Forecast Discussions mentioning any of "HRRR" "RR" "RUC13" "RUC" received at GSD on 11/16/11


AREA FORECAST DISCUSSION
NWS PUEBLO CO
307 PM MST MON NOV 14 2011 .SHORT TERM... (TONIGHT AND TUESDAY) CRITICAL FIRE WEATHER CONDITIONS WILL CONTINUE ACROSS EL PASO AND PUEBLO COUNTIES FOR THE NEXT COUPLE HOURS...DUE TO A COMBINATION OF LEE TROFFING AND NORTHWEST FLOW ALOFT. MODELS DID NOT HAVE A VERY GOOD HANDLE ON DEW POINTS TODAY...AS DRY AIR BEHIND YESTERDAY`S DEPARTING SYSTEM TANKED DEW POINTS INTO THE SINGLE DIGITS TO AROUND 10 DEGREES ALONG THE LOWER EASTERN SLOPES OF THE SOUTHEAST MOUNTAINS AND I-25 CORRIDOR. RUC13 AND HRRR WERE THE FIRST TO CATCH ON TO THIS. SFC PRESSURE GRADIENT IS TIGHTEST ACROSS NRN PORTIONS OF THE AREA WHICH WILL KEEP BREEZY WEST WINDS ACROSS PUEBLO AND EL PASO COUNTY THROUGH THE LATE AFTERNOON/EARLY EVENING. FARTHER EAST OF THE I-25 CORRIDOR...HAVE SEEN SOME OCCASIONALLY BREEZY WEST WINDS KICK IN AS FAR EAST AS LHX...HOWEVER THEY HAVE BEEN LESS PERSISTENT...AND THINK THAT IT WON`T QUITE MAKE THE 3 HOUR DURATION REQUIRED FOR A RED FLAG WARNING. WINDS SHOULD DIMINISH AFTER 00Z. WITH THE DRY AIR IN PLACE...CHALLENGE WILL BE HOW COOL LOW TEMPERATURES WILL DROP. LOWER EASTERN SLOPES NEAR THE MTS SHOULD CONTINUE TO EXPERIENCE SOME WESTERLY DRAINAGE WINDS OVERNIGHT WHICH SHOULD KEEP MIN TEMPS AROUND 40. HOWEVER WHERE WINDS DECOUPLE...EFFICIENT RADIATIONAL COOLING WILL ALLOW TEMPS TO DROP QUICKLY. HAVE GONE ABOVE GUIDANCE FOR LOWS NEAR THE MTS...BUT KEPT MINS ON THE LOWER SIDE OF GUIDANCE ELSEWHERE. FOR TOMORROW...NEXT WEAK WAVE EMBEDDED IN NW FLOW ALOFT WILL APPROACH THE AREA. SHOULD SEE SCATTERED SNOW SHOWERS RAMP UP FOR THE CENTRAL MTS. WINDS SHOULD BE LIGHTER TOMORROW ACROSS THE PLAINS...THOUGH A COLD FRONT WILL APPROACH NRN PORTIONS OF THE AREA IN THE AFTERNOON. OVERALL TEMPS SHOULD NET A FEW DEGREES COOLER ACROSS THE PLAINS. ISOLATED SNOW SHOWERS MAY SPREAD ACROSS NORTHERN EL PASO COUNTY IN THE LATE AFTN AS UPPER JET DYNAMICS MOVES IN ALOFT AND FRONT MOVES INTO THE AREA. THINK MAIN THREAT WILL BE IN THE EVENING...SO WILL MAINTAIN THE 10 POPS FOR NOW. -KT .LONG TERM... (TUESDAY NIGHT-MONDAY) TUESDAY NIGHT-WEDNESDAY NIGHT...MODERATE TO STRONG NORTHWEST FLOW CONTINUES ACROSS THE REGION AS ANOTHER EMBEDDED SHORT WAVE TRANSLATES ACROSS THE ROCKIES. MODEL SOUNDINGS AND CROSS SECTIONS