Forecast Discussions mentioning "ACARS", "MDCRS", "AIRCRAFT", "TAMDAR", or "AMDAR" received at FSL on 04/15/07

AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
920 PM CDT SAT APR 14 2007 .EVENING DISCUSSION... 920 PM CDT UPDATED ZONES TONIGHT MAINLY TO CLEAN UP PRECIP WORDING AND TO ACCOUNT FOR CLEARING TREND. UPPER JET AXIS HAS NOW SHIFTED INTO THE OHIO RIVER VALLEY...WITH UPPER TROUGH AXIS POSITIONED JUST ABOUT OVERHEAD AT 02Z THIS EVENING. WILL KEEP PARTLY CLOUDY CONDITIONS OVERNIGHT WITH SFC OBS/SATELLITE IMAGERY INDICATING SOME MID LEVEL CLOUDINESS IN ASSOCIATION WITH ANOTHER SHORT WAVE APPROACHING FROM NORTHWEST WISCONSIN. TEMPS APPEAR TO BE IN GOOD SHAPE AND NO SIGNIFICANT CHANGES WERE MADE TO MIN TEMPS OVERNIGHT FROM THE INHERITED FORECAST. MARSILI && .DISCUSSION... 300 PM CDT THE RAIN IS EXPECTED TO REMAIN SOUTH OF KANKAKEE THIS EVENING AND TONIGHT. THE AIR NORTH OF KANKAKEE IS DRY. A NORTHEAST FLOW EXIST UP TO 700 MB. THE ACARS SOUNDING FROM ORD 1919 UTC SHOWS THE NORTHEAST FLOW. PROFILER DATA SHOWS THE CIRCULATION OVER NORTHEAST ILLINOIS. THE LOCALLY RUN WRF ARW SHOWS THE 700 MB CIRCULATION INTO EASTERN INDIANA BY 03 UTC TONIGHT. THIS CIRCULATION CORRELATES WELL WITH THE GFS FORECAST OF THE 500 MB TROUGH. THE SURFACE LOW IS FORECAST TO BE IN WESTERN NORTH CAROLINA BY 06 UTC...GIVING A NORTH WIND OVER NORTHEAST ILLINOIS AND NORTHWEST INDIANA. WE ADJUSTED TONIGHT LOWS TO TO THE LOWER 30S FOR THE COLDER AIR MOVING IN. THE ANTICYCLONIC SIDE OF THE 500 MB TROUGH WILL PASS OVER THE FORECAST AREA AROUND 00 UTC MONDAY. COLD AIR AND INSTABILITY WITH A JET STREAK ALOFT MAY PRODUCE ISOLATED SHOWERS. WILL LEAVE A SLIGHT CHANCE OF SHOWERS IN THE GRID FORECASTS FOR SUNDAY. AS THE RIDGE BUILDS OVER THE MIDWEST. THE FORECAST TEMPERATURE WILL BE IN THE UPPER 50S AND THE LOWER 60S FOR HIGHS ON MONDAY AND TUESDAY. A 500 MB TROUGH MOVES SOUTH OVER ILLINOIS TUESDAY NIGHT. WILL ADD A SLIGHT CHANCE OF SHOWERS TUESDAY NIGHT. && .AVIATION DISCUSSION REGARDING 00Z TAFS... 650 PM CDT VISIBLE SATLT IMAGRY SHOWS NRN EDGE OF CLOUD SHIELD...ASSD WITH LOW PRES SYS DVLPG OVR TN VLY...NOW MOVG SLOLY EWD ACROSS TERMINAL AREA. AS THIS LOW CONTINUES TO SHIFT OFF TO E OVERNIGHT...VFR CIGS NOW OVR RGN ARE EXPECTED TO SCT OUT. ON SUN...CU FIELD IS EXPECTED TO DVLP AGAIN DURG LATE MRNG AND AFTN AS SFC WARMS UP A BIT. FCST SOUNDINGS SHOW LLVLS BCMG RATHER UNSTABLE BY 18Z SUN WITH CLOUD BASES EXPECTED TO BE AOA 45 HND FT. THESE CU WILL LIKELY LIFT AND SPREAD INTO MID LVL BKN DECK DURG MID-LATE AFTN...SIMILAR TO CLOUD CONDS NOW OVR NRN WI-SRN MN. NO VIS RESTRICTIONS THRU PERIOD. PCPN ASSD WITH LOW TO SE OF RGN WILL RMN S AND E OF TERMINAL AREA. NELY SFC WINDS IN 10-15 KT RANGE ON FRINGE OF LOW CIRCULATION WILL ABATE TO BLO 10 KTS THIS EVENING WITH FLOW BACKING IN A BIT INTO N-NNW OVERNIGHT. MERZLOCK && .LOT WATCHES/WARNINGS/ADVISORIES... .IL...NONE. .IN...NONE. .LM...NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
650 PM CDT SAT APR 14 2007 .DISCUSSION... 300 PM CDT THE RAIN IS EXPECTED TO REMAIN SOUTH OF KANKAKEE THIS EVENING AND TONIGHT. THE AIR NORTH OF KANKAKEE IS DRY. A NORTHEAST FLOW EXIST UP TO 700 MB. THE ACARS SOUNDING FROM ORD 1919 UTC SHOWS THE NORTHEAST FLOW. PROFILER DATA SHOWS THE CIRCULATION OVER NORTHEAST ILLINOIS. THE LOCALLY RUN WRF ARW SHOWS THE 700 MB CIRCULATION INTO EASTERN INDIANA BY 03 UTC TONIGHT. THIS CIRCULATION CORRELATES WELL WITH THE GFS FORECAST OF THE 500 MB TROUGH. THE SURFACE LOW IS FORECAST TO BE IN WESTERN NORTH CAROLINA BY 06 UTC...GIVING A NORTH WIND OVER NORTHEAST ILLINOIS AND NORTHWEST INDIANA. WE ADJUSTED TONIGHT LOWS TO TO THE LOWER 30S FOR THE COLDER AIR MOVING IN. THE ANTICYCLONIC SIDE OF THE 500 MB TROUGH WILL PASS OVER THE FORECAST AREA AROUND 00 UTC MONDAY. COLD AIR AND INSTABILITY WITH A JET STREAK ALOFT MAY PRODUCE ISOLATED SHOWERS. WILL LEAVE A SLIGHT CHANCE OF SHOWERS IN THE GRID FORECASTS FOR SUNDAY. AS THE RIDGE BUILDS OVER THE MIDWEST. THE FORECAST TEMPERATURE WILL BE IN THE UPPER 50S AND THE LOWER 60S FOR HIGHS ON MONDAY AND TUESDAY. A 500 MB TROUGH MOVES SOUTH OVER ILLINOIS TUESDAY NIGHT. WILL ADD A SLIGHT CHANCE OF SHOWERS TUESDAY NIGHT. && .AVIATION DISCUSSION REGARDING 00Z TAFS... VISIBLE SATLT IMAGRY SHOWS NRN EDGE OF CLOUD SHIELD...ASSD WITH LOW PRES SYS DVLPG OVR TN VLY...NOW MOVG SLOLY EWD ACROSS TERMINAL AREA. AS THIS LOW CONTINUES TO SHIFT OFF TO E OVERNIGHT...VFR CIGS NOW OVR RGN ARE EXPECTED TO SCT OUT. ON SUN...CU FIELD IS EXPECTED TO DVLP AGAIN DURG LATE MRNG AND AFTN AS SFC WARMS UP A BIT. FCST SOUNDINGS SHOW LLVLS BCMG RATHER UNSTABLE BY 18Z SUN WITH CLOUD BASES EXPECTED TO BE AOA 45 HND FT. THESE CU WILL LIKELY LIFT AND SPREAD INTO MID LVL BKN DECK DURG MID-LATE AFTN...SIMILAR TO CLOUD CONDS NOW OVR NRN WI-SRN MN. NO VIS RESTRICTIONS THRU PERIOD. PCPN ASSD WITH LOW TO SE OF RGN WILL RMN S AND E OF TERMINAL AREA. NELY SFC WINDS IN 10-15 KT RANGE ON FRINGE OF LOW CIRCULATION WILL ABATE TO BLO 10 KTS THIS EVENING WITH FLOW BACKING IN A BIT INTO N-NNW OVERNIGHT. MERZLOCK && .LOT WATCHES/WARNINGS/ADVISORIES... .IL...NONE. .IN...NONE. .LM...NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
300 PM CDT SAT APR 14 2007 .DISCUSSION... 300 PM CDT THE RAIN IS EXPECTED TO REMAIN SOUTH OF KANKAKEE THIS EVENING AND TONIGHT. THE AIR NORTH OF KANKAKEE IS DRY. A NORTHEAST FLOW EXIST UP TO 700 MB. THE ACARS SOUNDING FROM ORD 1919 UTC SHOWS THE NORTHEAST FLOW. PROFILER DATA SHOWS THE CIRCULATION OVER NORTHEAST ILLINOIS. THE LOCALLY RUN WRF ARW SHOWS THE 700 MB CIRCULATION INTO EASTERN INDIANA BY 03 UTC TONIGHT. THIS CIRCULATION CORRELATES WELL WITH THE GFS FORECAST OF THE 500 MB TROUGH. THE SURFACE LOW IS FORECAST TO BE IN WESTERN NORTH CAROLINA BY 06 UTC...GIVING A NORTH WIND OVER NORTHEAST ILLINOIS AND NORTHWEST INDIANA. WE ADJUSTED TONIGHT LOWS TO TO THE LOWER 30S FOR THE COLDER AIR MOVING IN. THE ANTICYCLONIC SIDE OF THE 500 MB TROUGH WILL PASS OVER THE FORECAST AREA AROUND 00 UTC MONDAY. COLD AIR AND INSTABILITY WITH A JET STREAK ALOFT MAY PRODUCE ISOLATED SHOWERS. WILL LEAVE A SLIGHT CHANCE OF SHOWERS IN THE GRID FORECASTS FOR SUNDAY. AS THE RIDGE BUILDS OVER THE MIDWEST. THE FORECAST TEMPERATURE WILL BE IN THE UPPER 50S AND THE LOWER 60S FOR HIGHS ON MONDAY AND TUESDAY. A 500 MB TROUGH MOVES SOUTH OVER ILLINOIS TUESDAY NIGHT. WILL ADD A SLIGHT CHANCE OF SHOWERS TUESDAY NIGHT. && .AVIATION DISCUSSION FOR 18Z TAFS... VERY LITTLE CHANGE TO PREVIOUS TAFS. BASED ON LATEST RADAR IMAGERY...ANY THREAT OF PCPN IS DECREASING AS THE MAIN PCPN AREA IS TRENDING EASTWARD. ALSO...THE LOWER LEVELS ARE QUITE DRY WITH VERY LITTLE CLOUD BELOW 080-100KFT WITH THE EXCEPTION OF A FEW STRATOCU. HAVE REMOVED ANY MENTION OF LOW CLOUD AND RAISED BASES OF THE MID CLOUDS TO 100 KFT FOR THE REMAINDER OF THE DAY AND THE OVERNIGHT HOURS. MODEL RH TIME SECTIONS INDICATING THAT THE MID CLOUD DECK SHOULD BE THINNING OUT WITH TIME AND GO SCT IN THE EARLY MORNING HRS. THIS IS GENERALLY CONFIRMED BY THE LATEST SATELLITE TRENDS WHICH SHOW DECREASING CLOUD COVER OVER THE MID MISSISSIPPI VALLEY AND UPPER MIDWEST. WINDS ARE FINALLY BACKING MORE ENELY AND SHOULD CONTINUE TO BACK TO NLY TONIGHT. FOR THE REMAINDER OF THE TAF PD...WINDS WL REMAIN NLY...DECREASING IN STRENGTH OVERNIGHT. SOME OCCASIONAL GUSTINESS IS LIKELY THROUGH THE REMAINDER OF THE AFTERNOON HOURS DUE TO SOME EVAPORATIVE COOLING AROUND OCCASIONAL VIRGA...BUT SHOULD NOT BE FREQUENT ENOUGH TO JUSTIFY PREVAILING CONDITION. VISBY WL REMAIN UNRESTRICTED THROUGH THE PERIOD AS THE LOW LEVELS REMAIN QUITE DRY. KREIN && .LOT WATCHES/WARNINGS/ADVISORIES... .IL...NONE. .IN...NONE. .LM...NONE. && $$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
