IN MOSTLY SUNNY SKIES FRI AND FOR MUCH OF SAT. HEIGHT FALLS ACROSS CENTRAL CAN AND THE GREAT LAKES...ASSOCIATED WITH A STRONG UPPER LOW...WILL SEND THE UPPER HIGH OFFSHORE AND A WEAKENING COLD FRONT INTO THE AREA SAT EVE. MODERATE INSTABILITY AND WEAK SHEAR MAY LEAD TO SCT STRONG THUNDERSTORMS WITH A PERHAPS AN ISOLATED PULSE SEVERE STORM. HOWEVER...THE TIMING OF THE FRONT AND LACK OF SHEAR DOES NOT FAVOR ORGANIZED CONVECTION. DAYTIME HIGHS WILL BE SIMILAR TO FRI...LOWER TO MIDDLE 80S INLAND AND IN THE 70S ALONG THE IMMEDIATE COAST. COLD FRONT MOVES THROUGH EAST OF THE AREA BY AROUND DAYBREAK SUN. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... A SECOND FRONT WILL LIKELY MOVE ACROSS THE AREA THE BEGINNING OF NEXT WEEK. THEREFORE...ANOTHER ROUND OF SHOWERS AND POSSIBLY THUNDER IS POSSIBLE LATER MONDAY THROUGH TUESDAY. HIGH PRESSURE BUILDS BACK IN ON WEDNESDAY. OVERALL...TEMPERATURES DURING THE LONG TERM FORECAST LOOK TO BE NEAR SEASONAL LEVELS. && .AVIATION /12Z THURSDAY THROUGH MONDAY/... VFR FOR THE NEXT 24 HOURS. WINDS RECENTLY SHIFTED NNW TO N WITH RECENT PASSAGE OF WEAKENING COLD FRONT. THE QUESTION WILL BE IF A SEA BREEZE CAN INITIATE AND MOVE THROUGH SOME OF THE TERMINALS THIS AFTERNOON/EVENING. IT WAS HELD IN CHECK YESTERDAY BY A DEEP NW FLOW. NAM FORECAST SOUNDINGS SHOW AN OPPOSING NORTHERLY FLOW UP TO A COUPLE THOUSAND FEET TOMORROW AFTERNOON/EVENING AT A MAGNITUDE AT OR STRONGER THAN YESTERDAY`S (BASED ON ACARS SOUNDINGS). GFS IS WEAKER...AND THUS OFFERS A BETTER CHANCE OF A SEA BREEZE INITIATION LATE IN THE AFTERNOON. THINK THAT THERE`S A BETTER CHANCE THAT A SEA BREEZE DOES NOT DEVELOP...AND IF IT WERE TO...IT PROBABLY WOULDN`T MAKE MUCH NORTHERN ADVANCEMENT. WILL THEREFORE NOT HAVE SEA BREEZE IN THE FORECAST. WINDS GO LIGHT AND VARIABLE AFTER DARK AS HIGH PRESSURE RIDGE AXIS MOVES INTO THE REGION. OUTLOOK FOR 12Z THURSDAY THROUGH MONDAY...VFR THROUGH AT LEAST FRIDAY. SUB VFR CONDITIONS POSSIBLE IN SHOWERS ON SATURDAY WITH THE APPROACH OF A COLD FRONT. VFR CONDITIONS WILL RETURN ON SUNDAY. ANOTHER COLD FRONT MAY BRING SUB VFR CONDITIONS ON MONDAY. && .MARINE... HIGH PRESSURE WILL SLOWLY BUILD ACROSS THE WATERS THROUGH FRIDAY. A WEAK COLD FRONT MOVES ACROSS THE WATERS ON SATURDAY NIGHT... TOUCHING OFF SCATTERED SHOWERS AND TSTMS SATURDAY AFTERNOON AND NIGHT. WEAK HIGH PRESSURE MOVES INTO THE WATERS ON SUNDAY...BUT ANOTHER WEAK COLD FRONT WILL AFFECT THE WATERS MONDAY NIGHT INTO TUESDAY. SUSTAINED WINDS THROUGH THE ENTIRE PERIOD ARE NOT FORECAST TO GO ABOVE 15 KT...SO WINDS AND SEAS ARE EXPECTED REMAIN BELOW SCA CRITERIA. && .HYDROLOGY... DRY THROUGH FRI. NEXT CHANCE OF RAIN IS WITH A COLD FRONTAL PASSAGE SAT NIGHT. RAINFALL AMOUNTS LOOK TO BE LESS THAN ONE HALF INCH...BUT LOCALLY HIGHER AMOUNTS POSSIBLE IN ANY THUNDERSTORMS. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ SYNOPSIS...DW NEAR TERM...DW SHORT TERM...DW LONG TERM...FIG AVIATION...JC MARINE...JC HYDROLOGY...DW
AREA FORECAST DISCUSSION
NWS UPTON NY
445 AM EDT THU JUN 12 2008 .SYNOPSIS... ON THE HEELS OF A COLD FRONTAL PASSAGE THIS MORNING...HIGH PRESSURE WILL BUILD IN BOTH ALOFT AND AT THE SURFACE THROUGH THE END OF THE WEEK. A COLD FRONT WILL MOVE ACROSS THE REGION LATE ON SATURDAY...THEN ANOTHER WEAK SYSTEM WILL AFFECT THE REGION MONDAY. AN UPPER LEVEL LOW WILL THEN PARK ITSELF OVER THE NORTHEAST EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... A WEAKENING COLD FRONT WILL DROP SOUTH OF THE AREA DURING THE NEXT FEW HOURS...BRINGING A REINFORCING SHOT OF DRY...MILD AIR INTO THE REGION. HEIGHTS WILL BUILD ALOFT...WHILE SFC HIGH PRESSURE OVER EASTERN CANADA BUILDS ACROSS THE NORTHEAST THE NEXT 24 HOURS. SUBSIDENCE AND A DEEP-LAYERED NORTHERLY FLOW WILL ALLOW THE AIRMASS TO HEAT UP THIS AFTERNOON INTO THE LOWER AND MIDDLE 80S MOST EVERYWHERE...EVEN COASTAL AREAS AS THE FLOW REMAINS OFFSHORE. A LARGE AREA OF CONVECTION UPSTREAM ACROSS THE UPPER MS VLY... ASSOCIATED WITH AN ANOMALOUSLY STRONG UPPER LOW (NEGATIVE HEIGHT ANOMALY OF 3-4 STANDARD DEVIATIONS)...MAY SEND SOME HIGH CLOUDS THIS WAY THE NEXT 24 HOURS. HOWEVER...BUILDING HEIGHTS ALOFT SHOULD HELP TO DISSIPATE THE CLOUDS ENOUGH SO FOR MOSTLY SUNNY/MOSTLY CLEAR SKIES. DAYTIME HIGHS TODAY WILL RUN 5 TO 10 DEGREES ABOVE NORMAL. A COMBINATION OF A DRY AIRMASS AND LIGHT WINDS TONIGHT WILL ALLOW THE OUTLYING SUBURBS TO RADIATE WELL...WITH MORNING LOWS FORECAST TO BE BELOW NORMAL BY SEVERAL DEGREES. METRO NY ON THE OTHER HAND WILL BE A FEW DEGREES ABOVE NORMAL. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... HIGH PRESSURE BUILDS OFFSHORE ON FRI WITH A RETURN FLOW BECOMING ESTABLISHED. VERTICAL TEMP PROFILE WILL BE SIMILAR TO THU...BUT THE ONSHORE FLOW WILL KEEP COASTAL LOCATIONS SEVERAL DEGREES COOLER. INLAND...TEMPS WILL BE AT OR SLIGHTLY HIGHER THAN ON THU. A HIGH AMPLITUDE RIDGE ALOFT WILL TRANSLATE SLOWLY EASTWARD THROUGH SAT. THIS WILL RESULT IN MOSTLY SUNNY SKIES FRI AND FOR MUCH OF SAT. HEIGHT FALLS ACROSS CENTRAL CAN AND THE GREAT LAKES...ASSOCIATED WITH A STRONG UPPER LOW...WILL SEND THE UPPER HIGH OFFSHORE AND A WEAKENING COLD FRONT INTO THE AREA SAT EVE. MODERATE INSTABILITY AND WEAK SHEAR MAY LEAD TO SCT STRONG THUNDERSTORMS WITH A PERHAPS AN ISOLATED PULSE SEVERE STORM. HOWEVER...THE TIMING OF THE FRONT AND LACK OF SHEAR DOES NOT FAVOR ORGANIZED CONVECTION. DAYTIME HIGHS WILL BE SIMILAR TO FRI...LOWER TO MIDDLE 80S INLAND AND IN THE 70S ALONG THE IMMEDIATE COAST. COLD FRONT MOVES THROUGH EAST OF THE AREA BY AROUND DAYBREAK SUN. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... A SECOND FRONT WILL LIKELY MOVE ACROSS THE AREA THE BEGINNING OF NEXT WEEK. THEREFORE...ANOTHER ROUND OF SHOWERS AND POSSIBLY THUNDER IS POSSIBLE LATER MONDAY THROUGH TUESDAY. HIGH PRESSURE BUILDS BACK IN ON WEDNESDAY. OVERALL...TEMPERATURES DURING THE LONG TERM FORECAST LOOK TO BE NEAR SEASONAL LEVELS. && .AVIATION /07Z THURSDAY THROUGH MONDAY/... VFR FOR THE NEXT 24 HOURS. THE QUESTION WILL BE IF A SEA BREEZE CAN INITIATE AND MOVE THROUGH SOME OF THE TERMINALS THURSDAY AFTERNOON/EVENING. IT WAS HELD IN CHECK YESTERDAY BY A DEEP NW FLOW. NAM FORECAST SOUNDINGS SHOW AN OPPOSING NORTHERLY FLOW UP TO A COUPLE THOUSAND FEET TOMORROW AFTERNOON/EVENING AT A MAGNITUDE AT OR STRONGER THAN YESTERDAY`S (BASED ON ACARS SOUNDINGS). GFS IS WEAKER...AND THUS OFFERS A BETTER CHANCE OF A SEA BREEZE INITIATION LATE IN THE AFTERNOON. THINK THAT THERE`S A BETTER CHANCE THAT A SEA BREEZE DOES NOT DEVELOP...AND IF IT WERE TO...IT PROBABLY WOULDN`T MAKE MUCH NORTHERN ADVANCEMENT. WILL THEREFORE NOT HAVE SEA BREEZE IN THE FORECAST. OUTLOOK FOR 06Z THURSDAY THROUGH MONDAY...VFR THROUGH AT LEAST FRIDAY. SUB VFR CONDITIONS POSSIBLE IN SHOWERS ON SATURDAY WITH THE APPROACH OF A COLD FRONT. VFR CONDITIONS WILL RETURN ON SUNDAY. ANOTHER COLD FRONT MAY BRING SUB VFR CONDITIONS ON MONDAY. && .MARINE... HIGH PRESSURE WILL SLOWLY BUILD ACROSS THE WATERS THROUGH FRIDAY. A WEAK COLD FRONT MOVES ACROSS THE WATERS ON SATURDAY NIGHT... TOUCHING OFF SCATTERED SHOWERS AND TSTMS SATURDAY AFTERNOON AND NIGHT. WEAK HIGH PRESSURE MOVES INTO THE WATERS ON SUNDAY...BUT ANOTHER WEAK COLD FRONT WILL AFFECT THE WATERS MONDAY NIGHT INTO TUESDAY. SUSTAINED WINDS THROUGH THE ENTIRE PERIOD ARE NOT FORECAST TO GO ABOVE 15 KT...SO WINDS AND SEAS ARE EXPECTED REMAIN BELOW SCA CRITERIA. && .HYDROLOGY... DRY THROUGH FRI. NEXT CHANCE OF RAIN IS WITH A COLD FRONTAL PASSAGE SAT NIGHT. RAINFALL AMOUNTS LOOK TO BE LESS THAN ONE HALF INCH...BUT LOCALLY HIGHER AMOUNTS POSSIBLE IN ANY THUNDERSTORMS. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ SYNOPSIS...DW NEAR TERM...DW SHORT TERM...DW LONG TERM...FIG AVIATION...JC MARINE...JC HYDROLOGY...DW
AREA FORECAST DISCUSSION
NWS UPTON NY
151 AM EDT THU JUN 12 2008 .SYNOPSIS... HIGH PRESSURE WILL SLOWLY BUILD THROUGH THE REGION THROUGH THE END OF THE WEEK. A STORM SYSTEM WILL MOVE ACROSS THE REGION ON SATURDAY...THEN ANOTHER WEAK SYSTEM WILL AFFECT THE REGION MONDAY. AN UPPER LEVEL LOW WILL THEN PARK ITSELF OVER THE NORTHEAST EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... FORECAST ON TRACK UNDER MOSTLY CLEAR SKIES AND LIGHT NORTHWEST FLOW. TEMPS ARE RUNNING 2-3 DEG ABOVE IN THE NYC METRO AREA...MOST LIKELY HEAT ISLAND EFFECTS. DO NOT SEE THE NEED FOR A FORECAST UPDATE AS TEMPS SHOULD RADIATED DOWN TO THE FORECAST RANGE OF MID 60S. TEMPS RIGHT ON ELSEWHERE. && .SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY NIGHT/... HIGH PRES SLOWLY MOVES THROUGH THE REGION ON THU...MOVING OFFSHORE AND SOUTH OF THE AREA BY FRI AFTERNOON. MILD TEMPERATURES REMAIN IN PLACE AS HIGHS ON THU WILL TOP OFF IN THE LOW TO MID 80S...COOLER NEAR THE SHORE. A WARM FRONT WILL LIFT THROUGH THE REGION ON FRI AFTERNOON...SETTING UP A RETURN FLOW. TEMPERATURES WILL RISE INTO THE UPPER 80S TO NEAR 90 AND AFC DEW POINTS WILL RISE INTO THE LOWER 60S. WITH SOUTHERLY FLOW AND INCREASED MOISTURE ACROSS THE AREA FRI NIGHT...WILL MENTION PATCHY FOG FOR OUTLYING AREAS FRI NIGHT. WEAK LOW PRES WILL PASS NORTH OF THE REGION ON SAT...DRAGGING A COLD FRONT THROUGH THE CWA. 12Z/12 OPERATIONAL GFS DEVELOPS A CLOSED LOW OVER EASTERN LONG ISLAND BY 06Z SUN...BUT THIS APPEARS TO BE ON THE AGGRESSIVE SIDE. FOR NOW...WILL CONTINUE TO CARRY CHANCE POPS. COLD FRONT WILL SLIDE EAST OF THE REGION BY SUN MORNING. SOME SHOWERS MAY LINGER BEHIND THE FRONT ACROSS EASTERN CT AND LONG ISLAND SUN MORNING...BUT THOSE SHOULD TAPER OFF BY EARLY AFTERNOON. WITH ZONAL FLOW...SKIES WILL PARTIALLY CLEAR OUT IN THE AFTERNOON. HIGHS ON SAT WILL BE IN THE MID TO UPPER 80S...THEN WILL BE IN THE UPPER 70S TO LOWER 80S ON SUN AS COOLER AIR FILTERS INTO THE REGION. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... A SECOND FRONT WILL LIKELY MOVE ACROSS THE AREA THE BEGINNING OF NEXT WEEK. THEREFORE...ANOTHER ROUND OF SHOWERS AND POSSIBLE THUNDER IS POSSIBLE LATER MONDAY THROUGH TUESDAY. HIGH PRESSURE BUILDS BACK IN ON WEDNESDAY. OVERALL...TEMPERATURES DURING THE LONG TERM FORECAST LOOK TO BE NEAR SEASONAL LEVELS. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... VFR FOR THE NEXT 24 HOURS. THE QUESTION WILL BE IF A SEA BREEZE CAN INITIATE AND MOVE THROUGH SOME OF THE TERMINALS THURSDAY AFTERNOON/EVENING. IT WAS HELD IN CHECK YESTERDAY BY A DEEP NW FLOW. NAM FORECAST SOUNDINGS SHOW AN OPPOSING NORTHERLY FLOW UP TO A COUPLE THOUSAND FEET TOMORROW AFTERNOON/EVENING AT A MAGNITUDE AT OR STRONGER THAN YESTERDAY`S (BASED ON ACARS SOUNDINGS). GFS IS WEAKER...AND THUS OFFERS A BETTER CHANCE OF A SEA BREEZE INITIATION LATE IN THE AFTERNOON. THINK THAT THERE`S A BETTER CHANCE THAT A SEA BREEZE DOES NOT DEVELOP...AND IF IT WERE TO...IT PROBABLY WOULDN`T MAKE MUCH NORTHERN ADVANCEMENT. WILL THEREFORE NOT HAVE SEA BREEZE IN THE FORECAST. OUTLOOK FOR 06Z THURSDAY THROUGH MONDAY...VFR THROUGH AT LEAST FRIDAY. SUB VFR CONDITIONS POSSIBLE IN SHOWERS ON SATURDAY WITH THE APPROACH OF A COLD FRONT. VFR CONDITIONS WILL RETURN ON SUNDAY. ANOTHER COLD FRONT MAY BRING SUB VFR CONDITIONS ON MONDAY. && .MARINE... HIGH PRES WILL SLOWLY BUILDS OVER THE WATERS THROUGH FRI NIGHT. A WEAK COLD FRONT MOVES ACROSS THE WATERS ON SAT/SAT NIGHT... TOUCHING OFF SCT SHOWERS AND TSTMS. WEAK HIGH PRES MOVES INTO THE WATERS ON SUN...BUT ANOTHER WEAK COLD FRONT WILL AFFECT THE WATERS SUN NIGHT/MON. NO FLAGS ARE ANTICIPATED DURING THE FCST PERIOD. && .HYDROLOGY... DRY THROUGH FRI. NEXT CHANCE OF PRECIP IS WITH THE NEXT FRONTAL SYSTEM ON SAT. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ AVIATION...JC