CONTINUE TO INDICATE A FAIRLY SHALLOW LAYER OF MID LEVEL MOISTURE STREAMING ACROSS THE AREA THROUGH TUESDAY NIGHT DIFFER ON LOCATION OF BEST UVV WITH WITH PASSING JET CORE. AT ANY RATE...WITH CONTINUED GOOD OROGRAPHIC FLOW...BEST POPS TO REMAIN ACROSS THE EASTERN SAWATCH AND MOSQUITO RANGES EARLY TUESDAY EVENING WITH ANY SNOWFALL DIMINISHING OVERNIGHT TUESDAY. HAVE ALSO KEPT SLIGHT POPS ACROSS THE PIKES PEAK REGION AS WELL...WITH THE POTENTIAL FOR A QUICK SHOT A FEW SNOW SHOWERS TUESDAY EVENING. TEMPERATURES LOOK TO BE GENERALLY BELOW SEASONAL AVERAGES WEDNESDAY...ESPECIALLY ACROSS THE PLAINS WITH LOW LEVEL UPSLOPE FLOW. THURSDAY-FRIDAY...MODERATING WESTERLY FLOW PROGGED ACROSS THE REGION THROUGH THE END OF THE WORK WEEK AS JET STREAM LIFTS ACROSS THE NORTHERN TIER OF STATES. DRY WEATHER WITH TEMPS WARMING BACK TO ABOVE SEASONAL AVERAGES CAN BE EXPECTED. LEE TROUGHING ON THE PLAINS WILL ALSO LEAD TO BREEZY CONDITIONS AND THE POTENTIAL FOR CRITICAL FIRE WEATHER CONDITIONS. FRIDAY NIGHT-MONDAY...MODELS COMING INTO THE BETTER AGREEMENT WITH SNOWFALL BECOMING INCREASINGLY LIKELY LATE FRIDAY NIGHT AND SATURDAY ALONG AND WEST OF THE CONTDVD AS WEST TO SOUTHWEST FLOW INCREASES AHEAD OF AN EASTERN PACIFIC SYSTEM DIGGING ACROSS THE GREAT BASIN FRIDAY WHICH CONTINUES TO LIFT OUT ACROSS THE STATE ON SATURDAY. PASSING WAVE LOOKS TO BRING ANOTHER BOUT OF WINDY TO VERY WINDY CONDITIONS TO THE EASTERN MTS AND PLAINS FRIDAY NIGHT AND SATURDAY WITH A STRONG COLD FRONT BRINGING IN A MODIFIED ARCTIC AIRMASS TO THE AREA ON SUNDAY. AT THIS TIME...THE BULK OF THE COLDEST AIR LOOKS TO REMAIN WELL EAST ACROSS THE CENTRAL HIGH PLAINS...THOUGH WILL NEED TO CONTINUE TO MONITOR. -MW && .AVIATION... VFR CONDITIONS EXPECTED AT ALL 3 TAF SITES THROUGH TUESDAY. SOME GUSTY SOUTHWEST WINDS WILL CONTINUE AT THE TAF SITES UNTIL 01-02Z...WITH LIGHT DRAINAGE WINDS EXPECTED OVERNIGHT. ON TUESDAY...WEAK FRONT WILL DROP THROUGH THE PLAINS WITH WINDS AT KCOS STAYING OUT OF THE NW DURING THE MORNING. FOR KPUB...FRONT WILL LIKELY BACKDOOR IN WITH WINDS SWITCHING AROUND FROM THE EAST DURING THE LATE AFTERNOON. MAIN NORTHERLY SURGE WITH THE FRONT WILL DROP IN TOMORROW EVENING BRINGING A BRIEF PERIOD OF GUSTY NORTH WINDS OF 15 TO 25 KTS. MEANWHILE...WINDS AT KALS WILL REMAIN LIGHT OVERNIGHT BEFORE INCREASING FROM THE SOUTH AROUND 10 KTS TUES AFTN. -KT && .PUB WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING UNTIL 5 PM MST THIS AFTERNOON FOR COZ226>228. && $$ 31/23