725 PM EDT SAT APR 14 2007 .AVIATION...DISCUSSION FOR 150000Z TAF ISSUANCE LIGHT PRECIPITATION HAS ENDED SOUTH OF INDIANAPOLIS AND IT SHOULD BE ENDING INDIANAPOLIS IN THE NEXT HOUR OR TWO AND KLAF SHORTLY AFTER THAT. 1003 MB LOW PRESSURE CENTERED OVER S CNTRL KENTUCKY WILL MOVE TO THE MID ATLANTIC STATES DURING THE DAY ON SUNDAY. GRADIENT WILL INCREASE SOME OVERNIGHT ACROSS OUR REGION MEANING GUSTY WINDS OVERNIGHT. MODEL SOUNDINGS LOW CLOUDS SCATTERED OUT LATE TONIGHT AND MODELS MAY EVEN BE A LITTLE SLOW ON THIS TREND BASED ON IMPROVING TRENDS TO OUR WEST. AN UPPER LEVEL DISTURBANCE WILL BRING SOME INCREASE IN CLOUDS TOWARDS END OF THE TAF PERIOD. BUT IT WILL STILL BE VFR FROM LATE TONIGHT AND ALL DAY ON SUNDAY. && .DISCUSSION...ONGOING PRECIP TYPE AND AMOUNTS REMAIN FOCUS THROUGH TONIGHT. COMPLEX UPPER PATTERN FEATURES ONE UPPER LOW NOW TRACKING NE NEAR STL WITHIN THE LARGER SCALE LONGWAVE TROUGH THAT CONTINUES TO DEEPEN OVER THE REGION. STRONG 850-700MB FRONTOGENESIS IS OCCURRING AHEAD OF THE UPPER LOW ACROSS THE REGION WHILE THE SFC LOW APPEARS TO BE A BIT FURTHER NORTH THAN FCST ACROSS CENTRAL KY. WIDESPREAD MOD/HVY PRECIP HAS DEVELOPED WITHIN THE ZONE OF FRONTOGENESIS ACROSS AREAS NORTH OF I-70 THIS AFTERNOON. QUICK CHECK OF FCST SOUNDINGS AND AIRCRAFT SOUNDINGS SHOW NEAR 0C AT 850MB WITH 1000-850MB THICKNESSES NOW COOLING TO BELOW 1300DM WITH REPORTS ALSO STARTING TO INDICATE A MIXTURE OF RAIN AND SNOW NORTH OF I-70. NO SIG INITIALIZATION ERRORS NOTED AND I WILL USE SHORT RANGE SREF ENSEMBLE AND SATELLITE/OBS AND RADAR FOR THE FCST TONIGHT. TONIGHT...DEVELOPING DEFORMATION ZONE/TROWEL WILL PIVOT ACROSS THE CWA. THE COMPONENT OF FORCING DUE TO 850-700MB FRONTOGENESIS WILL GRADUALLY SHIFT NE OF THE CWA WHILE A DRY SLOT EFFECTIVELY CUTS OFF THE STEADY PRECIP ACROSS MUCH OF THE SOUTHERN HALF OR MORE OF THE CWA. CROSS SECTIONS SHOW BOTH CONDITIONAL INSTABILITY ALONG WITH THE POTENTIAL FOR UPRIGHT CONVECTION ACROSS THE SOUTH IN THE DRY SLOT. AS A RESULT...EXPECT A CONTINUED STRONG RESPONSE TO THE ONGOING FORCING THROUGH 03Z WITH THE POTENTIAL FOR POCKETS OF HEAVY WET SNOW TO OCCUR MAINLY ACROSS THE NORTHERN THIRD OF THE CWA THROUGH 00Z. THAT SAID...UNCERTAINTY EXISTS ON HOW FAR THE DRY SLOT WILL MOVE NORTH BEFORE THE DEFORMATION ZONE PIVOTS BACK INTO THE AREA OVERNIGHT. IN A NUTSHELL...LOOK FOR A MIXTURE OF RAIN AND SNOW ACROSS THE NORTHERN TWO THIRDS OF THE CWA TONIGHT WITH AMOUNTS OF ONE INCH OR LESS POSSIBLE NORTH OF A CRAWFORDSVILLE TO LEBANON TO NOBLESVILLE AND NEW CASTLE LINE. SUN...WINDY CONDS WITH INSTABILITY SHOWERS WILL OCCUR AS THE UPPER SYSTEM PASSES. SOME SUN STILL APPEARS POSSIBLE SO MOS TEMPS AROUND 50 STILL LOOKS GOOD FOR IND. BUFKIT WINDS SUGGEST GUSTS TO 40 MPH APPEAR POSSIBLE BY AFTERNOON. SUN NIGHT AND BEYOND...A WEAK DISTURBANCE WILL SLIDE DOWN THE EAST SIDE OF A DEVELOPING OMEGA BLOCK TUES INTO WEDS. THIS MAY BRING LIGHT SHOWERS WITH A COOL DOWN BY MID WEEK. OTHERWISE...LOOK FOR QUIET CONDS WITH HIGHS IN THE 50S TO NEAR 60. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ AVIATION...JH PUBLIC...CO
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
325 PM EDT SAT APR 14 2007 .DISCUSSION...ONGOING PRECIP TYPE AND AMOUNTS REMAIN FOCUS THROUGH TONIGHT. COMPLEX UPPER PATTERN FEATURES ONE UPPER LOW NOW TRACKING NE NEAR STL WITHIN THE LARGER SCALE LONGWAVE TROUGH THAT CONTINUES TO DEEPEN OVER THE REGION. STRONG 850-700MB FRONTOGENESIS IS OCCURRING AHEAD OF THE UPPER LOW ACROSS THE REGION WHILE THE SFC LOW APPEARS TO BE A BIT FURTHER NORTH THAN FCST ACROSS CENTRAL KY. WIDESPREAD MOD/HVY PRECIP HAS DEVELOPED WITHIN THE ZONE OF FRONTOGENESIS ACROSS AREAS NORTH OF I-70 THIS AFTERNOON. QUICK CHECK OF FCST SOUNDINGS AND AIRCRAFT SOUNDINGS SHOW NEAR 0C AT 850MB WITH 1000-850MB THICKNESSES NOW COOLING TO BELOW 1300DM WITH REPORTS ALSO STARTING TO INDICATE A MIXTURE OF RAIN AND SNOW NORTH OF I-70. NO SIG INITIALIZATION ERRORS NOTED AND I WILL USE SHORT RANGE SREF ENSEMBLE AND SATELLITE/OBS AND RADAR FOR THE FCST TONIGHT. TONIGHT...DEVELOPING DEFORMATION ZONE/TROWEL WILL PIVOT ACROSS THE CWA. THE COMPONENT OF FORCING DUE TO 850-700MB FRONTOGENESIS WILL GRADUALLY SHIFT NE OF THE CWA WHILE A DRY SLOT EFFECTIVELY CUTS OFF THE STEADY PRECIP ACROSS MUCH OF THE SOUTHERN HALF OR MORE OF THE CWA. CROSS SECTIONS SHOW BOTH CONDITIONAL INSTABILITY ALONG WITH THE POTENTIAL FOR UPRIGHT CONVECTION ACROSS THE SOUTH IN THE DRY SLOT. AS A RESULT...EXPECT A CONTINUED STRONG RESPONSE TO THE ONGOING FORCING THROUGH 03Z WITH THE POTENTIAL FOR POCKETS OF HEAVY WET SNOW TO OCCUR MAINLY ACROSS THE NORTHERN THIRD OF THE CWA THROUGH 00Z. THAT SAID...UNCERTAINTY EXISTS ON HOW FAR THE DRY SLOT WILL MOVE NORTH BEFORE THE DEFORMATION ZONE PIVOTS BACK INTO THE AREA OVERNIGHT. IN A NUTSHELL...LOOK FOR A MIXTURE OF RAIN AND SNOW ACROSS THE NORTHERN TWO THIRDS OF THE CWA TONIGHT WITH AMOUNTS OF ONE INCH OR LESS POSSIBLE NORTH OF A CRAWFORDSVILLE TO LEBANON TO NOBLESVILLE AND NEW CASTLE LINE. SUN...WINDY CONDS WITH INSTABILITY SHOWERS WILL OCCUR AS THE UPPER SYSTEM PASSES. SOME SUN STILL APPEARS POSSIBLE SO MOS TEMPS AROUND 50 STILL LOOKS GOOD FOR IND. BUFKIT WINDS SUGGEST GUSTS TO 40 MPH APPEAR POSSIBLE BY AFTERNOON. SUN NIGHT AND BEYOND...A WEAK DISTURBANCE WILL SLIDE DOWN THE EAST SIDE OF A DEVELOPING OMEGA BLOCK TUES INTO WEDS. THIS MAY BRING LIGHT SHOWERS WITH A COOL DOWN BY MID WEEK. OTHERWISE...LOOK FOR QUIET CONDS WITH HIGHS IN THE 50S TO NEAR 60. && .AVIATION...DISCUSSION FOR 141818Z ISSUANCE. UPPR LO PROGRESSING EWD ACRS MO ATTM WITH WIDESPREAD RAIN/DRIZZLE OVR THE LOCAL AREA AHEAD OF THE UPPR LO. BASED ON SFC REPORTS...AMS IS COLD ENOUGH FOR A MIX OR CHANGE OVER TO SNOW UNDERNEATH THE UPPR LOW...SO AS THIS FEATURE MOVS ACRS THE AREA LT THIS AFT/EVEN...XPCTG PCPN TO GRAD CHANGE OVR TO A MIX OF RAIN/SNOW. BEEN SOME REPORTS OF ICE PELLETS AS WELL...SO SOME BRIEF PDS OF ICE PELLETS WITHIN THE CHANGE OVR PSBL. FOR THE MOST PART...IFR/OCNL MVFR CONDS XPCTD FOR THE REST OF AFT/EARLY EVEN HRS. EXCEPTION WL BE IN THE KLAF AREA WITH SOME DRIER AIR ADVECTING IN WHICH SHOULD KEEP MOST OF THE IFR AT BAY. 141200Z UA/MODEL SOUNDINGS SHOW SOME INSTABILITY ALOFT ABV 080 OVR THE SRN PARTS OF THE STATE...SO ISOLD CONVECTION CAN/T BE RULED OUT...HOWEVER MAIN THREAT S OF TAF SITES. PCPN SHOULD END DURG THE EVEN HRS. RATHER STG DRYING NOTED...SO CONDS SHOULD IMPRV FAIRLY QUICKLY AFT PCPN ENDS. E TO NE SFC WNDS SHOULD GRAD BACK TO A NNE HEADING THIS EVEN...WITH GUSTS ARND 25KTS BY 142200Z AS P-GRAD TIGHTENS UP. .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ AVIATION...JAS PUBLIC...CO
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
528 PM EDT SAT APR 14 2007 .UPDATE... WILL SEND OUT A QUICK UPDATE TO INCLUDE POPS FOR JACKSON COUNTY. NORTHERN EDGE OF THE PCPN SHIELD WILL JUST INCH INTO PORTION OF JACKSON COUNTY AND POSSIBLY SERN CALHOUN TOO. DEWPOINTS ARE ONLY IN THE UPPER TEENS...SO EXPECT ANY PCPN TO BE SNOWFALL. ANY SNOW WILL BE OUT OF THE CWA BY 03Z. JK .PREVIOUS DISCUSSION ISSUED AT 315 PM... AFTER NEARLY A MONTH OF PRECIPITATION ALMOST EVERY DAY...IT SEEMS SOUTHWEST MICHIGAN IS IN FOR A BREAK IN THE PRECIPITATION ACTION FOR A FEW DAYS. THERE IS VIRGA FALLING OVER SOUTHWEST LOWER MICHIGAN BUT AS TAMDAR SOUNDING FROM THE AREA SHOW... THE AIR BELOW 12000 FT IS VERY DRY AND FORECAST TO STAY THAT WAY THROUGH SUNDAY EVENING. THUS THE ONLY MAJOR ISSUE WITH THIS FORECAST PACKAGE IS WILL THE STRONG SHORTWAVE DROPPING SOUTH ACROSS THE CWA AROUND 00Z MONDAY BE STRONG ENOUGH TO OFFSET THE VERY DRY LOW LEVEL AIR? THE MODELS ARE SIMILAR WITH THE STRONG STORM PASSING OFF TO THE SOUTH OF SOUTHWEST LOWER MICHIGAN THIS EVENING. SO THERE IS LITTLE QUESTION THE BIGGEST EFFECT ON SOUTHWEST MICHIGAN WEATHER WILL BE THE HIGH AND MID CLOUDS. THE DRY LOW LEVEL ARE... BELOW 12000 FT BASED ON AFTERNOON TAMDAR SOUNDING WILL KEEP THE SNOW FALLING FROM THE MID LEVEL CLOUD DECK FROM REACHING THE GROUND OVER ANY PART OF THE GRR CWA THIS EVENING OR TONIGHT. ONCE THE SHORTWAVE...SEEN NICELY ON THE WATER VAPOR IMAGE OVER WI...PASSES EAST OF THE CWA LATER TONIGHT SKIES MAY ACTUALLY CLEAR TOTALLY. THAT WILL ALLOW FOR TEMPERATURES TO FALL BELOW FREEZING IN MOST AREAS. THERE WILL BE MORE WIND IN THE BOUNDARY LAYER SO THAT WILL LIMIT THE COOLING SOMEWHAT. ON SUNDAY THAT STRONG SHORTWAVE WILL DROP SOUTH ACROSS THE CWA IN THE AFTERNOON INTO THE EVENING. ONCE AGAIN DRY LOW LEVEL AIR WILL LIMIT ANY RISK OF SHOWERS. VERTICAL TOTAL ARE LESS THAT 25C FROM 850 MB TO 500 MB... THAT WILL LIMIT THE CONVECTIVE POTENTIAL. THE LOW LEVEL LAPSE RATES WILL APPROACH 8C IN THE AFTERNOON SO CU IS LIKELY...POSSIBLY MODERATE CU BUT ONLY ISOLATED SHOWERS SEEM POSSIBLE AND THAT WOULD BE EXPECTED MORE TOWARD THE DTX CWA. THUS I EXPUNGED THE SHOWERS FROM THE TEXT OF THE ZONES SUNDAY. ONCE THAT SHORTWAVE IS THROUGH AROUND 06Z MONDAY STRONG SUBSIDENCE FOLLOWS SINCE NOT ONLY IS THERE SINKING BEHIND THAT STRONG SHORTWAVE BUT THE CYCLONIC SIDE OF THE UPPER JET WILL BE EAST OF THE GRR CWA. THIS WILL RESULT IN CLEARING ONCE AGAIN AFTER MIDNIGHT. WESTERN SECTIONS OF THE CWA SHOULD BE NEARLY CLEAR FROM 06Z MONDAY TILL 15Z OR SO ANYWAY. SOME CU ARE POSSIBLE BUT WITH THE SURFACE AND UPPER RIDGE MOVING IN EVEN THAT WILL BE LIMITED. MONDAY SHOULD BE MUCH WARMER TOO WITH THE DEEP COLD AIR GONE AND SIGNIFICANTLY HIGHER 1000 TO 925 MB THICKNESS BY AFTERNOON. .LONG TERM... THE EXTENDED FORECAST BEGINS ON TUESDAY WITH A STACKED LOW OFF THE NEW ENGLAND COAST. THIS WILL TEND TO BLOCK THE NORMAL WEST TO EAST PROGRESSION OF WEATHER SYSTEMS. THE LOW ONLY DRIFTS SLOWLY OUT TO SEA IN THE WEDNESDAY NIGHT THROUGH FRIDAY NIGHT TIME FRAME. MEANWHILE SURFACE AND UPPER RIDGING WILL DOMINATE THE UPPER MIDWEST. THERE WILL BE A WEAKNESS IN THIS PATTERN TUESDAY NIGHT INTO WEDNESDAY AS A SHORT WAVE FROM THE NEW ENGLAND LOW ROTATES OVER THE CENTRAL GREAT LAKES. THIS COULD LEAD TO A FEW SCATTERED SHOWERS LATE TUESDAY NIGHT INTO WEDNESDAY. ALONG WITH SURROUNDING OFFICES...HAVE DECIDED TO ADD MORE CLOUDS AND LOW POPS IN THESE PERIODS. THURSDAY THROUGH SATURDAY WILL FEATURE THE SURFACE RIDGE BUILDING BACK INTO THE REGION. SOUTHEAST WINDS AND A SLIGHT WARMING TREND SHOULD BEGIN FRIDAY INTO SATURDAY. && .GRR WATCHES/WARNINGS/ADVISORIES...NONE. && $$ WDM JK
