AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
230 PM PDT THU OCT 18 2007
.SYNOPSIS...
FAIR AND WARMER THROUGH FRIDAY UNDER HIGH PRESSURE. UPPER LEVEL LOW
PRESSURE MOVING PAST TO THE NORTH WILL BRING A DEEPER MARINE LAYER
FOR LOW CLOUDS AND FOG WEST OF THE MOUNTAINS FRIDAY NIGHT AND
SATURDAY MORNING. COOLER SATURDAY. HIGH PRESSURE ALOFT AND LOCALLY
STRONG SANTA ANA WINDS WILL BRING MUCH WARMER WEATHER EARLY NEXT
WEEK...ESPECIALLY WEST OF THE MOUNTAINS. LOCAL STRONG GUSTY WINDS
THROUGH AND BELOW MOUNTAIN CANYONS AND PASSES EARLY NEXT WEEK.
WEAKENING HIGH PRESSURE AND OFFSHORE FLOW WILL RESULT IN A LITTLE
COOLING WEDNESDAY WITH MORE COOLING THURSDAY.
&&
.DISCUSSION...FOR SOUTHWEST CALIFORNIA INCLUDING SAN DIEGO...
ORANGE...SOUTHWEST SAN BERNARDINO AND WEST RIVERSIDE COUNTIES.
.SHORT TERM (TODAY-SUN)...
MOSTLY CLEAR SKIES TODAY. EARLY AFTERNOON ACARS SOUNDINGS INDICATED
A WEAK INVERSION BASED NEAR 1400 FT N AND 2400 FT S WITH NW WINDS
ALOFT. WEAK OFFSHORE GRADIENTS FROM THE N AND ONSHORE TO THE E.
A SHORT WAVE RIDGE ALOFT WILL MOVE PAST TO THE N AND WEAK GRADIENTS
WILL CONTINUE INTO FRI FOR FAIR AND WARMER WEATHER. THERE COULD BE A
FEW PATCHES OF STRATUS NEAR THE S COAST TONIGHT AND FRI MORNING. A
TROUGH WILL MOVE PAST TO THE N EARLY SAT WHICH WILL BRING A RETURN
OF MARINE LAYER CLOUDINESS AND COOLING. LOW CLOUDS AND LOCAL FOG
SHOULD COVER MOST COASTAL AREAS AND WRN VALLEYS BY SAT MORNING. DRY
NW FLOW WILL DEVELOP SAT AFTERNOON WITH LOCAL GUSTY WINDS IN THE
MOUNTAINS AND DESERTS INTO THE EVENING. THE FLOW WILL TURN OFFSHORE
BY SUN MORNING AND AN UPPER RIDGE WILL BUILD ALONG THE W COAST.
THERE WILL BE LIMITED THERMAL OR UPPER SUPPORT FOR OFFSHORE WINDS
BUT STRONG OFFSHORE GRADIENTS. THE STRONGEST NE WINDS WILL BE
THROUGH AND BELOW THE MOUNTAIN CANYONS AND PASSES IN THE NRN AREAS
SUCH AS IN AND BELOW THE SAN BERNARDINO AND SANTA ANA MOUNTAINS.
MUCH WARMER SUN...MAINLY W OF THE MOUNTAINS. THE DRY OFFSHORE FLOW
WILL INCREASE THE FIRE WEATHER HAZARD WITH NEAR CRITICAL FIRE
WEATHER CONDITIONS SUN.
$$
.LONG TERM (MON-THU)...
THE OFFSHORE WINDS SHOULD PEAK SUN NIGHT AND MON MORNING WHEN THEY
ARE EXPECTED TO BE LOCALLY STRONG AND HIGH WIND WARNINGS MAY BE
NEEDED. THE OFFSHORE FLOW AND RIDGING ALOFT WILL BRING MORE WARMING
WITH SOME RECORD HIGH MAX TEMPS POSSIBLE MON AND TUE. THE FLOW WILL
TURN MORE ELY BY TUE WITH THE STRONGEST OFFSHORE WINDS SHIFTING INTO
SAN DIEGO COUNTY. SLIGHTLY COOLER WED WITH MORE COOLING THU AS THE
HIGH ALOFT AND OFFSHORE FLOW WEAKEN. THE DRY OFFHORE WINDS WILL
LIKELY CAUSE CRITICAL FIRE WEATHER CONDITIONS...AT LEAST MON AND
TUE AND PROBABLY INTO WED.
&&
.AVIATION...
181930Z...MDCRS SOUNDINGS INDICATE THE MARINE LAYER DEPTH WAS AROUND
15200 FEET MSL. MARINE LAYER SHOULD LOWER A LITTLE TONIGHT THEN
DEEPEN SLIGHTLY FRIDAY NIGHT INTO SATURDAY MORNING. VFR CONDITIONS
SHOULD PREVAIL THROUGH FRIDAY WITH A MOSTLY CLEAR SKY AND
UNRESTRICTED VISIBILITIES. PATCHY FOG SHOULD DEVELOP ALONG THE
IMMEDIATE COAST TONIGHT BUT IS NOT EXPECTED TO HAVE MUCH IMPACT ON
THE COASTAL AIRPORTS. ANY FOG AT THE AIRPORTS SHOULD BE BRIEF AND
NEAR SUNRISE AND SHOULD BE GONE WITHIN AN HOUR OR TWO AFTER SUNRISE.
DENSE FOG COULD HAVE MORE OF AN IMPACT ON THE COASTAL AIRPORTS
FRIDAY NIGHT INTO SATURDAY MORNING AS THE MARINE LAYER RECOVERS.
HORTON
&&
SGX WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FOR THE MOUNTAINS...INLAND VALLEYS AND ORANGE
COUNTY SUNDAY MORNING THROUGH TUESDAY AFTERNOON. SEE LAXRFWSGX.
&&
PUBLIC...DVA
AVIATION...HORTON
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
930 AM PDT THU OCT 18 2007
.SYNOPSIS...
FAIR AND WARMER THROUGH FRIDAY UNDER HIGH PRESSURE. UPPER LEVEL LOW
PRESSURE MOVING PAST TO THE NORTH WILL BRING A DEEPER MARINE LAYER
FOR LOW CLOUDS AND FOG WEST OF THE MOUNTAINS FRIDAY NIGHT AND
SATURDAY MORNING. COOLER SATURDAY. HIGH PRESSURE ALOFT AND LOCALLY
STRONG SANTA ANA WINDS WILL BRING MUCH WARMER WEATHER EARLY NEXT
WEEK...ESPECIALLY WEST OF THE MOUNTAINS. LOCAL STRONG GUSTY WINDS
THROUGH AND BELOW MOUNTAIN CANYONS AND PASSES EARLY NEXT WEEK.
WEAKENING HIGH PRESSURE AND OFFSHORE FLOW WILL RESULT IN A LITTLE
COOLING WEDNESDAY WITH MORE COOLING THURSDAY.
&&
.DISCUSSION...FOR SOUTHWEST CALIFORNIA INCLUDING SAN DIEGO...
ORANGE...SOUTHWEST SAN BERNARDINO AND WEST RIVERSIDE COUNTIES.
.SHORT TERM (TODAY-SUN)...
MOSTLY CLEAR SKIES TODAY. THE 12Z NKX SOUNDING HAD AN INVERSION
BASED NEAR 2300 FT WITH DRY NW WINDS ALOFT. WEAK OFFSHORE GRADIENTS
FROM THE N AND ONSHORE TO THE E.
A SHORT WAVE RIDGE ALOFT WILL MOVE PAST TO THE N AND WEAK GRADIENTS
WILL CONTINUE INTO FRI FOR FAIR AND WARMER WEATHER. THERE COULD BE A
FEW PATCHES OF STRATUS NEAR THE S COAST TONIGHT AND FRI MORNING. A
TROUGH WILL MOVE PAST TO THE N EARLY SAT WHICH WILL BRING A RETURN
OF MARINE LAYER CLOUDINESS AND COOLING. LOW CLOUDS AND LOCAL FOG
SHOULD COVER MOST COASTAL AREAS AND WRN VALLEYS BY SAT MORNING. DRY
NW FLOW WILL DEVELOP SAT AFTERNOON WITH LOCAL GUSTY WINDS IN THE
MOUNTAINS AND DESERTS INTO THE EVENING. THE FLOW WILL TURN OFFSHORE
BY SUN MORNING AND AN UPPER RIDGE WILL BUILD ALONG THE W COAST.
THERE WILL BE LIMITED UPPER AND THERMAL SUPPORT FOR OFFSHORE WINDS
BUT GOOD GRADIENT SUPPORT. THE STRONGEST NE WINDS WILL BE THROUGH
AND BELOW THE MOUNTAIN CANYONS AND PASSES IN THE NRN AREAS SUCH AS
IN AND BELOW THE SAN BERNARDINO AND SANTA ANA MOUNTAINS. MUCH WARMER
SUN...MAINLY W OF THE MOUNTAINS. THE DRY OFFSHORE FLOW WILL INCREASE
THE FIRE WEATHER HAZARD WITH NEAR CRITICAL FIRE WEATHER CONDITIONS
SUN.
$$
.LONG TERM (MON-THU)...
THE OFFSHORE WINDS SHOULD PEAK SUN NIGHT AND MON MORNING WHEN THEY
ARE EXPECTED TO BE LOCALLY STRONG AND HIGH WIND WARNINGS MAY BE
NEEDED. THE OFFSHORE FLOW AND RIDGING ALOFT WILL BRING MORE WARMING
WITH SOME RECORD HIGH MAX TEMPS POSSIBLE MON AND TUE. THE FLOW WILL
TURN MORE ELY BY TUE WITH THE STRONGEST OFFSHORE WINDS SHIFTING INTO
SAN DIEGO COUNTY. SLIGHTLY COOLER WED WITH MORE COOLING THU AS THE
HIGH ALOFT AND OFFSHORE FLOW WEAKEN. THE DRY OFFHORE WINDS WILL
LIKELY CAUSE CRITICAL FIRE WEATHER CONDITIONS...AT LEAST MON AND
TUE AND PROBABLY INTO WED.
&&
.AVIATION...
181400Z...MDCRS SOUNDINGS INDICATE THE MARINE LAYER DEPTH WAS AROUND
1200 FEET MSL AND SHOULD LOWER TO LESS THAN 500 FEET TONIGHT INTO
FRIDAY MORNING. MARINE LAYER IS EXPECTED TO RECOVER FRIDAY NIGHT
INTO SATURDAY. VFR CONDITIONS SHOULD PREVAIL THROUGH FRIDAY WITH A
MOSTLY CLEAR SKY AND UNRESTRICTED VISIBILITIES. THERE COULD BE SOME
PATCHY FOG ALONG THE IMMEDIATE COAST NEAR SUNRISE FRIDAY MORNING
WITH LITTLE OR NO IMPACT ON COASTAL AIRPORTS BUT DENSE FOG COULD
IMPACT THE COASTAL AIRPORTS FRIDAY NIGHT INTO SATURDAY MORNING AS
THE MARINE LAYER RECOVERS. HORTON
&&
SGX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
PUBLIC...DVA
AVIATION...HORTON
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
326 AM CDT THU OCT 18 2007
.DISCUSSION...
DAYS 1-2...
FORECAST CHALLENGES FOR TODAY INCLUDE TIMING OF DISSIPATION OF THE
LIGHT SHOWERS MOVING ACROSS FAR SOUTHWESTERN KANSAS AND COVERAGE OF
LIGHT SHOWERS ACROSS THE NORTHERN ZONES WITH WEAK UPWARD VERTICAL
MOTION AND LOTS OF MID LEVEL MOISTURE WRAPPING AROUND THE DEPARTING
UPPER LEVEL CYCLONE OVER EASTERN NEBRASKA. TEMPERATURES TONIGHT ARE
PROBLEMATIC IN THE DRY ATMOSPHERE WITH DOWNSLOPE FLOW. FINALLY...THE
QUESTION OF REACHING RED FLAG CRITERIA NEAR THE COLORADO BORDER
MERITS CAREFUL CONSIDERATION.
A VERY STRONG JET CONTINUES FROM THE WESTERN PACIFIC INTO THE
SOUTHWESTERN UNITED STATES THIS MORNING...AND SEVERAL VIGOROUS UPPER
LEVEL TROUGHS EMBEDDED IN THE FLOW ARE EVIDENT ON SATELLITE IMAGERY.
THE GFS APPEARS TO HAVE INITIALIZED FAIRLY WELL OVER THE EASTERN
PACIFIC, BASED ON SATELLITE AND AIRCRAFT REPORTS. THE GFS, UKMET AND
CANADIAN ALL ARE IN FAIRLY GOOD AGREEMENT THROUGH THE FIRST 72 HOURS
OF THE FORECAST...BUT SOME DIVERGENCE IN SOLUTIONS OCCURS OVER THE
WEEKEND AS THE DEEP UPPER LEVEL TROUGH NEAR 152W DIGS INTO THE
CENTRAL PART OF THE COUNTRY. THE GFS WAS FOLLOWED CLOSELY FOR THE
FIRST PORTION OF THE FORECAST.
THE DEEP UPPER LEVEL CYCLONE OVER EASTERN NEBRASKA WILL CONTINUE TO
LIFT SLOWLY NORTHEASTWARD AND SHOULD REACH EASTERN MINNESOTA BY THIS
EVENING. THE STRONG PRESSURE GRADIENT OVER KANSAS GRADUALLY WILL
RELAX LATER TODAY AS THE SURFACE CYCLONE ALSO MOVES FROM EASTERN
NEBRASKA TO MINNESOTA BY EVENING. AN UPPER LEVEL SHORT WAVE TROUGH
EVIDENT ON SATELLITE IMAGERY OVER SOUTHEAST COLORADO EARLY THIS
MORNING WAS PROVIDING SOME UPWARD VERTICAL MOTION TO SUPPORT
SCATTERED SHOWERS FROM EASTERN COLORADO INTO FAR SOUTHWESTERN
KANSAS. AS THE UPPER LEVEL TROUGH MOVES SOUTHEAST INTO OKLAHOMA THIS
MORNING...THE AREA OF SHOWERS SHOULD DECREASE AND GRADUALLY
DISSIPATE BEFORE NOON. LOW POPS WERE MAINTAINED IN THE GRIDS FOR A
FEW HOURS THIS MORNING OVER THE SOUTHWESTERN ZONES.