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1030 AM MST MON NOV 14 2011 .UPDATE... MUCH DRIER AIR HAS MOVED INTO EL PASO COUNTY BEHIND YESTERDAY`S DEPARTING SYSTEM. DEW POINTS ARE CURRENTLY IN THE SINGLE DIGITS TO AROUND 10 DEGREES. RUC AND HRRR HAVE A BETTER HANDLE ON THE CURRENT CONDITIONS THAN NAM12. BREEZY WEST TO SOUTHWEST WINDS ARE EXPECTED TO KICK IN BY AFTERNOON...AND WITH HUMIDITIES NOW ANTICIPATED TO BE BELOW 15 PERCENT...THIS WILL RESULT IN CRITICAL CONDITIONS FOR FIRE WEATHER. THIS WILL BE LONGEST IN DURATION ACROSS EL PASO AND PUEBLO COUNTIES. HOWEVER...THERE IS THE POTENTIAL FOR THESE GUSTY WINDS AND LOW HUMIDITIES TO SPREAD ACROSS PORTIONS OF CROWLEY AND OTERO COUNTIES AS WELL. FOR NOW...THINK THE 3 HOUR DURATION OF CRITICAL CONDITIONS WILL NOT BE MET ACROSS CROWLEY AND OTERO...SO WILL LIMIT RED FLAG WARNING TO PUEBLO AND EL PASO COUNTIES FOR NOW AND CONTINUE TO MONITOR. && .AVIATION... VFR CONDITIONS EXPECTED AT TAF SITES TODAY. GUSTY WEST TO SOUTHWEST WINDS WILL INCREASE AT 15-25 KTS AT KCOS AND KPUB BETWEEN 19-20Z. PERIODIC MTN OBSCURATIONS WILL BE POSSIBLE ALONG THE CONTINENTAL DIVIDE TODAY WITH ISOLATED -SHSN. && .PREV DISCUSSION... /ISSUED 306 AM MST MON NOV 14 2011/ SHORT TERM... (TODAY AND TONIGHT) QUIET WX EXPECTED FOR TODAY AND TONIGHT. THE TROUGH THAT BROUGHT US STRONG WINDS OVR THE WEEKEND IS NOW MOVING INTO WRN KS. WILL SEE BREEZY CONDITIONS OVR THE MTNS AND PORTIONS OF THE PLAINS WIND DOWN THIS MORNING AS THIS SYSTEM MOVES EWD. TEMPS TODAY WILL BE A FEW DEG COOLER AS TEMPS ALOFT FALL A FEW DEGREES. WILL CONTINUE TO SEE A BIT OF MOISTURE STREAM OVR THE CONTDVD N OF KMYP...SO A FEW SHSN NOT OUT OF THE QUESTION FOR LAKE AND CHAFFEE COUNTIES...PARTICULARLY FOR THE HIGHER ELEVATIONS. BEST CHANCE FOR SN WILL BE EARLY MON MORNING. NOT EXPECTING ANY ACCUMS. IT WILL REMAIN DRY WITH A FAIR AMT OF SUN ELSEWHERE. 