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
736 PM EDT FRI JUN 13 2008 .UPDATE...ACARS DATA SHOWING CAPPING INVERSION AROUND 900MB AS SHOWERS CONTINUE TO DIMINISH ACROSS THE CWA. WILL DROP THE FLOOD WATCH AT 8PM SINCE LITTLE ADDITIONAL DEVELOPMENT IS EXPECTED. STORMS OVER IL ARE STRUGGLING TO MAINTAIN SO ANYTHING THAT DOES MANAGE TO DEVELOP WILL BE SHORT LIVED. MAY UPDATE TO REMOVE PRECIP AFTER MIDNIGHT AS THE COLD FRONT WILL PUSH THROUGH THE CWA ENDING CHANCES...BUT WILL CONTINUE TO MONITOR ACTIVITY IN IL BEFORE FINAL DECISION. NEW GRIDS/ZFP AVAILABLE AFT 00Z. && .AVIATION...DISCUSSION FOR THE 00Z TAFS A COLD FRONT WILL MOVE THROUGH INDIANA FROM 05Z-08Z. DRIER AIR WAS BEING PULLED INTO TAF LOCATIONS AHEAD OF THE FRONT. VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD. THE ONLY EXCEPTION WILL BE HUF WHERE THEY WILL START OUT WITH IFR CIGS. THESE WILL IMPROVE TO VFR BY 01Z. MUCH DRIER AIR WILL MOVE INTO AFT FROPA. SFC MSTR FROM THE SHOWERS AND TSTMS FRI AFTN WILL CAUSE SOME FOG FORMATION FROM 09Z-13Z. VSBYS SHOULD NOT DECREASE BELOW VFR LVLS. HIGH PRESSURE WILL BUILD INTO INDIANA ON SAT. ONLY SCT CU IS EXPECTED. && .DISCUSSION... MAIN FOCUS WILL WITH HEAVY RAIN EARLY TONIGHT AND THEN RAIN CHANCES SUNDAY NIGHT INTO MONDAY. SFC CHARTS INDICATED CD FNT WAS STILL ACROSS WRN ILLINOIS. HOWEVER OUTFLOW BOUNDARIES HAD CAUSED THUNDERSTORMS WERE FARTHER EAST MAINLY ACROSS OUR AREA. MAIN QUESTION IS HOW QUICK HEAVY RAIN WILL END. LOOKING UP STREAM IT COULD BE OVER WITH BY EVENING OVER THE NW HALF OF OUR AREA. WV IR INDICATED A S/W MOVG TOWARDS THE MID MISSISSIPPI VALLEY AND THIS SHOULD KEEP PRECIP ACROSS OUR AREA WELL INTO THE EVENING. I WILL END THE FLASH FLOOD WATCH ALONG AND NORTH OF I70 AS HEAVY RAIN WILL CERTAINLY BE OVER WITH BY THEN. IN THE SOUTH I WILL KEEP IT TO 4 AM. EVEN THOUGH PRECIP COULD END SOONER...I WOULD PREFER TO BE CONSERVATIVE IN SHORTENING FLASH FLOOD WATCH. COLD FRONT WILL BE NEAR THE OHIO RIVER BY 12Z SATURDAY. WILL ONLY MENTION SLIGHT CHANCE POPS IN OUR FAR SE EARLY SATURDAY. THEN DRY UNTIL LATE SUNDAY. WILL GO WITH COOLER MAV/MET TEMPERATURES ON SATURDAY BASED ON CURRENT TEMPERATURES UPSTREAM BEHIND CD FNT. ANOTHER CD FNT WILL MOVE THROUGH OUR REGION LATE SUNDAY NIGHT EARLY MONDAY. SPC HAS US IN A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR DAY 3 FOR OUR NW HALF WHICH WOULD BE MAINLY SUNDAY NIGHT. NAM SLOWS UP FRONT ON SUNDAY KEEPING PRECIP ACROSS OUR REGION...WHILE GFS IS MUCH MORE PROGRESSIVE AND ENDS PRECIP QUICKLY ON MONDAY. FOR NOW WILL USE BLEND DURING THE PERIOD WITH ONLY 20 PERCENT POPS NORTH. COOL AND MOSTLY DRY WEATHER WILL BE THE RULE REST OF THE WORK WEEK AS A LARGE UPPER LOW REMAINS ACROSS SOUTHERN ONTARIO AND THE GREAT LAKES. MODELS INDICATE 20 PERCENT POPS ARE POSSIBLE A FEW OF THOSE PERIODS...BUT WITH UNCERTAIN TIMING AND WITH AIRMASS BEING DRY WILL NOT MENTION ANY PRECIP DURING THE EXTENDED PERIOD FOR NOW. && .IND WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR INZ053>057-060>065- 067>072. FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR INZ021-028>031- 035>049-051-052. && $$ UPDATE...SALLY AVIATION...SH PUBLIC...JH
AREA FORECAST DISCUSSION...UPDATED
NWS MARQUETTE MI
708 PM EDT FRI JUN 13 2008 .SHORT TERM (TONIGHT AND SAT)... WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A DEEP MID/UPPER LOW JUST N OF MN. THIS WILL BE THE MAIN FEATURE INFLUENCING THE WEATHER ACROSS THE UPPER LAKES INTO EARLY NEXT WEEK AS IT MEANDERS/REDEVELOPS IN A GENERAL ERLY DIRECTION. TO THE SE OF THE CENTER OF THE LOW...SHARP DRYING JUST OFF THE SFC HAS SWEPT INTO THE FCST AREA TODAY AS NOTED BY MORNING TAMDAR SOUNDINGS FROM KSAW/KCMX. EXCEPT FOR AREAS VERY CLOSE TO LAKE MICHIGAN...THIS RESULTED IN LOW CLOUDS CLEARING OUT ACROSS THE FCST AREA AS MIXING DEPTH DEEPENED. OVER WRN UPPER MI...DRYING DUE TO MIXING IS ALSO NICELY REFLECTED BY THE VERY SHARP DROP IN SFC DWPTS FROM THE LWR 60S EARLY THIS MORNING TO THE UPPER 30S/LWR 40S AT SEVERAL REPORTING SITES THIS AFTN. IN THE SHORT TERM...MID/UPPER LEVEL LOW WILL HEAD NE TOWARD HUDSON BAY...AND ATTENTION WILL BE ON SHORTWAVES WRAPPING AROUND THE S SIDE OF THE SYSTEM. CURRENTLY...MAIN SHORTWAVE OF INTEREST IS ROTATING SE INTO ND. WITH THAT SHORTWAVE THEN HEADING E TO NE MN BY 12Z SAT... EXPECT TONIGHT TO BE DRY ACROSS THE BULK OF THE FCST AREA. EVEN AS WE APPROACH PEAK HEATING OF THE DAY...CURRENT REGIONAL RADAR IMAGERY SHOWS NO PCPN UPSTREAM ACROSS CNTRL MN INTO NW WI. RADAR RETURNS ARE SHOWING UP FARTHER N AND W IN NRN AND WRN MN...BUT EXPECT THESE TO EITHER PASS JUST NW OF UPPER MI ACROSS FAR WRN LAKE SUPERIOR OR DISSIPATE BEFORE REACHING THE AREA. WITH LOSS OF DIURNAL HEATING... ANY PCPN ACCOMPANYING APPROACHING SHORTWAVE LATE TONIGHT SHOULD BE CONFINED TO THE SMALL AREA OF STRONGEST DEEP LAYER FORCING. SINCE THE BEST FORCING...ALBEIT WEAK...WILL BE NEARING WRN LAKE SUPERIOR BY 12Z SAT...OPTED TO RETAIN INHERITED FCST OF SLIGHT CHC POPS OVER WRN LAKE SUPERIOR LATE IN THE NIGHT. SHORTWAVE AND ACCOMPANYING COOLER AIR ALOFT (500MB TEMPS SAT AFTN AROUND -18C WILL BE ABOUT 4C LWR THAN THIS AFTN) CONTINUE EWD SAT WITH TAIL END OF WAVE SWINGING ACROSS THE FCST AREA. FORCING ASSOCIATED WITH SHORTWAVE WILL ARRIVE MORE FAVORABLY WITH DIURNAL HEATING CYCLE OVER THE CNTRL AND ERN FCST AREA...SO BEST COVERAGE (HIGHER CHC POPS) OF SHRA/TSRA WILL OCCUR THERE SAT AFTN. IN ADDITION...THERE WILL BE BETTER LOW LEVEL CONVERGENCE OVER THE E HALF OF THE FCST AREA AS LAKE BREEZE FROM LAKE MICHIGAN PUSHES INLAND WITH POSSIBILITY OF LAKE BREEZE DEVELOPMENT NEAR LAKE SUPERIOR AS WELL. MODIFYING NAM/GFS FCST SOUNDINGS FOR T/TD OF ROUGHLY LWR 70S/AROUND 50F YIELD SBCAPE OF 200-700J/KG WITH THE NAM AT THE HIGHER END OF THE INSTABILITY RANGE. DEEP LAYER SHEAR ON THE ORDER OF 30-40KT SUPPORTS STORM ORGANIZATION...SO ISOLD SVR CAN`T BE RULED OUT...ESPECIALLY IF THERE IS ENOUGH DAYTIME HEATING. LOW WETBULB ZERO HEIGHTS GENERALLY BTWN 8.2-9KFT SHOULD SUPPORT MARGINAL SVR HAIL AS THE MAIN SVR THREAT. && .LONG TERM (SATURDAY NIGHT THROUGH FRIDAY)... THE UNSETTLED WEATHER WILL BE ON THE WAY OUT...EVENTUALLY. AS FOR TEMPERATURES FRIDAY NIGHT/SUNDAY MORNING...UTILIZING MET/NAM GUIDANCE WOULD RESULT IN A 10 DEGREE TEMPERATURE INCREASE FROM THE ONGOING FORECAST. WILL NOT GO THIS DRAMATIC YET...AND SAY CLOSER TO THE MAV/GFS GUIDANCE WHICH IS ONLY AROUND 5 DEGREES WARMER. HOWEVER...WE WILL STILL NEED TO KEEP AN EYE ON THE PESKY 500MB LOW. THIS LOW IS FIGURED TO MAKE A SOUTHEASTWARD PROGRESSION FROM WESTERN ONTARIO TODAY TO NEW YORK AND SOUTHEASTERN ONTARIO. IT SHOULD REMAIN FAIRLY STATIONARY OVER THIS AREA FROM WEDNESDAY EVENING THROUGH AT LEAST THURSDAY AFTERNOON. AT THAT POINT...IT IS UNKNOWN IF THE 13/06Z GFS WILL WIN OUT...CONTINUING TO KEEP THIS FEATURE STATIONARY OVER THE NEW ENGLAND STATES THROUGH FRIDAY...OR IF THE MORE PROGRESSIVE 13/00Z ECMWF WILL WIN OUT. THE ECMWF WOULD LEAD TO A STRONGER 500MB RIDGE FOR UPPER MICHIGAN TUESDAY THROUGH FRIDAY. MUCH OF THE THE LONG TERM FORECAST FOLLOWS THE OPERATIONAL ECMWF. WILL NEED TO KEEP AN EYE ON THIS...AND THE PROGRESSION OF A SHORTWAVE DIVING IN TUESDAY INTO THURSDAY...WHICH WAS MORE EVIDENT FROM THE GFS...CANADIAN...AND UKMET. THE ECMWF CONTINUES NW FLOW AT 500MB...WITH THE MAIN LOW QUICKLY SLIDING AWAY/ AFTERNOON CONVECTION MAY POP UP TOWARDS THE END OF THE WORK WEEK...FRIDAY MAINLY ACROSS THE WESTERN THIRD OF THE CWA. WILL LEAVE IT OUT FOR NOW...DUE TO THE LOW PROBABILITY...AND LEAVE AN OPTIMISTIC DRY FORECAST. && .AVIATION (FOR THE 00Z TAF ISSUANCE)... PREVAILING VFR CONDITIONS ARE EXPECTED AT KCMX/KSAW THRU THIS FCST PERIOD. DISTURBANCE APPROACHING FROM THE W SAT MORNING SHOULD TRIGGER A FEW -SHRA BY LATE SAT MORNING INTO THE AFTERNOON. WILL INCLUDE A PROB30 AT BOTH TAF SITES ALTHOUGH KSAW WILL HAVE A LONGER WINDOW FOR INSTABILITY TO BUILD INTO THE AFTERNOON HRS. && .MARINE (FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)... WINDS SHOULD REMAIN UNDER 25KT THRU THU. IN GENERAL...THE STRONGEST WINDS WILL LIKELY OCCUR SUN NIGHT THRU MON NIGHT AS LOW PRES E OF LAKE SUPERIOR SLOWLY MOVES TO SRN QUEBEC AND HIGH PRES BUILDS INTO THE NRN PLAINS. NW WINDS...ESPECIALLY GUSTS...SHOULD BE IN THE 15-25KT RANGE DURING THAT TIME...MAINLY OVER THE E HALF OF LAKE SUPERIOR. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...ROLFSON LONG TERM...KF AVIATION...VOSS MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