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
315 PM EDT SAT APR 14 2007 .SHORT TERM... AFTER NEARLY A MONTH OF PRECIPITATION ALMOST EVERY DAY...IT SEEMS SOUTHWEST MICHIGAN IS IN FOR A BREAK IN THE PRECIPITATION ACTION FOR A FEW DAYS. THERE IS VIRGA FALLING OVER SOUTHWEST LOWER MICHIGAN BUT AS TAMDAR SOUNDING FROM THE AREA SHOW... THE AIR BELOW 12000 FT IS VERY DRY AND FORECAST TO STAY THAT WAY THROUGH SUNDAY EVENING. THUS THE ONLY MAJOR ISSUE WITH THIS FORECAST PACKAGE IS WILL THE STRONG SHORTWAVE DROPPING SOUTH ACROSS THE CWA AROUND 00Z MONDAY BE STRONG ENOUGH TO OFFSET THE VERY DRY LOW LEVEL AIR? THE MODELS ARE SIMILAR WITH THE STRONG STORM PASSING OFF TO THE SOUTH OF SOUTHWEST LOWER MICHIGAN THIS EVENING. SO THERE IS LITTLE QUESTION THE BIGGEST EFFECT ON SOUTHWEST MICHIGAN WEATHER WILL BE THE HIGH AND MID CLOUDS. THE DRY LOW LEVEL ARE... BELOW 12000 FT BASED ON AFTERNOON TAMDAR SOUNDING WILL KEEP THE SNOW FALLING FROM THE MID LEVEL CLOUD DECK FROM REACHING THE GROUND OVER ANY PART OF THE GRR CWA THIS EVENING OR TONIGHT. ONCE THE SHORTWAVE...SEEN NICELY ON THE WATER VAPOR IMAGE OVER WI...PASSES EAST OF THE CWA LATER TONIGHT SKIES MAY ACTUALLY CLEAR TOTALLY. THAT WILL ALLOW FOR TEMPERATURES TO FALL BELOW FREEZING IN MOST AREAS. THERE WILL BE MORE WIND IN THE BOUNDARY LAYER SO THAT WILL LIMIT THE COOLING SOMEWHAT. ON SUNDAY THAT STRONG SHORTWAVE WILL DROP SOUTH ACROSS THE CWA IN THE AFTERNOON INTO THE EVENING. ONCE AGAIN DRY LOW LEVEL AIR WILL LIMIT ANY RISK OF SHOWERS. VERTICAL TOTAL ARE LESS THAT 25C FROM 850 MB TO 500 MB... THAT WILL LIMIT THE CONVECTIVE POTENTIAL. THE LOW LEVEL LAPSE RATES WILL APPROACH 8C IN THE AFTERNOON SO CU IS LIKELY...POSSIBLY MODERATE CU BUT ONLY ISOLATED SHOWERS SEEM POSSIBLE AND THAT WOULD BE EXPECTED MORE TOWARD THE DTX CWA. THUS I EXPUNGED THE SHOWERS FROM THE TEXT OF THE ZONES SUNDAY. ONCE THAT SHORTWAVE IS THROUGH AROUND 06Z MONDAY STRONG SUBSIDENCE FOLLOWS SINCE NOT ONLY IS THERE SINKING BEHIND THAT STRONG SHORTWAVE BUT THE CYCLONIC SIDE OF THE UPPER JET WILL BE EAST OF THE GRR CWA. THIS WILL RESULT IN CLEARING ONCE AGAIN AFTER MIDNIGHT. WESTERN SECTIONS OF THE CWA SHOULD BE NEARLY CLEAR FROM 06Z MONDAY TILL 15Z OR SO ANYWAY. SOME CU ARE POSSIBLE BUT WITH THE SURFACE AND UPPER RIDGE MOVING IN EVEN THAT WILL BE LIMITED. MONDAY SHOULD BE MUCH WARMER TOO WITH THE DEEP COLD AIR GONE AND SIGNIFICANTLY HIGHER 1000 TO 925 MB THICKNESS BY AFTERNOON. .LONG TERM... THE EXTENDED FORECAST BEGINS ON TUESDAY WITH A STACKED LOW OFF THE NEW ENGLAND COAST. THIS WILL TEND TO BLOCK THE NORMAL WEST TO EAST PROGRESSION OF WEATHER SYSTEMS. THE LOW ONLY DRIFTS SLOWLY OUT TO SEA IN THE WEDNESDAY NIGHT THROUGH FRIDAY NIGHT TIME FRAME. MEANWHILE SURFACE AND UPPER RIDGING WILL DOMINATE THE UPPER MIDWEST. THERE WILL BE A WEAKNESS IN THIS PATTERN TUESDAY NIGHT INTO WEDNESDAY AS A SHORT WAVE FROM THE NEW ENGLAND LOW ROTATES OVER THE CENTRAL GREAT LAKES. THIS COULD LEAD TO A FEW SCATTERED SHOWERS LATE TUESDAY NIGHT INTO WEDNESDAY. ALONG WITH SURROUNDING OFFICES...HAVE DECIDED TO ADD MORE CLOUDS AND LOW POPS IN THESE PERIODS. THURSDAY THROUGH SATURDAY WILL FEATURE THE SURFACE RIDGE BUILDING BACK INTO THE REGION. SOUTHEAST WINDS AND A SLIGHT WARMING TREND SHOULD BEGIN FRIDAY INTO SATURDAY. && .GRR WATCHES/WARNINGS/ADVISORIES...NONE. && $$ WDM JK
AREA FORECAST DISCUSSION...UPDATED
NWS BINGHAMTON NY
1031 PM EDT SAT APR 14 2007 .UPDATE... MAIN UPDATE TONIGHT WILL BE TO BACK UP THE START OF THE WARNING TO NOON AS BEFIT PROFILES FROM 12 AND 18Z GUIDANCE SUGGEST SNOW WILL TAKE OVER AS THE PREDOMINATE PCP TYPE DURING THE AFTERNOON. 18Z GUIDANCE CERTAINLY HASN`T CLEARED THINGS UP MUCH IN TERMS OF WHAT TO DO WITH THE WATCH...AND EVEN FINAL ACCUMS OVER THE WARNING AREAS. THE 18Z GFS BROUGHT OVER 3 INCHES OF TOTAL QPF TO MUCH OF OUR AREA WITH THE 18Z NAM NOT EVEN QUITE REACHING ONE INCH HERE IN BGM. FEEL REALITY WILL FALL SOMEWHERE IN BETWEEN...WITH A SLIGHT LEAN TOWARDS THE NAM. GFS SOLUTION WOULD CAUSE ALL KINDS OF PROBLEMS WITH SNOW AND EVEN HYDRO OVER SOUTHEASTERN AREAS...BUT IT APPEARS TO BE AN OUTLIER EVEN WITH RESPECT TO ITS PREVIOUS RUNS. WILL CERTAINLY HAVE TO SEE WHETHER THE 00Z RUN BACKS OFF. CONFIDENCE IS GROWING IN AN ADVISORY OR SUB ADVISORY LEVEL EVENT OVER THE WY VALLEY INTO THE POCONOS AS IT TAKES MUCH OF THE NIGHT SUNDAY NIGHT TO CHANGE THE PCP OVER TO ALL SNOW. EVEN FURTHER NORTHEAST OVER THE WESTERN CATSKILLS...PROFILES SUGGEST IP ALONG WITH THE SNOW THROUGH THE EVENING...WHICH WOULD HOLD DOWN ANY SNOW TOTALS. FURTHER NORTH ACROSS THE TWIN TIER/SOUTHERN SUSQUEHANNA REGIONS...CONFIDENCE IS GROWING IN A CHANGEOVER DURING THE AFTERNOON...BUT QUESTION WILL BE WHETHER MESCAL BANDING FEATURES SET UP OVER OR MOST LIKELY JUST NORTH OF THE AREA. FEEL ACCUMS WILL BE NEAR THE WARNING THRESHOLD HERE...SO WILL LET THE MID SHIFT TAKE A LOOK AT THE 00Z GUIDANCE TO DECIDE WHICH SIDE OF THE FENCE LOOKS BETTER. THIS SEEMS PRUDENT GIVEN THE FACT THAT ANY AC CUMS WILL HOLD OFF UNTIL AT LEAST MID AFTERNOON. OF SOME INTEREST WILL BE THE PCP TONIGHT. LAPS ANALYSIS SUGGESTS THAT WET BULBS ARE NEARING FREEZING OVER THE NORTHEASTERN THIRD OF THE CWA. SNOW REPORTED AT KBFD SUGGESTS WE WILL SEE SOME TONIGHT...ESP OVER THE HIGHER TERRAIN. HAVE GONE FOR 1-3 IN THE HIGHER TERRAIN OF WESTERN SECTIONS WITH 1-2 OVER THE HIGHER TERRAIN OF THE EAST GIVEN LATER TIMING. OVER THE WY VALLEY... IT WILL BE HARD TO GET MUCH SN TO THE VALLEY FLOOR...BUT THE HILLTOPS COULD SQUEEZE OUT AN INCH BEFORE THE COLUMN WARMS ENOUGH TO SUPPORT ALL RA BY MORNING. ACARS SOUNDINGS UPSTREAM INDICATE THAT AIR ABOVE ANY LLEVEL WARM LAYER IS BELOW FREEZING...SO SHOULD ONLY SEE RA OR SN TONIGHT WITH NOT MUCH OF A CONCERN FOR IP UNTIL MORNING. BEST SN POTENTIAL WILL BE SUN EVENING AND OVERNIGHT WITH VERY IMPRESSIVE BANDING SIGNATURES ALONG/WEST OF THE I81 CORRIDOR. THIS AGREES WELL WITH AN IMPRESSIVE EASTERLY 850 JET 4-5STD DEV STRONGER THAN CLIMATOLOGICAL NORMS...WHICH WOULD NEAR HISTORIC LEVELS. TIME WILL TELL WHETHER SNOWFALL TOTALS WILL FOLLOW THIS. HAVE UPDATED CURRENT T/TD TRENDS WITH ALL GRIDS/PRODUCTS...INCLUDING AN UPDATED HWO... NOW ON THE STREET. -JMA && .PREV DISCUSSION... /ISSUED 759 PM EDT SAT APR 14 2007/ AVIATION /00Z-24Z/... VFR CONDITIONS TO START THEN AS THE PRECIP COMES IN FROM THE SW TOWARD MIDNIGHT THE CIGS FALL TO THE LOWER END OF VFR. LATE TONIGHT CIGS FALL TO MVFR AS THE LIGHT RAIN OR RAIN AND SNOW BECOMES STEADY. AT ELM...SYR AND RME BETWEEN 13 AND 15Z VSBYS DROP TO MVFR...THEN TO IFR CIGS AND VSBYS DURING THE AFTN. AVP WILL DROP TO IFR CIGS AND MVFR VSBYS AROUND SUNRISE AND REMAIN THERE FOR THE DAY. AT ITH AND BGM AROUND 13Z BOTH WILL FALL TO IFR CIGS AND VSBYS AND REMAIN FOR THE DAY. PRECIP TO CHANGE OVER TO MAINLY SNOW DURING THE AFTN IN CENTRAL NY. LIGHT N TO NE WINDS AT UNDER 8 KTS TO BECOME E OVERNIGHT THEN INCREASE TO AROUND 10KTS SUNDAY MORNING. SUN AFTN WINDS SHIFT TO NE AND INCREASE TO 10 TO 15 KTS. WITH THE AREA UNDER THE INFLUENCE OF THE STORM THROUGH MONDAY CONDITIONS WILL REMAIN MVFR AND IFR AT BEST....LIFR AT WORST. PREV DISCUSSION... /ISSUED 402 PM EDT SAT APR 14 2007/ SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/... BUSY DAY WITH IMPENDING WINTER STORM EXPECTED ACROSS PARTS OF THE AREA STARTING TOMORROW. 