44 LONG TERM... (TUESDAY THROUGH SUNDAY) TWO WEATHER SYSTEMS WILL AFFECT PARTS OF THE REGION DURING THIS FCST PERIOD. THE FIRST WILL BE TUESDAY AND TUESDAY EVENING...AND THE 2ND WILL BE FRIDAY AFTERNOON AND NIGHT. BOTH OF THESE SYSTEMS WILL AFFECT MAINLY THE MTNS ALONG THE CONTDVD. TUESDAYS SYSTEM WILL BE A QUICK MOVING SHORT WAVE EMBEDDED IN THE STOUT NW FLOW THAT WILL BE OVER THE REGION DURING THIS TIME. THIS SYSTEM WILL BRING SOME LIGHT ACCUMULATING SNOWS TO THE C MTNS TUESDAY AND TUESDAY EVENING. IT MAY ALSO BRING SOME SHOWERS TO THE PIKES PEAK REGION TUESDAY EVENING. THE NEXT SYSTEM WILL BE A LARGE BROAD WAVE WHICH IS FCST TO TRANSLATE RATHER QUICKLY ACROSS THE W CONUS FRIDAY NIGHT AND SAT. THIS LARGE SCALE WAVE WILL MOVE ACROSS THE AREA AS AN OPEN WAVE AND EXPECT THE ONLY SENSIBLE WX (SNOW) WILL OCCUR ACROSS THE CONTDVD. SEVERAL INCHES OF SNOW WILL BE POSSIBLE. EXCEPT FOR TUESDAYS SYSTEM...THE PLAINS ARE EXPECTED TO REMAIN DRY DURING THIS PERIOD. TEMPERATURES DURING THIS PERIOD SHOULD BE SEASONABLE. GUSTY SOUTHWEST WINDS MAY OCCUR ON THE PLAINS IN ADVANCE OF THE LONG WAVE TROUGH ON SATURDAY. THE BEST CHANCE OF PRECIP FOR THE PLAINS CONTINUES TO BE BEYOND THIS FCST PERIOD...AND THIS CHANCE WILL OCCUR NEXT TUESDAY...22 NOV. /34 AVIATION... VFR CONDITIONS FOR THE TAF SITES NEXT 24 H. WINDS SHOULD RELAX THIS MORNING AND REMAIN GENERALLY LIGHT THROUGH TONIGHT. SOME PARTIAL MTN OBSCURATION POSSIBLE ALONG THE CONTDVD N OF KMYP IN PERSISTENT SCT SHSN. 44 && .PUB WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING UNTIL 5 PM MST THIS AFTERNOON FOR COZ226>228. && $$ 31/23
AREA FORECAST DISCUSSION
NWS ALBANY NY
113 PM EST MON NOV 14 2011 .SYNOPSIS... A COLD FRONT IS EXPECTED TO MOVE INTO THE EASTERN GREAT LAKES REGION THIS MORNING AND THROUGH OUR REGION BY TUESDAY MORNING. THE FRONTAL BOUNDARY WILL THEN STALL OVER THE MIDDLE ATLANTIC REGION AS A WAVE OF LOW PRESSURE MOVES NORTHEAST ALONG IT ON WEDNESDAY. THIS WILL RESULT IN THE POTENTIAL FOR UNSETTLED WEATHER FOR MUCH OF THE TIME THROUGH THE MID WEEK PERIOD. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 1PM EST...RAIN SHOWERS PASSING OVER THE CAPITAL REGION HAVE ALREADY COOLED TEMPS TO LOW 50S. ELSEWHERE...CLOUDS FINALLY STARTING TO SPREAD OVER THE REST OF THE CWA. PRECIP STILL CONFINED MOSTLY TO CENTER OF CWA. INCREASED POPS OVER THIS AREA AS PRECIP EXPECTED TO CONTINUE THERE. WINDS ALSO SLOW TO INCREASE WITH GUSTS ONLY CURRENTLY OCCURING AT GFL. HAVE ADJUSTED TEMPS AND WINDS TO ACCOUNT FOR CURRENT TRENDS. AS OF 1050 AM EST...CLOUDS HAVE INCREASED ACROSS MUCH OF THE REGION...WITH PATCHY LIGHT RAIN/SPRINKLES DEVELOPING ACROSS THE CAPITAL REGION...EXTENDING SOUTH AND WEST INTO THE SCHOHARIE