PROFILER WINDS ARE RUNNING AROUND 45 KNOTS AT BOTH HAVILAND AND
MCCOOK AND LIKELY WILL PERSIST FOR MUCH OF THE DAY. THERE WILL BE
ENOUGH SUN TO PROVIDE MIXING OF THE HIGHER MOMENTUM AIR TO THE
SURFACE...AND SURFACE WINDS SHOULD INCREASE TO AT LEAST 25 KNOTS
SUSTAINED BY MID MORNING ACROSS MUCH OF SOUTHWEST KANSAS WITH THE
EXCEPTION OF THE FAR SOUTHWEST COUNTIES...WHERE THE PRESSURE
GRADIENT WILL BE WEAKER. A WEAK VORTICITY MAXIMUM SUGGESTED ON
SATELLITE IMAGERY OVER NORTHEAST COLORADO EARLY THIS MORNING WILL
PROPAGATE OVER THE MOIST FLOW AROUND THE NEBRASKA CYCLONE LATER
TODAY AND SHOULD SUPPORT A FEW SHOWERS ACROSS NORTHERN KANSAS.
UPWARD VERTICAL MOTION WILL BE QUITE WEAK...AND RAINFALL
ACCUMULATIONS WILL BE VERY LIGHT.
WINDS AND RH VALUES WILL APPROACH RED FLAG CRITERIA NEAR THE
COLORADO BORDER THIS AFTERNOON...BUT IT APPEARS THAT LOWEST RH
VALUES SHOULD BE BETWEEN 15 AND 20 PERCENT. IF DEWPOINTS DROP BELOW
EXPECTED LEVELS...THE DAY SHIFT WILL HAVE TO REEVALUATE THE NEED FOR
A RED FLAG WARNING.
BY TONIGHT...THE PRESSURE GRADIENT WILL CONTINUE TO DIMINISH...AND
UPPER LEVEL RIDGING WILL BECOME ESTABLISHED OVER THE CENTRAL
ROCKIES. INCREASING FLOW PERPENDICULAR TO THE ROCKIES WILL SUPPORT
DEVELOPMENT OF A LEE TROUGH BY FRIDAY MORNING...AND LOW LEVEL FLOW
WILL RETURN TO THE SOUTH. LIGHT WINDS AND DRY AIR WILL SUPPORT RAPID
RADIATIONAL COOLING TONIGHT...AND TEMPERATURES WILL DROP INTO THE
30S IN MOST AREAS. SOME LOCALIZED FROST MAY OCCUR WHERE WINDS GO
NEARLY CALM TOWARD MORNING...AND PATCHY FROST WAS INTRODUCED IN THE
NORTHWESTERN GRIDS WHERE DEWPOINTS SHOULD BE LOWEST.
FRIDAY SHOULD BE FAIR AND MILD AS RIDGING CONTINUES TO BUILD OVER
THE CENTRAL PLAINS AND LOW LEVEL SOUTHERLY FLOW BECOMES ESTABLISHED.
BOTH THE GFS AND UKMET HAVE H8 TEMPERATURES BETWEEN 15C AND 20C OVER
SOUTHWEST KANSAS BY 00Z SATURDAY. WITH ABUNDANT SUNSHINE...SURFACE
TEMPERATURES SHOULD RISE WELL INTO THE 70S WITH FAR SOUTHWEST KANSAS
APPROACHING 80 DEGREES FRIDAY AFTERNOON.
DAYS 3-7...
THE MAIN CHALLENGE IN THE DAY 3-7 DAY FORECAST WILL BE THE TIMING OF
PRECIPITATION CHANCES...MAINLY TIED TO THE UPPER LOW PRESSURE DUE TO
CROSS THE PLAINS THIS WEEKEND. BOTH THE ECMWF AND THE GFS BRING
THIS UPPER FEATURE ACROSS THE NORTHERN ROCKIES AS AN ELONGATED N-S
ORIENTED WAVE...AND THEN CUT IT OFF ONCE IT PASSES WESTERN KANSAS
LATE SUNDAY INTO MONDAY. THE GFS FORMS AND CUTS THIS UPPER LOW OFF
FARTHER NORTH OVER NORTH CENTRAL KANSAS...AND THUS KEEPS MOST OF THE
PRECIPITATION IN NORTHERN KANSAS AND NEBRASKA. THE ECMWF ON THE
OTHER HAND HANDLES THIS SAME FEATURE BY CUTTING IT OFF IN THE TEXAS
PANHANDLE AND THEN LIFTS IT NORTHEAST MORE SLOWLY THAN THE GFS.
WITH THE GFS SOLUTION WE WILL SEE LITTLE SIGNIFICANT RAIN IN OUR
CWA...BUT WITH THE ECMWF SOLUTION...WE COULD SEE SOME SIGNIFICANT
RAINFALL IN PART OF DDC` CWA...MOST LIKELY THE EASTERN TIER. LOOKED
AT THE CANADIAN MODEL WHICH HANDLES THIS UPPER FEATURE BY DIGGING IT
DEEP IN TO THE TEXAS PANHANDLE BUT IS SLOWER IN CUTTING OFF THE
LOW. HAVE FOLLOWED THE ECMWF MODEL FOR THE MOST PART AND INTRODUCED
20 POPS IN MY WEST SUNDAY...AND KEPT WITH THE PREVIOUS FORECAST
TREND OF BLENDING UPWARDS TO 30 POPS IN MY EASTERN CWA LATE SUNDAY
AND CONTINUING INTO MONDAY. TWEAKED DOWN TO 20 POPS IN THE WEST
MONDAY AFTERNOON...AS THE UPPER FORCING AND LOW LEVEL MOISTURE
ADVECTION WILL FAVOR OUR EASTERN CWA. DROPPED ALL POPS BY 23/00Z
MONDAY NIGHT...AS HIGH PRESSURE WILL BUILD IN BEHIND THE EXITING
UPPER LOW MONDAY NIGHT. ONE FORECAST QUESTION IS HOW COLD WILL OUR
WESTERN TIER OF COUNTIES GET MONDAY MORNING WITH HIGH PRESSURE
BRINGING CLEARING SKIES AND DRIER AIR SINKING SOUTH FROM THE HIGHER
PLAINS. SUNDAY NIGHT COULD BE COLD IN OUR NORTHWEST COUNTIES...BUT
THE DRIEST AIR WILL NOT HAVE FILTERED DOWN THIS FAR SOUTH THAT
QUICKLY. FOR NOW...THINK TUESDAY/WEDNESDAY MORNINGS WILL BE THE
COLDEST...AND HAVE PLACED 31F MIN T`S IN HAMILTON COUNTY BOTH
TUESDAY AND WEDNESDAY MORNINGS. MAX TEMPS THROUGH THE 3 TO 7 DAY
PERIOD REMAINED UNCHANGED FROM THE PREVIOUS SHIFT`S FORECAST...AND
ARE IN GOOD COMPLIANCE WITH OUR ISC NEIGHBORS. VERY WARM ON MONDAY
BEFORE A COLD FRONTAL PASSAGE...THEN A COOLING TREND SUNDAY AND
MONDAY...FOLLOWED BY MODERATING HIGH TEMPS TUESDAY INTO THURSDAY.
&&
.AVIATION...
FOR THE MOST PART...CIGS WILL BE IN MID LEVEL RANGE...VARYING FROM
AROUND BKN050-060 AT HYS WITH A FEW 6SM+ RW- SHOWERS EARLY (THRU
08Z) TO CIGS IN THE BKN100 RANGE AT GCK AND DDC. THE MAIN WX
ELEMENT WILL BE STRONG NORTHWEST WINDS AT 15Z IN THE 30G40KT RANGE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 67 38 75 43 / 0 0 0 0
GCK 67 36 76 42 / 0 0 0 0
EHA 68 40 77 46 / 10 0 0 0
LBL 69 36 76 42 / 10 0 0 0
HYS 61 36 73 41 / 30 10 0 0
P28 68 42 76 43 / 10 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 10 AM CDT /9 AM MDT/ TO 7 PM CDT /6 PM MDT/
THURSDAY FOR KSZ030-031-043>046-062-066-076>081-086>090.
&&
$$
FN01/12/12
AREA FORECAST DISCUSSION
NWS PADUCAH KY
315 PM CDT THU OCT 18 2007
.SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT.
MAIN CONCERN FOR THIS PERIOD CONTINUES TO BE SEVERE WEATHER
POTENTIAL THIS AFTERNOON AND EVENING.
RADAR IMAGERY FINALLY SHOWING SOME DEVELOPMENT JUST WEST OF CARTER
COUNTY MISSOURI...ALONG WITH SOME SCATTERED ECHOES NEAR THE
MISSISSIPPI RIVER IN WEST KENTUCKY AND A STRAY APPARENTLY ELEVATED
SHOWER OVER THE PENNYRILE. TAMDAR SOUNDINGS FROM KPAH AROUND NOON
INDICATED A SIZABLE CAP...WHICH IS LIKELY CAPPING THE SHOWER
DEVELOPMENT OVER WEST KENTUCKY.
FEEL THAT SCATTERED THUNDERSTORMS WILL SLOWLY DEVELOP OVER SOUTHEAST
MISSOURI...AS THE UPDRAFTS STRUGGLE AGAINST THE IMMENSE DEEP LAYER
SHEAR. AS THEY MOVE FURTHER EAST THEY WILL BECOME MORE NUMEROUS AND
SUPERCELLULAR...AS THEY ENCOUNTER BETTER LOW-LEVEL MOISTURE AND
INSTABILITY. STRAIGHT-LINE HODOGRAPHS INDICATE SOME POTENTIAL FOR
SPLITTING STORMS...ESPECIALLY IN THE ORGANIZING STAGE. SO LONG AS
THE STORMS CAN STAY ISOLATED...DAMAGING WINDS...TORNADOES AND LARGE
HAIL WILL ALL BE POSSIBLE.
IF THE STORMS FORM INTO LINE SEGMENTS AS THEY PROGRESS INTO BETTER
MOISTURE OVER WEST KENTUCKY AND SOUTHWEST INDIANA THIS
EVENING...INTENSE BOW ECHOES WOULD BE THE DOMINANT SEVERE WEATHER
MODE. THE BEST LOW-LEVEL SHEAR AND INSTABILITY LOCATED OVER WEST
KENTUCKY AND SOUTHWEST INDIANA...WILL RESULT IN THIS AREA HAVING THE
GREATEST THREAT FOR A HIGH END SEVERE EVENT IN THE FORM OF TORNADOES
OR BOW ECHOES.
AS FOR THE GRIDS...GIVEN ONLY SCATTERED STORMS INITIALLY...WILL KEEP
POPS IN THE LIKELY CATEGORY...CENTERED OVER THE PURCHASE AREA AND
SOUTHERN ILLINOIS BEFORE 00Z...WITH CHANCE POPS FURTHER WEST NEAR
THE INITIAL DEVELOPMENT. WILL THEN FOCUS LIKELIES EASTERN HALF AFTER
00Z WITH ONLY A SLIGHT CHANCE OVER WESTERN SOUTHEAST MISSOURI
COUNTIES. WILL KEEP CHANCE POPS EAST OVERNIGHT...JUST IN CASE A FEW
SHOWERS OR STORMS LINGER OVER THE PENNYRILE.
AS FOR THE WIND ADVISORY...WILL KEEP IT GOING THROUGH 6 PM...EVEN
THOUGH WE HAVE NOT QUITE REACHED CRITERIA. THE 30+KT GUSTS SHOULD
SETTLE DOWN SOME WITH SUNSET...BUT WILL LIKELY STILL SEE SOME DECENT
SOUTH TO SOUTHWEST WINDS WELL INTO THE EVENING...WITH OR WITHOUT
CONVECTION.
FOR FRIDAY AND BEYOND...BASICALLY JUST FOLLOWED THE 12Z GFS AND ITS
MAV TEMPERATURE GUIDANCE. AFTER A COOLISH DAY FRIDAY...THE WEEKEND
WILL BE MOSTLY SUNNY WITH CONTINUED ABOVE NORMAL TEMPERATURES. THE
12Z GFS SUPPORTS THE POPS OVER THE WESTERN HALF OF THE AREA SUNDAY
NIGHT...SO LEFT THAT ALONE.
.LONG TERM...MONDAY THROUGH THURSDAY.
MODELS ARE IN SLIGHTLY BETTER AGREEMENT REGARDING THE SYSTEM TO
AFFECT THE REGION EARLY NEXT WEEK. THE ECMWF IS STILL FAR FROM THE
00Z GFS AND GFS ENSEMBLES. FORECAST WILL BE WEIGHTED MORE HEAVILY
TOWARD THE GFS/GFS ENSEMBLES...IN LINE WITH HPC GUIDANCE. THE GFS
PUTS MUCH MORE EMPHASIS ON THE NORTHERN BRANCH OF THE 500 MB
JET...DIGGING A FULL LATITUDE TROUGH THROUGH THE CENTRAL STATES.
THIS TROUGH THEN SHEARS OUT GRADUALLY DURING MID WEEK. AS A
RESULT...HIGHEST PRECIP CHANCES WILL BE MONDAY ASSOCIATED WITH THE
PROGRESSIVE COLD FRONT PASSING THROUGH THE LOWER OHIO VALLEY. LOWER
PRECIP CHANCES WILL LINGER INTO TUESDAY NIGHT AS THE WEAKENING 500
MB TROUGH PERSISTS NEAR OR JUST EAST OF THE FORECAST AREA.
CONFIDENCE DECREASES AFTER MONDAY SINCE MODEL VARIABILITY BECOMES
MUCH GREATER. TEMPS WILL BE CLOSE TO SEASONAL NORMS IN THE WAKE OF
THE COLD FRONT PASSAGE ON MONDAY.
&&
.AVIATION...
TIMING OF CONVECTION IS THE MAIN AVIATION CONCERN. HIGHEST
PROBABILITIES ARE IN EVV/OWB TAF AREAS...WHERE MOISTURE IS
RELATIVELY DEEP. THE DEEPER MOISTURE IS EVIDENT IN VISIBLE SATELLITE
IMAGERY...WITH MORE IMPRESSIVE CUMULUS DEVELOPMENT SOUTH AND EAST OF
PAH. INSTABILITY WILL WANE QUICKLY AFTER SUNSET...WHEN DRIER AIR
WILL CONTINUE TO INVADE FROM THE WEST. CONVECTIVE POTENTIAL SHOULD
BE MAINLY EAST OF THE TAF SITES BY 03Z...FOLLOWED BY A PERIOD OF
MOSTLY CLEAR SKIES AND DIMINISHING WINDS. WRAPAROUND LOW CLOUDINESS
OVER IOWA AND NW MISSOURI MAY OVERSPREAD THE REGION WELL AFTER 06Z.