422 PM EDT FRI JUN 13 2008 .SHORT TERM (TONIGHT AND SAT)... WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A DEEP MID/UPPER LOW JUST N OF MN. THIS WILL BE THE MAIN FEATURE INFLUENCING THE WEATHER ACROSS THE UPPER LAKES INTO EARLY NEXT WEEK AS IT MEANDERS/REDEVELOPS IN A GENERAL ERLY DIRECTION. TO THE SE OF THE CENTER OF THE LOW...SHARP DRYING JUST OFF THE SFC HAS SWEPT INTO THE FCST AREA TODAY AS NOTED BY MORNING TAMDAR SOUNDINGS FROM KSAW/KCMX. EXCEPT FOR AREAS VERY CLOSE TO LAKE MICHIGAN...THIS RESULTED IN LOW CLOUDS CLEARING OUT ACROSS THE FCST AREA AS MIXING DEPTH DEEPENED. OVER WRN UPPER MI...DRYING DUE TO MIXING IS ALSO NICELY REFLECTED BY THE VERY SHARP DROP IN SFC DWPTS FROM THE LWR 60S EARLY THIS MORNING TO THE UPPER 30S/LWR 40S AT SEVERAL REPORTING SITES THIS AFTN. IN THE SHORT TERM...MID/UPPER LEVEL LOW WILL HEAD NE TOWARD HUDSON BAY...AND ATTENTION WILL BE ON SHORTWAVES WRAPPING AROUND THE S SIDE OF THE SYSTEM. CURRENTLY...MAIN SHORTWAVE OF INTEREST IS ROTATING SE INTO ND. WITH THAT SHORTWAVE THEN HEADING E TO NE MN BY 12Z SAT... EXPECT TONIGHT TO BE DRY ACROSS THE BULK OF THE FCST AREA. EVEN AS WE APPROACH PEAK HEATING OF THE DAY...CURRENT REGIONAL RADAR IMAGERY SHOWS NO PCPN UPSTREAM ACROSS CNTRL MN INTO NW WI. RADAR RETURNS ARE SHOWING UP FARTHER N AND W IN NRN AND WRN MN...BUT EXPECT THESE TO EITHER PASS JUST NW OF UPPER MI ACROSS FAR WRN LAKE SUPERIOR OR DISSIPATE BEFORE REACHING THE AREA. WITH LOSS OF DIURNAL HEATING... ANY PCPN ACCOMPANYING APPROACHING SHORTWAVE LATE TONIGHT SHOULD BE CONFINED TO THE SMALL AREA OF STRONGEST DEEP LAYER FORCING. SINCE THE BEST FORCING...ALBEIT WEAK...WILL BE NEARING WRN LAKE SUPERIOR BY 12Z SAT...OPTED TO RETAIN INHERITED FCST OF SLIGHT CHC POPS OVER WRN LAKE SUPERIOR LATE IN THE NIGHT. SHORTWAVE AND ACCOMPANYING COOLER AIR ALOFT (500MB TEMPS SAT AFTN AROUND -18C WILL BE ABOUT 4C LWR THAN THIS AFTN) CONTINUE EWD SAT WITH TAIL END OF WAVE SWINGING ACROSS THE FCST AREA. FORCING ASSOCIATED WITH SHORTWAVE WILL ARRIVE MORE FAVORABLY WITH DIURNAL HEATING CYCLE OVER THE CNTRL AND ERN FCST AREA...SO BEST COVERAGE (HIGHER CHC POPS) OF SHRA/TSRA WILL OCCUR THERE SAT AFTN. IN ADDITION...THERE WILL BE BETTER LOW LEVEL CONVERGENCE OVER THE E HALF OF THE FCST AREA AS LAKE BREEZE FROM LAKE MICHIGAN PUSHES INLAND WITH POSSIBILITY OF LAKE BREEZE DEVELOPMENT NEAR LAKE SUPERIOR AS WELL. MODIFYING NAM/GFS FCST SOUNDINGS FOR T/TD OF ROUGHLY LWR 70S/AROUND 50F YIELD SBCAPE OF 200-700J/KG WITH THE NAM AT THE HIGHER END OF THE INSTABILITY RANGE. DEEP LAYER SHEAR ON THE ORDER OF 30-40KT SUPPORTS STORM ORGANIZATION...SO ISOLD SVR CAN`T BE RULED OUT...ESPECIALLY IF THERE IS ENOUGH DAYTIME HEATING. LOW WETBULB ZERO HEIGHTS GENERALLY BTWN 8.2-9KFT SHOULD SUPPORT MARGINAL SVR HAIL AS THE MAIN SVR THREAT. && .LONG TERM (SATURDAY NIGHT THROUGH FRIDAY)... THE UNSETTLED WEATHER WILL BE ON THE WAY OUT...EVENTUALLY. AS FOR TEMPERATURES FRIDAY NIGHT/SUNDAY MORNING...UTILIZING MET/NAM GUIDANCE WOULD RESULT IN A 10 DEGREE TEMPERATURE INCREASE FROM THE ONGOING FORECAST. WILL NOT GO THIS DRAMATIC YET...AND SAY CLOSER TO THE MAV/GFS GUIDANCE WHICH IS ONLY AROUND 5 DEGREES WARMER. HOWEVER...WE WILL STILL NEED TO KEEP AN EYE ON THE PESKY 500MB LOW. THIS LOW IS FIGURED TO MAKE A SOUTHEASTWARD PROGRESSION FROM WESTERN ONTARIO TODAY TO NEW YORK AND SOUTHEASTERN ONTARIO. IT SHOULD REMAIN FAIRLY STATIONARY OVER THIS AREA FROM WEDNESDAY EVENING THROUGH AT LEAST THURSDAY AFTERNOON. AT THAT POINT...IT IS UNKNOWN IF THE 13/06Z GFS WILL WIN OUT...CONTINUING TO KEEP THIS FEATURE STATIONARY OVER THE NEW ENGLAND STATES THROUGH FRIDAY...OR IF THE MORE PROGRESSIVE 13/00Z ECMWF WILL WIN OUT. THE ECMWF WOULD LEAD TO A STRONGER 500MB RIDGE FOR UPPER MICHIGAN TUESDAY THROUGH FRIDAY. MUCH OF THE THE LONG TERM FORECAST FOLLOWS THE OPERATIONAL ECMWF. WILL NEED TO KEEP AN EYE ON THIS...AND THE PROGRESSION OF A SHORTWAVE DIVING IN TUESDAY INTO THURSDAY...WHICH WAS MORE EVIDENT FROM THE GFS...CANADIAN...AND UKMET. THE ECMWF CONTINUES NW FLOW AT 500MB...WITH THE MAIN LOW QUICKLY SLIDING AWAY/ AFTERNOON CONVECTION MAY POP UP TOWARDS THE END OF THE WORK WEEK...FRIDAY MAINLY ACROSS THE WESTERN THIRD OF THE CWA. WILL LEAVE IT OUT FOR NOW...DUE TO THE LOW PROBABILITY...AND LEAVE AN OPTIMISTIC DRY FORECAST. && .AVIATION (FOR THE 18Z TAF ISSUANCE)... VFR CONDITIONS ARE EXPECTED AT KCMX/KSAW THRU THIS FCST PERIOD. DISTURBANCE APPROACHING FROM THE W SAT MORNING SHOULD SPARK A FEW -SHRA LATE SAT MORNING OR EARLY AFTN. WITH A BETTER OPPORTUNITY FOR INSTABILITY TO BUILD AT KSAW THAN AT KCMX...WILL ONLY INCLUDE A PROB MENTION OF SHRA IN THE EARLY AFTN AT KSAW. && .MARINE (FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)... WINDS SHOULD REMAIN UNDER 25KT THRU THU. IN GENERAL...THE STRONGEST WINDS WILL LIKELY OCCUR SUN NIGHT THRU MON NIGHT AS LOW PRES E OF LAKE SUPERIOR SLOWLY MOVES TO SRN QUEBEC AND HIGH PRES BUILDS INTO THE NRN PLAINS. NW WINDS...ESPECIALLY GUSTS...SHOULD BE IN THE 15-25KT RANGE DURING THAT TIME...MAINLY OVER THE E HALF OF LAKE SUPERIOR. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...ROLFSON LONG TERM...KF AVIATION...ROLFSON MARINE...ROLFSON
AREA FORECAST DISCUSSION...UPDATED
NWS MARQUETTE MI
135 PM EDT FRI JUN 13 2008 UPDATED AVIATION DISCUSSION FOR 18Z TAFS .DISCUSSION... ISSUED AT 345 AM EDT 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW DEEP UPR LO NEAR THE ND/CNDN BORDER DRIFTING SLOWLY EWD BTWN RDG OVER THE PAC NW AND HI AMPLITUDE RDG STRETCHING FM HUDSON BAY TO THE SE STATES. SURGE OF MSTR AHD OF THIS TROF WITH 02Z TAMDAR SDNG FM SAW SHOWING 190/50KT WIND AT H910 AND PWAT AS HI AS 2 INCHES AT DVN HAS FUELED RIBBON OF SHRA/TSRA THAT IS NOW IMPACTING THE SE PART OF THE FA. ALTHOUGH UPR LO AND ATTENDANT SFC COLD FNT REMAINS TO THE W IN MN...ARRIVAL OF DRIER AIR SHOWN ON THE 00Z MPX SDNG IN THE SW FLOW ALF AHEAD OF THE SFC FNT HAS CAUSED THE PCPN OVER THE W HALF OF THE FA TO DIMINISH TO JUST ISOLD -SHRA. WHERE DRYING ALF HAS OCCURRED OVER THE W...SOME PLACES ARE REPORTING VSBY AS LO AS 1/4SM IN FG. CLOSER TO THE SFC COLD FNT/UPR LO (WHERE H5 TEMPS ARE AOB -20C AS FAR E AS INL)...SOME SHRA/TSRA ARE IMPACTING NCNTRL MN. MUCH COLDER LLVL AIR IS NOTED TO THE W OF THE UPR LO POSITIONS WITH 00Z H85 TEMPS 5C AT BIS/GGW. MAIN FCST CONCERNS THIS PACKAGE INVOLVE SHRA/TSRA CHCS WITH SHRTWVS ROTATING ARND UPR LO NOW IN THE NRN PLAINS THAT IS FCST TO DRIFT SLOWLY EWD THE NEXT COUPLE OF DAYS. FOR TDAY...NAM/GFS SHOW UPR LO DRIFTING NEWD INTO NW ONTARIO THRU 00Z SAT. WSW FLOW ON THE SE FLANK OF THIS SYS LOOKS TO ADVECT VERY DRY AIRMASS SHOWN ON THE 00Z MPX RAOB. THIS MOTION OF THE UPR LO WL ALSO RESTRICT THE TEMP DROP ALF...WITH CORE OF -20C AIR AT H5 REMAINING WELL TO THE NW. IN FACT...NAM/GFS FCST SDNGS SHOW FAIRLY IMPRESSIVE MID LVL CAPPING DVLPG ABV H7-6 AND LIMITING DEPTH OF ANY UPDRAFTS ABV RELATIVELY HI LCL NR H85. SO...EVEN THOUGH SFC COLD FNT WL DRIFT INTO THE WRN ZNS THIS AFTN...THINK CHCS OF CNVCTN ALG THIS BNDRY WL BE QUITE A BIT LESS THAN OBSVD IN MN YDAY AFTN/EVNG. CONSIDERING THE STRENGTH OF THE CAP/LO EQUILIBRIUM LVL WITH ENVIRONMENTAL TEMP ABV -10C AT THAT LVL...REMOVED MENTION OF TS AND JUST MENTIONED ISOLD -SHRA WITH 00Z SAT FCST KINX AT IWD ONLY ARND 20. OTRW...ANY MRNG FOG/ST WL DSPT QUICKLY WITH ARRIVAL OF DRY AIR/ DIURNAL HTG/MIXING. AS FOR TEMPS...WL TEND TO BUMP UP FCST MAX TEMPS THIS AFTN CONSIDERING UPSTREAM REPORTS IN THE UPR 70S OVER SRN MN YDAY AND MIXING TO H75 OVER THE CNTRL ZNS ON GFS/NAM FCST SDNGS. EXPECT LOWER HI TEMPS DOWNWIND OF LK MI AND OVER THE W. AS UPR LO OVER NW ONTARIO DRIFTS OFF TO THE NE TNGT...A SHRTWV ROTATING ARND THIS FEATURE IS FCST TO PUSH INTO THE MN ARROWHEAD BY 12Z SAT. IN THE ABSENCE OF DIURNAL HTG AND UNDER DRY/STABLE AIRMASS ALF...MOST OF THE NGT WL BE QUIET AHD OF THIS NEXT FEATURE. ANY ISOLD -SHRA OVER THE W THIS AFTN WL END QUICKLY WITH LOSS OF DIURNAL HTG...PROBABLY BY 00Z. INTRODUCED SLGT CHC POPS LATE OVER WRN LK SUP TO ACCOUNT FOR INCOMING H5 THERMAL TROFFING/WEAKENING OF MID LVL CAP/MID LVL MOISTENING AHD OF APRCHG SHRTWV IN MN. COMBINATION OF INCOMING SHRTWV/DIURNAL HTG WL RESULT IN SCT SHRA/ TSRA ON SAT AS H5 THERMAL TROF (TEMPS AS LO AS -18C) SWINGS OVHD WITH SHRTWV AND CONVECTIVE TEMPS ARE FCST IN THE MID 60S. SINCE THE ARRIVAL OF THE SHRTWV WL BE BEST IN SYNC WITH THE SOLAR HTG CYCLE OVER THE CNTRL AND E...WL PAINT A BIT HIER CHC POPS THERE... ESPECIALLY OVER THE INTERIOR WHERE BREEZE OFF LK MI MIGHT ENHANCE LLVL CNVGC A BIT. DESPITE ARRIVAL OF H5 THERMAL TROFFING...GFS/NAM FCST SDNGS SHOW ONLY MODEST MID LVL LAPSE RATES...SO THREAT OF SVR TS SHOULD BE MINIMAL DESPITE RATHER IMPRESSIVE 0-6KM BULK SHEAR FCST IN THE 40 KT RANGE. LO WBZ FCST ARND 8.5K FT WOULD SUPPORT MORE LIKE PEA SIZED HAIL UNDER THE STRONGER CNVCTN. WITH CONVECTIVE TEMPS SO LO AND MORE CLD ARND... HI TEMPS WL BE QUITE A BIT LOWER THAN TDAY. PREFER TO TEND TOWARD THE LOWER GFS MOS GUIDANCE FOR HI TEMPS. AS UPR LO TRACKS SLOWLY ACRS ONTARIO ON SAT NGT/SUN...NUMERICAL MODELS HINT AT THE PASSAGE OF ADDITIONAL SHRTWVS ON ITS SRN FLANK ACRS THE UPR GRT LKS. BUT TIMING OF THESE SHRTWVS IS PROBLEMATIC AT BEST. SINCE THERE IS LIKELY TO BE SOME DRYING IN THE WAKE OF THE SHRTWV RESPONSIBLE FOR THE SHRA CHCS ON SAT...CUT POPS ON SAT NGT TO TO SCHC TO TAKE INTO ACCOUNT LOSS OF DIURNAL HTG...EXCEPT IN THE EVNG OVER THE E DUE TO RESIDUAL IMPACT OF DEPARTING SHRTWV. THEN MAINTAINED GOING 30 POP ON SUN WITH DIURNAL HTG UNDER H5 THERMAL TROFFING AND APRCH OF ANOTHER SHRTWV. WITH CONVECTIVE TEMPS FCST A BIT HIER ON SUN...EXPECT MAX TEMPS A COUPLE OF DEGREES HIER THAN ON SAT. MAINTAINED LO CHC POPS SUN NGT/MON TO REFLECT DIGGING OF CUTOFF LO FM ONTARIO INTO THE UPR GRT LKS. EXPECT TEMPS FALLING BLO NORMAL AS LLVL COOL AIR NOW ON THE WRN FLANK OF THIS SYS FINALLY SURGES INTO THE FA. && .AVIATION (FOR THE 18Z TAF ISSUANCE)... VFR CONDITIONS ARE EXPECTED AT KCMX/KSAW THRU THIS FCST PERIOD. DISTURBANCE APPROACHING FROM THE W SAT MORNING SHOULD SPARK A FEW -SHRA LATE SAT MORNING OR EARLY AFTN. WITH A BETTER OPPORTUNITY FOR INSTABILITY TO BUILD AT KSAW THAN AT KCMX...WILL ONLY INCLUDE A PROB MENTION OF SHRA IN THE EARLY AFTN AT KSAW. && .MARINE (FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... WINDS CONTINUE TO DECREASE ACROSS LAKE SUPERIOR OVERNIGHT AS A COLD FRONT HAS BEEN MOVING SLOWLY ACROSS. WINDS NOW ACROSS LAKE SUPERIOR ARE BELOW 25 KNOTS...AND THIS WILL REMAIN THROUGH THE FORECAST PERIOD. ONLY ITEM OF INTEREST IS A COLD FRONT THAT PASSES SUNDAY NIGHT ASSOCIATED WITH LOW PRESSURE MOVING SE INTO SE CANADA. THE PRESSURE GRADIENT MAY BE TIGHT ENOUGH TO RESULT IN SOME 15 TO 25 KNOT NW WINDS ON EASTERN LAKE SUPERIOR ON MONDAY...AIDED BY COLD AIR FLOWING SOUTH ACROSS LAKE SUPERIOR. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ DISCUSSION...KC AVIATION...ROLFSON MARINE...AJ