VALLEY AND CATSKILLS. INCREASING MID LEVEL ISENTROPIC LIFT SHOULD SUPPORT A GENERAL EXPANSION OF LIGHT RAIN THIS AFTERNOON INTO THE CAPITAL REGION...AND EVENTUALLY AREAS N OF THE MOHAWK RIVER BY EARLY/MID AFTERNOON...WHICH IS SUPPORTED BY THE LATEST HRRR AND RUC13. THE LOW LEVELS REMAIN SOMEWHAT DRY...ESP IN THE VALLEYS...WHERE LATEST DEWPOINTS REMAINED IN THE MID TO UPPER 30S. SO...ONCE RAIN DEVELOPS...WET BULB COOLING SHOULD COMMENCE...LIMITING MUCH FURTHER RISE IN TEMPS. SO...HAVE TWEAKED MAX TEMPS DOWNWARD BY A COUPLE OF DEGREES...ALTHOUGH NORTHERN PORTIONS OF THE REGION MAY STILL EXPERIENCE A BIT MORE WARMING AS THE RAIN HOLDS OFF A BIT. PLACES SUCH AS BENNINGTON VT WILL LIKELY REACH THE MID 60S BEFORE COOLING DURING THE AFTERNOON HOURS. WE HAVE ALSO BOOSTED WINDS A BIT OVER THE NEXT 1-3 HOURS WITHIN THE IMMEDIATE HUDSON RIVER VALLEY...WHERE SOME GUSTS OF 25-30 MPH ARE POSSIBLE...ESP AS THE RAIN BEGINS...AND STRONG EVAPORATIONAL COOLING HELPS DRAG STRONGER WINDS FROM ALOFT DOWNWARD. OTHERWISE...JUST SOME MODIFICATIONS TO HOURLY TEMPS/DEWPOINTS BASED ON RECENT OBS. PREVIOUS DISCUSSION FOLLOWS... AS OF 630 AM...PARTLY TO MOSTLY CLOUDY SKIES AND VERY MILD TEMPS PREVAILED ACROSS THE FA WITH READINGS MAINLY IN THE 40S TO MID 50S. HAVE ADJUSTED SKY GRIDS TO REFLECT INCREASING CLOUDS THIS MORNING AND HAVE BACKED OFF TIMING OF ONSET OF SHOWERS BY SEVERAL HOURS AS MUCH OF LEADING EDGE OF PCPN ON MOSAIC RADAR LOOP CURRENTLY VIRGA WITH PCPN REACHING THE GROUND BACK ACROSS WESTERN PA. AS OF 4 AM...CLOUDY SKIES AND MILD TEMPS PREVAILED ACROSS THE FA WITH READINGS GENERALLY IN THE 40S AND 50S. MUCH OF THE FA WAS DRY EXCEPT FOR A FEW SPRINKLES ACROSS THE WESTERN ADIRONDACKS. THE MODEL GUIDANCE IS NOW IN BETTER AGREEMENT IN TERMS OF THE H5 TROF AXIS ACRS THE MIDDLE OF THE COUNTRY TODAY AND THE LOW PRESSURE CENTER AT THE SURFACE MOVING INTO THE EASTERN GREAT LAKES THIS EVENING. HOWEVER...SOME SIGNIFICANT DIFFERENCES EXIST IN THE QPF FIELDS ESPECIALLY CONCERNING THE AREA OF SHOWERS LIFTING EAST NORTHEAST FROM WESTERN PENNSYLVANIA EARLY THIS MORNING. THE GFS AND TO A LESSER DEGREE THE NAM HAVE QPF AMOUNTS OF A QUARTER TO A HALF INCH ACROSS SOUTHERN PORTIONS OF THE FA WITH THESE SHOWERS WHILE THE ECMWF AND THE GGEM HAVE THE SHOWERS WEAKENING AS THEY MOVE INTO THE FA WITH THE HIGHEST QPF AMOUNTS DURING THE AFTERNOON