12Z MODELS ARE VERY CONSISTENT WITH EACH OTHER ON TRACK OF SFC LOW DUE TO SHIFT OFF OF EAST COAST BY 18Z TOMORROW NR THE DELMARVA PENINSULA. THIS LOW TRACKS TO NR LONG ISLAND SUNDAY NIGHT. PCPN INITIALLY SPREADS INTO NEPA AFTER MIDNIGHT TONIGHT. WITH EVAP COOLING POSSIBLE EARLY ON...COULD SEE A RAIN/SNOW MIX FOR A BRIEF PERIOD OF TIME TO START OFF TONIGHT. BOTH GFS/NAM AND NGM INDICATE THAT THIS WILL CHG OVER TO ALL LIQUID ACROSS NEPA BY APPROX 09Z AND HAVE INDICATED THIS IN THE GRIDS. BUFKIT PROFILES FROM NAM AND GFS DIFFER ON WHAT THE TEMPS DO ALOFT AFTER THIS POINT. HAVE STUCK CLOSER TO NAM IN COORDINATION WITH HPC AND SURROUNDING OFFICES. THIS WOULD LEAD TO A RAIN/SNOW MIX NORTH OF THE TWIN TIERS TONIGHT UNTIL TOMORROW AFTERNOON. ACROSS THE TWIN TIERS...COULD SEE RAIN AND SNOW AND POSSIBLY SLEET AS WELL ACCORDING TO THE PROFILES. MOST OF NEPA WILL STAY RAIN UNTIL SUNDAY AFTERNOON. AFTER THIS POINT...COLD AIR BEGINS TO BE PULLED DOWN INTO CYCLONE AND CHANGES MOST OF THE PCPN TO ALL SNOW NORTH OF THE TWIN TIERS AFTER 18Z SUNDAY. THE SNOW WILL BECOME HEAVY AT TIMES OVERNIGHT WITH GOOD FRONTOGENETICAL FORCING AND STRONG LIFT. NAM INDICATES MESOSCALE BANDING SETTING UP ACROSS THE FINGER LAKES AND WESTERN MOHAWK VALLEY...THUS HAVE UPGRADED TO A WARNING OVER THESE AREAS FOR SUNDAY EVENING TO MONDAY EVENING. SNOWFALL TOTALS RANGING FRO, 6 TO 16 INCHES...HIGHER AMOUNTS IN THE HIGHEST TERRAIN TO THE EAST. REMAINDER OF THE AREA IS A QUESTION MARK. PCPN WILL BE MIXED LONGER AND WILL CUT DOWN ON AMOUNTS SIGNIFICANTLY. CUD BE MINIMAL WRNG CRITERIA SNOWS OVER TWIN TIERS...POSSIBLE 6-10 INCHES IN THESE AREAS. OVER NEPA...PCPN WILL REMAIN RAIN MOST OF THE DAY SUNDAY AND NOT SWITCH OVER UNTIL SUNDAY NIGHT. WHILE THE VALLEY AREAS MAY ONLY SEE A FEW INCHES...THE POCONOS AND CATSKILLS CUD SEE WARNING CRITERIA SNOWS. THUS HAVE KEPT THE WATCH GOING FROM THE TWIN TIERS AND SOUTH. HOWEVER...ANY WOBBLE TO THE LOW PRESSURE SYSTEM WILL CHG AMOUNTS. A JOG TO THE EAST BY ABOUT 50 MILES WILL BRING IN COLDER AIR AND LEAD TO HIGHER ACCUMS ALL AREAS. AS THE MODELS HAVE GIVEN US A LITTLE OF EVERYTHING OVER THE PAST FEW DAYS...THE ONLY PRUDENT SOLN IS TO KEEP THE WATCH GOING. POSSIBLE UPGRADE TO WARNINGS OR DOWNGRADE TO ADVISORIES MAY BE ISSUED TONIGHT OR TOMORROW. LONG TERM /TUESDAY THROUGH SATURDAY/... MAJOR CYCLONE OCCLUDES OVER THE NEW ENGLAND STATES EARLY THIS PERIOD...WHICH THEN LEADS TO A SPRING TIME OMEGA BLOCK DEVELOPING ACROSS THE CONUS DURING THE WEEK...WHICH ONLY GRADUALLY LOOSENS IT/S GRIP TOWARD THE WEEKEND. THIS WILL MAINTAIN THE BELOW NORMAL TEMPERATURES THROUGH THE WEEK. PLENTY OF LOW LEVEL CLOUD COVER WILL LINGER IN NORTHWEST FLOW BEHIND THE STORM SYSTEM FROM TUESDAY THROUGH THURSDAY...WITH GRADUAL INCREASES OF SUNSHINE BY SATURDAY. AFTER LINGERING SNOW SHOWERS IN NW UPSLOPE FLOW THROUGH TUESDAY NIGHT...ANY PRECIPITATION CHANCE FOR THE REST OF THE WEEK LOOKS NIL AT THIS POINT. WENT WITH MOST OF HPC GUIDANCE EXCEPT HAD TO MAKE MAJOR CHANGES TO EXPECTED CLOUD COVER...AND RESULTANT TEMPS PER LATEST 06Z AND 12Z GFS MEAN RH AND THERMAL PROG TRENDS. DROPPED ABOUT 5-6 DEGREES OFF HPC/MEX GUIDANCE ON TUESDAY THROUGH WEDNESDAY...AS MIXING UP TO 925 MB TEMPS ARE NOT SUPPORTIVE OF MOS/HPC GUIDANCE IN THE 40S-50S...ESPECIALLY OVER A SNOW PACK AND OVERCAST SKIES. ALSO CONTINUED WITH A COOLER TREND RIGHT THROUGH SATURDAY...PER ENSEMBLE MOS GUIDANCE AND ADIABATIC MIXING OF 2-4C AIR AT 925 MB. && .BGM WATCHES/WARNINGS/ADVISORIES... NY...WINTER STORM WARNING FROM 12 PM SUNDAY TO 8 PM EDT MONDAY FOR NYZ009-015>018-022-023-025-036-037-044>046. WINTER STORM WATCH FROM SUNDAY EVENING THROUGH MONDAY EVENING FOR NYZ024-055>057-062. PA...WINTER STORM WATCH FROM SUNDAY EVENING THROUGH MONDAY EVENING FOR PAZ038>040-043-044-047-048-072. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1227 AM CDT SUN APR 15 2007 .EVENING DISCUSSION... 920 PM CDT UPDATED ZONES TONIGHT MAINLY TO CLEAN UP PRECIP WORDING AND TO ACCOUNT FOR CLEARING TREND. UPPER JET AXIS HAS NOW SHIFTED INTO THE OHIO RIVER VALLEY...WITH UPPER TROUGH AXIS POSITIONED JUST ABOUT OVERHEAD AT 02Z THIS EVENING. WILL KEEP PARTLY CLOUDY CONDITIONS OVERNIGHT WITH SFC OBS/SATELLITE IMAGERY INDICATING SOME MID LEVEL CLOUDINESS IN ASSOCIATION WITH ANOTHER SHORT WAVE APPROACHING FROM NORTHWEST WISCONSIN. TEMPS APPEAR TO BE IN GOOD SHAPE AND NO SIGNIFICANT CHANGES WERE MADE TO MIN TEMPS OVERNIGHT FROM THE INHERITED FORECAST. MARSILI && .DISCUSSION... 300 PM CDT THE RAIN IS EXPECTED TO REMAIN SOUTH OF KANKAKEE THIS EVENING AND TONIGHT. THE AIR NORTH OF KANKAKEE IS DRY. A NORTHEAST FLOW EXIST UP TO 700 MB. THE ACARS SOUNDING FROM ORD 1919 UTC SHOWS THE NORTHEAST FLOW. PROFILER DATA SHOWS THE CIRCULATION OVER NORTHEAST ILLINOIS. THE LOCALLY RUN WRF ARW SHOWS THE 700 MB CIRCULATION INTO EASTERN INDIANA BY 03 UTC TONIGHT. THIS CIRCULATION CORRELATES WELL WITH THE GFS FORECAST OF THE 500 MB TROUGH. THE SURFACE LOW IS FORECAST TO BE IN WESTERN NORTH CAROLINA BY 06 UTC...GIVING A NORTH WIND OVER NORTHEAST ILLINOIS AND NORTHWEST INDIANA. WE ADJUSTED TONIGHT LOWS TO TO THE LOWER 30S FOR THE COLDER AIR MOVING IN. THE ANTICYCLONIC SIDE OF THE 500 MB TROUGH WILL PASS OVER THE FORECAST AREA AROUND 00 UTC MONDAY. COLD AIR AND INSTABILITY WITH A JET STREAK ALOFT MAY PRODUCE ISOLATED SHOWERS. WILL LEAVE A SLIGHT CHANCE OF SHOWERS IN THE GRID FORECASTS FOR SUNDAY. AS THE RIDGE BUILDS OVER THE MIDWEST. THE FORECAST TEMPERATURE WILL BE IN THE UPPER 50S AND THE LOWER 60S FOR HIGHS ON MONDAY AND TUESDAY. A 500 MB TROUGH MOVES SOUTH OVER ILLINOIS TUESDAY NIGHT. WILL ADD A SLIGHT CHANCE OF SHOWERS TUESDAY NIGHT. && .AVIATION... 06Z TAFS...MID DECK SLOWLY PUSHING SE AWAY FROM TERMINALS EARLY THIS MORNING WITH MORE MID CLOUDS ACROSS WI/MN BUT GENERALLY EXPECT SKC THRU SUNRISE. WEAK TROUGH/UPPER LEVEL WAVE MOVES SOUTH ACROSS THE WESTERN LAKES LATER TODAY. MODELS WERE SUGGESTING A BETTER CHANCE OF RAIN SHOWERS 24 HRS AGO BUT HAVE BACKED OFF WITH LATEST RUNS. BACK EDGE OF THIS SYSTEM CURRENTLY ACROSS CENTRAL IA WHERE THERE ARE A FEW SHOWERS. WOULDN/T BE SURPRISED TO SEE AN ISOLATED SHOWER BY LATE MORNING/EARLY AFTERNOON BUT FOR NOW WILL STAY DRY. MAY NEED TO INCLUDE VCSH WITH 12Z TAFS DEPENDING ON TRENDS. ANY ISOLATED SHOWERS SHOULD BE SHORT-LIVED AND LIGHT. AS THIS WAVES APPROACHES EXPECT A BKN/OVC CU/STRATOCU DECK TO DEVELOP BY EARLY AFTERNOON THEN SCATTER OUT WITH SUNSET. LIGHT NORTHERLY WINDS WILL INCREASE TO 15KTS OR SO BY LATE MORNING AND TURN MORE NNE THRU THE AFTERNOON BEFORE DIMINISHING THIS EVENING. SOME HIGHER GUSTS POSSIBLE DURING THE AFTERNOON AS WELL. CMS && .LOT WATCHES/WARNINGS/ADVISORIES... .IL...NONE. .IN...NONE. .LM...NONE. && $$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
115 AM EDT SUN APR 15 2007 .AVIATION...DISCUSSION FOR 150600Z TAF ISSUANCE STRONG LOW PRESSURE OVER SOUTHEAST KENTUCKY WILL CONTINUE MOVING TO THE MID ATLANTIC STATES ON SUNDAY. A FAIRLY STRONG NORTHERLY GRADIENT WILL CONTINUE UNTIL SUNDAY EVENING AND WIND GUSTS SUNDAY MAY BE NEAR OR A LITTLE ABOVE 25 KNOTS AT TIMES. DRIER AIR FROM THE NORTHWEST WILL SPREAD SOUTHEAST ACROSS CENTRAL INDIANA. THUS KLAF SHOULD START OUT VFR AND OTHER TAFS SHOULD BE VFR BY 09Z. SKIES MAY EVEN BE MOSTLY CLEAR AT TIMES DURING THE MORNING AND EARLY AFTERNOON. MODELS BRING INCREASING RH AROUND 5 THOUSAND LATE SUNDAY AFTERNOON AND EARLY EVENING SO A PERIOD OF 5 THOUSAND BROKEN AND THIS MAY CLEAR AGAIN TOWARDS END OF THE TAF PERIOD. && .DISCUSSION...ONGOING PRECIP TYPE AND AMOUNTS REMAIN FOCUS THROUGH TONIGHT. COMPLEX UPPER PATTERN FEATURES ONE UPPER LOW NOW TRACKING NE NEAR STL WITHIN THE LARGER SCALE LONGWAVE TROUGH THAT CONTINUES TO DEEPEN OVER THE REGION. STRONG 850-700MB FRONTOGENESIS IS OCCURRING AHEAD OF THE UPPER LOW ACROSS THE REGION WHILE THE SFC LOW APPEARS TO BE A BIT FURTHER NORTH THAN FCST ACROSS CENTRAL KY. WIDESPREAD MOD/HVY PRECIP HAS DEVELOPED WITHIN THE ZONE OF FRONTOGENESIS ACROSS AREAS NORTH OF I-70 THIS AFTERNOON. QUICK CHECK OF FCST SOUNDINGS AND AIRCRAFT SOUNDINGS SHOW NEAR 0C AT 850MB WITH 1000-850MB THICKNESSES NOW COOLING TO BELOW 1300DM WITH REPORTS ALSO STARTING TO INDICATE A MIXTURE OF RAIN AND SNOW NORTH OF I-70. NO SIG INITIALIZATION ERRORS NOTED AND I WILL USE SHORT RANGE SREF ENSEMBLE AND SATELLITE/OBS AND RADAR FOR THE FCST TONIGHT. TONIGHT...DEVELOPING DEFORMATION ZONE/TROWEL WILL PIVOT ACROSS THE CWA. THE COMPONENT OF FORCING DUE TO 850-700MB FRONTOGENESIS WILL GRADUALLY SHIFT NE OF THE CWA WHILE A DRY SLOT EFFECTIVELY CUTS OFF THE STEADY PRECIP ACROSS MUCH OF THE SOUTHERN HALF OR MORE OF THE CWA. CROSS SECTIONS SHOW BOTH CONDITIONAL INSTABILITY ALONG WITH THE POTENTIAL FOR UPRIGHT CONVECTION ACROSS THE SOUTH IN THE DRY SLOT. AS A RESULT...EXPECT A CONTINUED STRONG RESPONSE TO THE ONGOING FORCING THROUGH 03Z WITH THE POTENTIAL FOR POCKETS OF HEAVY WET SNOW TO OCCUR MAINLY ACROSS THE NORTHERN THIRD OF THE CWA THROUGH 00Z. THAT SAID...UNCERTAINTY EXISTS ON HOW FAR THE DRY SLOT WILL MOVE NORTH BEFORE THE DEFORMATION ZONE PIVOTS BACK INTO THE AREA OVERNIGHT. IN A NUTSHELL...LOOK FOR A MIXTURE OF RAIN AND SNOW ACROSS THE NORTHERN TWO THIRDS OF THE CWA TONIGHT WITH AMOUNTS OF ONE INCH OR LESS POSSIBLE NORTH OF A CRAWFORDSVILLE TO LEBANON TO NOBLESVILLE AND NEW CASTLE LINE. SUN...WINDY CONDS WITH INSTABILITY SHOWERS WILL OCCUR AS THE UPPER SYSTEM PASSES. SOME SUN STILL APPEARS POSSIBLE SO MOS TEMPS AROUND 50 STILL LOOKS GOOD FOR IND. BUFKIT WINDS SUGGEST GUSTS TO 40 MPH APPEAR POSSIBLE BY AFTERNOON. SUN NIGHT AND BEYOND...A WEAK DISTURBANCE WILL SLIDE DOWN THE EAST SIDE OF A DEVELOPING OMEGA BLOCK TUES INTO WEDS. THIS MAY BRING LIGHT SHOWERS WITH A COOL DOWN BY MID WEEK. OTHERWISE...LOOK FOR QUIET CONDS WITH HIGHS IN THE 50S TO NEAR 60. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ AVIATION...JH PUBLIC...CO