CIGS ARE EXPECTED TO BE IN THE MVFR RANGE AT WORST.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
MO...NONE.
IL...NONE.
IN...NONE.
&&
$$
SHORT TERM......DRS
LONG TERM.......MY
AVIATION........MY
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
235 PM CDT THU OCT 18 2007
.SYNOPSIS...
THE 6.7U WATER VAPOR IMAGERY SHOWED A DEVELOPING WAVE OVER
NORTHWEST WASHINGTON AND A MATURE VORTEX IN THE NORTH PACIFIC NEAR
THE GULF OF ALASKA. THE RADAR MOSAIC INDICATED WIDESPREAD RAIN OVER
THE EASTERN HALF OF NEBRASKA ROTATING ABOUT THE MATURE CYCLONE
CENTERED OVER EAST CENTRAL MINNESOTA. MESONET AND METAR OBSERVATIONS
INDICATED THAT HIGH WIND CRITERIA WAS MEASURED IN THE SOUTHERN
NEBRASKA PANHANDLE.
&&
.SHORT TERM...TONIGHT THROUGH SATURDAY.
DRY AIR IS EXPECTED TO WORK INTO THE REST OF WESTERN AND NORTH
CENTRAL NEBRASKA THIS EVENING...BRINGING AN END TO THE
PRECIPITATION. WIND SHOULD ALSO TAPER OFF BY 06Z. FOR NOW WE WILL
KEEP THE WIND WARNING IN EFFECT UNTIL 00Z...THOUGH THE WIND ADVISORY
WILL PROBABLY NEED TO BE EXTENDED THROUGH LATE THIS EVENING. THE
AREA CURRENTLY UNDER THE HIGH WIND WARNING WILL NEED TO BE
RE-EVALUATED THIS EVENING FOR EXPIRATION VERSUS DOWNGRADING TO AN
ADVISORY.
AFTERWARD...A FAIRLY QUIET PATTERN APPEARS TO BE ON TAP THROUGH
SATURDAY. RETURN FLOW IN THE BOUNDARY LAYER IS LIKELY TO RE-OPEN A
TRAJECTORY FROM THE TEXAS GULF COAST BY EARLY SATURDAY. THIS SHOULD
PRIME THE PUMP SOMEWHAT FOR THE NEXT SYSTEM COMING THROUGH SATURDAY
EVENING.
&&
.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY.
THERE ARE STILL SIGNIFICANT DIFFERENCES AMONG THE MEDIUM TO LONG
RANGE SIMULATIONS AFTER SATURDAY...SO CONFIDENCE IN THE FORECAST IS
STILL LOW.
THERE IS SOME AGREEMENT THAT A SURFACE SYSTEM AND UPPER LOW WILL
INTERACT TO PRODUCE PRECIPITATION IN WESTERN NEBRASKA SATURDAY
NIGHT. BEYOND THAT...THE GFS AND ECMWF DIVERGE...WITH THE GFS
SHOWING A PROGRESSIVE PATTERN AND THE ECMWF SHOWING GREATER
PERSISTENCE OF THE FRONT AND UPPER LOW OVER THE CENTRAL PLAINS. A
BLEND OF THE TWO HAS RAIN BEGINNING IN NORTHWEST NEBRASKA SATURDAY
NIGHT...SPREADING OVER THE REST OF WESTERN AND NORTH CENTRAL
NEBRASKA SUNDAY AND TAPERING OFF SUNDAY NIGHT. WIND MAY BE A PROBLEM
WITH THIS SYSTEM AS WELL. THE SURFACE SYSTEM SHOWS A PRETTY TIGHT
PRESSURE GRADIENT AGAIN IN THE WAKE OF THE FRONT.
ANOTHER FRONT IS LIKELY TO MOVE ACROSS THE PLAINS WEDNESDAY AND
THURSDAY...BUT THERE IS A LACK OF ANTECEDENT MOISTURE ADVECTION
AHEAD OF ITS PASSAGE. SO...FOR THE TIME BEING...WE WILL KEEP THE
FORECAST DRY.
&&
.AVIATION...
IFR/MVFR CONDITIONS WILL SLOWLY IMPROVE ACROSS NORTH CENTRAL AND
EASTERN NEBRASKA THROUGH THE EVENING HOURS AS THE SYSTEM PULLS
FARTHER INTO THE GREAT LAKES REGION. A MAJORITY OF THE RESTRICTIONS
WILL BE DUE TO CIG HEIGHTS...HOWEVER ISOLATED SHOWERS MAY REDUCE
VISIBILITIES DOWN TO THE MVFR CONDITIONS AS WELL. WINDS WILL
CONTINUE TO BE A THREAT TO LIGHT AIRCRAFT THROUGH SUNSET WITH THE
STRONGEST WINDS...GUSTING UP TO NEAR 60 MPH...FOUND OVER THE
COLORADO PLAINS INTO THE SOUTHERN PANHANDLE AND SOUTHWEST NEBRASKA
WEST OF HIGHWAY 61. THESE WINDS SHOULD RAPIDLY QUIET DOWN AFTER
SUNSET AND CLEARING SKIES SHOULD WORK EASTWARD THROUGH
SUNRISE...LEAVING VFR CONDITIONS IN PLACE FOR THE DAYLIGHT HOURS
FRIDAY.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NEZ022-035-056>058-069...HIGH WIND WARNING UNTIL 00Z.
NEZ004>010-023>029-036>038-059-070-071...WIND ADVISORY UNTIL 03Z.
&&
$$
SPRINGER/13
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
100 AM CDT THU OCT 18 2007
.UPDATE...
FORECAST UPDATED TO REMOVE OVERNIGHT WIND ADVISORY FOR THE EASTERN
PANHANDLE INTO THE NORTHWEST. WINDS BELOW CRITERIA LEVEL AND NOT
EXPECTED TO BE ON THE INCREASE UNTIL BETWEEN 7 TO 9 AM...WITH WIND
ADVISORY CANCELLED. HIGH WIND WATCH CANCELLED ALSO WITH WIND
ADVISORY ISSUED FOR ALL BUT THE FAR FOUR EASTERN NORTH CENTRAL
ZONES. AS THE SURFACE LOW LIFT NORTHEAST INTO WESTERN IOWA
THURSDAY MORNING THE SYSTEM WILL MOVE RAPIDLY NORTHEAST WITH GUSTY
NORTHWEST WINDS TO INCREASE THROUGH THE MORNING...PEAK AROUND NOON
AND DIMINISH INTO THE EVENING. MODELS SHOW SYSTEM WEAKER THAN IN
PREVIOUS RUNS WITH HIGH END WIND ADVISORY TO IMPACT THE WEST INTO
PORTIONS OF THE NORTH CENTRAL THURSDAY. ALSO LOWERED POPS ACROSS
THE WEST THURSDAY MORNING WITH DRIER NAM SOLUTION BETTER
REPRESENTATION OF ONGOING CONDITIONS FOR SCATTERED SHOWERS ACROSS
THE WEST.
&&
.PREV DISCUSSION... /ISSUED 851 PM CDT WED OCT 17 2007/
UPDATE...
PRECIP WINDING DOWN ACROSS THE WEST WITH AREAL COVERAGE FURTHER
EAST DECREASING WITH FORECAST GRIDS AND TEXT UPDATED TO REFLECT
LOWERING POPS. OTHERWISE NO SIGNIFICANT CHANGES TO GOING FORECAST.
PREV DISCUSSION... /ISSUED 315 PM CDT WED OCT 17 2007/
SYNOPSIS...
THE 18Z SURFACE ANALYSIS SHOWED LOW PRESSURE CENTERS IN WESTERN
KANSAS...EAST CENTRAL WYOMING AND INTO SOUTHWEST SASKATCHEWAN AND
NORTHERN ALBERTA. THE ASSOCIATED FRONT SNAKED ACROSS NEBRASKA...
KANSAS...COLORADO AND WYOMING. SATELLITE DERIVED PRODUCT IMAGERY
SHOWED HINTS OF A MOISTURE PLUME OVER CENTRAL AND EASTERN
NEBRASKA...AND ALSO INSTABILITY IN THE PANHANDLE AND SOUTHWEST
NEBRASKA AND OVER EASTERN NEBRASKA. SURFACE LAPS ANALYSIS SUPPORTED
THIS.
SHORT TERM...TONIGHT THROUGH FRIDAY.
FORECAST CHALLENGES WITH THIS CYCLE ARE PRECIPITATION AND WIND
TONIGHT AND THURSDAY.
REGARDING THE WIND...A TIGHT PRESSURE GRADIENT BEHIND THE
CYCLONE CROSSING THE AREA TONIGHT IS LIKELY TO PRODUCE STRONG
WIND...ESPECIALLY FROM EARLY THURSDAY THROUGH THE EVENING. THE WIND
SPEEDS INDICATED MAY REACH 45MPH SUSTAINED BY 12Z THURSDAY IN
WESTERN NEBRASKA AND CENTRAL AND NORTH CENTRAL NEBRASKA BY 15Z. HIGH
WIND IS NOT FAVORED DIURNALLY...BUT COLD ADVECTION IN THE BOUNDARY
LAYER MAY BE SUFFICIENT TO OVERCOME THAT LIMITATION. IT IS A SAFE
BET THAT THE WIND THAT DOES DEVELOP WILL REACH SPEEDS IN THE HIGH
END ADVISORY OR LOW END WARNING THRESHOLDS. FOR NOW...WE WILL KEEP
THE CURRENT HIGH WIND WATCH IN EFFECT. ALSO...WE WILL NOT CANCEL THE
ADVISORY FOR THE PANHANDLE AND NORTHWEST SAND HILLS.
REGARDING THE PRECIPITATION...IT APPEARS THAT HIGH PROBABILITIES
ARE APPROPRIATE FOR THE NORTH AND EAST TONIGHT AND THURSDAY. WE ARE
LESS CONFIDENT ABOUT THE SOUTHWEST...SO WILL KEEP THE PROBABILITY AT
OR BELOW 50 PERCENT. INSTABILITY SUPPORTS THUNDERSTORMS RATHER THAN
STRATIFORM. FOR FRIDAY...THINGS SHOULD CLEAR OUT AND WARMER
TEMPERATURES ARE LIKELY.
LONG TERM...SATURDAY THROUGH WEDNESDAY.
THE FORECAST CHALLENGE IN THE EXTENDED PERIOD IS THE NEXT SYSTEM
ON TAP FOR THE WEEKEND.
THE MEDIUM RANGE SIMULATIONS ARE SIMILAR IN DEVELOPING A CLOSED
UPPER LOW OVER SOUTHWEST COLORADO SATURDAY NIGHT. AFTER THAT...THEY
DIVERGE SIGNIFICANTLY. THE ECMWF IS AN OUTLIER...DIGGING THE UPPER
TROUGH TO THE SOUTHWEST AND PUTTING THE CLOSED UPPER LOW OVER THE
DESERT SOUTHWEST AND KEEPING IT THERE. THOUGH WE ARE LEANING TO THE
MORE PROGRESSIVE SOLUTIONS...CONFIDENCE IN THE FORECAST IS PRETTY
LOW FOR THE FORECAST PERIODS BEYOND SATURDAY.
THAT SAID...A FRONT IS EXPECTED TO MOVE INTO WESTERN NEBRASKA BY
SATURDAY EVENING. CONVERGENCE AND ELEVATED 2D-FRONTOGENESIS WILL
WORK TOGETHER TO GENERATE GOOD LIFT IN WESTERN NEBRASKA SATURDAY
NIGHT AND OVER MOST OF CENTRAL AND WESTERN NEBRASKA SUNDAY. IT
SHOULD ALL MOVE OUT OF THE AREA BY LATE SUNDAY EVENING.
AFTER THAT...AN UPPER RIDGE WILL BUILD OVER THE WESTERN STATES
MONDAY AND CONTINUE THROUGH TUESDAY. THEN...IT APPEARS THAT THE
RIDGE WILL BEGIN TO FLATTEN WEDNESDAY. AS A RESULT...DRY WEATHER AND
WARMING TEMPERATURES MAY BE EXPECTED TUESDAY AND WEDNESDAY.
AVIATION...
IFR/MVFR CONDITIONS WILL PERSIST ACROSS MUCH OF WESTERN AND
NORTH CENTRAL NEBRASKA OVER THE NEXT 24 HOURS. VFR CONDITIONS ACROSS
THE PANHANDLE SHOULD EVENTUALLY DROP TO MVFR CONDITIONS AS WELL AS
THE COLORADO PLAINS. CEILING HEIGHTS WILL BE THE MAIN THREAT HOWEVER
VSBYS WILL ALSO BE REDUCED TO IFR/MVFR CONDITIONS FROM EITHER FOG OR
PRECIPITATION FALLING. NORTHWEST WINDS ARE ALSO EXPECTED TO INCREASE
TO AT LEAST THE 30 TO 40 MPH RANGE ON THURSDAY...HOWEVER OPEN AREAS
ACROSS THE WEST MAY SEE WINDS OF UP TO 45 MPH WITH GUSTS APPROACHING
60 MPH WHICH MAY LIMIT SMALL AIRCRAFT OPERATION.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 7 AM CDT /6 AM MDT/ THIS MORNING TO 7 PM CDT
/6 PM MDT/ THIS EVENING FOR NEZ004>006-008-009-022>027-035>038-
056>059-069>071-094.
&&
$$
SPRINGER/13/TLK
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1214 PM EDT THU OCT 18 2007
.SYNOPSIS...
DEEP LOW PRESSURE CENTERED OVER THE NATIONS MIDSECTION THIS MORNING
WILL CONTINUE TO PUMP VERY MILD AIR NORTHWARD ACROSS OUR PART OF THE
COUNTRY THROUGH FRIDAY AS IT TRACKS NORTHEAST INTO THE UPPER GREAT
LAKES REGION. ALTHOUGH THERE IS A THREAT OF WARM FRONTAL
PRECIPITATION LATER TODAY...IT LOOKS LIKE A HIGH PROBABILITY OF
THUNDERSTORMS FRIDAY AS AN ASSOCIATED COLD FRONT CROSSES THE REGION.