ACROSS NORTHERN AND WESTERN SECTIONS OF THE FA AHEAD OF THE LOW MOVING INTO THE EASTERN GREAT LAKES. HAVE GENERALLY GONE WITH A COMPROMISE SOLUTION ON QPF AND MAINLY CHANCE POPS AS MUCH OF THE SHOWER ACTIVITY SHOULD BE SCATTERED IN NATURE BY THE TIME IT REACHES FA STARTING LATER THIS MORNING. TEMPS ARE EXPECTED TO BE MILD TODAY WITH HIGHS GENERALLY IN THE MID 50S TO LOWER 60S AS H8 TEMPS GENERALLY IN THE +8 TO +9 C RANGE. IT WILL ALSO CONTINUE TO BE WINDY AS PRESSURE GRADIENT REMAINS FAIRLY STRONG AHEAD OF APPROACHING LOW. GENERALLY EXPECT SOUTHWEST WINDS 1O TO 20 MPH WITH GUSTS UP TO 30 MPH. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... TONIGHT...THE LOW PRESSURE SYSTEM MOVING INTO THE EASTERN GREAT LAKES WILL RESULT IN THE BULK OF THE PCPN FALLING ACROSS THE NORTHERN AND WESTERN PORTIONS OF THE FA THIS EVENING. THIS WILL BE FOLLOWED BY IMPROVING CONDITIONS LATE TONIGHT AS THE COLD FRONT WILL DROP SOUTH THROUGH THE FA IN THE WAKE OF THE LOW AND BE POSITIONED JUST SOUTH OF THE FA BY TUESDAY MORNING. FOR TONIGHT HAVE PLACED HIGHEST POPS NORTH AND WEST THIS EVENING AND LOWEST POPS SOUTH AND EAST. ALSO EXPECT THAT THERE MAY BE A RUMBLE OF THUNDER THIS EVENING AND HAVE PLACED ISOLATED THUNDERSTORMS IN THE GRIDS AS SHOWALTER INDICES FALL TO JUST BELOW ZERO ALONG WITH ML MUCAPES OF SEVERAL HUNDRED J/KG. EXPECT QPF AMOUNTS THROUGH TONIGHT TO GENERALLY BE BETWEEN A QUARTER AND A HALF INCH IN MOST PLACES WITH HIGHEST AMOUNTS NORTHWEST AND LOWEST AMOUNTS SOUTHEAST. LOWS OVERNIGHT ARE EXPECTED TO BE IN THE MID 40S TO LOWER 50S. TUESDAY LOOKS TO BE DRY AT THIS POINT AS A WEAK RIDGE OF HIGH PRESSURE WILL SETTLE ACROSS THE FA IN THE WAKE OF THE COLD FRONT WHICH IS EXPECTED TO SETTLE ACROSS THE MIDDLE ATLANTIC REGION. EXPECT THAT THERE WILL BE MORE SUN NORTH AND LESS SUN SOUTH WITH HIGHS STILL RELATIVELY MILD IN THE MID 50S TO MID 60S. FOR THE PERIOD FROM TUESDAY NIGHT THROUGH WEDNESDAY NIGHT THE MODELS DIVERGE AGAIN IN SOLUTIONS REGARDING A WAVE OR WAVES OF LOW PRESSURE TRACKING NORTHEAST ALONG THE FRONTAL BOUNDARY STALLED TO OUR SOUTH. THE NAM IS MUCH QUICKER AND HAS MUCH LESS OF AN IMPACT ON THE FA THAN THE OTHER MODELS REGARDING THIS FEATURE...WHILE THE GGEM AND GFS ARE SIMILAR WITH A MAINLY WED EVENT AND THE ECMWF IS CONSIDERABLY SLOWER WITH A FARTHER NORTH AND WEST EXTENT OF THE PCPN SHIELD AND A LATER