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
405 AM EDT SUN APR 15 2007 .SHORT TERM (TODAY THROUGH TONIGHT)... WATER VAPOR LOOP SHOWS A WAVE MOVING INTO THE TENNESSEE VALLEY AS A SECOND SHORT WAVE DROPS SOUTH INTO THE MIDWEST. ACARS 400-250MB WIND OBSERVATIONS REVEAL A POSITIVELY TILTED UPPER LEVEL TROUGH ACROSS THE MIDDLE MISSISSIPPI RIVER VALLEY...WITH A 120-160KT SOUTHWESTERLY JET EXTENDING FROM THE PLAINS THROUGH THE EASTERN GREAT LAKES. 03Z SURFACE ANALYSIS PLACED A 1001MB CYCLONE IN EASTERN KENTUCKY...ALONG THE NEXT COLD FRONT. A WARM FRONT EXTENDED NORTHEAST FROM A 1002MB CYCLONE IN EAST CENTRAL ALABAMA THROUGH CENTRAL NORTH CAROLINA. ACARS UPPER LEVEL WIND DATA HAS BEEN ABLE TO SHOW A SUBTLE 120-140KT SOUTHWESTERLY JETLET ACROSS THE EASTERN GREAT LAKES. PRECIPITATION ACROSS THE OHIO VALLEY LINES UP WELL WHERE JET COUPLING SEEMS TO BE OCCURRING. THE FLIP SIDE TO THIS IS THE DEVELOPMENT OF A DRY SLOT (DRAWN IN FROM BACKSIDE OF SOUTHEAST CONUS CONVECTION) OVERHEAD. AS THE JETLET ACROSS THE EASTERN GREAT LAKES MOVES AWAY FROM THE REGION...EXPECT RESULTANT VERTICAL CIRCULATIONS TO DIMINISH. MEANWHILE...5MB PRESSURE FALLS HAVE BEEN OCCURRING ACROSS CENTRAL VIRGINIA BETWEEN 3-6Z. THERE IS STILL A DYNAMIC SITUATION ACROSS THE REGION...EVIDENCED BY SHOWER AND THUNDERSTORM REDEVELOPMENT WITHIN THE DRYSLOT DURING THE PAST SEVERAL HOURS. ISENTROPIC LIFT OVER THE WARM FRONT TO THE SOUTHEAST WILL PERSIST THROUGH THE MORNING...WHICH SHOULD LEAD TO THE REDEVELOPMENT OF MODERATE TO HEAVY RAIN ACROSS THE REGION. WHILE 00Z MODEL SUITE (ESPECIALLY GFS AND KLWX WRF-NMM) DID NOT CLEARLY INDICATE BREAK IN PRECIPITATION...OBSERVATIONAL TRENDS DO SUPPORT MODEL INDICATIONS OF RAIN AXIS DURING THE MORNING HOURS. RAIN PROCESS WILL BE EFFICIENT THIS MORNING...OWING TO WARM CLOUD DEPTH UP TO 15KFT (-5C LEVEL)...PRECIPITABLE WATER VALUES GREATER THAN 2 STANDARD DEVIATIONS ABOVE CLIMATOLOGY...AND AMOUNT OF LOW LEVEL FORCING ASSOCIATED WITH FRONTOGENESIS. WARM FRONT MAY LIFT INTO SOUTHEAST ZONES THIS MORNING...WHERE WARMEST HIGHS ARE INDICATED. COLD ADVECTION WILL BEGIN DURING THE MID AFTERNOON IN THE HIGHER TERRAIN...WHERE COOLING TEMPERATURES MAY SUPPORT SNOW SHOWERS MIXING IN WITH RAIN. TONIGHT WILL BE A TRANSITION PERIOD. AS THE COASTAL STORM DEEPENS WITHIN THE NEW ENGLAND WATERS...PRESSURE/HEIGHT GRADIENT WILL SUPPORT STRENGTHENING NORTHWEST WIND GUSTS. WHILE UPPER LOW WILL BE NEARBY...EXPECT DRYING BOUNDARY LAYER TO CONTRIBUTE TO DRYING CONDITIONS EAST OF THE MOUNTAINS DURING THE NIGHT. ACROSS THE UPSLOPE AREAS...00Z NAM AND 21Z SHORT RANGE ENSEMBLES INDICATE POSSIBILITY OF 1-3 INCHES OF SNOW. WILL HAVE TO MONITOR PAN HANDLE REGION OF WEST VIRGINIA AND MARYLAND...WITH SUCH STRONG FLOW...SHOWERS MAY MAKE IT TO THE BLUE RIDGE. HAVE WARMED UP MOS GUIDANCE TONIGHT GIVEN GUSTY NORTHWEST FLOW. TEMPERATURES WILL BE CLOSE TO A FREEZE WARNING CRITERIA IN THE HIGHER TERRAIN ALONG AND WEST OF THE BLUE RIDGE...BUT CONFIDENCE NOT HIGH ENOUGH TO WARRANT A WATCH FOR SUCH A SMALL AREA. && .AVIATION... MODERATE TO HEAVY RAIN AXIS EXPECTED TO DEVELOP OVER TERMINALS EARLY THIS MORNING...CONTINUING TO SUPPORT LIFR-IFR CEILINGS/VISIBILITIES. DOWNSLOPE COMPONENT INCREASES THIS AFTERNOON...ALLOWING FOR IMPROVEMENT. GRADIENT BEHIND DEEPENING COASTAL STORM WILL SUPPORT GUSTY NORTHWEST WINDS THIS EVENING AND OVERNIGHT. && .MARINE... 00Z GFS/ETA MOS AT THOMAS POINT INDICATE SUSTAINED WINDS 25KTS EARLY THIS MORNING....DECREASING TO 15-20KTS THIS AFTERNOON...BEFORE INCREASING BACK TO 25KTS TONIGHT. 00Z NAM/GFS PROXIMITY BUFKIT FORECAST SOUNDINGS INDICATE WIND GUSTS NEARING GALES AFTER MIDNIGHT. GALE CONDITIONS EXPECTED FOR MON INTO MON EVENING. EXPECT NW WINDS OF NEAR SMALL CRAFT TO CONTINUE OVERNIGHT MON NIGHT THROUGH TUE. WINDS WILL SLACKEN ON WED AND THUR AS WEAK HIGH PRES OVER THE GREAT LAKES BUILDS ACROSS THE REGION. && .TIDES... WATER LEVELS ARE CURRENTLY LESS THAN A HALF FOOT BELOW ASTRONOMICAL PREDICTIONS. THE CHESAPEAKE BAY OPERATIONAL FORECAST SYSTEM AND NOAA EXTRATROPICAL STORM SURGE MODEL INDICATE WATER LEVELS WILL RISE TO ABOUT A FOOT ABOVE ASTRONOMICAL PREDICTIONS THIS MORNING. THE LUNAR PHASE IS WANING TOWARD A NEW MOON (7% FULL). WATER LEVELS WILL HAVE TO BE MONITORED THIS MORNING AS STRONG SOUTHEAST FLOW IS EXPECTED ALLOW POSITIVE TIDAL DEPARTURES TO DEVELOP. DO NOT EXPECT DEPARTURES TO RISE ABOVE NUISANCE COASTAL FLOOD LEVELS GIVEN THE SPEED OF THE SYSTEM. EXPECT BLOWOUT CONDITIONS TO DEVELOP TONIGHT INTO EARLY NEXT WEEK AS THE DEEP COASTAL STORM MOVES OFFSHORE. && .LONG TERM /MONDAY THROUGH SATURDAY/... DEEP LOW PRESSURE WILL BRING DREARY AND UNSEASONABLY COLD CONTINUES THROUGH THURS THEN A MODERATION OF TEMPERATURES BEGINS TOWARDS THE WEEKEND. AN UNSEASONABLY DEEP SURFACE LOW PRESSURE CENTER IS PROGGED TO BE LOCATED SOMEWHERE NEAR NYC. BASED UPON 21Z/14 SREFS CENTRAL PRESSURE WILL BE 979MB BY 12Z MON. THE 00Z GFS HAS IT DOWN TO 974 MB. BY NOON ON MON THE LOW BECOMES NEARLY VERTICALLY STACKED WITH THE UPPER LEVELS AND BEGINS TO FILL. THE LOW WILL DRIFT EAST AND AWAY FROM THE AREA ON TUE AND WED...THEN HIGH PRESSURE WILL BUILD ACROSS THE REGION FOR THE LATER PART OF THE WEEK. FOR SATURDAY THE HIGH NESTLES OVER THE MID ATLANTIC REGION AND PERHAPS GIVES THE AREA ANOTHER TASTE OF SPRING. FOR MON...TWO CONCERNS: WINDS AND UPSLOPE SNOW. A VERY TIGHT SURFACE PRESSURE GRADIENT AND STRONG LOW-LEVEL CYCLONIC FLOW AROUND THE LOW OVER SOUTHERN NY WILL DOMINATE THE WEATHER. STRONG AND GUSTY NORTHWEST WINDS ACCROSS THE REGION WILL LIKELY APPROACH WIND ADVISORY CONDITIONS BUT WILL NOT BE STRONG ENOUGH TO WARRANT ANY TYPE OF HIGH WIND WARCH. THE OTHER CONCERN WILL BE THE CONTINUATION OF ACCUMULATING SNOW IN THE FAR WESTERN ZONES IN UPSLOPE PORTIONS. FOR MON NIGHT...COLD TEMPS ONCE AGAIN ARE FORECAST...WITH SOME SPOTS ALONG AND TO THE WEST OF THE BLUE RIDGE EXPECTED TO DROP TO NEAR FREEZING. HOWEVER...STRONG NW CYCLONIC FLOW WILL STILL BE WITH US WHICH WLL HELP MINIMZIE THREAT OF WIDESPREAD FREEZING CONDITIONS. FOR TUE...GRADUAL DRYING AND ABATEMENT OF WINDS AS THE SURFACE LOW PUSHES OUT TO SEA. FOR WED TO SAT...HIGH PRES OVER THE GREAT LAKES ON WED WILL MOVE SLOWLY EAST TO A POSITION OVER THE MID ATLANTIC BY LATE FRI. DID NOT MAKE SIGNIFICANT CHANGES IN THIS PART OF THE LONG TERM...AND CONTINUED WITH DRY WEATHER AND GRADUAL MODERATION IN TEMPS. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...FLOOD WATCH THROUGH THIS AFTERNOON FOR DCZ001. MD...FLOOD WATCH THROUGH THIS AFTERNOON FOR MDZ004>007-009>011-013- 014-016>018. WINTER STORM WATCH FROM THIS EVENING THROUGH MONDAY MORNING FOR MDZ501. VA...FLOOD WATCH THROUGH THIS AFTERNOON FOR VAZ036>042-050>057. WV...WINTER STORM WATCH FROM THIS EVENING THROUGH MONDAY MORNING FOR WVZ501-503. MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT MONDAY FOR ANZ530>537. GALE WARNING FROM 4 AM TO 11 PM EDT MONDAY FOR ANZ530>537. && $$ SHORT TERM/AVIATION/TIDES...ROGOWSKI LONG TERM...SMZ MARINE...ROGOWSKI/SMZ
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