THERE IS A POTENTIAL OF SEVERE WEATHER WITH SOME OF THE STORMS
MIDDAY FRIDAY INTO THE AFTERNOON HOURS. MORE SEASONAL TEMPERATURES
WILL FOLLOW THE COLD FRONT INTO THE EARLY PART OF THE WEEKEND BEFORE
ANOTHER WARMING TREND SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
BAND OF WARM FRONTAL SHOWERS CONTINUES TO SLOWLY TRACK EASTWARD
ACROSS EAST-CENTRAL OHIO...WESTERN LAKE ERIE...AND SOUTHERN
ONTARIO AT THIS HOUR...IN ASSOCIATION WITH A 50-60KT 850 MB JET
AND ZONE OF DIFFLUENT FLOW ALOFT BETWEEN TWO DISTINCT 300 MB JET
STREAKS. CLE/PBZ RADARS BEGINNING TO SHOW SOME WEAKENING OVER THE
PAST HOUR OR TWO...AND WOULD EXPECT THIS TREND TO CONTINUE THIS
AFTERNOON AS THE LOW LEVEL JET WEAKENS DRAMATICALLY...AND THE ZONE
OF BEST UPPER LEVEL DIFFLUENT FLOW IS SHUNTED OFF OUR NORTHWEST.
FOR THIS REASON...HAVE KEPT CURRENT CHANCE POPS IN PLACE FOR THE
AFTERNOON WITH THE HIGHEST VALUES /40S/ ACROSS CHAUTAUQUA
COUNTY...AND HAVE SLOWED THE EASTWARD PROGRESSION AN HOUR OR
TWO...IN LINE WITH CURRENT RADAR TRENDS AND THE 06Z GFS...WHICH
HAS A GOOD HANDLE ON THE SITUATION.
A FAIR AMOUNT OF WARM ADVECTIVE MID AND UPPER CLOUD STREAMING
NORTHEASTWARD INTO THE AREA IS RESULTING IN MOSTLY CLOUDY SKIES
WEST OF THE GENESEE VALLEY AT THIS HOUR...THOUGH THERE ARE SOME
THIN SPOTS WHERE THE SUN IS STILL SHINING THROUGH. HAVE TWEAKED
THE SKY COVER TO REFLECT MORE CLOUDS ACROSS THE WESTERN HALF OF
THE AREA /THOUGH HAVE KEPT IN A MENTION OF LIMITED SUN/...WHILE
HAVE MAINTAINED THE PARTLY SUNNY SKIES ACROSS THE EASTERN HALF.
WITH THE INCREASED CLOUD COVER...HAVE ALSO KNOCKED BACK TEMPS A
DEGREE OR TWO ACROSS THE WEST...WHILE LEAVING THEM PRETTY MUCH AS
IS ACROSS THE EAST...RESULTING IN LOW- MID 70S ACROSS THE BOARD.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
A WARM NIGHT EXPECTED TONIGHT AS THE SOUTHERLY FLOW CONTINUES AT ALL
LEVELS ACROSS OUR REGION. OVERNIGHT LOWS SHOULD IN THE 60S IN MOST
AREAS AND AT LEAST UPPER 50S OVER THE NORMALLY COLDER AREAS OF THE
SOUTHERN TIER. CURRENT POP GRIDS FOR TONIGHT LOOK VERY GOOD WITH
CHANCE POPS RESERVED FOR THE EASTERN LAKE ONTARIO REGION FOR JUST
THE FIRST PART OF THE NIGHT AS THE WARM FRONT CONTINUES TO PUSH
NORTHWARD.
FRIDAY WILL BE THE MOST IMPORTANT PART OF THIS FORECAST AS THE NEAR
RECORD WARMTH CONTINUES. THE DEEP SURFACE LOW IS FORECAST TO
CONTINUE FURTHER NORTHWARD TO NORTH OF LAKE SUPERIOR WITH A COLD
FRONT WRAPPING AROUND IT AND APPROACHING US DURING THE DAY. SURFACE
DEW POINTS ARE EXPECTED TO BE IN THE LOWER 60S. PROJECTED HODOGRAPHS
OFF BUFKIT DATA ARE IMPRESSIVE FOR THE POTENTIAL FOR SEVERE STORMS.
HPC HAS US IN A SLIGHT RISK AREA.
850 MB TEMPERATURES WILL SUPPORT VERY WARM READINGS AGAIN BUT ANY
RECORDS WILL DEPEND ON HOW MUCH IF ANY SUNSHINE WE GET BEFORE THE
RAIN STARTS. RECORD HIGH TEMPERATURE RECORDS FOR FRIDAY ARE AS
FOLLOWS:
KBUF...77 IN 1961
KROC...81 IN 1953
KART...77 IN 1961
BEHIND THE COLD FRONT...MUCH COOLER AIR WILL SWEEP IN FRIDAY NIGHT
AND SATURDAY...WITH 850 MB TEMPERATURES FALLING TO A MORE NORMAL +4C
TO +6C...ALONG WITH DECREASING HUMIDITY. SURFACE RIDGING BUILDING IN
BEHIND THE FRONT SHOULD RESULT IN A NARROW WINDOW OF DRY WEATHER FOR
A WHILE FRIDAY NIGHT...BEFORE THE UPPER TROUGH/COOL POOL SWINGS
THROUGH WITH ANOTHER CHANCE OF SHOWERS LATE FRIDAY NIGHT AND
SATURDAY. TEMPS SATURDAY LOOK TO BE MUCH CLOSER TO
NORMAL...GENERALLY LOWER 60S.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
MAIN FEATURE DURING THIS PERIOD WILL BE A SLOW MOVING FRONTAL
PASSAGE NOW SCHEDULED FOR LATE MON NT AND TUES MORNING. PRIOR TO
THIS WE WILL BE TREATED TO YET ANOTHER TASTE OF SUMMERLIKE WX ON
MONDAY AS WE SHOULD RETAIN PLENTY OF SUNSHINE AND DOWNSLOPE
SOUTHERLY FLOW TO MIX OUT OUR 14-15C 850 MB TEMPS TO 75-80 RANGE
ACROSS MOST LOWER ELEVS. (MON RECORDS OF 81 AND 82 AT BUF/ROC MAY
EVEN BE THREATENED). 12Z GFS A LITTLE QUICKER WITH THE
FRONT...WHICH WOULD BRING SOME CLOUD INTO WEST IN AFTERNOON AND
HOLD TEMPS BACK A BIT...BUT STILL WILL BE UNUSUALLY WARM.
THEN...WILL BRING CHC POPS IN FROM THE WEST MON NT AND CONTINUE
WITH 50 POPS ALL SECTIONS ON TUES AS THE FRONT WORKS ACROSS THE
STATE. SOME DISCREPENCY IN MODELS THEREAFTER WITH GFS DEVELOPING A
COASTAL AND ALLOWING TROF TO HANG BACK THROUGH WED AND WED NT
WITH SHOWER THREAT HERE...WHILE HPC GRAPHICS TAKE FRONT ON TO COAST WITH
IMPROVEMENT FOR US ON WED. WILL CARRY CHC POPS ALL AREAS ON WED ON
BACKSIDE OF SYSTEM WITH COOL ADVECTION AND UPSLOPE WITH SLIGHTLY
HIGHER POPS E AND SE OF LAKES WITH SOME LAKE ENHANCEMENT...BUT
850`S BOTTOM OUT AT ABOUT -2C...TOO WARM FOR SNOW...SO WILL JUST
KEEP IT LIQUID. QUITE A BIT COOLER ON WED THOUGH. WE WILL BEGIN A
WARMING TREND AGAIN ON THURS AS HIGH CRESTS OVER US AND THEN
DRIFTS OFF TO OUR EAST.
&&
.AVIATION /16Z THURSDAY THROUGH MONDAY/...
BROAD AREA OF WARM ADVECTION WILL CONTINUE TODAY ACROSS THE EASTERN
GREAT LAKES AND OVER WESTERN TO CENTRAL NY. MAINLY CLEAR SKIES
OVER THE REGION EARLY THIS MORNING WITH LIGHT WINDS AND HIGHER
DEWPOINTS HAVE DEVELOPED WIDESPREAD FOG...LOCALLY DENSE. SURFACE
CONDITIONS WILL BE IFR TO LIFR AT MANY LOCATIONS THROUGH
SUNRISE...AND UNTIL ABOUT AN HOUR THEREAFTER.
ANOTHER IN A SERIES OF WARM FRONTS WILL APPROACH WESTERN NY THURSDAY
AFTERNOON. THERE WILL BE A CHANCE OF SHOWERS WITH THIS
FEATURE...ALTHOUGH CIGS/VSBY SHOULD REMAIN VFR THURSDAY AFTERNOON.
LOOKING FURTHER AHEAD...A STRONG COLD FRONT WILL CROSS THE REGION ON
FRIDAY. STRONG WIND FIELDS AND MARGINAL TO PERHAPS MODERATE
INSTABILITY MAY SET THE STAGE FOR WIDESPREAD THUNDERSTORM
DEVELOPMENT. STRONG WIND FIELDS SUGGEST STORMS MAY BECOME STRONG AND
ORGANIZE INTO LINE SEGMENTS...WHICH MAY REQUIRE EXTENSIVE AIRCRAFT
REROUTING. FOLLOWING THE COLD FRONT...WRAP AROUND MOISTURE ON
SATURDAY MAY BRING WIDESPREAD MVFR CIGS...GUSTY WINDS...AND
SHOWERS...FOLLOWED BY A CLEARING TREND FOR SUNDAY AND MONDAY.
&&
.MARINE...
A WARM FRONT WILL DISSIPATE OVER LAKE ONTARIO EARLY THIS MORNING
WITH VARIABLE WINDS UNDER 10 KNOTS. WINDS WILL BE SOUTHERLY FOR
AWHILE LATER TODAY AND THIS EVENING BEFORE BACKING TO EASTERLY ONCE
AGAIN TONIGHT AHEAD OF YET ANOTHER WARM FRONT. WINDS WILL BE LIGHT
WITH MINOR WAVES ON THE LAKES.
WINDS WILL FINALLY TURN SOUTH TO SOUTHWEST DURING FRIDAY AND
INCREASE AHEAD OF A SHARP COLD FRONT WHICH WILL CROSS THE EASTERN
LAKES FRIDAY EVENING. THEY WILL THEN VEER TO WESTERLY FOLLOWING THE
FRONT AND REMAIN QUITE BRISK THROUGH SATURDAY. MARINE FLAGS WILL
PROBABLY BE NECESSARY FRIDAY NIGHT AND SATURDAY.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SAGE
NEAR TERM...JJR
SHORT TERM...JJR/SAGE
LONG TERM...SFM
AVIATION...WCH
MARINE...WCH
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1133 AM EDT THU OCT 18 2007
.SYNOPSIS...
DEEP LOW PRESSURE CENTERED OVER THE NATIONS MIDSECTION THIS MORNING
WILL CONTINUE TO PUMP VERY MILD AIR NORTHWARD ACROSS OUR PART OF THE
COUNTRY THROUGH FRIDAY AS IT TRACKS NORTHEAST INTO THE UPPER GREAT
LAKES REGION. ALTHOUGH THERE IS A THREAT OF WARM FRONTAL
PRECIPITATION LATER TODAY...IT LOOKS LIKE A HIGH PROBABILITY OF
THUNDERSTORMS FRIDAY AS AN ASSOCIATED COLD FRONT CROSSES THE REGION.
THERE IS A POTENTIAL OF SEVERE WEATHER WITH SOME OF THE STORMS
MIDDAY FRIDAY INTO THE AFTERNOON HOURS. MORE SEASONAL TEMPERATURES
WILL FOLLOW THE COLD FRONT INTO THE EARLY PART OF THE WEEKEND BEFORE
ANOTHER WARMING TREND SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
BAND OF WARM FRONTAL SHOWERS CONTINUES TO SLOWLY TRACK EASTWARD
ACROSS EAST-CENTRAL OHIO...WESTERN LAKE ERIE...AND SOUTHERN
ONTARIO AT THIS HOUR...IN ASSOCIATION WITH A 50-60KT 850 MB JET
AND ZONE OF DIFFLUENT FLOW ALOFT BETWEEN TWO DISTINCT 300 MB JET
STREAKS. CLE/PBZ RADARS BEGINNING TO SHOW SOME WEAKENING OVER THE
PAST HOUR OR TWO...AND WOULD EXPECT THIS TREND TO CONTINUE THIS
AFTERNOON AS THE LOW LEVEL JET WEAKENS DRAMATICALLY...AND THE ZONE
OF BEST UPPER LEVEL DIFFLUENT FLOW IS SHUNTED OFF OUR NORTHWEST.
FOR THIS REASON...HAVE KEPT CURRENT CHANCE POPS IN PLACE FOR THE
AFTERNOON WITH THE HIGHEST VALUES /40S/ ACROSS CHAUTAUQUA
COUNTY...AND HAVE SLOWED THE EASTWARD PROGRESSION AN HOUR OR
TWO...IN LINE WITH CURRENT RADAR TRENDS AND THE 06Z GFS...WHICH
HAS A GOOD HANDLE ON THE SITUATION.
A FAIR AMOUNT OF WARM ADVECTIVE MID AND UPPER CLOUD STREAMING
NORTHEASTWARD INTO THE AREA IS RESULTING IN MOSTLY CLOUDY SKIES
WEST OF THE GENESEE VALLEY AT THIS HOUR...THOUGH THERE ARE SOME
THIN SPOTS WHERE THE SUN IS STILL SHINING THROUGH. HAVE TWEAKED
THE SKY COVER TO REFLECT MORE CLOUDS ACROSS THE WESTERN HALF OF
THE AREA /THOUGH HAVE KEPT IN A MENTION OF LIMITED SUN/...WHILE
HAVE MAINTAINED THE PARTLY SUNNY SKIES ACROSS THE EASTERN HALF.