AREA FORECAST DISCUSSION
NWS SEATTLE WA
900 AM PDT THU JUN 12 2008 .SYNOPSIS...A WEAK UPPER LEVEL RIDGE MOVING ACROSS THE AREA TODAY WILL GIVE SOME AFTERNOON SUNSHINE AND ALLOW TEMPERATURES IN THE INTERIOR TO RETURN CLOSER TO NORMAL. A FRONTAL SYSTEM ASSOCIATED WITH AN UPPER LEVEL TROUGH OF LOW PRESSURE PASSING BY TO THE NORTH WILL BRING AN INCREASE IN CLOUDS AND A CHANCE OF LIGHT PRECIPITATION TONIGHT AND FRIDAY MORNING. ONSHORE FLOW WILL PRODUCE NIGHT AND MORNING CLOUDS THIS WEEKEND WITH PARTLY SUNNY AFTERNOONS. ANOTHER UPPER LEVEL LOW WILL MOVE ACROSS THE AREA THE MIDDLE OF NEXT WEEK. IT WILL RETURN CONDITIONS TO COOLER AND WETTER THAN NORMAL. && .SHORT TERM...CONDITIONS ALOFT HAVE WARMED SIGNIFICANTLY AS AN UPPER LEVEL RIDGE MOVES ACROSS THE AREA TODAY...KUIL REPORTED A 10200FT FREEZING LEVEL EARLY THIS MORNING. VISIBLE SATELLITE IMAGERY SHOWS SIGNIFICANT HOLES OVER THE OLYMPICS...VANCOUVER ISLAND...AND THE SOUTH INTERIOR. THESE WOULD ARGUE STRONGLY FOR A MIDDAY BREAKOUT AND TEMPERATURES NEAR THE NORMAL HIGH OF 69 DEGREES THIS AFTERNOON. HOWEVER ACARS SOUNDINGS OUT OF SEATAC THIS MORNING SHOW A WEAKLY MIXED MOIST BOUNDARY LAYER UP TO 5000 FT TOPPED BY A STRONG INVERSION. IN MANY CASES THIS POINTS TOWARD CONVECTIVE HEATING OF THE DAY LIFTING THE STRATUS INTO A CUMULUS DECK THEN THE TOPS SPREADING OUT AT THE BASE OF THE INVERSION...KEEPING CLOUDS IN PLACE. TODAYS HIGH MAY STAY IN THE LOWER 60S WITH THE CLOUDS...OR SPIKE INTO THE UPPER 60S WITH MOSTLY SUNNY CONDITIONS. WE ARE AT THE CUSP. AT THIS POINT WE WILL HOLD ONTO OUR MID 60S FORECAST AND PARTLY SUNNY SKIES. FLOW OVER THE PACIFIC HAS BECOME MORE ZONAL. A COLD FRONT EXTENDING WSW FROM THE CHARLOTTES...ASSOCIATED WITH A SURFACE AND UPPER LEVEL LOW APPROACHING THE ALASKAN PANHANDLE...IS MOVING RAPIDLY SOUTHEAST AND APPEARS DESTINED TO SLIDE SE ACROSS THE AREA FRI MORNING. AN INCREASE IN ONSHORE FLOW WITH THIS FEATURE WILL ALLOW A LOW CLOUD DECK TO FORM OVERNIGHT THEN LIFT AS IT ENCOUNTERS THE OLYMPICS...COASTAL HILLS...AND CASCADES. THE INTERIOR LOWLANDS REMAIN GENERALLY SHADOWED BY THE COASTAL TERRAIN IN THE WESTERLY FLOW ALOFT...BUT IT DOES APPEAR THAT THERE WOULD BE SOME PUGET SOUND CONVERGENCE OVER CENTRAL PUGET SOUND. CURRENT FORECAST POPS AND PRECIPITATION CHARACTER...WITH -RA IN THE UPSLOPE AREAS AND AREAS -DZ ELSEWHERE...ARE QUITE REASONABLE. TEMPERATURE FORECASTS FOR FRI MAY BE OPTIMISTIC GIVEN THE ONSHORE FLOW AND CLOUDS...BUT WILL AWAIT THE FULL SUITE OF MODELS AND DATA BEFORE MAKING CHANGES. STRONG POST FRONTAL ONSHORE FLOW FRI NIGHT WILL LIKELY KEEP DEEPER LOW CLOUDS AND MARINE AIR IN THE AREA SAT MORNING WITH A LATER BREAKOUT RESULTING IN COOLER SAT MAX TEMPERATURES THAN MOS CURRENTLY INDICATES. CURRENT FORECASTS MAY BE A DEG OR TWO OPTIMISTIC...BUT APPEAR IN THE BALL PARK. ANTICIPATE NO UPDATES THIS MORNING. ALBRECHT .LONG TERM...PREVIOUS LONG TERM DISCUSSION FOLLOWS...GFS/ECMWF BOTH HAVE ANOTHER UPPER LEVEL LOW APPROACHING THE REGION EARLY NEXT WEEK. STILL SOME DIFFERENCES IN DETAILS AT THIS POINT...BUT OVERALL THE MODELS AGREE WELL. WITH THE CURRENT MODEL TIMING...THE LOW IS STILL A BIT TOO FAR AWAY FOR ANY PRECIP MONDAY...BUT WILL LET THE DAY SHIFT TAKE A SHOT AT THIS CHANGE. BOTH GFS/ECMWF AGREE ON A CHANCE OF SHOWERS TUESDAY/WEDNESDAY...BUT UNFORTUNATELY DIFFER ON JUST WHICH SYSTEM IS PROVIDING THE FORCING. KAM && .AVIATION...ACARS DATA SHOWS A STRONG TEMPERATURE INVERSION THIS MORNING NEAR 6K FT. MARINE STRATUS DECK REMAINS UNDERNEATH IT BUT SOME HOLES IN IT MAINLY S OF KOLM AND THE EASTERN STRAIT AND SAN JUANS. S TO N ONSHORE GRADIENTS ARE QUITE WEAK BUT W TO E GRADIENTS ACROSS THE CASCADES REMAINS RATHER STRONG. CEILINGS VARY FROM MVFR TO VFR WITH LOCAL IFR IN THE CENTRAL SOUND. EXPECT IFR CIGS TO IMPROVE BEFORE NOON. BIG QUESTION IS WILL THE MARINE STRATUS BREAK UP THIS AFTERNOON. WITH THE INVERSION SO STRONG..IT IS LIKELY MUCH OF THE MARINE STRATUS WILL HOLD AND WILL HAVE SOME DRIFTING HOLES IN IT. CLOUD LEVELS WILL LIKELY BE A BIT UNDER THE INVERSION...CLOSE TO 045. ANOTHER SHORTWAVE MOVING FROM THE NE PACIFIC INTO BC WILL LIKELY RECONSOLIDATE THE STRATUS DECK AFT 03Z. KSEA...IFR CEILINGS TO GIVE WAY BEFORE 18Z AND LOOKS LIKE THE PREVIOUSLY MENTIONED CIG NEAR 045 WILL PREDOMINATE THE REST OF THE DAY INTO THIS EVENING. LIGHT SW WIND 3-6 KNOTS THROUGH TODAY BUT COULD SWING TO W OR WNW 22Z-03Z. BUEHNER && .MARINE...S TO N PRESSURE GRADIENTS ARE LIGHT BUT W TO E GRADIENTS ACROSS THE CASCADES. SO LOW LEVEL ONSHORE FLOW REMAINS WITH NO CHANGE IN SIGHT. SMALL CRAFT ADVISORY WINDS TO CONTINUE IN THE CENTRAL AND EASTERN STRAIT EACH EVENING. ONE SIGNIFICANT CHANGE WILL BE THE PASSING WEAK WEATHER SYSTEM FROM THE NE PACIFIC E THROUGH BC ON FRI. IT WILL INCREASE THE W TO E PRES GRADIENTS AND GALE FORCE WINDS ARE LIKELY IN THE STRAIT LATER FRI ALONG WITH SMALL CRAFT ADVISORY WINDS IN ADJACENT WATERS. BUEHNER && WA...NONE. PZ...SMALL CRAFT ADVISORY CENTRAL AND EASTERN STRAIT. $$ WEATHER.GOV/SEATTLE
ISSUANCE OF THE FORECAST DISCUSSION -- MODELS HAVE BACKED OFF ON THE
RIDING OVER THE WEEKEND AND NOW SHOW A PERIOD OF WESTERLY FLOW
ALOFT. THE 12Z GFS EVEN HINTS AT SOME SOME WEAK TROUGHING ALONG THE COAST BY SATURDAY NIGHT AND SUNDAY...THOUGH THE MAIN LARGE SCALE TROUGH REMAINS OFFSHORE THROUGH AT LEAST MONDAY. SURFACE GRADIENTS ARE W/WNW IN THE AFTERNOON WHICH USUALLY SUPPORTS AFTERNOON CLEARING. WILL STICK WITH THE MORNING CLOUD/AFTERNOON SUNSHINE SCENARIO FOR THE WEEKEND. CLOUDS WILL BECOME MORE PREVALENT MONDAY AS ONSHORE FLOW PICKS UP. THE TROUGH OFFSHORE MOVES CLOSE ENOUGH TO THE COAST FOR A CHANCE OF DRIZZLE MONDAY...THEN SHOWERS WITH THE LOW SLOWLY MOVING ACROSS TUESDAY AND WEDNESDAY. LOOKS LIKE A REPEAT OF THE LAST FEW DAYS...UNSEASONABLY COOL...WET...AND CLOUDY. MERCER && .AVIATION...STRATUS DECK LOCKED IN OVER WESTERN WASHINGTON TONIGHT. ACARS SOUNDINGS SHOW TOP OF THE MARINE LAYER NEAR 6000 FEET WITH WINDS IN THE LOWER LEVELS...850 MB AND BELOW 10 KNOTS OR LESS. WEAK ONSHORE GRADIENTS CONTINUING OVERNIGHT INTO THURSDAY MORNING. WITH THESE VARIABLES EXPECT THE CEILINGS...WHICH RANGE FROM 1500 TO 3500 FEET AT 03Z TO SLOWLY LOWER OVERNIGHT DOWN TO NEAR 1000 TO 2000 FEET BY 12Z THURSDAY. SOME IMPROVEMENT IN THE MORNING HOURS BUT THE UPPER LEVEL RIDGE MOVING ACROSS THE AREA IS WEAK SO WILL KEEP BROKEN LAYER IN THE 3500 TO 5000 FOOT RANGE THURSDAY AFTERNOON. KSEA...CEILINGS NEAR 3000 FEET AT 04Z SLOWLY LOWERING TO NEAR 1000 FEET BY 12Z. CEILINGS SLOWLY LIFTING THURSDAY MORNING BACK UP TO NEAR 2000 FEET BY 19Z. CONDITIONS IMPROVING TO THE LOW END OF VFR BY 00Z. SOUTHWEST WIND 5 TO 10 KNOTS THROUGH THURSDAY MORNING. FELTON && .MARINE...LIGHT ONSHORE GRADIENTS CONTINUING THROUGH THURSDAY MORNING. GRADIENTS THROUGH THE STRAIT PICKING UP AGAIN THURSDAY AFTERNOON WITH SMALL CRAFT WINDS EXPECTED FOR THE CENTRAL AND EASTERN STRAIT THURSDAY NIGHT. SHORTWAVE MOVING THROUGH EARLY FRIDAY WILL INCREASE THE LOW LEVEL ONSHORE FLOW FRIDAY AFTERNOON WITH GALE FORCE WINDS POSSIBLE IN THE CENTRAL AND EASTERN STRAIT FRIDAY EVENING. NO OTHER ADVISORIES EXPECTED OVER THE MARINE WATERS. && PZ...NONE. $$ WEATHER.GOV/SEATTLE
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1258 AM EDT SAT JUN 14 2008 .AVIATION...DISCUSSION FOR THE 06Z TAFS A COLD FRONT WILL MOVE THROUGH INDIANA DURING THE BEGINNING OF THE TAFS. SCT SHWRS WITH ISOLATED TSTMS WILL BE E OF IND AND CONTINUE TO MOVE E SO DID NOT INCLUDE THEM IN THE TAF. SFC MSTR ALND WITH VERY LIGHT WIND AND SKC MAY ALLOW FOG TO FORM BUT VSBYS SHOULD NOT GO BELOW VFR LVLS. HIGH PRESSURE WITH A VERY DRY ATMOSPHERE WILL MOVE INTO INDIANA AFTER SR. AT THE MOST SCT CU MAY DEVELOP. && .UPDATE...ACARS DATA SHOWING CAPPING INVERSION AROUND 900MB AS SHOWERS CONTINUE TO DIMINISH ACROSS THE CWA. WILL DROP THE FLOOD WATCH AT 8PM SINCE LITTLE ADDITIONAL DEVELOPMENT IS EXPECTED. STORMS OVER IL ARE STRUGGLING TO MAINTAIN SO ANYTHING THAT DOES MANAGE TO DEVELOP WILL BE SHORT LIVED. MAY UPDATE TO REMOVE PRECIP AFTER MIDNIGHT AS THE COLD FRONT WILL PUSH THROUGH THE CWA ENDING CHANCES...BUT WILL CONTINUE TO MONITOR ACTIVITY IN IL BEFORE FINAL DECISION. NEW GRIDS/ZFP AVAILABLE AFT 00Z. && .DISCUSSION... MAIN FOCUS WILL WITH HEAVY RAIN EARLY TONIGHT AND THEN RAIN CHANCES SUNDAY NIGHT INTO MONDAY. SFC CHARTS INDICATED CD FNT WAS STILL ACROSS WRN ILLINOIS. HOWEVER OUTFLOW BOUNDARIES HAD CAUSED THUNDERSTORMS WERE FARTHER EAST MAINLY ACROSS OUR AREA. MAIN QUESTION IS HOW QUICK HEAVY RAIN WILL END. LOOKING UP STREAM IT COULD BE OVER WITH BY EVENING OVER THE NW HALF OF OUR AREA. WV IR INDICATED A S/W MOVG TOWARDS THE MID MISSISSIPPI VALLEY AND THIS SHOULD KEEP PRECIP ACROSS OUR AREA WELL INTO THE EVENING. I WILL END THE FLASH FLOOD WATCH ALONG AND NORTH OF I70 AS HEAVY RAIN WILL CERTAINLY BE OVER WITH BY THEN. IN THE SOUTH I WILL KEEP IT TO 4 AM. EVEN THOUGH PRECIP COULD END SOONER...I WOULD PREFER TO BE CONSERVATIVE IN SHORTENING FLASH FLOOD WATCH. COLD FRONT WILL BE NEAR THE OHIO RIVER BY 12Z SATURDAY. WILL ONLY MENTION SLIGHT CHANCE POPS IN OUR FAR SE EARLY SATURDAY. THEN DRY UNTIL LATE SUNDAY. WILL GO WITH COOLER MAV/MET TEMPERATURES ON SATURDAY BASED ON CURRENT TEMPERATURES UPSTREAM BEHIND CD FNT. ANOTHER CD FNT WILL MOVE THROUGH OUR REGION LATE SUNDAY NIGHT EARLY MONDAY. SPC HAS US IN A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR DAY 3 FOR OUR NW HALF WHICH WOULD BE MAINLY SUNDAY NIGHT. NAM SLOWS UP FRONT ON SUNDAY KEEPING PRECIP ACROSS OUR REGION...WHILE GFS IS MUCH MORE PROGRESSIVE AND ENDS PRECIP QUICKLY ON MONDAY. FOR NOW WILL USE BLEND DURING THE PERIOD WITH ONLY 20 PERCENT POPS NORTH. COOL AND MOSTLY DRY WEATHER WILL BE THE RULE REST OF THE WORK WEEK AS A LARGE UPPER LOW REMAINS ACROSS SOUTHERN ONTARIO AND THE GREAT LAKES. MODELS INDICATE 20 PERCENT POPS ARE POSSIBLE A FEW OF THOSE PERIODS...BUT WITH UNCERTAIN TIMING AND WITH AIRMASS BEING DRY WILL NOT MENTION ANY PRECIP DURING THE EXTENDED PERIOD FOR NOW. && .IND WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR INZ053>057-060>065- 067>072. FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR INZ021-028>031- 035>049-051-052. && $$ UPDATE...SALLY AVIATION...SH PUBLIC...JH