400 AM EDT SUN APR 15 2007 .SHORT TERM (TODAY THROUGH TONIGHT)... WATER VAPOR LOOP SHOWS A WAVE MOVING INTO THE TENNESSEE VALLEY AS A SECOND SHORT WAVE DROPS SOUTH INTO THE MIDWEST. ACARS 400-250MB WIND OBSERVATIONS REVEAL A POSITIVELY TILTED UPPER LEVEL TROUGH ACROSS THE MIDDLE MISSISSIPPI RIVER VALLEY...WITH A 120-160KT SOUTHWESTERLY JET EXTENDING FROM THE PLAINS THROUGH THE EASTERN GREAT LAKES. 03Z SURFACE ANALYSIS PLACED A 1001MB CYCLONE IN EASTERN KENTUCKY...ALONG THE NEXT COLD FRONT. A WARM FRONT EXTENDED NORTHEAST FROM A 1002MB CYCLONE IN EAST CENTRAL ALABAMA THROUGH CENTRAL NORTH CAROLINA. ACARS UPPER LEVEL WIND DATA HAS BEEN ABLE TO SHOW A SUBTLE 120-140KT SOUTHWESTERLY JETLET ACROSS THE EASTERN GREAT LAKES. PRECIPITATION ACROSS THE OHIO VALLEY LINES UP WELL WHERE JET COUPLING SEEMS TO BE OCCURRING. THE FLIP SIDE TO THIS IS THE DEVELOPMENT OF A DRY SLOT (DRAWN IN FROM BACKSIDE OF SOUTHEAST CONUS CONVECTION) OVERHEAD. AS THE JETLET ACROSS THE EASTERN GREAT LAKES MOVES AWAY FROM THE REGION...EXPECT RESULTANT VERTICAL CIRCULATIONS TO DIMINISH. MEANWHILE...5MB PRESSURE FALLS HAVE BEEN OCCURRING ACROSS CENTRAL VIRGINIA BETWEEN 3-6Z. THERE IS STILL A DYNAMIC SITUATION ACROSS THE REGION...EVIDENCED BY SHOWER AND THUNDERSTORM REDEVELOPMENT WITHIN THE DRYSLOT DURING THE PAST SEVERAL HOURS. ISENTROPIC LIFT OVER THE WARM FRONT TO THE SOUTHEAST WILL PERSIST THROUGH THE MORNING...WHICH SHOULD LEAD TO THE REDEVELOPMENT OF MODERATE TO HEAVY RAIN ACROSS THE REGION. WHILE 00Z MODEL SUITE (ESPECIALLY GFS AND KLWX WRF-NMM) DID NOT CLEARLY INDICATE BREAK IN PRECIPITATION...OBSERVATIONAL TRENDS DO SUPPORT MODEL INDICATIONS OF RAIN AXIS DURING THE MORNING HOURS. WARM FRONT MAY LIFT INTO SOUTHEAST ZONES THIS MORNING...WHERE WARMEST HIGHS ARE INDICATED. COLD ADVECTION WILL BEGIN DURING THE MID AFTERNOON IN THE HIGHER TERRAIN...WHERE COOLING TEMPERATURES MAY SUPPORT SNOW SHOWERS MIXING IN WITH RAIN. TONIGHT WILL BE A TRANSITION PERIOD. AS THE COASTAL STORM DEEPENS WITHIN THE NEW ENGLAND WATERS...PRESSURE/HEIGHT GRADIENT WILL SUPPORT STRENGTHENING NORTHWEST WIND GUSTS. WHILE UPPER LOW WILL BE NEARBY...EXPECT DRYING BOUNDARY LAYER TO CONTRIBUTE TO DRYING CONDITIONS EAST OF THE MOUNTAINS DURING THE NIGHT. ACROSS THE UPSLOPE AREAS...00Z NAM AND 21Z SHORT RANGE ENSEMBLES INDICATE POSSIBILITY OF 1-3 INCHES OF SNOW. WILL HAVE TO MONITOR PAN HANDLE REGION OF WEST VIRGINIA AND MARYLAND...WITH SUCH STRONG FLOW...SHOWERS MAY MAKE IT TO THE BLUE RIDGE. HAVE WARMED UP MOS GUIDANCE TONIGHT GIVEN GUSTY NORTHWEST FLOW. TEMPERATURES WILL BE CLOSE TO A FREEZE WARNING CRITERIA IN THE HIGHER TERRAIN ALONG AND WEST OF THE BLUE RIDGE...BUT CONFIDENCE NOT HIGH ENOUGH TO WARRANT A WATCH FOR SUCH A SMALL AREA. && .AVIATION... MODERATE TO HEAVY RAIN AXIS EXPECTED TO DEVELOP OVER TERMINALS EARLY THIS MORNING...CONTINUING TO SUPPORT LIFR-IFR CEILINGS/VISIBILITIES. DOWNSLOPE COMPONENT INCREASES THIS AFTERNOON...ALLOWING FOR IMPROVEMENT. GRADIENT BEHIND DEEPENING COASTAL STORM WILL SUPPORT GUSTY NORTHWEST WINDS THIS EVENING AND OVERNIGHT. && .MARINE... 00Z GFS/ETA MOS AT THOMAS POINT INDICATE SUSTAINED WINDS 25KTS EARLY THIS MORNING....DECREASING TO 15-20KTS THIS AFTERNOON...BEFORE INCREASING BACK TO 25KTS TONIGHT. 00Z NAM/GFS PROXIMITY BUFKIT FORECAST SOUNDINGS INDICATE WIND GUSTS NEARING GALES AFTER MIDNIGHT. GALE CONDITIONS EXPECTED FOR MON INTO MON EVENING. EXPECT NW WINDS OF NEAR SMALL CRAFT TO CONTINUE OVERNIGHT MON NIGHT THROUGH TUE. WINDS WILL SLACKEN ON WED AND THUR AS WEAK HIGH PRES OVER THE GREAT LAKES BUILDS ACROSS THE REGION. && .TIDES... WATER LEVELS ARE CURRENTLY LESS THAN A HALF FOOT BELOW ASTRONOMICAL PREDICTIONS. THE CHESAPEAKE BAY OPERATIONAL FORECAST SYSTEM AND NOAA EXTRATROPICAL STORM SURGE MODEL INDICATE WATER LEVELS WILL RISE TO ABOUT A FOOT ABOVE ASTRONOMICAL PREDICTIONS THIS MORNING. THE LUNAR PHASE IS WANING TOWARD A NEW MOON (7% FULL). WATER LEVELS WILL HAVE TO BE MONITORED THIS MORNING AS STRONG SOUTHEAST FLOW IS EXPECTED ALLOW POSITIVE TIDAL DEPARTURES TO DEVELOP. DO NOT EXPECT DEPARTURES TO RISE ABOVE NUISANCE COASTAL FLOOD LEVELS GIVEN THE SPEED OF THE SYSTEM. EXPECT BLOWOUT CONDITIONS TO DEVELOP TONIGHT INTO EARLY NEXT WEEK AS THE DEEP COASTAL STORM MOVES OFFSHORE. && .LONG TERM /MONDAY THROUGH SATURDAY/... DEEP LOW PRESSURE WILL BRING DREARY AND UNSEASONABLY COLD CONTINUES THROUGH THURS THEN A MODERATION OF TEMPERATURES BEGINS TOWARDS THE WEEKEND. AN UNSEASONABLY DEEP SURFACE LOW PRESSURE CENTER IS PROGGED TO BE LOCATED SOMEWHERE NEAR NYC. BASED UPON 21Z/14 SREFS CENTRAL PRESSURE WILL BE 979MB BY 12Z MON. THE 00Z GFS HAS IT DOWN TO 974 MB. BY NOON ON MON THE LOW BECOMES NEARLY VERTICALLY STACKED WITH THE UPPER LEVELS AND BEGINS TO FILL. THE LOW WILL DRIFT EAST AND AWAY FROM THE AREA ON TUE AND WED...THEN HIGH PRESSURE WILL BUILD ACROSS THE REGION FOR THE LATER PART OF THE WEEK. FOR SATURDAY THE HIGH NESTLES OVER THE MID ATLANTIC REGION AND PERHAPS GIVES THE AREA ANOTHER TASTE OF SPRING. FOR MON...TWO CONCERNS: WINDS AND UPSLOPE SNOW. A VERY TIGHT SURFACE PRESSURE GRADIENT AND STRONG LOW-LEVEL CYCLONIC FLOW AROUND THE LOW OVER SOUTHERN NY WILL DOMINATE THE WEATHER. STRONG AND GUSTY NORTHWEST WINDS ACCROSS THE REGION WILL LIKELY APPROACH WIND ADVISORY CONDITIONS BUT WILL NOT BE STRONG ENOUGH TO WARRANT ANY TYPE OF HIGH WIND WARCH. THE OTHER CONCERN WILL BE THE CONTINUATION OF ACCUMULATING SNOW IN THE FAR WESTERN ZONES IN UPSLOPE PORTIONS. FOR MON NIGHT...COLD TEMPS ONCE AGAIN ARE FORECAST...WITH SOME SPOTS ALONG AND TO THE WEST OF THE BLUE RIDGE EXPECTED TO DROP TO NEAR FREEZING. HOWEVER...STRONG NW CYCLONIC FLOW WILL STILL BE WITH US WHICH WLL HELP MINIMZIE THREAT OF WIDESPREAD FREEZING CONDITIONS. FOR TUE...GRADUAL DRYING AND ABATEMENT OF WINDS AS THE SURFACE LOW PUSHES OUT TO SEA. FOR WED TO SAT...HIGH PRES OVER THE GREAT LAKES ON WED WILL MOVE SLOWLY EAST TO A POSITION OVER THE MID ATLANTIC BY LATE FRI. DID NOT MAKE SIGNIFICANT CHANGES IN THIS PART OF THE LONG TERM...AND CONTINUED WITH DRY WEATHER AND GRADUAL MODERATION IN TEMPS. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...FLOOD WATCH THROUGH THIS AFTERNOON FOR DCZ001. MD...FLOOD WATCH THROUGH THIS AFTERNOON FOR MDZ004>007-009>011-013- 014-016>018. WINTER STORM WATCH FROM THIS EVENING THROUGH MONDAY MORNING FOR MDZ501. VA...FLOOD WATCH THROUGH THIS AFTERNOON FOR VAZ036>042-050>057. WV...WINTER STORM WATCH FROM THIS EVENING THROUGH MONDAY MORNING FOR WVZ501-503. MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT MONDAY FOR ANZ530>537. GALE WARNING FROM 4 AM TO 11 PM EDT MONDAY FOR ANZ530>537. && $$ SHORT TERM/AVIATION/TIDES...ROGOWSKI LONG TERM...SMZ MARINE...ROGOWSKI/SMZ
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
149 AM EDT SUN APR 15 2007 .AVIATION /06Z-06Z/... MAJOR STORM HAS JUST BEGUN TO IMPACT THE AREA AND WILL CONTINUE TO DO SO THRU THE TAF PERIOD AND BEYOND. CONDITIONS WILL DETERIORATE QUICKLY WITH THE START OF PRECIPITATION, WHICH HAS ALREADY BEGUN AT MOST TAF SITES OR WILL IN THE FIRST COUPLE OF HOURS. PRECIP TYPE IS MAINLY RAIN WITH SNOW AT BGM. EXPECT MAINLY RAIN INTO THIS MORNING BEFORE A CHANGE OVER TO SNOW DURING THE AFTN, EXCEPT AT AVP WHERE RAIN SHOULD CONTINUE MOST OF THE DAY. MVFR CEILINGS AND OCCASIONALLY VISBY WILL LIKELY LOWER TO IFR DURING THE MORNING. EASTERLY WINDS GENERALLY LESS THAN 10 KTS WILL INCREASE THIS AFTN 10 TO 15 KTS. WINDS SWITCH TO NW EARLY THIS EVENING WITH INCREASE TO 15 TO 25 KTS WITH GUSTS 30 KTS. && .PREV DISCUSSION... /ISSUED 1031 PM EDT SAT APR 14 2007/ UPDATE... MAIN UPDATE TONIGHT WILL BE TO BACK UP THE START OF THE WARNING TO NOON AS BEFIT PROFILES FROM 12 AND 18Z GUIDANCE SUGGEST SNOW WILL TAKE OVER AS THE PREDOMINATE PCP TYPE DURING THE AFTERNOON. 18Z GUIDANCE CERTAINLY HASN`T CLEARED THINGS UP MUCH IN TERMS OF WHAT TO DO WITH THE WATCH...AND EVEN FINAL ACCUMS OVER THE WARNING AREAS. THE 18Z GFS BROUGHT OVER 3 INCHES OF TOTAL QPF TO MUCH OF OUR AREA WITH THE 18Z NAM NOT EVEN QUITE REACHING ONE INCH HERE IN BGM. FEEL REALITY WILL FALL SOMEWHERE IN BETWEEN...WITH A SLIGHT LEAN TOWARDS THE NAM. GFS SOLUTION WOULD CAUSE ALL KINDS OF PROBLEMS WITH SNOW AND EVEN HYDRO OVER SOUTHEASTERN AREAS...BUT IT APPEARS TO BE AN OUTLIER EVEN WITH RESPECT TO ITS PREVIOUS RUNS. WILL CERTAINLY HAVE TO SEE WHETHER THE 00Z RUN BACKS OFF. CONFIDENCE IS GROWING IN AN ADVISORY OR SUB ADVISORY LEVEL EVENT OVER THE WY VALLEY INTO THE POCONOS AS IT TAKES MUCH OF THE NIGHT SUNDAY NIGHT TO CHANGE THE PCP OVER TO ALL SNOW. EVEN FURTHER NORTHEAST OVER THE WESTERN CATSKILLS...PROFILES SUGGEST IP ALONG WITH THE SNOW THROUGH THE EVENING...WHICH WOULD HOLD DOWN ANY SNOW TOTALS. FURTHER NORTH ACROSS THE TWIN TIER/SOUTHERN SUSQUEHANNA REGIONS...CONFIDENCE IS GROWING IN A CHANGEOVER DURING THE AFTERNOON...BUT QUESTION WILL BE WHETHER MESCAL BANDING FEATURES SET UP OVER OR MOST LIKELY JUST NORTH OF THE AREA. FEEL ACCUMS WILL BE NEAR THE WARNING THRESHOLD HERE...SO WILL LET THE MID SHIFT TAKE A LOOK AT THE 00Z GUIDANCE TO DECIDE WHICH SIDE OF THE FENCE LOOKS BETTER. THIS SEEMS PRUDENT GIVEN THE FACT THAT ANY AC CUMS WILL HOLD OFF UNTIL AT LEAST MID AFTERNOON. OF SOME INTEREST WILL BE THE PCP TONIGHT. LAPS ANALYSIS SUGGESTS THAT WET BULBS ARE NEARING FREEZING OVER THE NORTHEASTERN THIRD OF THE CWA. SNOW REPORTED AT KBFD SUGGESTS WE WILL SEE SOME TONIGHT...ESP OVER THE HIGHER TERRAIN. HAVE GONE FOR 1-3 IN THE HIGHER TERRAIN OF WESTERN SECTIONS WITH 1-2 OVER THE HIGHER