ARRIVAL AND DEPARTURE TIME OF THE PCPN MAINLY LATE WEDNESDAY MORNING THROUGH WEDNESDAY EVENING. WILL COMPROMISE ON THESE LATER TWO SOLUTIONS AND HAVE HIGHEST POPS SOUTHEAST AND LOWEST POPS NORTHWEST FROM LATE TUESDAY NIGHT INTO WEDNESDAY EVENING. IT IS ALSO POSSIBLE THAT ANY LINGERING PCPN ACROSS SRN VT AND THE NRN BERKS WED EVENING MAY END AS A LITTLE BIT OF SNOW WITH H8 TEMPS DROPPING TO -2 TO -4 C BY 06Z THU. THE SECOND HALF OF WED NIGHT LOOKS DRY IN THE WAKE OF DEPARTING LOW. EXPECT LOWS TUESDAY NIGHT TO BE IN THE UPPER 30S TO MID 40S...HIGHS ON WEDNESDAY IN THE UPPER 40S TO MID 50S AND LOWS WEDNESDAY NIGHT IN THE MID 20S TO MID 30S. TOTAL QPF AMOUNTS FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY EVENING ARE EXPECTED TO RANGE FROM AROUND A TENTH OF AN INCH NORTHWEST TO AROUND HALF AN INCH SOUTHEAST. && .LONG TERM /THURSDAY THROUGH SUNDAY/... AT THE START OF THIS PERIOD...AN UPPER TROF WILL APPROACH THE REGION AND PASS THROUGH FAIRLY QUICKLY. BROAD RIDGING WILL BEGIN TO SET IN ON FRIDAY. BRISK WEST NORTHWEST WINDS WILL USHER IN COOLER AIR FOR THE START...ALONG WITH SOME DIURNALLY DRIVEN INSTABILITY SHOWERS...ESPECIALLY NORTH AND WEST OF THE ALBANY AREA WHERE SOME LAKE ENHANCEMENT MAY ALLOW FOR SOME RAIN AND SNOW SHOWER ACTIVITY. HIGHS WILL RANGE FROM THE UPPER 30S ACROSS THE HIGHER TERRAIN TO AROUND 50 IN THE HUDSON VALLEY SOUTH OF ALBANY...COOLER THAN RECENT DAYS WITH THE UPPER TROUGH OVERHEAD...WITH LOTS OF CLOUDS AND CHANCE POPS NORTH AND WEST DIMINISHING TO NO POPS OVER MUCH OF THE HUDSON VALLEY...OR LOWER ELEVATIONS OF WESTERN NEW ENGLAND. SOME LAKE EFFECT SNOW SHOWERS MAY LINGER ACROSS THE WESTERN ADIRONDACKS AND UPPER MOHAWK VALLEY...BUT THE REST OF THE REGION SHOULD BE DRY AND CHILLY THURSDAY NIGHT...WITH LOWS RANGING FROM THE LOWER 20S ACROSS THE HIGHER ELEVATIONS OF THE ADIRONDACKS... CATSKILLS...SOUTHERN VERMONT...AND THE BERKSHIRES TO THE MID AND UPPER 20S IN THE MOHAWK...HUDSON...AND HOUSATONIC VALLEYS...WITH CONSIDERABLE CLOUDINESS NORTH AND WEST AND MOSTLY CLEAR SKIES OVER THE HUDSON VALLEY AND FARTHER EAST. THE TROUGH EXITS OUT THE REGION AS BROAD SOUTHWEST FLOW AT 500 HPA TAKES OVER FOR FRIDAY INTO THE WEEKEND ACROSS THE REGION...WHICH WILL ALLOW FOR WARMING STARTING ON FRIDAY. WITH PARTLY TO MOSTLY SUNNY SKIES HIGHS FRIDAY WILL RANGE FROM THE UPPER 30S TO THE UPPER 40S. IT