AREA FORECAST DISCUSSION
NWS WICHITA KS
316 AM CDT SAT JUN 14 2008 .DISCUSSION... THE MAIN CONCERN WITH THIS FORECAST PACKAGE IS THE FOG POTENTIAL THIS MORNING AND PRECIPITATION CHANCES ENTERING THE PICTURE AGAIN TONIGHT AND CONTINUING THROUGH WEDNESDAY. TODAY-TONIGHT: SURFACE HIGH PRESSURE WILL CONTINUE TO SETTLE ACROSS SOUTHEAST KANSAS EARLY THIS MORNING...BEFORE RETURN FLOW SETS UP AGAIN THIS AFTERNOON. AS A RESULT...THE AREAS OF DENSE FOG SHOULD BURN OFF FAIRLY QUICKLY THIS MORNING DUE LIMITED DEPTH. THIS RETURN FLOW WILL ALSO BRING BACK THE LOW LEVEL MOISTURE AND INSTABILITY...MAINLY ACROSS AREAS ALONG AND WEST OF THE I-35/135 CORRIDOR. THIS AREA MAY START SEEING SCATTERED ELEVATED CONVECTION DEVELOP MAINLY AFTER 00Z WITH SOME OF THE STORMS POSSIBLY BECOME SEVERE DUE TO GOOD DIRECTIONAL SHEAR IN THE 0-6KM LAYER (35-40KTS). MOST OF THE STORMS SHOULD TRAVEL IN A WEST TO EAST MANNER...BUT THE DEVIANT RIGHT MOVERS WILL GENERALLY MOVE SOUTH-SOUTHEAST. THESE STORMS COULD PERSIST THROUGH MUCH OF THE NIGHT DUE TO GOOD ISENTROPIC LIFT IN THE 310-315K LAYER. SUNDAY-SUNDAY NIGHT: LATEST WATER VAPOR LOOP WAS SHOWING A FAIRLY WOUND UP PIECE OF ENERGY ROTATING THROUGH BRITISH COLUMBIA. THIS FEATURE IS EXPECTED TO MOVE EAST AND CAUSE MORE JET ENERGY TO MOVE THROUGH THE NORTHERN AND CENTRAL PLAINS MAINLY ON SUNDAY NIGHT. THIS WILL ALLOW FOR A FRONTAL BOUNDARY TO TRAVEL THROUGH THE FORECAST AREA ON SUNDAY NIGHT. THE GFS IS THE MOST PROGRESSIVE IN DRIVING THIS BOUNDARY SOUTH ON SUNDAY NIGHT WHILE THE ECMWF/UKMET ARE A LITTLE SLOWER. WE ARE FAVORING MORE OF THE SLOWER ECMWF/UKMET APPROACH...DUE TO THE BULK OF THE ENERGY REMAINING IN THE NORTHERN PLAINS. HOWEVER...WE WILL NEED TO KEEP AN EYE ON THE AIRCRAFT DATA FOR POTENTIAL JET MAXES MOVING THROUGH THE REGION. WE SHOULD BEGIN TO SEE THE CONVECTION FIRING UP ALONG THE COLD FRONT ON SUNDAY NIGHT. THE POSITION OF THIS FRONT WILL BE QUITE TRICKY THIS FAR OUT...BUT IT APPEARS LIKE SOUTHEAST KANSAS MAY BE LESS CAPPED SO THEY MAY SEE THE CONVECTION FIRE FIRST WITH THE CONVECTION BUILDING WESTWARD ALONG THE COLD FRONT DURING THE EVENING. SOME OF THESE STORMS WILL ALSO HAVE THE POTENTIAL TO BECOME SEVERE WITH LARGE HAIL AND DAMAGING WINDS BEING THE MAIN THREATS AT THIS TIME. MORE HEAVY RAINFALL/FLOODING ALSO LOOKS PROMISING FOR SOUTHEAST KANSAS...BUT WE WILL HOLD OFF ON THE FLOOD WATCH FOR NOW. MONDAY: THE COLD FRONT SHOULD CONTINUE TO SLIDE SOUTH INTO AREAS NEAR THE KANSAS AND OKLAHOMA BORDER ON MONDAY MORNING...WITH MOST OF THE CONVECTION ENDING BY AFTERNOON. THE REMAINDER OF DAY...SHOULD BE FAIRLY MILD WITH LOWER DEWPOINTS DUE TO DECENT SUBSIDENCE BEHIND THE FRONT/CONVECTION. MONDAY NIGHT-TUESDAY NIGHT: THE UPPER LEVEL RIDGE IS EXPECTED TO CONTINUE BUILDING IN THE ROCKIES AND ALLOW FOR THE LOW LEVEL FLOW TO BECOME MORE EASTERLY. THIS COULD SET UP A PATTERN FOR THUNDERSTORM COMPLEXES DEVELOPING IN THE HIGH PLAINS AND ROLLING INTO PORTIONS OF OUR FORECAST AREA BEGINNING MONDAY NIGHT AND CONTINUING THROUGH THE MIDDLE OF THE WEEK. THE FIRST COMPLEX COULD MOVE THROUGH SOUTH CENTRAL AND POSSIBLY SOUTHEAST KANSAS BEGINNING MONDAY NIGHT. BEYOND THIS TIMEFRAME...TIMING AND PLACEMENT OF THESE COMPLEXES ARE QUITE DIFFICULT TO PREDICT. THEREFORE...WE HAVE KEPT A CHANCE IN THE FORECAST THROUGH MUCH OF THE PERIOD. COX && .AVIATION... FOR 06Z TAFS...MAIN AVIATION CONCERN WILL BE SOME SHALLOW FOG FOR AREAS ALONG AND EAST OF THE TURNPIKE. WEAK SURFACE FRONT HAS PUSHED INTO OK WHERE STORMS HAVE BEEN FESTERING ALL EVENING. MEANWHILE MID LEVEL SUBSIDENCE HAS SETTLED OVER THE AREA ALLOWING SKIES TO CLEAR. WEAK SURFACE RIDGING WILL SHIFT EAST OVERNIGHT ALLOWING WINDS TO FLIP BACK AROUND TO THE SOUTH. WHILE TEMP-DEW SPREADS ARE FAIRLY CLOSE OVER SE KS WITH CLEAR SKIES...FORECAST SOUNDINGS INDICATE THAT MOISTURE IS FAIRLY SHALLOW. HOWEVER WITH EVAPORATION TAKING PLACE ALL DAY OVER RAIN SOAKED AREAS...WILL INTRODUCE SOME PATCHY FOG AT KICT AND KCNU WITH MOST OF IT EXPECTED TO BE FAIRLY SHALLOW. VFR CONDITIONS ARE EXPECTED FOR THE MAJORITY OF THE DAY SAT. LAWSON && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 88 68 90 66 / 10 30 20 40 HUTCHINSON 88 67 90 65 / 10 30 20 40 NEWTON 88 67 89 65 / 10 20 30 50 ELDORADO 86 67 89 65 / 10 30 30 50 WINFIELD-KWLD 87 69 90 66 / 10 30 20 40 RUSSELL 90 67 91 64 / 20 30 30 40 GREAT BEND 90 67 92 65 / 20 30 20 40 SALINA 90 68 90 65 / 10 30 30 40 MCPHERSON 88 67 89 64 / 10 30 30 40 COFFEYVILLE 87 68 89 66 / 10 10 30 50 CHANUTE 86 66 88 66 / 10 10 30 50 IOLA 87 66 88 65 / 10 10 30 50 PARSONS-KPPF 87 67 89 66 / 10 10 30 50 && .ICT WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY UNTIL 9 AM CDT THIS MORNING FOR KSZ070>072- 094>096-098>100. && $$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
405 AM EDT SAT JUN 14 2008 .DISCUSSION... 00Z ROABS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW DEEP CLOSED UPR LO WITH POCKET OF -20C H5 TEMPS CENTERED OVER NW ONTARIO. SEVERAL SHRTWS OF NOTE ROTATING ARND THIS UPR LO. THE FIRST IS JUST ABOUT ON TOP OF DLH AT MIDNGT...WITH A CLUSTER OF CLD COVER OVER THE W HALF OF THE FA. DRY AIR IN THE LLVLS AS SHOWN ON THE 00Z GRB ROAB/TAMDAR SDNG FM SAW HAS LIMITED ANY PCPN TO JUST A SPRINKLE OR TWO UNDER THIS CLD COVER. SCT SHRA NOTED OVER THE MN ARROWHEAD...WHERE DEEPER MSTR SHOWN ON THE 00Z TAMDAR SDNG FM DLH AND ESPECIALLY THE 00Z INL RAOB SUGGESTS BETTER SUPPORT FOR SHRA. TEMP PROFILE ON THE INL RAOB IS ABOUT MOIST ADIABATIC...SO JUST A LTG STRIKE OR TWO WAS OBSVD EARLIER. ANOTHER SHRTWV IS NOTED JUST SW OF LK WINNIPEG ON THE SW FLANK OF THE UPR LO. SCT SHRA...WITH A FEW LTG STRIKES EARLIER... NOTED ALG ACCOMPANYING SFC LO PRES TROF STRETCHING FM ND THRU NW MN INTO FAR WRN ONTARIO. ANOTHER CLOSED UPR LO UNDER A POOL OF -20C AIR AT H5 IS PRESENT OVER WRN ALBERTA AND MOVING SLOWLY ESEWD. MAIN FCST CONCERNS THIS PACKAGE ARE SHRA/TSRA CHCS THIS WEEKEND INTO MON ASSOCIATED WITH CLOSED LOWS OVER ONTARIO AND ALBERTA. FOR TDAY...SHRTWV NOW OVER DLH WL SHIFT ACRS THE FA DURING THE EARLY MRNG HRS. COMBINATION OF DIURNAL COOLING/DRY AIRMASS IN PLACE SUG ANY SHRA WL LIKELY DSPT DURING THE NGT. STRONGER SHRTWV NOW SW OF LK WINNIPEG IS PROGGED TO MOVE TO THE MN ARROWHEAD BY 12Z SAT AND THEN SWING ACRS LK SUP INTO ONTARIO BY 00Z SUN. TIMING OF THIS SHRTWV INDICATES THE ACCOMPANYING DPVA/H85-5 QVECTOR CNVGC WL BE BEST IN SYNC WITH THE DIURNAL HTG CYCLE OVER THE CNTRL AND ERN ZNS AS H5 THERMAL TROF (TEMP ARND -18C) SWINGS OVHD. 00Z NAM/RUC13/LOCAL REGIONAL HI RES WRF MODEL SUG CNVCTN WL DVLP OVER THE INTERIOR WCNTRL TOWARD NOON WITH CONVECTIVE TEMPS NOT FAR FM 70. HOWEVER... 00Z RUC13/LOCAL HI RES WRF MODEL SHOW COMBINATION OF FAIRLY STRONG LLVL SLY FLOW AHEAD OF SHRTWV AND LK BREEZE OFF LK MI WL OVERSPREAD THE ERN ZNS DURING THE DAY AND LIMITS DESTABILIZATION THERE WITH LK COOLING...WITH NO LK SUP BREEZE MOVING INLAND INTO THE E TO ENHANCE LLVL CNVGC AT INTERSECTION OF THESE BNDRYS. WL GO WITH HIER POPS OVER THE INTERIOR CNTRL ZNS WHERE SPC SREF PAGE SHOWS HIER PROBABILITY OF SUBSTANTIVE CAPSES AOA 500 J/KG. SPC FCST SHOWS MUCH OF THE FA IN A SLGT RISK FOR SVR TS TDAY. FCST MODEST LAPSE RATES CLOSE TO MOIST ADIABATIC (H7-5 LAPSE RATES ARND 6.5C/KM) SHOWN BY ALL NUMERICAL MODELS (AND SHOWN ON THE 00Z INL RAOB) DO NOT SEEM TO JUSTIFY THIS LISTING...BUT FAST UNIDIRECTIONAL MID LVL FLOW...MID LVL DRYING ON THE SRN FLANK OF SHRTWV TRACK (MAX SFC-H7 THETA E DIFFERENCE FCST TO REACH 18C AT ERY LATE IN THE DAY)...AND FCST 0-6KM BULK SHEAR APRCHG 40 KTS IN CONCERT WITH UNSTABLE PBL MIGHT INDICATE A THREAT OF DAMAGING WINDS AND LARGE HAIL...ESPECIALLY WITH FCST WBZ IN THE FVRBL 8.5-9.5K FT RANGE. IN FACT...MOT IN ND REPORTED A WIND GUST OF 44 KT LAST EVNG AT 01Z WHEN TS PASSED THERE. BEST CHC FOR SVR TS WOULD SEEM TO BE OVER THE CENTRAL IN AREA OF HIER CAPES AND WHERE LK BREEZE CNVGC WOULD SEEM TO MOST LIKELY WITH CNVGC NEAR THE LIMITING STREAMLINE OFF LK MI. DRYING/DVLPG MID LVL CAP OVER THE W IN THE AFTN IN THE WAKE OF THE SHRTWV WL LIMIT POPS THERE...ESPECIALLY WITH AN INFLUX OF LK SUP COOLING/STABILIZATION. WITH DRYING IN THE WAKE OF DEPARTING SHRTWV/LOSS OF DIURNAL HTG... LOOKS LIKE THERE WL BE A DRY PD AFT ANY LINGERING EVNG CNVCTN OVER THE SCNTRL AND E WANES IN THE EVNG. HOWEVER...RETURN SW FLOW/DPVA/ DEEP LYR H85-3 QVECTOR CNVGC/DESTABILIZATION WITH HGT FALLS AHEAD OF APRCHG ALBERTA SHRTWV WHICH IS FCST TO MOVE TO NEAR KDLH BY 12Z SUN JUSTIFY A RETURN OF CHC POPS OVER THE W HALF OF THE FA LATE. WITH MORE RAPID RETURN OF MSTR AHD OF THIS SYS... CONTINUED TREND OF RAISING LO TEMPS. ON SUN...SHRTWV IS FCST TO PUSH ACRS LK SUP DURING THE DAY...WITH ATTENDANT SFC COLD FNT CROSSING THE FA AS WELL. SEEMS BEST CHC FOR SHRA/TSRA WL BE OVER THE CNTRL AND E AGAIN PER TIMING OF THE SFC COLD FNT. THE NAM/UKMET ARE QUITE AGGRESSIVE WITH MID LVL DRYING THAT OUTRUNS THE SFC COLD FNT...BUT THE GFS SHOWS A SLOWER DRYING TREND SO THAT SHRA/TSRA WOULD BE MORE LIKELY ALG THE FNT. CONSIDERING THE SHRTWV TRACKS JUST TO THE N...WOULD TEND TO FAVOR THE FASTER DRYING/LOWER QPF EXHIBITED BY THE NAM/UKMET. FASTER DRYING ALF ALSO WOULD INCRS SFC HTG WITH LESS CLD COVER. IN FACT... MODIFIED NAM FCST SDNG