TERRAIN OF THE EAST GIVEN LATER TIMING. OVER THE WY VALLEY... IT WILL BE HARD TO GET MUCH SN TO THE VALLEY FLOOR...BUT THE HILLTOPS COULD SQUEEZE OUT AN INCH BEFORE THE COLUMN WARMS ENOUGH TO SUPPORT ALL RA BY MORNING. ACARS SOUNDINGS UPSTREAM INDICATE THAT AIR ABOVE ANY LLEVEL WARM LAYER IS BELOW FREEZING...SO SHOULD ONLY SEE RA OR SN TONIGHT WITH NOT MUCH OF A CONCERN FOR IP UNTIL MORNING. BEST SN POTENTIAL WILL BE SUN EVENING AND OVERNIGHT WITH VERY IMPRESSIVE BANDING SIGNATURES ALONG/WEST OF THE I81 CORRIDOR. THIS AGREES WELL WITH AN IMPRESSIVE EASTERLY 850 JET 4-5STD DEV STRONGER THAN CLIMATOLOGICAL NORMS...WHICH WOULD NEAR HISTORIC LEVELS. TIME WILL TELL WHETHER SNOWFALL TOTALS WILL FOLLOW THIS. HAVE UPDATED CURRENT T/TD TRENDS WITH ALL GRIDS/PRODUCTS...INCLUDING AN UPDATED HWO... NOW ON THE STREET. -JMA PREV DISCUSSION... /ISSUED 759 PM EDT SAT APR 14 2007/ AVIATION /00Z-24Z/... VFR CONDITIONS TO START THEN AS THE PRECIP COMES IN FROM THE SW TOWARD MIDNIGHT THE CIGS FALL TO THE LOWER END OF VFR. LATE TONIGHT CIGS FALL TO MVFR AS THE LIGHT RAIN OR RAIN AND SNOW BECOMES STEADY. AT ELM...SYR AND RME BETWEEN 13 AND 15Z VSBYS DROP TO MVFR...THEN TO IFR CIGS AND VSBYS DURING THE AFTN. AVP WILL DROP TO IFR CIGS AND MVFR VSBYS AROUND SUNRISE AND REMAIN THERE FOR THE DAY. AT ITH AND BGM AROUND 13Z BOTH WILL FALL TO IFR CIGS AND VSBYS AND REMAIN FOR THE DAY. PRECIP TO CHANGE OVER TO MAINLY SNOW DURING THE AFTN IN CENTRAL NY. LIGHT N TO NE WINDS AT UNDER 8 KTS TO BECOME E OVERNIGHT THEN INCREASE TO AROUND 10KTS SUNDAY MORNING. SUN AFTN WINDS SHIFT TO NE AND INCREASE TO 10 TO 15 KTS. WITH THE AREA UNDER THE INFLUENCE OF THE STORM THROUGH MONDAY CONDITIONS WILL REMAIN MVFR AND IFR AT BEST....LIFR AT WORST. PREV DISCUSSION... /ISSUED 402 PM EDT SAT APR 14 2007/ SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/... BUSY DAY WITH IMPENDING WINTER STORM EXPECTED ACROSS PARTS OF THE AREA STARTING TOMORROW. 12Z MODELS ARE VERY CONSISTENT WITH EACH OTHER ON TRACK OF SFC LOW DUE TO SHIFT OFF OF EAST COAST BY 18Z TOMORROW NR THE DELMARVA PENINSULA. THIS LOW TRACKS TO NR LONG ISLAND SUNDAY NIGHT. PCPN INITIALLY SPREADS INTO NEPA AFTER MIDNIGHT TONIGHT. WITH EVAP COOLING POSSIBLE EARLY ON...COULD SEE A RAIN/SNOW MIX FOR A BRIEF PERIOD OF TIME TO START OFF TONIGHT. BOTH GFS/NAM AND NGM INDICATE THAT THIS WILL CHG OVER TO ALL LIQUID ACROSS NEPA BY APPROX 09Z AND HAVE INDICATED THIS IN THE GRIDS. BUFKIT PROFILES FROM NAM AND GFS DIFFER ON WHAT THE TEMPS DO ALOFT AFTER THIS POINT. HAVE STUCK CLOSER TO NAM IN COORDINATION WITH HPC AND SURROUNDING OFFICES. THIS WOULD LEAD TO A RAIN/SNOW MIX NORTH OF THE TWIN TIERS TONIGHT UNTIL TOMORROW AFTERNOON. ACROSS THE TWIN TIERS...COULD SEE RAIN AND SNOW AND POSSIBLY SLEET AS WELL ACCORDING TO THE PROFILES. MOST OF NEPA WILL STAY RAIN UNTIL SUNDAY AFTERNOON. AFTER THIS POINT...COLD AIR BEGINS TO BE PULLED DOWN INTO CYCLONE AND CHANGES MOST OF THE PCPN TO ALL SNOW NORTH OF THE TWIN TIERS AFTER 18Z SUNDAY. THE SNOW WILL BECOME HEAVY AT TIMES OVERNIGHT WITH GOOD FRONTOGENETICAL FORCING AND STRONG LIFT. NAM INDICATES MESOSCALE BANDING SETTING UP ACROSS THE FINGER LAKES AND WESTERN MOHAWK VALLEY...THUS HAVE UPGRADED TO A WARNING OVER THESE AREAS FOR SUNDAY EVENING TO MONDAY EVENING. SNOWFALL TOTALS RANGING FRO, 6 TO 16 INCHES...HIGHER AMOUNTS IN THE HIGHEST TERRAIN TO THE EAST. REMAINDER OF THE AREA IS A QUESTION MARK. PCPN WILL BE MIXED LONGER AND WILL CUT DOWN ON AMOUNTS SIGNIFICANTLY. CUD BE MINIMAL WRNG CRITERIA SNOWS OVER TWIN TIERS...POSSIBLE 6-10 INCHES IN THESE AREAS. OVER NEPA...PCPN WILL REMAIN RAIN MOST OF THE DAY SUNDAY AND NOT SWITCH OVER UNTIL SUNDAY NIGHT. WHILE THE VALLEY AREAS MAY ONLY SEE A FEW INCHES...THE POCONOS AND CATSKILLS CUD SEE WARNING CRITERIA SNOWS. THUS HAVE KEPT THE WATCH GOING FROM THE TWIN TIERS AND SOUTH. HOWEVER...ANY WOBBLE TO THE LOW PRESSURE SYSTEM WILL CHG AMOUNTS. A JOG TO THE EAST BY ABOUT 50 MILES WILL BRING IN COLDER AIR AND LEAD TO HIGHER ACCUMS ALL AREAS. AS THE MODELS HAVE GIVEN US A LITTLE OF EVERYTHING OVER THE PAST FEW DAYS...THE ONLY PRUDENT SOLN IS TO KEEP THE WATCH GOING. POSSIBLE UPGRADE TO WARNINGS OR DOWNGRADE TO ADVISORIES MAY BE ISSUED TONIGHT OR TOMORROW. LONG TERM /TUESDAY THROUGH SATURDAY/... MAJOR CYCLONE OCCLUDES OVER THE NEW ENGLAND STATES EARLY THIS PERIOD...WHICH THEN LEADS TO A SPRING TIME OMEGA BLOCK DEVELOPING ACROSS THE CONUS DURING THE WEEK...WHICH ONLY GRADUALLY LOOSENS IT/S GRIP TOWARD THE WEEKEND. THIS WILL MAINTAIN THE BELOW NORMAL TEMPERATURES THROUGH THE WEEK. PLENTY OF LOW LEVEL CLOUD COVER WILL LINGER IN NORTHWEST FLOW BEHIND THE STORM SYSTEM FROM TUESDAY THROUGH THURSDAY...WITH GRADUAL INCREASES OF SUNSHINE BY SATURDAY. AFTER LINGERING SNOW SHOWERS IN NW UPSLOPE FLOW THROUGH TUESDAY NIGHT...ANY PRECIPITATION CHANCE FOR THE REST OF THE WEEK LOOKS NIL AT THIS POINT. WENT WITH MOST OF HPC GUIDANCE EXCEPT HAD TO MAKE MAJOR CHANGES TO EXPECTED CLOUD COVER...AND RESULTANT TEMPS PER LATEST 06Z AND 12Z GFS MEAN RH AND THERMAL PROG TRENDS. DROPPED ABOUT 5-6 DEGREES OFF HPC/MEX GUIDANCE ON TUESDAY THROUGH WEDNESDAY...AS MIXING UP TO 925 MB TEMPS ARE NOT SUPPORTIVE OF MOS/HPC GUIDANCE IN THE 40S-50S...ESPECIALLY OVER A SNOW PACK AND OVERCAST SKIES. ALSO CONTINUED WITH A COOLER TREND RIGHT THROUGH SATURDAY...PER ENSEMBLE MOS GUIDANCE AND ADIABATIC MIXING OF 2-4C AIR AT 925 MB. && .BGM WATCHES/WARNINGS/ADVISORIES... NY...WINTER STORM WARNING FROM NOON TODAY TO 8 PM EDT MONDAY FOR NYZ009-015>018-022-023-025-036-037-044>046. WINTER STORM WATCH FROM THIS EVENING THROUGH MONDAY EVENING FOR NYZ024-055>057-062. PA...WINTER STORM WATCH FROM THIS EVENING THROUGH MONDAY EVENING FOR PAZ038>040-043-044-047-048-072. && $$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
300 AM CDT SUN APR 15 2007 .SHORT TERM...100 KNOT JET STREAK CREATING ENOUGH LIFT TO PRODUCE SOME SCATTERED MIDDLE CLOUDS ACROSS THE WESTERN PORTION OF THE STATE EARLY TODAY. THESE WILL SHIFT EAST ACROSS THE AREA TODAY. TOOK OUT THE SLIGHT CHANCE OF SHOWERS FOR THIS AFTERNOON...AS TAMDAR SOUNDINGS FROM YESTERDAY EVENING AND FORECAST SOUNDINGS FOR TODAY LOOK VERY DRY. NORTHEAST WINDS WILL KEEP IT COOLER TODAY NEAR THE LAKE AND BAY. WINDS BECOME NORTHWEST MONDAY WITH INCREASING 850MB TEMPERATURES. THIS SHOULD RESULT IN HIGHS AROUND 60F IN MOST PLACES. .LONG TERM...MONDAY NIGHT THROUGH NEXT SATURDAY. FIRST SYSTEM WILL MOVE ACROSS THE AREA LATE MONDAY NIGHT INTO TUESDAY. MODELS CONTINUE TO SHOW DIFFERENCES IN TIMING OF THE SYSTEM...BUT HAVE LEANED TOWARD THE GFS SOLUTION FOR NOW. HIGHEST RAIN/SNOW CHANCES ACROSS THE WEST AND OVER THE NORTH ON TUESDAY. DID REMOVE ANY MENTION OF PRECIPITATION TUESDAY NIGHT. REMAINDER OF FORECAST APPEARS QUIET...ALTHOUGH GFS SHOW PRECIPITATION DEVELOPING WEST OF THE FORECAST AREA THURSDAY NIGHT AND MOVES ACROSS THE FORECAST ON FRIDAY. OFFICES TO THE WEST REMAINED DRY AND THINK MOST OF THE AREA WOULD SEE SPRINKLES ON FRIDAY AT BEST. WILL LET DAY SHIFT LOOK AT THIS FEATURE. TEMPERATURES LOOK GOOD THROUGH THE PERIOD. && .AVIATION...VFR CONDITIONS EXPECTED OVERNIGHT...WITH BASES OF ANY CLOUDS ABOVE 8K. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ RDM WEATHER.GOV/GREENBAY
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
1104 AM EDT SUN APR 15 2007 .SHORT TERM /REST OF TODAY/... LOPRES IN WRN NC ATTM...MVG NE. ALNG THE METRO CORRIDOR...THERE HV BEEN SVRL ATTEMPTS AT A DRY SLOT...EACH OF WHICH HAS FILLED IN. SOLID STREAM OF MSTR UP THE SPINE OF THE PTMC HIGHLANDS THO. WL MAKE NO CHGS TO THE FAA...ALTHO MOST OF THAT AREA ALREADY HAS ACTV FLW. ALSO FLWS FOR MOST OF THE PTMC HIGHLANDS. SEE SPECIFIC STMTS FOR VALID TIMES AND DETAILS. RGNL MOSAIC INDICATES THAT BACK EDGE SVRL HRS AWAY. EVEN A LTL ENHANCEMENT IN RAFL RATES THX TO CNVCTV ELEMENTS. RUC/NAM INSIST THAT HVYST RAFL WL BE IN THE I-95 CORRIDOR BTWN DC-BALT. WL BLEND RADAR AND GDNC. OVRALL THEME WL BE TO SLOW DOWN THE ENDING TIME OF THE PCPN. FEW OTR CHGS TO GRIDS ATTM. RUNNING LATE. UPDTS OUT ASAP. && .AVIATION /15Z-12Z/... IFR/LIFR CIGS AND IFR VSBYS ATTM. IMPVMNT COMES TNGT ONCE LOPRES CLEARS AREA. && .MARINE... TPLM2 AT STRONG SCA. MOST OTR SITES MARGINAL AT BEST. STILL A POWERFUL CYCLONE HEADING THIS WAY /992 MB IN WRN NC/...SO WL RIDE OUT ANY LULL. ALL HEADLINES CONTINUE. && .PREV DISCUSSION... /ISSUED 405 AM EDT SUN APR 15 2007/ SHORT TERM (TODAY THROUGH TONIGHT)... WATER VAPOR LOOP SHOWS A WAVE MOVING INTO THE TENNESSEE VALLEY AS A SECOND SHORT WAVE DROPS SOUTH INTO THE MIDWEST. ACARS 400-250MB WIND OBSERVATIONS REVEAL A POSITIVELY TILTED UPPER LEVEL TROUGH ACROSS THE MIDDLE MISSISSIPPI RIVER VALLEY...WITH A 120-160KT SOUTHWESTERLY JET EXTENDING FROM THE PLAINS THROUGH THE EASTERN GREAT LAKES. 