WITH THE INCREASED CLOUD COVER...HAVE ALSO KNOCKED BACK TEMPS A
DEGREE OR TWO ACROSS THE WEST...WHILE LEAVING THEM PRETTY MUCH AS
IS ACROSS THE EAST...RESULTING IN LOW- MID 70S ACROSS THE BOARD.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
A WARM NIGHT EXPECTED TONIGHT AS THE SOUTHERLY FLOW CONTINUES AT ALL
LEVELS ACROSS OUR REGION. OVERNIGHT LOWS SHOULD IN THE 60S IN MOST
AREAS AND AT LEAST UPPER 50S OVER THE NORMALLY COLDER AREAS OF THE
SOUTHERN TIER. CURRENT POP GRIDS FOR TONIGHT LOOK VERY GOOD WITH
CHANCE POPS RESERVED FOR THE EASTERN LAKE ONTARIO REGION FOR JUST
THE FIRST PART OF THE NIGHT AS THE WARM FRONT CONTINUES TO PUSH
NORTHWARD.
FRIDAY WILL BE THE MOST IMPORTANT PART OF THIS FORECAST AS THE NEAR
RECORD WARMTH CONTINUES. THE DEEP SURFACE LOW IS FORECAST TO
CONTINUE FURTHER NORTHWARD TO NORTH OF LAKE SUPERIOR WITH A COLD
FRONT WRAPPING AROUND IT AND APPROACHING US DURING THE DAY. SURFACE
DEW POINTS ARE EXPECTED TO BE IN THE LOWER 60S. PROJECTED HODOGRAPHS
OFF BUFKIT DATA ARE IMPRESSIVE FOR THE POTENTIAL FOR SEVERE STORMS.
HPC HAS US IN A SLIGHT RISK AREA.
850 MB TEMPERATURES WILL SUPPORT VERY WARM READINGS AGAIN BUT ANY
RECORDS WILL DEPEND ON HOW MUCH IF ANY SUNSHINE WE GET BEFORE THE
RAIN STARTS. RECORD HIGH TEMPERATURE RECORDS FOR FRIDAY ARE AS
FOLLOWS:
KBUF...77 IN 1961
KROC...81 IN 1953
KART...77 IN 1961
BEHIND THE COLD FRONT...MUCH COOLER AIR WILL SWEEP IN FRIDAY NIGHT
AND SATURDAY...WITH 850 MB TEMPERATURES FALLING TO A MORE NORMAL +4C
TO +6C...ALONG WITH DECREASING HUMIDITY. SURFACE RIDGING BUILDING IN
BEHIND THE FRONT SHOULD RESULT IN A NARROW WINDOW OF DRY WEATHER FOR
A WHILE FRIDAY NIGHT...BEFORE THE UPPER TROUGH/COOL POOL SWINGS
THROUGH WITH ANOTHER CHANCE OF SHOWERS LATE FRIDAY NIGHT AND
SATURDAY. TEMPS SATURDAY LOOK TO BE MUCH CLOSER TO
NORMAL...GENERALLY LOWER 60S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
MOISTURE BEHIND RETREATING LOW PRESSURE WILL PROVIDE A CHANCE OF
LINGER SHOWERS EAST OF LAKE ONTARIO SATURDAY NIGHT, THEN HIGH
PRESSURE BUILDS OVER THE AREA. TEMPERATURES WILL BE UNSEASONABLY
WARM WITH 850 MB TEMPERATURE RISING TO 16C. WITH SHORTER DAYS AND
LOWER SUN ANGLE WE HAVE KEPT WITH THE NATIONAL GUIDANCE OF MID
70S, BUT 80S ARE NOT BEYOND REACH...DEPENDING ON WIND DIRECTION
ADDING SUBSIDENCE, AND AMOUNT OF SUN. THE PREFERRED TIMING OF THE
NEXT FRONT HOLDS IT UNTIL OVERNIGHT MONDAY NIGHT...A BIT SLOWER
THAN THE GFS. THE FOLLOWING UPPER TROUGH AND SURFACE LOW WILL
BRING SCATTERED SHOWERS AND TEMPERATURES BACK TO NEAR NORMAL FOR
TUESDAY AND WEDNESDAY. THE GFS SHOWS 850MB TEMPERATURES DIPPING TO
-4C ON WEDNESDAY...COLD ENOUGH FOR A MIX...BUT WE HAVE FOLLOWED
THE MILDER NATIONAL GUIDANCE AND WILL KEEP PRECIPITATION LIQUID
AND WAIT FOR LATER MODEL RUNS FOR REINFORCING COOLER TEMPERATURES.
&&
.AVIATION /16Z THURSDAY THROUGH MONDAY/...
BROAD AREA OF WARM ADVECTION WILL CONTINUE TODAY ACROSS THE EASTERN
GREAT LAKES AND OVER WESTERN TO CENTRAL NY. MAINLY CLEAR SKIES
OVER THE REGION EARLY THIS MORNING WITH LIGHT WINDS AND HIGHER
DEWPOINTS HAVE DEVELOPED WIDESPREAD FOG...LOCALLY DENSE. SURFACE
CONDITIONS WILL BE IFR TO LIFR AT MANY LOCATIONS THROUGH
SUNRISE...AND UNTIL ABOUT AN HOUR THEREAFTER.
ANOTHER IN A SERIES OF WARM FRONTS WILL APPROACH WESTERN NY THURSDAY
AFTERNOON. THERE WILL BE A CHANCE OF SHOWERS WITH THIS
FEATURE...ALTHOUGH CIGS/VSBY SHOULD REMAIN VFR THURSDAY AFTERNOON.
LOOKING FURTHER AHEAD...A STRONG COLD FRONT WILL CROSS THE REGION ON
FRIDAY. STRONG WIND FIELDS AND MARGINAL TO PERHAPS MODERATE
INSTABILITY MAY SET THE STAGE FOR WIDESPREAD THUNDERSTORM
DEVELOPMENT. STRONG WIND FIELDS SUGGEST STORMS MAY BECOME STRONG AND
ORGANIZE INTO LINE SEGMENTS...WHICH MAY REQUIRE EXTENSIVE AIRCRAFT
REROUTING. FOLLOWING THE COLD FRONT...WRAP AROUND MOISTURE ON
SATURDAY MAY BRING WIDESPREAD MVFR CIGS...GUSTY WINDS...AND
SHOWERS...FOLLOWED BY A CLEARING TREND FOR SUNDAY AND MONDAY.
&&
.MARINE...
A WARM FRONT WILL DISSIPATE OVER LAKE ONTARIO EARLY THIS MORNING
WITH VARIABLE WINDS UNDER 10 KNOTS. WINDS WILL BE SOUTHERLY FOR
AWHILE LATER TODAY AND THIS EVENING BEFORE BACKING TO EASTERLY ONCE
AGAIN TONIGHT AHEAD OF YET ANOTHER WARM FRONT. WINDS WILL BE LIGHT
WITH MINOR WAVES ON THE LAKES.
WINDS WILL FINALLY TURN SOUTH TO SOUTHWEST DURING FRIDAY AND
INCREASE AHEAD OF A SHARP COLD FRONT WHICH WILL CROSS THE EASTERN
LAKES FRIDAY EVENING. THEY WILL THEN VEER TO WESTERLY FOLLOWING THE
FRONT AND REMAIN QUITE BRISK THROUGH SATURDAY. MARINE FLAGS WILL
PROBABLY BE NECESSARY FRIDAY NIGHT AND SATURDAY.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SAGE
NEAR TERM...JJR
SHORT TERM...JJR/SAGE
LONG TERM...APB
AVIATION...WCH
MARINE...WCH
AREA FORECAST DISCUSSION
NWS BUFFALO NY
823 AM EDT THU OCT 18 2007
.SYNOPSIS...
DEEP LOW PRESSURE CENTERED OVER THE NATIONS MIDSECTION THIS MORNING
WILL CONTINUE TO PUMP VERY MILD AIR NORTHWARD ACROSS OUR PART OF THE
COUNTRY THROUGH FRIDAY AS IT TRACKS NORTHEAST INTO THE UPPER GREAT
LAKES REGION. ALTHOUGH THERE IS A THREAT OF WARM FRONTAL
PRECIPITATION LATER TODAY...IT LOOKS LIKE A HIGH PROBABILITY OF
THUNDERSTORMS FRIDAY AS AN ASSOCIATED COLD FRONT CROSSES THE REGION.
THERE IS A POTENTIAL OF SEVERE WEATHER WITH SOME OF THE STORMS
MIDDAY FRIDAY INTO THE AFTERNOON HOURS. MORE SEASONAL TEMPERATURES
WILL FOLLOW THE COLD FRONT INTO THE EARLY PART OF THE WEEKEND BEFORE
ANOTHER WARMING TREND SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HAVE JUST ISSUED A QUICK UPDATE TO DROP THE DENSE FOG ADVISORY
FROM THE ZONES...AS THIS EXPIRED AT 8 AM. VISBYS ARE COMING UP
ACROSS THE WESTERN HALF OF THE AREA...AND SHOULD BE DOING SO SOON
ACROSS THE EAST...HENCE THERE IS LITTLE NEED FOR A NEW ADVISORY AT
THIS TIME. OTHERWISE...
MODELS ARE IN CLOSE AGREEMENT IN HANDLING THE DEEP SURFACE LOW OVER
THE CENTER OF THE COUNTRY. THE TRACK WILL BE NORTHWARD TOWARD
MINNESOTA AND LAKE SUPERIOR WITH VERY MILD AIR STREAMING NORTHWARD
ACROSS THE ENTIRE EASTERN PART OF THE COUNTRY.
850 MB TEMPERATURES ARE EXPECTED TO BE WARMER THAN WEDNESDAY ACROSS
OUR REGION...SOARING TO AROUND 14C. THIS WILL SUPPORT SURFACE HIGHS
WELL UP INTO THE 70S AND MAYBE 80 IN AREAS LIKE DANSVILLE THAT
REACHED 77 WEDNESDAY. RECORD TEMPERATURES ARE IN THE LOW 80S TODAY
AT BUFFALO...ROCHESTER AND WATERTOWN...82 AT BUFFALO IN
1947...83 AT ROCHESTER IN 1947 AND 80 AT WATERTOWN IN 1998/.
WITH THE SURGE OF WARMER AIR TODAY WILL COME A THREAT OF SHOWERS BUT
IT APPEARS THAT THE BULK OF ANY ACTIVITY WILL BE WELL TO OUR WEST
ACROSS THE CENTRAL GREAT LAKES WHERE THE SURFACE DEW POINTS WILL
RISE INTO THE LOW TO MID 60S ALONG WITH A FAIRLY STRONG 850 MB JET.
WE WILL KEEP OUR POPS IN THE 30 PERCENT RANGE FOR THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
A WARM NIGHT EXPECTED TONIGHT AS THE SOUTHERLY FLOW CONTINUES AT ALL
LEVELS ACROSS OUR REGION. OVERNIGHT LOWS SHOULD IN THE 60S IN MOST
AREAS AND AT LEAST UPPER 50S OVER THE NORMALLY COLDER AREAS OF THE
SOUTHERN TIER. CURRENT POP GRIDS FOR TONIGHT LOOK VERY GOOD WITH
CHANCE POPS RESERVED FOR THE EASTERN LAKE ONTARIO REGION FOR JUST
THE FIRST PART OF THE NIGHT AS THE WARM FRONT CONTINUES TO PUSH
NORTHWARD.
FRIDAY WILL BE THE MOST IMPORTANT PART OF THIS FORECAST AS THE NEAR
RECORD WARMTH CONTINUES. THE DEEP SURFACE LOW IS FORECAST TO
CONTINUE FURTHER NORTHWARD TO NORTH OF LAKE SUPERIOR WITH A COLD
FRONT WRAPPING AROUND IT AND APPROACHING US DURING THE DAY. SURFACE
DEW POINTS ARE EXPECTED TO BE IN THE LOWER 60S. PROJECTED HODOGRAPHS
OFF BUFKIT DATA ARE IMPRESSIVE FOR THE POTENTIAL FOR SEVERE STORMS.
HPC HAS US IN A SLIGHT RISK AREA.
850 MB TEMPERATURES WILL SUPPORT VERY WARM READINGS AGAIN BUT ANY
RECORDS WILL DEPEND ON HOW MUCH IF ANY SUNSHINE WE GET BEFORE THE
RAIN STARTS. RECORD HIGH TEMPERATURE RECORDS FOR FRIDAY ARE AS
FOLLOWS:
KBUF...77 IN 1961
KROC...81 IN 1953
KART...77 IN 1961
BEHIND THE COLD FRONT...MUCH COOLER AIR WILL SWEEP IN FRIDAY NIGHT
AND SATURDAY...WITH 850 MB TEMPERATURES FALLING TO A MORE NORMAL +4C
TO +6C...ALONG WITH DECREASING HUMIDITY. SURFACE RIDGING BUILDING IN
BEHIND THE FRONT SHOULD RESULT IN A NARROW WINDOW OF DRY WEATHER FOR
A WHILE FRIDAY NIGHT...BEFORE THE UPPER TROUGH/COOL POOL SWINGS
THROUGH WITH ANOTHER CHANCE OF SHOWERS LATE FRIDAY NIGHT AND
SATURDAY. TEMPS SATURDAY LOOK TO BE MUCH CLOSER TO
NORMAL...GENERALLY LOWER 60S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
MOISTURE BEHIND RETREATING LOW PRESSURE WILL PROVIDE A CHANCE OF
LINGER SHOWERS EAST OF LAKE ONTARIO SATURDAY NIGHT, THEN HIGH
PRESSURE BUILDS OVER THE AREA. TEMPERATURES WILL BE UNSEASONABLY
WARM WITH 850 MB TEMPERATURE RISING TO 16C. WITH SHORTER DAYS AND
LOWER SUN ANGLE WE HAVE KEPT WITH THE NATIONAL GUIDANCE OF MID
70S, BUT 80S ARE NOT BEYOND REACH...DEPENDING ON WIND DIRECTION
ADDING SUBSIDENCE, AND AMOUNT OF SUN. THE PREFERRED TIMING OF THE
NEXT FRONT HOLDS IT UNTIL OVERNIGHT MONDAY NIGHT...A BIT SLOWER
THAN THE GFS. THE FOLLOWING UPPER TROUGH AND SURFACE LOW WILL
BRING SCATTERED SHOWERS AND TEMPERATURES BACK TO NEAR NORMAL FOR
TUESDAY AND WEDNESDAY. THE GFS SHOWS 850MB TEMPERATURES DIPPING TO
-4C ON WEDNESDAY...COLD ENOUGH FOR A MIX...BUT WE HAVE FOLLOWED
THE MILDER NATIONAL GUIDANCE AND WILL KEEP PRECIPITATION LIQUID
AND WAIT FOR LATER MODEL RUNS FOR REINFORCING COOLER TEMPERATURES.