FOR ERY AT 18Z FOR T/TD 70/55 YIELDS CAPE CLOSE TO 1300 J/KG. FCST DRYING ALF (MODEL SHOWS SFC-10K FT THETA E DIFFERENCE APRCHG 25C AT ERY AT 18Z)/STEEPENING LAPSE RATES WITH UNIDIRECTIONAL MID LVL WSW FLOW ALF WL ENHANCE THE RISK OF SVR TSRA WITH WBZ A FVRBL 8K FT. IN FACT...LATEST SPC OUTLOOK SHOWS THE SE PORTIONS OF THE FA IN THE SLGT RISK. WL TEND TOWARD THE HIER ETA MOS GUIDANCE FOR TEMP FCST. MUCH COOLER AIR LOOKS TO INVADE THE UPR LKS SUN NGT/MON AS 00Z GFS/ UKMET/ECMWF SHOW CLOSED LO MOVING SE FM ONTARIO TO NOT FAR NE OF ANJ. SINCE THE GFS/UKMET SHOW DRYING ALF ON THE SW FLANK OF THIS LO AND THE ARRIVAL OF COOLER LLVL AIR CONTRIBUTING TOWARD GREATER STABILIZATION SUN NGT IN THE ABSENCE OF ANY SFC HTG...RESTRICTED MENTION OF POPS AFT DEPARTURE OF EVNG CNVCTN OVER THE SCNTRL AND E TO UPSLOPE AREAS OF THE NW. BUT JUST SOME LIGHT SPRINKLES/-SHRA EXPECTED THERE WITH RELATIVELY SHALLOW MSTR. GFS AND ESPECIALLY THE ECWMF SHOW SOMEWHAT DEEPER MSTR ARRIVING ON MON/MON NGT WITH REINFORCING SHRTWV/SFC COLD FNT. WENT WITH THE HIER POPS OVER THE KEWEENAW AND E OF MQT CLOSER TO THE CUTOFF LO/LOWER MID LVL TEMPS/UPSLOPE FLOW IN CYC NW FLOW. WITH H85 TEMPS ON FCST 2-4C ON MON...HI TEMPS WL DO NO BETTER THAN ABOUT 65. && .AVIATION (FOR THE 06Z TAF ISSUANCE)... PREVAILING VFR CONDITIONS ARE EXPECTED AT KCMX/KSAW THRU THIS FCST PERIOD. DISTURBANCE APPROACHING FROM THE W THIS MORNING SHOULD TRIGGER A FEW -SHRA BY LATE THIS MORNING INTO THIS AFTERNOON. THUS I WILL INCLUDE A PROB30 AT BOTH TAF SITES ALTHOUGH KSAW WILL HAVE A LONGER WINDOW FOR INSTABILITY TO BUILD INTO THE AFTERNOON HRS. && .MARINE (FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... WINDS SHOULD REMAIN UNDER 25KT THROUGH THURSDAY. IN GENERAL...THE STRONGEST WINDS WILL LIKELY OCCUR SUNDAY NIGHT THRU MONDAY NIGHT AS LOW PRESSURE EAST OF LAKE SUPERIOR SLOWLY MOVES TO SOUTHERN QUEBEC AND HIGH PRESSURE BUILDS INTO THE NORTHERN PLAINS. NORTHWEST WINDS SHOULD BE IN THE 15-25KT RANGE DURING THAT TIME...MAINLY OVER THE EAST HALF OF LAKE SUPERIOR. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ DISCUSSION...KC AVIATION...VOSS MARINE...DLG
AREA FORECAST DISCUSSION...UPDATED
NWS MARQUETTE MI
123 AM EDT SAT JUN 14 2008 .SHORT TERM (TONIGHT AND SAT)... WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A DEEP MID/UPPER LOW JUST N OF MN. THIS WILL BE THE MAIN FEATURE INFLUENCING THE WEATHER ACROSS THE UPPER LAKES INTO EARLY NEXT WEEK AS IT MEANDERS/REDEVELOPS IN A GENERAL ERLY DIRECTION. TO THE SE OF THE CENTER OF THE LOW...SHARP DRYING JUST OFF THE SFC HAS SWEPT INTO THE FCST AREA TODAY AS NOTED BY MORNING TAMDAR SOUNDINGS FROM KSAW/KCMX. EXCEPT FOR AREAS VERY CLOSE TO LAKE MICHIGAN...THIS RESULTED IN LOW CLOUDS CLEARING OUT ACROSS THE FCST AREA AS MIXING DEPTH DEEPENED. OVER WRN UPPER MI...DRYING DUE TO MIXING IS ALSO NICELY REFLECTED BY THE VERY SHARP DROP IN SFC DWPTS FROM THE LWR 60S EARLY THIS MORNING TO THE UPPER 30S/LWR 40S AT SEVERAL REPORTING SITES THIS AFTN. IN THE SHORT TERM...MID/UPPER LEVEL LOW WILL HEAD NE TOWARD HUDSON BAY...AND ATTENTION WILL BE ON SHORTWAVES WRAPPING AROUND THE S SIDE OF THE SYSTEM. CURRENTLY...MAIN SHORTWAVE OF INTEREST IS ROTATING SE INTO ND. WITH THAT SHORTWAVE THEN HEADING E TO NE MN BY 12Z SAT... EXPECT TONIGHT TO BE DRY ACROSS THE BULK OF THE FCST AREA. EVEN AS WE APPROACH PEAK HEATING OF THE DAY...CURRENT REGIONAL RADAR IMAGERY SHOWS NO PCPN UPSTREAM ACROSS CNTRL MN INTO NW WI. RADAR RETURNS ARE SHOWING UP FARTHER N AND W IN NRN AND WRN MN...BUT EXPECT THESE TO EITHER PASS JUST NW OF UPPER MI ACROSS FAR WRN LAKE SUPERIOR OR DISSIPATE BEFORE REACHING THE AREA. WITH LOSS OF DIURNAL HEATING... ANY PCPN ACCOMPANYING APPROACHING SHORTWAVE LATE TONIGHT SHOULD BE CONFINED TO THE SMALL AREA OF STRONGEST DEEP LAYER FORCING. SINCE THE BEST FORCING...ALBEIT WEAK...WILL BE NEARING WRN LAKE SUPERIOR BY 12Z SAT...OPTED TO RETAIN INHERITED FCST OF SLIGHT CHC POPS OVER WRN LAKE SUPERIOR LATE IN THE NIGHT. SHORTWAVE AND ACCOMPANYING COOLER AIR ALOFT (500MB TEMPS SAT AFTN AROUND -18C WILL BE ABOUT 4C LWR THAN THIS AFTN) CONTINUE EWD SAT WITH TAIL END OF WAVE SWINGING ACROSS THE FCST AREA. FORCING ASSOCIATED WITH SHORTWAVE WILL ARRIVE MORE FAVORABLY WITH DIURNAL HEATING CYCLE OVER THE CNTRL AND ERN FCST AREA...SO BEST COVERAGE (HIGHER CHC POPS) OF SHRA/TSRA WILL OCCUR THERE SAT AFTN. IN ADDITION...THERE WILL BE BETTER LOW LEVEL CONVERGENCE OVER THE E HALF OF THE FCST AREA AS LAKE BREEZE FROM LAKE MICHIGAN PUSHES INLAND WITH POSSIBILITY OF LAKE BREEZE DEVELOPMENT NEAR LAKE SUPERIOR AS WELL. MODIFYING NAM/GFS FCST SOUNDINGS FOR T/TD OF ROUGHLY LWR 70S/AROUND 50F YIELD SBCAPE OF 200-700J/KG WITH THE NAM AT THE HIGHER END OF THE INSTABILITY RANGE. DEEP LAYER SHEAR ON THE ORDER OF 30-40KT SUPPORTS STORM ORGANIZATION...SO ISOLD SVR CAN`T BE RULED OUT...ESPECIALLY IF THERE IS ENOUGH DAYTIME HEATING. LOW WETBULB ZERO HEIGHTS GENERALLY BTWN 8.2-9KFT SHOULD SUPPORT MARGINAL SVR HAIL AS THE MAIN SVR THREAT. && .LONG TERM (SATURDAY NIGHT THROUGH FRIDAY)... THE UNSETTLED WEATHER WILL BE ON THE WAY OUT...EVENTUALLY. AS FOR TEMPERATURES FRIDAY NIGHT/SUNDAY MORNING...UTILIZING MET/NAM GUIDANCE WOULD RESULT IN A 10 DEGREE TEMPERATURE INCREASE FROM THE ONGOING FORECAST. WILL NOT GO THIS DRAMATIC YET...AND SAY CLOSER TO THE MAV/GFS GUIDANCE WHICH IS ONLY AROUND 5 DEGREES WARMER. HOWEVER...WE WILL STILL NEED TO KEEP AN EYE ON THE PESKY 500MB LOW. THIS LOW IS FIGURED TO MAKE A SOUTHEASTWARD PROGRESSION FROM WESTERN ONTARIO TODAY TO NEW YORK AND SOUTHEASTERN ONTARIO. IT SHOULD REMAIN FAIRLY STATIONARY OVER THIS AREA FROM WEDNESDAY EVENING THROUGH AT LEAST THURSDAY AFTERNOON. AT THAT POINT...IT IS UNKNOWN IF THE 13/06Z GFS WILL WIN OUT...CONTINUING TO KEEP THIS FEATURE STATIONARY OVER THE NEW ENGLAND STATES THROUGH FRIDAY...OR IF THE MORE PROGRESSIVE 13/00Z ECMWF WILL WIN OUT. THE ECMWF WOULD LEAD TO A STRONGER 500MB RIDGE FOR UPPER MICHIGAN TUESDAY THROUGH FRIDAY. MUCH OF THE THE LONG TERM FORECAST FOLLOWS THE OPERATIONAL ECMWF. WILL NEED TO KEEP AN EYE ON THIS...AND THE PROGRESSION OF A SHORTWAVE DIVING IN TUESDAY INTO THURSDAY...WHICH WAS MORE EVIDENT FROM THE GFS...CANADIAN...AND UKMET. THE ECMWF CONTINUES NW FLOW AT 500MB...WITH THE MAIN LOW QUICKLY SLIDING AWAY/ AFTERNOON CONVECTION MAY POP UP TOWARDS THE END OF THE WORK WEEK...FRIDAY MAINLY ACROSS THE WESTERN THIRD OF THE CWA. WILL LEAVE IT OUT FOR NOW...DUE TO THE LOW PROBABILITY...AND LEAVE AN OPTIMISTIC DRY FORECAST. && .AVIATION (FOR THE 06Z TAF ISSUANCE)... PREVAILING VFR CONDITIONS ARE EXPECTED AT KCMX/KSAW THRU THIS FCST PERIOD. DISTURBANCE APPROACHING FROM THE W THIS MORNING SHOULD TRIGGER A FEW -SHRA BY LATE THIS MORNING INTO THIS AFTERNOON. THUS I WILL INCLUDE A PROB30 AT BOTH TAF SITES ALTHOUGH KSAW WILL HAVE A LONGER WINDOW FOR INSTABILITY TO BUILD INTO THE AFTERNOON HRS. && .MARINE (FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)... WINDS SHOULD REMAIN UNDER 25KT THRU THU. IN GENERAL...THE STRONGEST WINDS WILL LIKELY OCCUR SUN NIGHT THRU MON NIGHT AS LOW PRES E OF LAKE SUPERIOR SLOWLY MOVES TO SRN QUEBEC AND HIGH PRES BUILDS INTO THE NRN PLAINS. NW WINDS...ESPECIALLY GUSTS...SHOULD BE IN THE 15-25KT RANGE DURING THAT TIME...MAINLY OVER THE E HALF OF LAKE SUPERIOR. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...ROLFSON LONG TERM...KF AVIATION...VOSS MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS SEATTLE WA
310 AM PDT SAT JUN 14 2008 .SYNOPSIS...ONSHORE FLOW THROUGH EARLY NEXT WEEK WILL RESULT IN NIGHT AND MORNING CLOUDS WITH VARYING DEGREES OF AFTERNOON CLEARING. TEMPERATURES WILL BE NEAR NORMAL. AN UPPER LEVEL LOW ALONG THE BRITISH COLUMBIA COAST WILL AFFECT THE AREA MONDAY NIGHT... INCREASING THE ONSHORE FLOW AND BRINGING MORE LOW CLOUDS INLAND TUESDAY. WEAK UPPER LEVEL TROUGHS MOVING AROUND THE UPPER LEVEL LOW WILL BRING A CHANCE OF THE SHOWERS TO THE AREA TUESDAY NIGHT THROUGH FRIDAY. && .SHORT TERM...MODELS REMAIN CONSISTENT FOR THE SHORT TERM SO HARDLY ANY CHANGES WERE NEEDED FOR THE FORECAST THIS MORNING. THE DOMINANT FACTOR CONTINUES TO BE THE LARGE NE PACIFIC SURFACE HIGH CENTERED OUT NEAR 42N/140W. THE SURFACE HIGH WILL MAINTAIN ONSHORE FLOW OVER WA FOR THE FORESEEABLE FUTURE. THE UPPER LEVEL PATTERN WILL MODULATE THE STRENGTH AND DIRECTION OF THE ONSHORE FLOW THE NEXT FEW DAYS...WHICH IN TURN WILL AFFECT THE AMOUNT OF MORNING STRATUS AND MAX TEMPERATURES EACH DAY. SOMEWHAT WEAKER WEST FLOW ALOFT WILL CONTINUE TODAY AND THEN WEAKENS FURTHER SUNDAY AS WEAK UPPER LEVEL SHORTWAVE RIDGE MOVES OVER THE AREA. THUS EXPECT LESS STRATUS THIS MORNING THAN YESTERDAY AND WARMER MAX TEMPS. SHOULD BE EVEN BETTER SUNDAY SO WILL WORD THE STRATUS AS ONLY AREAS OF MORNING CLOUDS FOR MOST ZONES...WITH WARMEST MAX TEMPS NUDGING UP TO THE LOWER 70S. MONDAY SHOULD BE ABOUT LIKE SUNDAY...THOUGH WITH THE SHORTWAVE RIDGE MOVING EAST THERE MIGHT BE A BIT MORE STRATUS IN THE MORNING. KAM .LONG TERM...GFS/ECMWF SEEM TO HAVE REACHED BETTER AGREEMENT IN BRINGING A LARGE UPPER LEVEL LOW TO THE CENTRAL B.C. COAST ON MONDAY WITH TROUGHING DEVELOPING OFFSHORE OVER THE NE PACIFIC. BOTH MODELS SWING A WEAK SHORTWAVE TROUGH AROUND THE LOW AND OVER W WA BY TUESDAY MORNING. THE MODEL AGREEMENT ADDS CONFIDENCE TO A SW MARINE PUSH MONDAY NIGHT FOR STRATUS ALL OVER THE PLACE TUESDAY. WOULD EXPECT LITTLE IN THE WAY OF BREAKOUT. ECMWF IS SLIGHTLY STRONGER WITH THE SHORTWAVE TROUGH THAN THE GFS AND HAS SOME LIGHT PRECIP OVER THE AREA. FORECASTS ARE ON TRACK WITH THIS. MODELS DIVERGE WITH THE DETAILS WEDNESDAY AS THE GFS BRINGS A STRONGER SHORTWAVE TROUGH ACROSS THE AREA FOR MORE SHOWERS. ECMWF IS MUCH SLOWER AND DELAYS THIS UNTIL THURSDAY OR THURSDAY NIGHT. CURRENT BROADBRUSH CHANCE OF SHOWERS WORKS. KAM && .AVIATION...CEILINGS OVERNIGHT HAVE GENERALLY GONE ACCORDING TO PLAN WITH VFR AND HIGHER END MVFR. IT APPEARS THAT SOME KIND OF EDDY MAY HAVE FORMED EAST OF THE OLYMPICS OVERNIGHT...WITH ACARS DATA OUT OF SEATAC FROM A COUPLE HOURS AGO SHOWING A FAIRLY NONDESCRIPT WIND PATTERN BELOW ABOUT 7000 FEET. ANYWAY...THIS SEEMS TO HAVE HELPED EXPAND A LAYER BETWEEN 025-045 OVERNIGHT. STRATUS THIS MORNING STILL GENERALLY REMAINS ONLY A REMOTE POSSIBILITY...EXCEPT NEAR THE COAST. THE TREND OF THE FORECAST REMAINS THE SAME WITH THE STRATOCU DECK EXPECTED TO SCATTER OUT BY ABOUT 18Z WITH VFR ACROSS THE REGION FOR THE REMAINDER OF THE DAY. KSEA...SO FAR SO GOOD. CEILINGS REMAINED ON TARGET OVERNIGHT AND I STILL DO NOT SEE ANY REASON TO MENTION ANY LOW STRATUS. WILL CONTINUE WITH BKN025-BKN040 CEILINGS THIS MORNING SCATTERING OUT BETWEEN 16Z AND 18Z FOR A FINE VFR AFTERNOON. NORTH WIND TO CONTINUE GENERALLY UNDER 10 KT. && .MARINE...ONSHORE FLOW CONTINUING THROUGH MUCH OF THE UPCOMING FORECAST. SMALL CRAFT ADVISORIES HAVE BEEN POSTED FOR THE COASTAL WATERS...CENTRAL STRAIT...AND EAST ENTRANCE FOR A DIURNAL SUMMER-LIKE WIND PATTERN. WE MAY SEE ANOTHER DECENT CHANCE AT GALES IN THE CENTRAL AND EAST STRAIT AGAIN LATE MONDAY AS MODELS CONTINUE TO INDICATE INCREASING ONSHORE GRADIENTS THEN. 27 && SEW WATCHES/WARNINGS/ADVISORIES...SMALL CRAFT ADVISORY COAST... CENTRAL STRAIT OF JUAN DE FUCA AND EAST ENTRANCE. $$ WEATHER.GOV/SEATTLE