03Z SURFACE ANALYSIS PLACED A 1001MB CYCLONE IN EASTERN KENTUCKY...ALONG THE NEXT COLD FRONT. A WARM FRONT EXTENDED NORTHEAST FROM A 1002MB CYCLONE IN EAST CENTRAL ALABAMA THROUGH CENTRAL NORTH CAROLINA. ACARS UPPER LEVEL WIND DATA HAS BEEN ABLE TO SHOW A SUBTLE 120-140KT SOUTHWESTERLY JETLET ACROSS THE EASTERN GREAT LAKES. PRECIPITATION ACROSS THE OHIO VALLEY LINES UP WELL WHERE JET COUPLING SEEMS TO BE OCCURRING. THE FLIP SIDE TO THIS IS THE DEVELOPMENT OF A DRY SLOT (DRAWN IN FROM BACKSIDE OF SOUTHEAST CONUS CONVECTION) OVERHEAD. AS THE JETLET ACROSS THE EASTERN GREAT LAKES MOVES AWAY FROM THE REGION...EXPECT RESULTANT VERTICAL CIRCULATIONS TO DIMINISH. MEANWHILE...5MB PRESSURE FALLS HAVE BEEN OCCURRING ACROSS CENTRAL VIRGINIA BETWEEN 3-6Z. THERE IS STILL A DYNAMIC SITUATION ACROSS THE REGION...EVIDENCED BY SHOWER AND THUNDERSTORM REDEVELOPMENT WITHIN THE DRYSLOT DURING THE PAST SEVERAL HOURS. ISENTROPIC LIFT OVER THE WARM FRONT TO THE SOUTHEAST WILL PERSIST THROUGH THE MORNING...WHICH SHOULD LEAD TO THE REDEVELOPMENT OF MODERATE TO HEAVY RAIN ACROSS THE REGION. WHILE 00Z MODEL SUITE (ESPECIALLY GFS AND KLWX WRF-NMM) DID NOT CLEARLY INDICATE BREAK IN PRECIPITATION...OBSERVATIONAL TRENDS DO SUPPORT MODEL INDICATIONS OF RAIN AXIS DURING THE MORNING HOURS. RAIN PROCESS WILL BE EFFICIENT THIS MORNING...OWING TO WARM CLOUD DEPTH UP TO 15KFT (-5C LEVEL)...PRECIPITABLE WATER VALUES GREATER THAN 2 STANDARD DEVIATIONS ABOVE CLIMATOLOGY...AND AMOUNT OF LOW LEVEL FORCING ASSOCIATED WITH FRONTOGENESIS. WARM FRONT MAY LIFT INTO SOUTHEAST ZONES THIS MORNING...WHERE WARMEST HIGHS ARE INDICATED. COLD ADVECTION WILL BEGIN DURING THE MID AFTERNOON IN THE HIGHER TERRAIN...WHERE COOLING TEMPERATURES MAY SUPPORT SNOW SHOWERS MIXING IN WITH RAIN. TONIGHT WILL BE A TRANSITION PERIOD. AS THE COASTAL STORM DEEPENS WITHIN THE NEW ENGLAND WATERS...PRESSURE/HEIGHT GRADIENT WILL SUPPORT STRENGTHENING NORTHWEST WIND GUSTS. WHILE UPPER LOW WILL BE NEARBY...EXPECT DRYING BOUNDARY LAYER TO CONTRIBUTE TO DRYING CONDITIONS EAST OF THE MOUNTAINS DURING THE NIGHT. ACROSS THE UPSLOPE AREAS...00Z NAM AND 21Z SHORT RANGE ENSEMBLES INDICATE POSSIBILITY OF 1-3 INCHES OF SNOW. WILL HAVE TO MONITOR PAN HANDLE REGION OF WEST VIRGINIA AND MARYLAND...WITH SUCH STRONG FLOW...SHOWERS MAY MAKE IT TO THE BLUE RIDGE. HAVE WARMED UP MOS GUIDANCE TONIGHT GIVEN GUSTY NORTHWEST FLOW. TEMPERATURES WILL BE CLOSE TO A FREEZE WARNING CRITERIA IN THE HIGHER TERRAIN ALONG AND WEST OF THE BLUE RIDGE...BUT CONFIDENCE NOT HIGH ENOUGH TO WARRANT A WATCH FOR SUCH A SMALL AREA. AVIATION... MODERATE TO HEAVY RAIN AXIS EXPECTED TO DEVELOP OVER TERMINALS EARLY THIS MORNING...CONTINUING TO SUPPORT LIFR-IFR CEILINGS/VISIBILITIES. DOWNSLOPE COMPONENT INCREASES THIS AFTERNOON...ALLOWING FOR IMPROVEMENT. GRADIENT BEHIND DEEPENING COASTAL STORM WILL SUPPORT GUSTY NORTHWEST WINDS THIS EVENING AND OVERNIGHT. MARINE... 00Z GFS/ETA MOS AT THOMAS POINT INDICATE SUSTAINED WINDS 25KTS EARLY THIS MORNING....DECREASING TO 15-20KTS THIS AFTERNOON...BEFORE INCREASING BACK TO 25KTS TONIGHT. 00Z NAM/GFS PROXIMITY BUFKIT FORECAST SOUNDINGS INDICATE WIND GUSTS NEARING GALES AFTER MIDNIGHT. GALE CONDITIONS EXPECTED FOR MON INTO MON EVENING. EXPECT NW WINDS OF NEAR SMALL CRAFT TO CONTINUE OVERNIGHT MON NIGHT THROUGH TUE. WINDS WILL SLACKEN ON WED AND THUR AS WEAK HIGH PRES OVER THE GREAT LAKES BUILDS ACROSS THE REGION. TIDES... WATER LEVELS ARE CURRENTLY LESS THAN A HALF FOOT BELOW ASTRONOMICAL PREDICTIONS. THE CHESAPEAKE BAY OPERATIONAL FORECAST SYSTEM AND NOAA EXTRATROPICAL STORM SURGE MODEL INDICATE WATER LEVELS WILL RISE TO ABOUT A FOOT ABOVE ASTRONOMICAL PREDICTIONS THIS MORNING. THE LUNAR PHASE IS WANING TOWARD A NEW MOON (7% FULL). WATER LEVELS WILL HAVE TO BE MONITORED THIS MORNING AS STRONG SOUTHEAST FLOW IS EXPECTED ALLOW POSITIVE TIDAL DEPARTURES TO DEVELOP. DO NOT EXPECT DEPARTURES TO RISE ABOVE NUISANCE COASTAL FLOOD LEVELS GIVEN THE SPEED OF THE SYSTEM. EXPECT BLOWOUT CONDITIONS TO DEVELOP TONIGHT INTO EARLY NEXT WEEK AS THE DEEP COASTAL STORM MOVES OFFSHORE. LONG TERM /MONDAY THROUGH SATURDAY/... DEEP LOW PRESSURE WILL BRING DREARY AND UNSEASONABLY COLD CONTINUES THROUGH THURS THEN A MODERATION OF TEMPERATURES BEGINS TOWARDS THE WEEKEND. AN UNSEASONABLY DEEP SURFACE LOW PRESSURE CENTER IS PROGGED TO BE LOCATED SOMEWHERE NEAR NYC. BASED UPON 21Z/14 SREFS CENTRAL PRESSURE WILL BE 979MB BY 12Z MON. THE 00Z GFS HAS IT DOWN TO 974 MB. BY NOON ON MON THE LOW BECOMES NEARLY VERTICALLY STACKED WITH THE UPPER LEVELS AND BEGINS TO FILL. THE LOW WILL DRIFT EAST AND AWAY FROM THE AREA ON TUE AND WED...THEN HIGH PRESSURE WILL BUILD ACROSS THE REGION FOR THE LATER PART OF THE WEEK. FOR SATURDAY THE HIGH NESTLES OVER THE MID ATLANTIC REGION AND PERHAPS GIVES THE AREA ANOTHER TASTE OF SPRING. FOR MON...TWO CONCERNS: WINDS AND UPSLOPE SNOW. A VERY TIGHT SURFACE PRESSURE GRADIENT AND STRONG LOW-LEVEL CYCLONIC FLOW AROUND THE LOW OVER SOUTHERN NY WILL DOMINATE THE WEATHER. STRONG AND GUSTY NORTHWEST WINDS ACCROSS THE REGION WILL LIKELY APPROACH WIND ADVISORY CONDITIONS BUT WILL NOT BE STRONG ENOUGH TO WARRANT ANY TYPE OF HIGH WIND WARCH. THE OTHER CONCERN WILL BE THE CONTINUATION OF ACCUMULATING SNOW IN THE FAR WESTERN ZONES IN UPSLOPE PORTIONS. FOR MON NIGHT...COLD TEMPS ONCE AGAIN ARE FORECAST...WITH SOME SPOTS ALONG AND TO THE WEST OF THE BLUE RIDGE EXPECTED TO DROP TO NEAR FREEZING. HOWEVER...STRONG NW CYCLONIC FLOW WILL STILL BE WITH US WHICH WLL HELP MINIMZIE THREAT OF WIDESPREAD FREEZING CONDITIONS. FOR TUE...GRADUAL DRYING AND ABATEMENT OF WINDS AS THE SURFACE LOW PUSHES OUT TO SEA. FOR WED TO SAT...HIGH PRES OVER THE GREAT LAKES ON WED WILL MOVE SLOWLY EAST TO A POSITION OVER THE MID ATLANTIC BY LATE FRI. DID NOT MAKE SIGNIFICANT CHANGES IN THIS PART OF THE LONG TERM...AND CONTINUED WITH DRY WEATHER AND GRADUAL MODERATION IN TEMPS. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...FLOOD WATCH UNTIL 4 PM EDT THIS AFTERNOON FOR DCZ001. MD...FLOOD WATCH UNTIL 4 PM EDT THIS AFTERNOON FOR MDZ004>007- 009>011-013-014-016>018. WINTER STORM WATCH FROM 8 PM EDT THIS EVENING THROUGH MONDAY MORNING FOR MDZ501. VA...FLOOD WATCH UNTIL 4 PM EDT THIS AFTERNOON FOR VAZ036>042- 050>057. WV...WINTER STORM WATCH FROM 8 PM EDT THIS EVENING THROUGH MONDAY MORNING FOR WVZ501-503. MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT MONDAY FOR ANZ530>537. GALE WARNING FROM 4 AM TO 11 PM EDT MONDAY FOR ANZ530>537. && $$ SHORT TERM/AVIATION/MARINE...HTS PREVIOUS DISCUSSION...ROGOWSKI/SMZ
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1015 AM CDT SUN APR 15 2007 .UPDATE...TEMPERATURES ARE RUNNING WELL ABOVE WHAT IS FORECAST IN THE HOURLY GRIDS. READINGS ARE SIMILAR TO WHAT THEY WERE YESTERDAY AT THE SAME TIME IN MOST LOCATIONS...12Z SOUNDING HAD SFC TO 750 MB TEMPERATURES A LITTLE WARMER THAN 12Z YESTERDAY AND THERE IS PLENTY OF SUNSHINE. UPDATED TO GO WITH WARMER HIGHS FOR THESE REASONS. GRIDS HAVE BEEN UPDATED AND ZONES...PUBILC AND FIRE WX...WILL BE OUT SHORTLY. PREVIOUS DISCUSSION... .SHORT TERM...100 KNOT JET STREAK CREATING ENOUGH LIFT TO PRODUCE SOME SCATTERED MIDDLE CLOUDS ACROSS THE WESTERN PORTION OF THE STATE EARLY TODAY. THESE WILL SHIFT EAST ACROSS THE AREA TODAY. TOOK OUT THE SLIGHT CHANCE OF SHOWERS FOR THIS AFTERNOON...AS TAMDAR SOUNDINGS FROM YESTERDAY EVENING AND FORECAST SOUNDINGS FOR TODAY LOOK VERY DRY. NORTHEAST WINDS WILL KEEP IT COOLER TODAY NEAR THE LAKE AND BAY. WINDS BECOME NORTHWEST MONDAY WITH INCREASING 850MB TEMPERATURES. THIS SHOULD RESULT IN HIGHS AROUND 60F IN MOST PLACES. .LONG TERM...MONDAY NIGHT THROUGH NEXT SATURDAY. FIRST SYSTEM WILL MOVE ACROSS THE AREA LATE MONDAY NIGHT INTO TUESDAY. MODELS CONTINUE TO SHOW DIFFERENCES IN TIMING OF THE SYSTEM...BUT HAVE LEANED TOWARD THE GFS SOLUTION FOR NOW. HIGHEST RAIN/SNOW CHANCES ACROSS THE WEST AND OVER THE NORTH ON TUESDAY. DID REMOVE ANY MENTION OF PRECIPITATION TUESDAY NIGHT. REMAINDER OF FORECAST APPEARS QUIET...ALTHOUGH GFS SHOW PRECIPITATION DEVELOPING WEST OF THE FORECAST AREA THURSDAY NIGHT AND MOVES ACROSS THE FORECAST ON FRIDAY. OFFICES TO THE WEST REMAINED DRY AND THINK MOST OF THE AREA WOULD SEE SPRINKLES ON FRIDAY AT BEST. WILL LET DAY SHIFT LOOK AT THIS FEATURE. TEMPERATURES LOOK GOOD THROUGH THE PERIOD. && .AVIATION...VFR CONDITIONS EXPECTED OVERNIGHT...WITH BASES OF ANY CLOUDS ABOVE 8K. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MG WEATHER.GOV/GREENBAY