&&
.AVIATION /13Z THURSDAY THROUGH MONDAY/...
BROAD AREA OF WARM ADVECTION WILL CONTINUE TODAY ACROSS THE EASTERN
GREAT LAKES AND OVER WESTERN TO CENTRAL NY. MAINLY CLEAR SKIES
OVER THE REGION EARLY THIS MORNING WITH LIGHT WINDS AND HIGHER
DEWPOINTS HAVE DEVELOPED WIDESPREAD FOG...LOCALLY DENSE. SURFACE
CONDITIONS WILL BE IFR TO LIFR AT MANY LOCATIONS THROUGH
SUNRISE...AND UNTIL ABOUT AN HOUR THEREAFTER.
ANOTHER IN A SERIES OF WARM FRONTS WILL APPROACH WESTERN NY THURSDAY
AFTERNOON. THERE WILL BE A CHANCE OF SHOWERS WITH THIS
FEATURE...ALTHOUGH CIGS/VSBY SHOULD REMAIN VFR THURSDAY AFTERNOON.
LOOKING FURTHER AHEAD...A STRONG COLD FRONT WILL CROSS THE REGION ON
FRIDAY. STRONG WIND FIELDS AND MARGINAL TO PERHAPS MODERATE
INSTABILITY MAY SET THE STAGE FOR WIDESPREAD THUNDERSTORM
DEVELOPMENT. STRONG WIND FIELDS SUGGEST STORMS MAY BECOME STRONG AND
ORGANIZE INTO LINE SEGMENTS...WHICH MAY REQUIRE EXTENSIVE AIRCRAFT
REROUTING. FOLLOWING THE COLD FRONT...WRAP AROUND MOISTURE ON
SATURDAY MAY BRING WIDESPREAD MVFR CIGS...GUSTY WINDS...AND
SHOWERS...FOLLOWED BY A CLEARING TREND FOR SUNDAY AND MONDAY.
&&
.MARINE...
A WARM FRONT WILL DISSIPATE OVER LAKE ONTARIO EARLY THIS MORNING
WITH VARIABLE WINDS UNDER 10 KNOTS. WINDS WILL BE SOUTHERLY FOR
AWHILE LATER TODAY AND THIS EVENING BEFORE BACKING TO EASTERLY ONCE
AGAIN TONIGHT AHEAD OF YET ANOTHER WARM FRONT. WINDS WILL BE LIGHT
WITH MINOR WAVES ON THE LAKES.
WINDS WILL FINALLY TURN SOUTH TO SOUTHWEST DURING FRIDAY AND
INCREASE AHEAD OF A SHARP COLD FRONT WHICH WILL CROSS THE EASTERN
LAKES FRIDAY EVENING. THEY WILL THEN VEER TO WESTERLY FOLLOWING THE
FRONT AND REMAIN QUITE BRISK THROUGH SATURDAY. MARINE FLAGS WILL
PROBABLY BE NECESSARY FRIDAY NIGHT AND SATURDAY.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SAGE
NEAR TERM...JJR/SAGE
SHORT TERM...JJR/SAGE
LONG TERM...APB
AVIATION...WCH
MARINE...WCH
AREA FORECAST DISCUSSION
NWS BUFFALO NY
300 AM EDT THU OCT 18 2007
.SYNOPSIS...
DEEP LOW PRESSURE CENTERED OVER THE NATIONS MIDSECTION THIS MORNING
WILL CONTINUE TO PUMP VERY MILD AIR NORTHWARD ACROSS OUR PART OF THE
COUNTRY THROUGH FRIDAY AS IT TRACKS NORTHEAST INTO THE UPPER GREAT
LAKES REGION. ALTHOUGH THERE IS A THREAT OF WARM FRONTAL
PRECIPITATION LATER TODAY...IT LOOKS LIKE A HIGH PROBABILITY OF
THUNDERSTORMS FRIDAY AS AN ASSOCIATED COLD FRONT CROSSES THE REGION.
THERE IS A POTENTIAL OF SEVERE WEATHER WITH SOME OF THE STORMS
MIDDAY FRIDAY INTO THE AFTERNOON HOURS. MORE SEASONAL TEMPERATURES
WILL FOLLOW THE COLD FRONT INTO THE EARLY PART OF THE WEEKEND BEFORE
ANOTHER WARMING TREND SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
OUR EARLY CONCERN TODAY WILL BE VISIBILITIES IN AREAS OF DENSE FOG
THROUGH AROUND 8 AM. ALTHOUGH THE DENSE FOG IS NOT EXPECTED TO BE
WIDESPREAD...THERE ARE ENOUGH AREAS THAT WILL LIKELY DROP TO A
QUARTER OF A MILE OR LESS TO JUSTIFY AN ADVISORY. WE WILL KEEP IT UP
UNTIL THAT TIME.
MODELS ARE IN CLOSE AGREEMENT IN HANDLING THE DEEP SURFACE LOW OVER
THE CENTER OF THE COUNTRY. THE TRACK WILL BE NORTHWARD TOWARD
MINNESOTA AND LAKE SUPERIOR WITH VERY MILD AIR STREAMING NORTHWARD
ACROSS THE ENTIRE EASTERN PART OF THE COUNTRY.
850 MB TEMPERATURES ARE EXPECTED TO BE WARMER THAN WEDNESDAY ACROSS
OUR REGION...SOARING TO AROUND 14C. THIS WILL SUPPORT SURFACE HIGHS
WELL UP INTO THE 70S AND MAYBE 80 IN AREAS LIKE DANSVILLE THAT
REACHED 77 WEDNESDAY. RECORD TEMPERATURES ARE IN THE LOW 80S TODAY
AT BUFFALO...ROCHESTER AND WATERTOWN...82 AT BUFFALO IN
1947...83 AT ROCHESTER IN 1947 AND 80 AT WATERTOWN IN 1998/.
WITH THE SURGE OF WARMER AIR TODAY WILL COME A THREAT OF SHOWERS BUT
IT APPEARS THAT THE BULK OF ANY ACTIVITY WILL BE WELL TO OUR WEST
ACROSS THE CENTRAL GREAT LAKES WHERE THE SURFACE DEW POINTS WILL
RISE INTO THE LOW TO MID 60S ALONG WITH A FAIRLY STRONG 850 MB JET.
WE WILL KEEP OUR POPS IN THE 30 PERCENT RANGE FOR THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
A WARM NIGHT EXPECTED TONIGHT AS THE SOUTHERLY FLOW CONTINUES AT ALL
LEVELS ACROSS OUR REGION. OVERNIGHT LOWS SHOULD IN THE 60S IN MOST
AREAS AND AT LEAST UPPER 50S OVER THE NORMALLY COLDER AREAS OF THE
SOUTHERN TIER. CURRENT POP GRIDS FOR TONIGHT LOOK VERY GOOD WITH
CHANCE POPS RESERVED FOR THE EASTERN LAKE ONTARIO REGION FOR JUST
THE FIRST PART OF THE NIGHT AS THE WARM FRONT CONTINUES TO PUSH
NORTHWARD.
FRIDAY WILL BE THE MOST IMPORTANT PART OF THIS FORECAST AS THE NEAR
RECORD WARMTH CONTINUES. THE DEEP SURFACE LOW IS FORECAST TO
CONTINUE FURTHER NORTHWARD TO NORTH OF LAKE SUPERIOR WITH A COLD
FRONT WRAPPING AROUND IT AND APPROACHING US DURING THE DAY. SURFACE
DEW POINTS ARE EXPECTED TO BE IN THE LOWER 60S. PROJECTED HODOGRAPHS
OFF BUFKIT DATA ARE IMPRESSIVE FOR THE POTENTIAL FOR SEVERE STORMS.
HPC HAS US IN A SLIGHT RISK AREA.
850 MB TEMPERATURES WILL SUPPORT VERY WARM READINGS AGAIN BUT ANY
RECORDS WILL DEPEND ON HOW MUCH IF ANY SUNSHINE WE GET BEFORE THE
RAIN STARTS. RECORD HIGH TEMPERATURE RECORDS FOR FRIDAY ARE AS
FOLLOWS:
KBUF...77 IN 1961
KROC...81 IN 1953
KART...77 IN 1961
BEHIND THE COLD FRONT...MUCH COOLER AIR WILL SWEEP IN FRIDAY NIGHT
AND SATURDAY...WITH 850 MB TEMPERATURES FALLING TO A MORE NORMAL +4C
TO +6C...ALONG WITH DECREASING HUMIDITY. SURFACE RIDGING BUILDING IN
BEHIND THE FRONT SHOULD RESULT IN A NARROW WINDOW OF DRY WEATHER FOR
A WHILE FRIDAY NIGHT...BEFORE THE UPPER TROUGH/COOL POOL SWINGS
THROUGH WITH ANOTHER CHANCE OF SHOWERS LATE FRIDAY NIGHT AND
SATURDAY. TEMPS SATURDAY LOOK TO BE MUCH CLOSER TO
NORMAL...GENERALLY LOWER 60S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
MOISTURE BEHIND RETREATING LOW PRESSURE WILL PROVIDE A CHANCE OF
LINGER SHOWERS EAST OF LAKE ONTARIO SATURDAY NIGHT, THEN HIGH
PRESSURE BUILDS OVER THE AREA. TEMPERATURES WILL BE UNSEASONABLY
WARM WITH 850 MB TEMPERATURE RISING TO 16C. WITH SHORTER DAYS AND
LOWER SUN ANGLE WE HAVE KEPT WITH THE NATIONAL GUIDANCE OF MID
70S, BUT 80S ARE NOT BEYOND REACH...DEPENDING ON WIND DIRECTION
ADDING SUBSIDENCE, AND AMOUNT OF SUN. THE PREFERRED TIMING OF THE
NEXT FRONT HOLDS IT UNTIL OVERNIGHT MONDAY NIGHT...A BIT SLOWER
THAN THE GFS. THE FOLLOWING UPPER TROUGH AND SURFACE LOW WILL
BRING SCATTERED SHOWERS AND TEMPERATURES BACK TO NEAR NORMAL FOR
TUESDAY AND WEDNESDAY. THE GFS SHOWS 850MB TEMPERATURES DIPPING TO
-4C ON WEDNESDAY...COLD ENOUGH FOR A MIX...BUT WE HAVE FOLLOWED
THE MILDER NATIONAL GUIDANCE AND WILL KEEP PRECIPITATION LIQUID
AND WAIT FOR LATER MODEL RUNS FOR REINFORCING COOLER TEMPERATURES.
&&
.AVIATION /07Z THURSDAY THROUGH MONDAY/...
BROAD AREA OF WARM ADVECTION WILL CONTINUE TODAY ACROSS THE EASTERN
GREAT LAKES AND OVER WESTERN TO CENTRAL NY. MAINLY CLEAR SKIES
OVER THE REGION EARLY THIS MORNING WITH LIGHT WINDS AND HIGHER
DEWPOINTS HAVE DEVELOPED WIDESPREAD FOG...LOCALLY DENSE. SURFACE
CONDITIONS WILL BE IFR TO LIFR AT MANY LOCATIONS THROUGH
SUNRISE...AND UNTIL ABOUT AN HOUR THEREAFTER.
ANOTHER IN A SERIES OF WARM FRONTS WILL APPROACH WESTERN NY THURSDAY
AFTERNOON. THERE WILL BE A CHANCE OF SHOWERS WITH THIS
FEATURE...ALTHOUGH CIGS/VSBY SHOULD REMAIN VFR THURSDAY AFTERNOON.
LOOKING FURTHER AHEAD...A STRONG COLD FRONT WILL CROSS THE REGION ON
FRIDAY. STRONG WIND FIELDS AND MARGINAL TO PERHAPS MODERATE
INSTABILITY MAY SET THE STAGE FOR WIDESPREAD THUNDERSTORM
DEVELOPMENT. STRONG WIND FIELDS SUGGEST STORMS MAY BECOME STRONG AND
ORGANIZE INTO LINE SEGMENTS...WHICH MAY REQUIRE EXTENSIVE AIRCRAFT
REROUTING. FOLLOWING THE COLD FRONT...WRAP AROUND MOISTURE ON
SATURDAY MAY BRING WIDESPREAD MVFR CIGS...GUSTY WINDS...AND
SHOWERS...FOLLOWED BY A CLEARING TREND FOR SUNDAY AND MONDAY.
&&
.MARINE...
A WARM FRONT WILL DISSIPATE OVER LAKE ONTARIO EARLY THIS MORNING
WITH VARIABLE WINDS UNDER 10 KNOTS. WINDS WILL BE SOUTHERLY FOR
AWHILE LATER TODAY AND THIS EVENING BEFORE BACKING TO EASTERLY ONCE
AGAIN TONIGHT AHEAD OF YET ANOTHER WARM FRONT. WINDS WILL BE LIGHT
WITH MINOR WAVES ON THE LAKES.
WINDS WILL FINALLY TURN SOUTH TO SOUTHWEST DURING FRIDAY AND
INCREASE AHEAD OF A SHARP COLD FRONT WHICH WILL CROSS THE EASTERN
LAKES FRIDAY EVENING. THEY WILL THEN VEER TO WESTERLY FOLLOWING THE
FRONT AND REMAIN QUITE BRISK THROUGH SATURDAY. MARINE FLAGS WILL
PROBABLY BE NECESSARY FRIDAY NIGHT AND SATURDAY.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...DENSE FOG ADVISORY UNTIL 8 AM EDT THIS MORNING FOR NYZ001>008-
010>014-019>021-085.
MARINE...NONE.
&&
$$
SYNOPSIS...SAGE
NEAR TERM...SAGE
SHORT TERM...JJR/SAGE
LONG TERM...APB
AVIATION...WCH
MARINE...WCH
AREA FORECAST DISCUSSION
NWS BUFFALO NY
228 AM EDT THU OCT 18 2007
.SYNOPSIS...