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
650 AM CDT SAT JUN 14 2008 .DISCUSSION... 349 AM CDT SURFACE COLD FRONT HAS PUSHED THROUGH FORECAST AREA EARLY THIS MORNING...WITH WEAK PRESSURE RISES AND CLEARING SKIES ACROSS THE CWA AS OF 08Z. WHILE WEAK HIGH PRESSURE SPREADING ACROSS LOWER MISSOURI VALLEY BEHIND FRONT...SURFACE PRESSURE FALLS ALREADY DEVELOPING ACROSS UPPER MISSISSIPPI VALLEY IN RESPONSE TO MID LEVEL SHORT WAVE TROUGH ROTATING THROUGH SOUTHERN PERIPHERY OF ONTARIO UPPER LOW. THIS ONE IN A SERIES OF MINOR AMPLITUDE MID LEVEL DISTURBANCES TRANSLATING FROM THE PACIFIC NORTHWEST THROUGH THE NORTHERN PLAINS IN REGION OF STRONG WESTERLIES. WEAK SURFACE TROUGH ASSOCIATED WITH INITIAL WAVE TO TRAIL ACROSS WISCONSIN TO THE MINNESOTA/IOWA BORDER THIS AFTERNOON...WITH SOUTHWEST LOW LEVEL RETURN FLOW RESULTING IN WEAK LOW LEVEL MOISTURE CONVERGENCE ALONG/SOUTH OF THIS BOUNDARY FROM NORTHERN IOWA INTO SOUTHERN WISCONSIN. WHILE PREVIOUS MODEL RUNS HAVE TRIED TO SNEAK A LITTLE QPF INTO FAR NORTH/NORTHWEST PARTS OF CWA BY EVENING...FORECAST SOUNDINGS INDICATE 70-80 J/KG OF CIN FOR SURFACE PARCEL DESPITE STEEP LAPSE RATES. WITH MAIN LOW LEVEL MOIST/INSTABILITY AXIS AND CONVERGENCE ZONE NORTH/NORTHWEST OF CWA THROUGH EVENING...AM FAIRLY CONFIDENT IN GOING WITH DRY FORECAST THROUGH SUNSET. CONVECTIVE EVOLUTION MORE QUESTIONABLE TONIGHT/SUNDAY. NEXT UPSTREAM SHORT WAVE FORECAST TO RIPPLE ACROSS THE NORTHERN PLAINS TONIGHT...WITH MODELS INDICATING PHASING OF THIS FEATURE WITH VORT ROTATING THROUGH WESTERN SIDE OF ONTARIO UPPER LOW. THIS THEN STARTS AMPLIFICATION OF UPPER TROUGH ACROSS UPPER MIDWEST/WESTERN GREAT LAKES REGION WHICH ULTIMATELY DEVELOPS LONG WAVE TROUGH OVER EASTERN CONUS EARLY/MIDDLE OF NEXT WEEK. FOR TONIGHT...DIGGING OF WAVE OVER UPPER MIDWEST AND INTENSIFICATION OF UPPER JET ACROSS THE MIDWEST INDUCES STRENGTHENING LOW LEVEL SOUTH/SOUTHWEST FLOW ACROSS PLAINS...WITH 30-40 KNOT SOUTHWESTERLY LOW LEVEL JET FROM SOUTHERN PLAINS TO IOWA BY 12Z SUNDAY MORNING. NAM...BOTH 00Z AND NEWLY ARRIVING 06Z RUNS...AND GFS BOTH INDICATE DEVELOPMENT OF CONVECTION OVERNIGHT FROM NORTHERN IOWA INTO IL/WI BORDER REGION. NOSE OF LOW LEVEL JET VEERS MORE WEST/SOUTHWEST BY MORNING...AND 850-300 MB THICKNESS FIELD SUPPORTS EAST/SOUTHEAST PROPAGATION OF MCS TO VICINITY FAR NORTHERN IL BY SUNDAY MORNING. SOME ELEVATED CAPE NOTED IN BOTH NAM/GFS SOUNDINGS ACROSS NORTHERN IL TONIGHT...THOUGH IT DECREASES THE FARTHER EASTWARD YOU GO. BASED ON THESE FACTORS WILL CARRY GRADIENT OF SLIGHT CHANCE POPS THIS EVENING INCREASING FARTHER NORTHWEST OF I-88 CORRIDOR...THEN CHANCE POPS ROUGHLY ALONG/NORTH INTERSTATE 80 AFTER MIDNIGHT AS LOW LEVEL JET VEERS MORE WEST/SOUTHWEST TOWARD MORNING. OF INTEREST...00Z NCEP 4 KM WRF EXPLICIT CONVECTION RUN DEPICTS THIS SCENARIO AS WELL...WITH WEAK MCS DEVELOPING ACROSS IA AND MOVING INTO NORTHERN IL AFTER MIDNIGHT THOUGH DECAYING AS IT PROPAGATES ACROSS SOUTHERN WI/NORTHERN IL EARLY SUNDAY MORNING. NORTHWEST COUNTIES OF CWA INCLUDED IN SPC DAY 1 SLGT RISK...MAINLY FOR WIND/HAIL POTENTIAL DURING LATE AFTERNOON/EVENING PERIOD TO OUR NORTHWEST WHEN LOW LEVEL INSTABILITY IS GREATEST. ON SUNDAY...UPPER TROUGH CONTINUES TO DEEPEN ACROSS UPPER MIDWEST AS NOTED PREVIOUSLY...WITH SURFACE WAVE DEVELOPING ACROSS WISCONSIN DURING THE DAY AND MOVING ACROSS THE LAKE INTO LOWER MICHIGAN SUNDAY NIGHT AS COLD FRONT MOVES THROUGH. PRECIP THREAT CONTINUES THROUGH THE DAY WITH FRONT MOVING THROUGH...THOUGH EFFECT OF ANY MORNING ACTIVITY WILL LIKELY MODULATE CONVECTIVE EVOLUTION AND KEEP THINGS SOMEWHAT UNCERTAIN. WHILE DECENT AGREEMENT EXISTS IN MODELS DEVELOPING SIGNIFICANT CONVECTION ALONG SOUTHERN PORTION OF COLD FRONT ACROSS KANSAS/MISSOURI DURING THE AFTERNOON...DIFFERENCES REMAIN WITH DEGREE OF INSTABILITY/FORCING ACROSS WFO CHICAGO FORECAST AREA. GFS DEVELOPS 1.5-2.00 INCH QPF AXIS ACROSS NORTHERN IL AS FRONT MOVES THROUGH SUNDAY AFTERNOON... THOUGH OTHER MODELS NOT NEARLY AS BULLISH WITH PRECIP. AT THIS POINT WILL MAINTAIN FAIRLY HEALTHY CHANCE POPS ACROSS THE FORECAST AREA INTO SUNDAY NIGHT AS FRONT SAGS ACROSS AREA. WITH STRONG MID/UPPER JET ACROSS AREA...INSTABILITY/DEEP SHEAR PROFILES CONTINUE TO BEFAVORABLE FOR WIND/HAIL THREAT FROM THUNDERSTORMS SUNDAY AND AREA REMAINS IN SPC DAY 2 OUTLOOK AS WELL. HEAVY PRECIP WILL HAVE TO BE MONITORED TOO. PRECIP EXPECTED TO END FROM NORTHWEST TO SOUTHEAST SUNDAY NIGHT AS FRONT CONTINUES TO SAG SOUTHEAST. DEVELOPING LONG WAVE TROUGH ACROSS EASTERN CONUS THEN SETS UP PERIOD OF MAINLY DRY/COOLER WEATHER FOR MIDWEST DAYS 3-7. GFS/ECMWF BUILD SURFACE HIGH PRESSURE AND ANCHOR IT JUST WEST OF MISSISSIPPI VALLEY DURING THIS PERIOD. WHILE SERIES OF DISTURBANCES INDICATED DROPPING THROUGH WEST SIDE OF UPPER TROUGH OFF TO OUR EAST...PRECIP THREATS APPEAR MINIMAL AT THIS TIME. RATZER && .AVIATION... 648 AM CDT 1200 UTC TAFS...MAIN AVIATION CONCERN WILL BE WINDS TODAY...AND CONVECTIVE CHANCES MAINLY TONIGHT. LATEST ACARS DATA THIS MORNING INDICATING WINDS OF AROUND 20 KNOTS AT 2K FT. HAVE NOT MADE MANY CHANGES TO THE PREVIOUS TAFS IN REGARDS TO WIND FORECAST TODAY. AS NOCTURNAL INVERSION ERODES THIS MORNING...SHOULD BEGIN TO SEE SOME GUSTS TO AROUND 15 KNOTS BY THE 15Z-16Z TIME FRAME...WITH GUSTS TO 20 TO 25 KNOTS THIS AFTERNOON. BAND OF MID LEVEL CLOUDINESS ACROSS SOUTHEAST MINNESOTA INTO WEST CENTRAL WISCONSIN IS EXPECTED TO REMAIN MAINLY NORTH OF THE AREA THIS MORNING...ALTHOUGH EXPECTING SOME OF THESE MID LEVEL CLOUDS TO DEVELOP SOUTHWARD BY LATE THIS MORNING INTO THIS AFTERNOON. OTHERWISE FOR SKY COVER...JUST SOME FEW-SCT HIGH BASED CU EXPECTED FOR THIS AFTERNOON. FORECAST SOUNDINGS SUGGEST MOST OF NORTHERN ILLINOIS/NORTHWEST INDIANA WILL BE CAPPED TO ANY SURFACE BASED THUNDERSTORM DEVELOPMENT GIVEN DRY LOW LEVELS SO HAVE CONTINUED DRY FORECAST THROUGH THIS AFTERNOON. WIND GUSTS SHOULD DIMINISH THIS EVENING AS MIXED LAYER ERODES BUT CONCERN WILL THEN TURN TO POTENTIAL FOR SHOWERS/STORMS ACROSS FAR NORTHERN ILLINOIS AND SOUTHERN WISCONSIN. LOW LEVEL MOISTURE ADVECTION ON THE NORTHERN PERIPHERY OF THE ANTICYCLONE TO THE SOUTH WILL ALLOW FOR MORE CONDUCIVE MOISTURE PROFILES FOR ELEVATED INSTABILITY ACROSS FAR NORTHERN ILLINOIS THIS EVENING. IN ADDITION...AN UPPER LEVEL JET STREAK WILL BE DIVING SOUTHEAST INTO THE MID/UPPER MS VALLEY TONIGHT AIDING IN LARGE SCALE FORCING. AT THIS TIME HAVE INCLUDED A PROB30 MENTION FOR THUNDER AT RFD WHERE LOW LEVEL MOISTURE WILL BE MORE SUBSTANTIAL. TIMING STILL UNCERTAIN AT THIS POINT...BUT BASED ON TIMING OF UPPER FORCING HAVE INDICATED THIS POTENTIAL FOR THUNDER IN TH 03Z-07Z TIME FRAME TONIGHT. MARSILI && .MARINE... 352 AM CDT A SURFACE HIGH FROM THE CENTRAL PLAINS WILL MOVE INTO THE LOWER AND MID MS RIVER VALLEY TODAY AS AN AREA OF LOW PRESSURE CONTINUES TO MOVE ACROSS NORTHERN ONTARIO. THE COMBINATION OF THESE TWO PRESSURE SYSTEMS WILL RESULT IN CONTINUED SOUTH SOUTHWEST WINDS TODAY. THE SFC HIGH TO THE SOUTH WILL MOVE INTO THE OHIO RIVER VALLEY TOMORROW AS ANOTHER AREA OF LOW PRESSURE DEVELOPS ACROSS SOUTHERN ONTARIO IN RESPONSE TO A FAIRLY STRONG UPPER TROUGH MOVING ALONG THE US CANADIAN BORDER. THIS LOW AND ASSOCIATED COLD FRONT WILL PASS ACROSS LAKE MICHIGAN SUNDAY NIGHT WITH AN EXTENDED PERIOD OF NORTHWEST WINDS IN STORE THROUGH THE MIDDLE OF NEXT WEEK AS THIS LOW MOVES INTO QUEBEC AND A STRONGER RIDGE OF HIGH PRESSURE BUILDS ACROSS THE CENTRAL PLAINS. A RATHER COOL AIR MASS FOR MID TO LATE JUNE SHOULD PROMOTE ENOUGH MIXING FOR SOME GUSTS TO AROUND 20 KNOTS EARLY NEXT WEEK WITH THE NORTHWEST WINDS. MARSILI && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$
AREA FORECAST DISCUSSION
NWS WICHITA KS