IT WILL BE UNSEASONABLY WARM ACROSS ALL OF WESTERN AND NORTH
CENTRAL NEW YORK DURING THE NEXT TWO DAYS...WITH NEAR RECORD
WARMTH POSSIBLE IN SOME LOCATIONS ON FRIDAY. THE WARM CONDITIONS
ON FRIDAY WILL BE ACCOMPANIED BY GUSTY THUNDERSTORMS...SOME OF
WHICH WILL LIKELY BE SEVERE. STAY TUNED...
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS EXPECTED...THE SKY COVER ACROSS THE MAJORITY OF WESTERN NEW
YORK HAS THINNED OUT. THIS HAS AT LEAST PARTIALLY EXPOSED THE SFC
WHICH HAS ALREADY COOLED TO NEAR THE DEW POINT. RADIATINOAL
COOLING DURING THE NEXT FEW HOURS WILL PUCH THOSE DEW POINTS DOWN
A DEGREE OR TWO...WHILE ALSO ALLOWING AREAS OF 1-2SM FOG TO FORM
IN THE RELATIVELY HIGH DEW POINT AIRMASS.
THE 00Z KBUF SOUNDING IS ALSO LOOKING MORE FAVORABLE FOR FOG AS A
FAIRLY SATURATED BOUNDARY LAYER IS NOW OVERLAIN BY VERY DRY AIR
FROM ABT H85 UP THROUGH H25. UPSTREAM TAMDAR/ACARS SOUNDINGS
ACROSS OHIO/SE MICHIGAN ARE SIMILAR IN THEIR PROFILES.
HAVE EXPRESSED A GREATER CONCERN/CONFIDENCE IN THE FOG FORMING
IN THE WORDING...ALTHOUGH MOST NUMERICAL GUIDANCE IS LEANING IN
THE OPPOSITE DIRECTION. GIVEN THE CURRENT TREND IN THE OBS VER THE
WRN COUNTIES AND INCREASED COVERAGE OF LOW CLOUDS/FOG ON THE
11-3.9U IMAGERY...WILL BASE FORECAST ON EXPERIENCE AND COMMON
SENSE RATHER THAN THE MODELS.
FURTHER EAST...FOG IS ALSO LIKELY TO FORM BUT IS EXPECTED TO BE
SOMEWHAT LESS WIDESPREAD.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY/...
AMPLIFICATION OF CENTRAL PLAINS TROUGH/LOW WILL MAINTAIN A SOUTH TO
SOUTHWEST FLOW OF MILD AIR INTO THE AREA INTO FRIDAY...AS THE
EASTERN CONUS REMAINS UNDER THE INFLUENCE OF THE DOWNSTREAM RIDGE.
SECOND AND FINAL WARM FRONTAL ZONE OVER THE OHIO VALLEY THURSDAY
MORNING IS EXPECTED TO WORK NORTHEAST ACROSS THE AREA DURING
THURSDAY AFTERNOON AND EVENING...THOUGH WITH THE BEST LOWER AND
UPPER LEVEL JET DYNAMICS EXPECTED TO REMAIN TO OUR NORTH AND WEST
AND INSTABILITY LOOKING TO BE LIMITED...THE CHANCES FOR PRECIP LOOK
TO BE A BIT LESS THAN PREVIOUSLY INDICATED. HAVE THUS DROPPED POPS
BACK TO THE LOW CHANCE RANGE FOR THIS PERIOD...WITH JUST A CHANCE OF
SHOWERS INDICATED IN THE FORECAST ALONG WITH A FAIR AMOUNT OF
CLOUDS. DESPITE THE CLOUD COVER...850 MB TEMPERATURES OF +12C TO
+14C COUPLED WITH AN INCREASING SOUTHEAST/SOUTH FLOW WILL STILL
YIELD AN UNSEASONABLY MILD DAY...WITH TEMPERATURES REACHING WELL
INTO THE 70S. THAT SAID...THESE READING WILL BE SHORT OF RECORD
VALUES FOR OCT 18TH WHICH ARE IN THE LOW 80S /82 AT KBUF IN
1947...83 AT KROC IN 1947 AND 80 AT KART IN 1998/.
THE UNSEASONABLY WARM CONDITIONS WILL CONTINUE THROUGH THURSDAY
NIGHT AND INTO FRIDAY...AS THE DEEP LOW OVER THE UPPER MISSISSIPPI
VALLEY LIFTS NORTHEAST ACROSS THE UPPER GREAT LAKES...AND THE
SOUTHERLY FLOW OF WARM AND INCREASINGLY HUMID AIR DEEPENS AND
INTENSIFIES ACROSS THE AREA. THE INCREASING HUMIDITY AND DOWNSLOPING
EFFECTS WILL KEEP TEMPERATURES IN THE UNSEASONABLY MILD LOWER TO MID
60S THURSDAY NIGHT...FOLLOWED BY AT LEAST MID TO UPPER 70S ON FRIDAY
IF NOT A FEW 80 DEGREE READINGS ACROSS THE CENTRAL AND EASTERN
ZONES DEPENDING UPON THE AMOUNT OF SUNSHINE WE SEE AHEAD OF THE
APPROACHING COLD FRONT. HIGH TEMPERATURE RECORDS FOR FRIDAY ARE AS
FOLLOWS:
KBUF...77 IN 1961
KROC...81 IN 1953
KART...77 IN 1961
AT THE VERY LEAST...IT APPEARS AT THIS TIME THAT THE RECORDS FOR
KBUF AND KART SHOULD BE IN SERIOUS JEOPARDY...AND KROC COULD GET
PRETTY CLOSE.
THE UNSEASONABLY WARM AND MOIST CONDITIONS COULD SET THE STAGE FOR A
RATHER ACTIVE FRIDAY AFTERNOON AND EVENING AS THE COLD FRONT
APPROACHES AND CROSSES THE AREA...WITH SOME OF THE SHORT TERM
GUIDANCE SUGGESTING THE POTENTIAL FOR SBCAPES OF 500-1000 J/KG.
SHOULD ENOUGH INSTABILITY BE REALIZED...THE STRONG FRONTAL
DYNAMICS AND STRONG AMBIENT WIND FIELD /SOUTH-SOUTHWESTERLY WINDS
INCREASING FROM 40 TO 70 KNOTS BETWEEN 700 AND 500 MB/ COULD VERY
WELL RESULT IN A ROUND OF SEVERE THUNDERSTORMS WITH DAMAGING WINDS
BEING THE PRIMARY THREAT. FOR NOW...WILL CONTINUE TO MENTION THIS
POSSIBILITY IN THE HWO...AND CONTINUE TTO COVER THE FROPA WITH
CATEGORICAL POPS FRIDAY AFTERNOON AND EVENING.
BEHIND THE COLD FRONT...MUCH COOLER AIR WILL SWEEP IN FRIDAY NIGHT
AND SATURDAY...WITH 850 MB TEMPERATURES FALLING TO A MORE NORMAL +4C
TO +6C...ALONG WITH DECREASING HUMIDITY. SURFACE RIDGING BUILDING IN
BEHIND THE FRONT SHOULD RESULT IN A NARROW WINDOW OF DRY WEATHER FOR
A WHILE FRIDAY NIGHT...BEFORE THE UPPER TROUGH/COOL POOL SWINGS
THROUGH WITH ANOTHER CHANCE OF SHOWERS LATE FRIDAY NIGHT AND
SATURDAY. TEMPS SATURDAY LOOK TO BE MUCH CLOSER TO
NORMAL...GENERALLY LOWER 60S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
MOISTURE BEHIND RETREATING LOW PRESSURE WILL PROVIDE A CHANCE OF
LINGER SHOWERS EAST OF LAKE ONTARIO SATURDAY NIGHT, THEN HIGH
PRESSURE BUILDS OVER THE AREA. TEMPERATURES WILL BE UNSEASONABLY
WARM WITH 850 MB TEMPERATURE RISING TO 16C. WITH SHORTER DAYS AND
LOWER SUN ANGLE WE HAVE KEPT WITH THE NATIONAL GUIDANCE OF MID
70S, BUT 80S ARE NOT BEYOND REACH...DEPENDING ON WIND DIRECTION
ADDING SUBSIDENCE, AND AMOUNT OF SUN. THE PREFERRED TIMING OF THE
NEXT FRONT HOLDS IT UNTIL OVERNIGHT MONDAY NIGHT...A BIT SLOWER
THAN THE GFS. THE FOLLOWING UPPER TROUGH AND SURFACE LOW WILL
BRING SCATTERED SHOWERS AND TEMPERATURES BACK TO NEAR NORMAL FOR
TUESDAY AND WEDNESDAY. THE GFS SHOWS 850MB TEMPERATURES DIPPING TO
-4C ON WEDNESDAY...COLD ENOUGH FOR A MIX...BUT WE HAVE FOLLOWED
THE MILDER NATIONAL GUIDANCE AND WILL KEEP PRECIPITATION LIQUID
AND WAIT FOR LATER MODEL RUNS FOR REINFORCING COOLER TEMPERATURES.
&&
.AVIATION /07Z THURSDAY THROUGH MONDAY/...
BROAD AREA OF WARM ADVECTION WILL CONTINUE TODAY ACROSS THE EASTERN
GREAT LAKES AND OVER WESTERN TO CENTRAL NY. MAINLY CLEAR SKIES
OVER THE REGION EARLY THIS MORNING WITH LIGHT WINDS AND HIGHER
DEWPOINTS HAVE DEVELOPED WIDESPREAD FOG...LOCALLY DENSE. SURFACE
CONDITIONS WILL BE IFR TO LIFR AT MANY LOCATIONS THROUGH
SUNRISE...AND UNTIL ABOUT AN HOUR THEREAFTER.
ANOTHER IN A SERIES OF WARM FRONTS WILL APPROACH WESTERN NY THURSDAY
AFTERNOON. THERE WILL BE A CHANCE OF SHOWERS WITH THIS
FEATURE...ALTHOUGH CIGS/VSBY SHOULD REMAIN VFR THURSDAY AFTERNOON.
LOOKING FURTHER AHEAD...A STRONG COLD FRONT WILL CROSS THE REGION ON
FRIDAY. STRONG WIND FIELDS AND MARGINAL TO PERHAPS MODERATE
INSTABILITY MAY SET THE STAGE FOR WIDESPREAD THUNDERSTORM
DEVELOPMENT. STRONG WIND FIELDS SUGGEST STORMS MAY BECOME STRONG AND
ORGANIZE INTO LINE SEGMENTS...WHICH MAY REQUIRE EXTENSIVE AIRCRAFT
REROUTING. FOLLOWING THE COLD FRONT...WRAP AROUND MOISTURE ON
SATURDAY MAY BRING WIDESPREAD MVFR CIGS...GUSTY WINDS...AND
SHOWERS...FOLLOWED BY A CLEARING TREND FOR SUNDAY AND MONDAY.
&&
.MARINE...
A WARM FRONT WILL DISSIPATE OVER LAKE ONTARIO EARLY THIS MORNING
WITH VARIABLE WINDS UNDER 10 KNOTS. WINDS WILL BE SOUTHERLY FOR
AWHILE LATER TODAY AND THIS EVENING BEFORE BACKING TO EASTERLY ONCE
AGAIN TONIGHT AHEAD OF YET ANOTHER WARM FRONT. WINDS WILL BE LIGHT
WITH MINOR WAVES ON THE LAKES.
WINDS WILL FINALLY TURN SOUTH TO SOUTHWEST DURING FRIDAY AND
INCREASE AHEAD OF A SHARP COLD FRONT WHICH WILL CROSS THE EASTERN
LAKES FRIDAY EVENING. THEY WILL THEN VEER TO WESTERLY FOLLOWING THE
FRONT AND REMAIN QUITE BRISK THROUGH SATURDAY. MARINE FLAGS WILL
PROBABLY BE NECESSARY FRIDAY NIGHT AND SATURDAY.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...DENSE FOG ADVISORY UNTIL 8 AM EDT THIS MORNING FOR NYZ001>008-
010>014-019>021-085.
MARINE...NONE.
&&
$$
SYNOPSIS...RSH
NEAR TERM...JJR/RSH
SHORT TERM...JJR
LONG TERM...APB
AVIATION...WCH
MARINE...WCH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1055 PM EDT FRI OCT 19 2007
.SYNOPSIS...A COLD FRONT AND UPPER LEVEL TROUGH WILL CROSS CENTRAL
NORTH CAROLINA TONIGHT. MILD HIGH PRESSURE WILL BUILD INTO THE
REGION FROM THE SOUTHWEST OVER THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
COLD FRONT HAS JUST PASSED REIDSVILLE AND WINSTON-SALEM ON ITS WAY
EASTWARD. PRECIPITABLE WATER HAS DROPPED TO LESS THAN AN INCH OVER
THE NORTHWESTERN CWA... BUT LOW LEVEL CONFLUENCE AND POSITIVE
DIFFERENTIAL VORTICITY ADVECTION HAS ALLOWED A FINE LINE OF SHOWERS
TO DEVELOP ALONG THE FRONT. HAVE KEPT A MENTION OF ISOLATED TO
LOW-END SCATTERED SHOWERS FOR THE NEXT SEVERAL HOURS. EXPECT SHOWER
CHANCES TO TAPER OFF AFTER 08Z... IN LINE WITH THE LATEST RUC
OUTPUT. LOWS TONIGHT WILL BE TRICKY OF COURSE WITH THE FRONT MOVING
THROUGH AND THE POTENTIAL FOR DELAYED COLD AIR ADVECTION... BUT
OVERALL SEE LITTLE REASON TO DEPART MUCH FROM THE CURRENT LOWS. HAVE
RAISED THEM SLIGHTLY THOUGH ESPECIALLY IN THE EAST SINCE THE FRONT
WILL NOT ARRIVE THERE UNTIL LATE TONIGHT... AND HAVE ALSO ADJUSTED
THE HOURLY TEMPERATURES TO BETTER DEPICT A SLOWER RISE UNTIL A MORE
RAPID DROP TOWARD DAYBREAK. LOWS STILL 55-65 NORTHWEST TO EAST.-GIH
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
MID AND UPPER LEVEL TROUGH CROSSES THE FORECAST AREA SATURDAY
AFTERNOON. STRONG MID-LEVEL VORTMAX PASSES THROUGH THE FA IN A
DEEPLY DRY AIRMASS AS FORECAST SOUNDINGS INDICATE PWAT DROPPING TO
0.40"...SO VORT PASSAGE WILL BE RATHER UNEVENTFUL...ALTHOUGH THE
VORT MAX SHOULD HELP PROMOTE MIXING BY MIDDAY AS LOW-LEVEL LAPSE
RATES INCREASE TO 7-7.5 WITH 20 TO 25 KTS ATOP THE MIXED LAYER.
OTHERWISE...S/W RIDGE ALOFT COMBINED WITH BUILDING PACIFIC SURFACE
HIGH FROM THE GULF COAST STATES WILL RESULT IN DRY AND WARM
CONDITIONS THROUGH THE WEEKEND. FORECAST THICKNESSES SUPPORT HIGHS
IN THE MID TO UPPER 70S ON SATURDAY TO UPPER 70S TO LOWER 80S ON
SUNDAY. COOLEST NIGHT WILL BE ON SATURDAY NIGHT WITH SURFACE HIGH
DIRECTLY OVERHEAD WITH IDEAL RADIATIONAL COOLING. LOWS 45 TO 50
SUNDAY MORNING...48 TO 53 SUNDAY NIGHT.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
MEDIUM RANGE MODELS ARE STILL NOT WHERE THEY NEED TO BE REGARDING
THE THE EVOLUTION OF A CUT-OFF LOW SOMEWHERE ACROSS THE LOWER 48
STATES(RANGING FROM OVER BAJA(NOGAPS)TO OVER THE CENTRAL MS VALLEY
(GFS). ADD IN A LARGE STANDARD DEVIATION AMONG GFS ENSEMBLE MEMBERS
WITH LOW RUN-TO-RUN MODEL CONTINUITY IN THE GFS AND ECMWF AND YOU
HAVE ONE EXTREMELY LOW CONFIDENCE FORECAST IN THE DAY 4 TO DAY 7
PERIOD. A CUT-OFF LOCATION OF THAT NEAR THE GFS WOULD GREATLY
BENEFIT THE SOUTHEAST...RESULTING IN AN EXTENDED PERIOD OF DEEP
MOISTURE TRANSPORT FROM OUT OF THE GULF. HOWEVER...ANY FURTHER WEST
OF THAT WOULD RESULT IN DRYER CONDITIONS AS BERMUDA RIDGE WOULD
EXTEND TO FAR WEST OVER THE SOUTHEAST. EXPECT BETTER MODEL
RESOLUTION AND FORECAST DETAIL BY THE NEXT 24 TO 36 HR AS PRINCIPLE
SHORTWAVE TROUGH MOVES ONTO NW PACIFIC COAST.
GIVEN THE OVERWHELMING DIFFERENCES...THE GFS MEAN ENSEMBLE 500H MEAN
WAS PREFERRED OVER A SINGLE MODEL OF CHOICE. AS A RESULT...A
GENERALIZED FORECAST OF PARTLY TO MOSTLY CLOUDY SKY CONDITIONS WITH
LOW CHANCE POPS (20-30%) AND MILD TEMPERATURES WILL BE USED FOR THE
DAY 4 TO 7 PERIOD.
&&
.AVIATION /00Z FRIDAY THROUGH WEDNESDAY/...
23Z SFC ANALYSIS SHOWS THE COLD FRONT EAST OF MT AIRY AND
WILKSBORO BUT NOT YET THROUGH MORGANTOWN AND ASHEVILLE. LATEST WV
IMAGERY SHOWS SHORTWAVES NEAR DC AND THE CENTRAL APPALACHIANS
MOVING AWAY AND LEAVING CENTRAL IN AREA OF SHORT TERM SUBSIDENCE.
LOW LEVEL LOW HAS BEEN GENRALLY DIVERGENT THIS EVENING AND THE AXIS
OF BEST INSTABILITY HAS SHIFTED NE OF AREA. RADAR IMAGERY SHOWS THE
BORKEN LINE OF SHOWERS NW OF THE TRIAD HAS DISSIPATED. ALL OF
THIS POINTS TO A SIGNIFICANT DECREASED THREAT OF RAIN AND HAVE
REMOVED ALL PRECIP FROM THE TAFS.
LATEST RUC AND NAM20 RUNS ALONG WITH SFC ANALYSIS SUGGEST WIND
SHIFT SHOULD REACH KINT AROUND 01Z...KGSO AROUND 03Z AND KRDU
AROUND 06Z. FRONT WONT REACH KRWI AND KFAY UNTIL AROUND DAYBREAK.
CONDITIONS CLOSE TO LOW LEVEL WIND SHEAR THRESHOLD BUT LATEST
AMADAR AIRCRAFT SOUNDING FROM KRDU AT 2230Z SUGGEST THAT FLOW
JUST ABOVE THE SFC BASED INVERSION IS A LITTLE WEAKER THAN PROGEED
BY THE NAM AND GFS BUFR SOUNDINGS. WILL HOLD OFF ANY MENTION OF
WIND SHEAR.
FOR SATURDAY...EXPECT VFR CONDITIONS BUT IT WILL BE BREEZY WITH
WLY LOW LEVEL FLOW FREQUENTLY GUSTING BETWEEN 20-25 MPH.
VFR CONDITIONS EXPECTED SUNDAY THROUGH TUESDAY WITH HIGH PRESSURE
RIDGE CENTERED ACROSS THE SOUTHEAST.
&&
.FIRE WEATHER...
BOTH WIND GUSTS AND AFTN RH VALUES ARE EXPECTED TO BE AT MINIMAL
CRITERIA AS WIND GUSTS ARE EXPECTED TO TOP OUT AT 15 TO 18KTS WITH
MIN RH BOTTOMING OUT IN 30 TO 35 PERCENT SATURDAY AFTERNOON.
RAINFALL OVER THE PAST 24 HOURS AND THE POTENTIAL FOR ADDITIONAL
RAINFALL THROUGH THE REMAINDER OF THE AFTERNOON AND EVENING SHOULD
MORE THAN SETTLE THE DUST AND MOISTEN THE FINE FUELS.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CBL
NEAR TERM...HARTFIELD
SHORT TERM...CBL
LONG TERM...CBL
AVIATION...BLAES
FIRE WEATHER...CBL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
743 PM EDT FRI OCT 19 2007
.SYNOPSIS...A COLD FRONT AND UPPER LEVEL TROUGH WILL CROSS CENTRAL
NORTH CAROLINA TONIGHT. HIGH PRESSURE WILL BUILD INTO THE REGION FOR
THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
COLD FRONT HAS JUST PASSED THROUGH MT AIRY ON ITS WAY EASTWARD.
WHILE SURFACE DEWPOINTS AND PRECIPITABLE WATER REMAIN HIGH FROM THE
PIEDMONT EAST... INSTABILITIES ARE MEAGER AND DECREASING QUICKLY
WITH THE SETTING SUN. LONG LOBE OF MID LEVEL VORTICITY ALONG THE
APPALACHIANS IS EXPECTED TO MOVE NNE ALLOWING LITTLE IN THE WAY OF
POSITIVE VORTICITY ADVECTION IN CENTRAL NC THROUGH THE REST OF THE
EVENING. THE SAME IS TRUE OF THE UPPER DIVERGENCE ACCOMPANYING THE
NORTHEAST-MOVING JET CORE. WITH THIS LOW POTENTIAL BUOYANCY AND
SCANT LARGE SCALE ASCENT MECHANISMS... HAVE LOWERED POPS TO
CHANCE... HIGHER NORTH THAN SOUTHEAST... AND HAVE REMOVED THE RISK
OF THUNDER. STILL EXPECT SHOWER CHANCES TO TAPER OFF QUICKLY NEAR TO
SHORTLY AFTER MIDNIGHT. QPF WAS LOWERED AS WELL. NO CHANGE TO
TEMPERATURES AT THIS TIME... STILL HOLDING WITH MID TO UPPER 50S
WEST/CENTRAL AND 60 TO 65 EAST... BUT WILL RE-EVALUATE THESE LATER
THIS EVENING. -GIH
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
MID AND UPPER LEVEL TROUGH CROSSES THE FORECAST AREA SATURDAY
AFTERNOON. STRONG MID-LEVEL VORTMAX PASSES THROUGH THE FA IN A
DEEPLY DRY AIRMASS AS FORECAST SOUNDINGS INDICATE PWAT DROPPING TO
0.40"...SO VORT PASSAGE WILL BE RATHER UNEVENTFUL...ALTHOUGH THE
VORT MAX SHOULD HELP PROMOTE MIXING BY MIDDAY AS LOW-LEVEL LAPSE
RATES INCREASE TO 7-7.5 WITH 20 TO 25 KTS ATOP THE MIXED LAYER.
OTHERWISE...S/W RIDGE ALOFT COMBINED WITH BUILDING PACIFIC SURFACE
HIGH FROM THE GULF COAST STATES WILL RESULT IN DRY AND WARM
CONDITIONS THROUGH THE WEEKEND. FORECAST THICKNESSES SUPPORT HIGHS
IN THE MID TO UPPER 70S ON SATURDAY TO UPPER 70S TO LOWER 80S ON
SUNDAY. COOLEST NIGHT WILL BE ON SATURDAY NIGHT WITH SURFACE HIGH
DIRECTLY OVERHEAD WITH IDEAL RADIATIONAL COOLING. LOWS 45 TO 50
SUNDAY MORNING...48 TO 53 SUNDAY NIGHT.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
MEDIUM RANGE MODELS ARE STILL NOT WHERE THEY NEED TO BE REGARDING
THE THE EVOLUTION OF A CUT-OFF LOW SOMEWHERE ACROSS THE LOWER 48
STATES(RANGING FROM OVER BAJA(NOGAPS)TO OVER THE CENTRAL MS VALLEY
(GFS). ADD IN A LARGE STANDARD DEVIATION AMONG GFS ENSEMBLE MEMBERS
WITH LOW RUN-TO-RUN MODEL CONTINUITY IN THE GFS AND ECMWF AND YOU
HAVE ONE EXTREMELY LOW CONFIDENCE FORECAST IN THE DAY 4 TO DAY 7
PERIOD. A CUT-OFF LOCATION OF THAT NEAR THE GFS WOULD GREATLY
BENEFIT THE SOUTHEAST...RESULTING IN AN EXTENDED PERIOD OF DEEP
MOISTURE TRANSPORT FROM OUT OF THE GULF. HOWEVER...ANY FURTHER WEST
OF THAT WOULD RESULT IN DRYER CONDITIONS AS BERMUDA RIDGE WOULD
EXTEND TO FAR WEST OVER THE SOUTHEAST. EXPECT BETTER MODEL
RESOLUTION AND FORECAST DETAIL BY THE NEXT 24 TO 36 HR AS PRINCIPLE
SHORTWAVE TROUGH MOVES ONTO NW PACIFIC COAST.
GIVEN THE OVERWHELMING DIFFERENCES...THE GFS MEAN ENSEMBLE 500H MEAN
WAS PREFERRED OVER A SINGLE MODEL OF CHOICE. AS A RESULT...A
GENERALIZED FORECAST OF PARTLY TO MOSTLY CLOUDY SKY CONDITIONS WITH
LOW CHANCE POPS (20-30%) AND MILD TEMPERATURES WILL BE USED FOR THE
DAY 4 TO 7 PERIOD.
&&
.AVIATION /00Z FRIDAY THROUGH WEDNESDAY/...
23Z SFC ANALYSIS SHOWS THE COLD FRONT EAST OF MT AIRY AND
WILKSBORO BUT NOT YET THROUGH MORGANTOWN AND ASHEVILLE. LATEST WV
IMAGERY SHOWS SHORTWAVES NEAR DC AND THE CENTRAL APPALACHIANS
MOVING AWAY AND LEAVING CENTRAL IN AREA OF SHORT TERM SUBSIDENCE.
LOW LEVEL LOW HAS BEEN GENRALLY DIVERGENT THIS EVENING AND THE AXIS
OF BEST INSTABILITY HAS SHIFTED NE OF AREA. RADAR IMAGERY SHOWS THE
BORKEN LINE OF SHOWERS NW OF THE TRIAD HAS DISSIPATED. ALL OF
THIS POINTS TO A SIGNIFICANT DECREASED THREAT OF RAIN AND HAVE
REMOVED ALL PRECIP FROM THE TAFS.
LATEST RUC AND NAM20 RUNS ALONG WITH SFC ANALYSIS SUGGEST WIND
SHIFT SHOULD REACH KINT AROUND 01Z...KGSO AROUND 03Z AND KRDU
AROUND 06Z. FRONT WONT REACH KRWI AND KFAY UNTIL AROUND DAYBREAK.
CONDITIONS CLOSE TO LOW LEVEL WIND SHEAR THRESHOLD BUT LATEST
AMADAR AIRCRAFT SOUNDING FROM KRDU AT 2230Z SUGGEST THAT FLOW
JUST ABOVE THE SFC BASED INVERSION IS A LITTLE WEAKER THAN PROGEED
BY THE NAM AND GFS BUFR SOUNDINGS. WILL HOLD OFF ANY MENTION OF
WIND SHEAR.
FOR SATURDAY...EXPECT VFR CONDITIONS BUT IT WILL BE BREEZY WITH
WLY LOW LEVEL FLOW FREQUENTLY GUSTING BETWEEN 20-25 MPH.
VFR CONDITIONS EXPECTED SUNDAY THROUGH TUESDAY WITH HIGH PRESSURE
RIDGE CENTERED ACROSS THE SOUTHEAST.
&&
.FIRE WEATHER...
BOTH WIND GUSTS AND AFTN RH VALUES ARE EXPECTED TO BE AT MINIMAL
CRITERIA AS WIND GUSTS ARE EXPECTED TO TOP OUT AT 15 TO 18KTS WITH
MIN RH BOTTOMING OUT IN 30 TO 35 PERCENT SATURDAY AFTERNOON.
RAINFALL OVER THE PAST 24 HOURS AND THE POTENTIAL FOR ADDITIONAL
RAINFALL THROUGH THE REMAINDER OF THE AFTERNOON AND EVENING SHOULD
MORE THAN SETTLE THE DUST AND MOISTEN THE FINE FUELS.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CBL
NEAR TERM...HARTFIELD
SHORT TERM...CBL
LONG TERM...CBL
AVIATION...BLAES
FIRE WEATHER...CBL
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