637 AM CDT SAT JUN 14 2008 .AVIATION... 12Z TAF UPDATE...LIFR CIGS AND VISIBILITIES WILL CONTINUE TO AFFECT CNU TERMINAL UNTIL MID MORNING...WITH LIFR CIGS ALSO HITTING HUT/ICT TERMINALS DURING THE EARLY MORNING HOURS. SOUTHERLY WINDS WILL GRADUALLY INCREASE ACROSS THE REGION WITH VFR CONDITIONS EXPECTED FOR THE AFTERNOON/EVENING TIME FRAME. A FEW STORMS COULD DEVELOP JUST WEST OF CENTRAL KANSAS AND MOVE INTO THE AREA AFTER 6PM...HOWEVER DUE TO THE SPARSE COVERAGE WILL NOT MENTION THUNDER FOR ANY TERMINAL AT THIS JUNCTURE. JAKUB && .PREV DISCUSSION... /ISSUED 316 AM CDT SAT JUN 14 2008/ DISCUSSION... THE MAIN CONCERN WITH THIS FORECAST PACKAGE IS THE FOG POTENTIAL THIS MORNING AND PRECIPITATION CHANCES ENTERING THE PICTURE AGAIN TONIGHT AND CONTINUING THROUGH WEDNESDAY. TODAY-TONIGHT: SURFACE HIGH PRESSURE WILL CONTINUE TO SETTLE ACROSS SOUTHEAST KANSAS EARLY THIS MORNING...BEFORE RETURN FLOW SETS UP AGAIN THIS AFTERNOON. AS A RESULT...THE AREAS OF DENSE FOG SHOULD BURN OFF FAIRLY QUICKLY THIS MORNING DUE LIMITED DEPTH. THIS RETURN FLOW WILL ALSO BRING BACK THE LOW LEVEL MOISTURE AND INSTABILITY...MAINLY ACROSS AREAS ALONG AND WEST OF THE I-35/135 CORRIDOR. THIS AREA MAY START SEEING SCATTERED ELEVATED CONVECTION DEVELOP MAINLY AFTER 00Z WITH SOME OF THE STORMS POSSIBLY BECOME SEVERE DUE TO GOOD DIRECTIONAL SHEAR IN THE 0-6KM LAYER (35-40KTS). MOST OF THE STORMS SHOULD TRAVEL IN A WEST TO EAST MANNER...BUT THE DEVIANT RIGHT MOVERS WILL GENERALLY MOVE SOUTH-SOUTHEAST. THESE STORMS COULD PERSIST THROUGH MUCH OF THE NIGHT DUE TO GOOD ISENTROPIC LIFT IN THE 310-315K LAYER. SUNDAY-SUNDAY NIGHT: LATEST WATER VAPOR LOOP WAS SHOWING A FAIRLY WOUND UP PIECE OF ENERGY ROTATING THROUGH BRITISH COLUMBIA. THIS FEATURE IS EXPECTED TO MOVE EAST AND CAUSE MORE JET ENERGY TO MOVE THROUGH THE NORTHERN AND CENTRAL PLAINS MAINLY ON SUNDAY NIGHT. THIS WILL ALLOW FOR A FRONTAL BOUNDARY TO TRAVEL THROUGH THE FORECAST AREA ON SUNDAY NIGHT. THE GFS IS THE MOST PROGRESSIVE IN DRIVING THIS BOUNDARY SOUTH ON SUNDAY NIGHT WHILE THE ECMWF/UKMET ARE A LITTLE SLOWER. WE ARE FAVORING MORE OF THE SLOWER ECMWF/UKMET APPROACH...DUE TO THE BULK OF THE ENERGY REMAINING IN THE NORTHERN PLAINS. HOWEVER...WE WILL NEED TO KEEP AN EYE ON THE AIRCRAFT DATA FOR POTENTIAL JET MAXES MOVING THROUGH THE REGION. WE SHOULD BEGIN TO SEE THE CONVECTION FIRING UP ALONG THE COLD FRONT ON SUNDAY NIGHT. THE POSITION OF THIS FRONT WILL BE QUITE TRICKY THIS FAR OUT...BUT IT APPEARS LIKE SOUTHEAST KANSAS MAY BE LESS CAPPED SO THEY MAY SEE THE CONVECTION FIRE FIRST WITH THE CONVECTION BUILDING WESTWARD ALONG THE COLD FRONT DURING THE EVENING. SOME OF THESE STORMS WILL ALSO HAVE THE POTENTIAL TO BECOME SEVERE WITH LARGE HAIL AND DAMAGING WINDS BEING THE MAIN THREATS AT THIS TIME. MORE HEAVY RAINFALL/FLOODING ALSO LOOKS PROMISING FOR SOUTHEAST KANSAS...BUT WE WILL HOLD OFF ON THE FLOOD WATCH FOR NOW. MONDAY: THE COLD FRONT SHOULD CONTINUE TO SLIDE SOUTH INTO AREAS NEAR THE KANSAS AND OKLAHOMA BORDER ON MONDAY MORNING...WITH MOST OF THE CONVECTION ENDING BY AFTERNOON. THE REMAINDER OF DAY...SHOULD BE FAIRLY MILD WITH LOWER DEWPOINTS DUE TO DECENT SUBSIDENCE BEHIND THE FRONT/CONVECTION. MONDAY NIGHT-TUESDAY NIGHT: THE UPPER LEVEL RIDGE IS EXPECTED TO CONTINUE BUILDING IN THE ROCKIES AND ALLOW FOR THE LOW LEVEL FLOW TO BECOME MORE EASTERLY. THIS COULD SET UP A PATTERN FOR THUNDERSTORM COMPLEXES DEVELOPING IN THE HIGH PLAINS AND ROLLING INTO PORTIONS OF OUR FORECAST AREA BEGINNING MONDAY NIGHT AND CONTINUING THROUGH THE MIDDLE OF THE WEEK. THE FIRST COMPLEX COULD MOVE THROUGH SOUTH CENTRAL AND POSSIBLY SOUTHEAST KANSAS BEGINNING MONDAY NIGHT. BEYOND THIS TIMEFRAME...TIMING AND PLACEMENT OF THESE COMPLEXES ARE QUITE DIFFICULT TO PREDICT. THEREFORE...WE HAVE KEPT A CHANCE IN THE FORECAST THROUGH MUCH OF THE PERIOD. COX && .PRELIMINARY POINT TEMPS/POPS... WICHITA-KICT 88 68 90 66 / 10 30 20 40 HUTCHINSON 88 67 90 65 / 10 30 20 40 NEWTON 88 67 89 65 / 10 20 30 50 ELDORADO 86 67 89 65 / 10 30 30 50 WINFIELD-KWLD 87 69 90 66 / 10 30 20 40 RUSSELL 90 67 91 64 / 20 30 30 40 GREAT BEND 90 67 92 65 / 20 30 20 40 SALINA 90 68 90 65 / 10 30 30 40 MCPHERSON 88 67 89 64 / 10 30 30 40 COFFEYVILLE 87 68 89 66 / 10 10 30 50 CHANUTE 86 66 88 66 / 10 10 30 50 IOLA 87 66 88 65 / 10 10 30 50 PARSONS-KPPF 87 67 89 66 / 10 10 30 50 && .ICT WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY UNTIL 9 AM CDT THIS MORNING FOR KSZ070>072- 094>096-098>100. && $$
AREA FORECAST DISCUSSION...UPDATE
NWS MARQUETTE MI
808 AM EDT SAT JUN 14 2008 .DISCUSSION... 00Z ROABS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW DEEP CLOSED UPR LO WITH POCKET OF -20C H5 TEMPS CENTERED OVER NW ONTARIO. SEVERAL SHRTWS OF NOTE ROTATING ARND THIS UPR LO. THE FIRST IS JUST ABOUT ON TOP OF DLH AT MIDNGT...WITH A CLUSTER OF CLD COVER OVER THE W HALF OF THE FA. DRY AIR IN THE LLVLS AS SHOWN ON THE 00Z GRB ROAB/TAMDAR SDNG FM SAW HAS LIMITED ANY PCPN TO JUST A SPRINKLE OR TWO UNDER THIS CLD COVER. SCT SHRA NOTED OVER THE MN ARROWHEAD...WHERE DEEPER MSTR SHOWN ON THE 00Z TAMDAR SDNG FM DLH AND ESPECIALLY THE 00Z INL RAOB SUGGESTS BETTER SUPPORT FOR SHRA. TEMP PROFILE ON THE INL RAOB IS ABOUT MOIST ADIABATIC...SO JUST A LTG STRIKE OR TWO WAS OBSVD EARLIER. ANOTHER SHRTWV IS NOTED JUST SW OF LK WINNIPEG ON THE SW FLANK OF THE UPR LO. SCT SHRA...WITH A FEW LTG STRIKES EARLIER... NOTED ALG ACCOMPANYING SFC LO PRES TROF STRETCHING FM ND THRU NW MN INTO FAR WRN ONTARIO. ANOTHER CLOSED UPR LO UNDER A POOL OF -20C AIR AT H5 IS PRESENT OVER WRN ALBERTA AND MOVING SLOWLY ESEWD. MAIN FCST CONCERNS THIS PACKAGE ARE SHRA/TSRA CHCS THIS WEEKEND INTO MON ASSOCIATED WITH CLOSED LOWS OVER ONTARIO AND ALBERTA. FOR TDAY...SHRTWV NOW OVER DLH WL SHIFT ACRS THE FA DURING THE EARLY MRNG HRS. COMBINATION OF DIURNAL COOLING/DRY AIRMASS IN PLACE SUG ANY SHRA WL LIKELY DSPT DURING THE NGT. STRONGER SHRTWV NOW SW OF LK WINNIPEG IS PROGGED TO MOVE TO THE MN ARROWHEAD BY 12Z SAT AND THEN SWING ACRS LK SUP INTO ONTARIO BY 00Z SUN. TIMING OF THIS SHRTWV INDICATES THE ACCOMPANYING DPVA/H85-5 QVECTOR CNVGC WL BE BEST IN SYNC WITH THE DIURNAL HTG CYCLE OVER THE CNTRL AND ERN ZNS AS H5 THERMAL TROF (TEMP ARND -18C) SWINGS OVHD. 00Z NAM/RUC13/LOCAL REGIONAL HI RES WRF MODEL SUG CNVCTN WL DVLP OVER THE INTERIOR WCNTRL TOWARD NOON WITH CONVECTIVE TEMPS NOT FAR FM 70. HOWEVER... 00Z RUC13/LOCAL HI RES WRF MODEL SHOW COMBINATION OF FAIRLY STRONG LLVL SLY FLOW AHEAD OF SHRTWV AND LK BREEZE OFF LK MI WL OVERSPREAD THE ERN ZNS DURING THE DAY AND LIMITS DESTABILIZATION THERE WITH LK COOLING...WITH NO LK SUP BREEZE MOVING INLAND INTO THE E TO ENHANCE LLVL CNVGC AT INTERSECTION OF THESE BNDRYS. WL GO WITH HIER POPS OVER THE INTERIOR CNTRL ZNS WHERE SPC SREF PAGE SHOWS HIER PROBABILITY OF SUBSTANTIVE CAPSES AOA 500 J/KG. SPC FCST SHOWS MUCH OF THE FA IN A SLGT RISK FOR SVR TS TDAY. FCST MODEST LAPSE RATES CLOSE TO MOIST ADIABATIC (H7-5 LAPSE RATES ARND 6.5C/KM) SHOWN BY ALL NUMERICAL MODELS (AND SHOWN ON THE 00Z INL RAOB) DO NOT SEEM TO JUSTIFY THIS LISTING...BUT FAST UNIDIRECTIONAL MID LVL FLOW...MID LVL DRYING ON THE SRN FLANK OF SHRTWV TRACK (MAX SFC-H7 THETA E DIFFERENCE FCST TO REACH 18C AT ERY LATE IN THE DAY)...AND FCST 0-6KM BULK SHEAR APRCHG 40 KTS IN CONCERT WITH UNSTABLE PBL MIGHT INDICATE A THREAT OF DAMAGING WINDS AND LARGE HAIL...ESPECIALLY WITH FCST WBZ IN THE FVRBL 8.5-9.5K FT RANGE. IN FACT...MOT IN ND REPORTED A WIND GUST OF 44 KT LAST EVNG AT 01Z WHEN TS PASSED THERE. BEST CHC FOR SVR TS WOULD SEEM TO BE OVER THE CENTRAL IN AREA OF HIER CAPES AND WHERE LK BREEZE CNVGC WOULD SEEM TO MOST LIKELY WITH CNVGC NEAR THE LIMITING STREAMLINE OFF LK MI. DRYING/DVLPG MID LVL CAP OVER THE W IN THE AFTN IN THE WAKE OF THE SHRTWV WL LIMIT POPS THERE...ESPECIALLY WITH AN INFLUX OF LK SUP COOLING/STABILIZATION. WITH DRYING IN THE WAKE OF DEPARTING SHRTWV/LOSS OF DIURNAL HTG... LOOKS LIKE THERE WL BE A DRY PD AFT ANY LINGERING EVNG CNVCTN OVER THE SCNTRL AND E WANES IN THE EVNG. HOWEVER...RETURN SW FLOW/DPVA/ DEEP LYR H85-3 QVECTOR CNVGC/DESTABILIZATION WITH HGT FALLS AHEAD OF APRCHG ALBERTA SHRTWV WHICH IS FCST TO MOVE TO NEAR KDLH BY 12Z SUN JUSTIFY A RETURN OF CHC POPS OVER THE W HALF OF THE FA LATE. WITH MORE RAPID RETURN OF MSTR AHD OF THIS SYS... CONTINUED TREND OF RAISING LO TEMPS. ON SUN...SHRTWV IS FCST TO PUSH ACRS LK SUP DURING THE DAY...WITH ATTENDANT SFC COLD FNT CROSSING THE FA AS WELL. SEEMS BEST CHC FOR SHRA/TSRA WL BE OVER THE CNTRL AND E AGAIN PER TIMING OF THE SFC COLD FNT. THE NAM/UKMET ARE QUITE AGGRESSIVE WITH MID LVL DRYING THAT OUTRUNS THE SFC COLD FNT...BUT THE GFS SHOWS A SLOWER DRYING TREND SO THAT SHRA/TSRA WOULD BE MORE LIKELY ALG THE FNT. CONSIDERING THE SHRTWV TRACKS JUST TO THE N...WOULD TEND TO FAVOR THE FASTER DRYING/LOWER QPF EXHIBITED BY THE NAM/UKMET. FASTER DRYING ALF ALSO WOULD INCRS SFC HTG WITH LESS CLD COVER. IN FACT... MODIFIED NAM FCST SDNG FOR ERY AT 18Z FOR T/TD 70/55 YIELDS CAPE CLOSE TO 1300 J/KG. FCST DRYING ALF (MODEL SHOWS SFC-10K FT THETA E DIFFERENCE APRCHG 25C AT ERY AT 18Z)/STEEPENING LAPSE RATES WITH UNIDIRECTIONAL MID LVL WSW FLOW ALF WL ENHANCE THE RISK OF SVR TSRA WITH WBZ A FVRBL 8K FT. IN FACT...LATEST SPC OUTLOOK SHOWS THE SE PORTIONS OF THE FA IN THE SLGT RISK. WL TEND TOWARD THE HIER ETA MOS GUIDANCE FOR TEMP FCST. MUCH COOLER AIR LOOKS TO INVADE THE UPR LKS SUN NGT/MON AS 00Z GFS/ UKMET/ECMWF SHOW CLOSED LO MOVING SE FM ONTARIO TO NOT FAR NE OF ANJ. SINCE THE GFS/UKMET SHOW DRYING ALF ON THE SW FLANK OF THIS LO AND THE ARRIVAL OF COOLER LLVL AIR CONTRIBUTING TOWARD GREATER STABILIZATION SUN NGT IN THE ABSENCE OF ANY SFC HTG...RESTRICTED MENTION OF POPS AFT DEPARTURE OF EVNG CNVCTN OVER THE SCNTRL AND E TO UPSLOPE AREAS OF THE NW. BUT JUST SOME LIGHT SPRINKLES/-SHRA EXPECTED THERE WITH RELATIVELY SHALLOW MSTR. GFS AND ESPECIALLY THE ECWMF SHOW SOMEWHAT DEEPER MSTR ARRIVING ON MON/MON NGT WITH REINFORCING SHRTWV/SFC COLD FNT. WENT WITH THE HIER POPS OVER THE KEWEENAW AND E OF MQT CLOSER TO THE CUTOFF LO/LOWER MID LVL TEMPS/UPSLOPE FLOW IN CYC NW FLOW. WITH H85 TEMPS ON FCST 2-4C ON MON...HI TEMPS WL DO NO BETTER THAN ABOUT 65. && .AVIATION (FOR THE 12Z TAF ISSUANCE)... PREVAILING VFR CONDITIONS ARE EXPECTED AT KCMX/KSAW THRU THIS FCST PERIOD. THE SHORTWAVE DISTURBANCE APPROACHING FROM THE WEST THIS MORNING COULD TRIGGER A FEW -SHRA BY LATE THIS MORNING INTO THIS AFTERNOON AS GUIDANCE SHOWING AN INCREASE MUCAPE OVER THE AREA. THUS I WILL INCLUDE TEMPO AT BOTH TAF SITES ALTHOUGH KSAW WILL HAVE A LONGER WINDOW FOR INSTABILITY TO BUILD INTO THE AFTERNOON HOURS. CONDITIONS WILL DETERORATE AS THE COLD FRONT MOVES THROUGH SUNDAY MORNING. && .MARINE (FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... WINDS SHOULD REMAIN UNDER 25KT THROUGH THURSDAY. IN GENERAL...THE STRONGEST WINDS WILL LIKELY OCCUR SUNDAY NIGHT THRU MONDAY NIGHT AS LOW PRESSURE EAST OF LAKE SUPERIOR SLOWLY MOVES TO SOUTHERN QUEBEC AND HIGH PRESSURE BUILDS INTO THE NORTHERN PLAINS. NORTHWEST WINDS SHOULD BE IN THE 15-25KT RANGE DURING THAT TIME...MAINLY OVER THE EAST HALF OF LAKE SUPERIOR. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ DISCUSSION...KC AVIATION...VOSS MARINE...DLG