WILL NOT BE AS COLD FRIDAY NIGHT...WITH LOWS FROM THE MID 20S TO THE LOWER 30S. ON SATURDAY...ANOTHER SYSTEM MOVING OUT OF THE PLAINS INTO THE GREAT LAKES WILL BEGIN TO SPREAD SOME CLOUDINESS INTO THE REGION WITH AN APPROACHING WARM FRONT. IN SPITE OF INCREASED CLOUDINESS SATURDAY WILL BE WARMER WITH HIGHS FROM THE MID 40S TO THE LOW 50S. AS THE WARM FRONT GETS CLOSER SATURDAY NIGHT IT WILL BRING ABOUT AN INCREASING CHANCE OF SHOWERS NORTH AND WEST. IT WILL BE MILDER ON SATURDAY NIGHT WITH LOWS MOSTLY IN THE 30S. SUNDAY WILL BE MOSTLY CLOUDY WITH A POSSIBILITY OF SHOWERS...ESPECIALLY NORTH AND WEST OF THE HUDSON VALLEY. HIGHS WILL BE FROM THE MID 40S TO THE LOWER 50S...ABOUT 5 DEGREES ABOVE NORMAL. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... AS OF 1245 PM EST...LIGHT RAIN HAS DEVELOPED AT KALB...WHILE REMAINING GENERALLY NORTH OF KPOU...AND THUS FAR...SOUTH OF KGFL. HOWEVER...THE RAIN SHOULD EXPAND NORTH AND EAST DURING THE EARLY AFTERNOON HOURS...WITH OCCASIONAL LIGHT RAIN AFFECTING KALB AND KGFL THROUGH SUNSET. DESPITE THIS LIGHT RAIN...EXPECT MAINLY VFR CONDITIONS...POSSIBLY BECOMING MVFR FOR CIGS TOWARD SUNSET. AT KPOU...OTHER THAN PERHAPS A FEW SPRINKLES...EXPECT MAINLY DRY CONDITIONS THROUGH SUNSET. FOR TONIGHT...THE RAIN SHOULD BECOME MORE SHOWERY AT KALB AND KGFL...AS A WEAK WARM FRONT LIFTS NORTH. THEN...AS A COLD FRONT APPROACHES FROM THE NW...EXPECT A BAND OF SHOWERS TO GRADUALLY SETTLE SOUTHEAST ACROSS KGFL AND KALB ONCE AGAIN LATER THIS EVENING THROUGH THE OVERNIGHT HOURS. A RUMBLE OF THUNDER COULD BE EMBEDDED WITHIN THESE SHOWERS...BUT DUE TO OVERALL LOW PROBABILITY...HAVE KEPT OUT ANY MENTION AT THIS TIME. EXPECT MVFR TO ISOLATED IFR CONDITIONS OVERNIGHT. THE SHOWERS SHOULD THEN SETTLE SOUTHWARD AFTER MIDNIGHT...TAPERING OFF AT KGFL AND KALB BEFORE SUNRISE. AT KPOU...LITTLE IF ANY RAIN IS EXPECTED UNTIL TUESDAY MORNING...WITH MVFR CIGS POSSIBLE AS THE COLD FRONT MOVES THROUGH. ALL AREAS SHOULD THEN TREND INTO VFR BY MID TO LATE MORNING TUE IN THE WAKE OF THE FRONT. OUTLOOK... TUE...IFR/MVFR IMPROVING TO VFR BY AFTERNOON. TUE NGT...SUB-VFR CIG...LIKELY -SHRA. WED-WED NGT...VFR/MVFR...CHC -SHRA. THU...VFR...BREEZY. FRI-SAT...VFR...NO SIG WX. && .HYDROLOGY... NO HYDRO PROBLEMS ARE ANTICIPATED THROUGH LATE IN THE WEEK. UP TO A HALF INCH OF RAIN IS POSSIBLE THIS EVENING AND TONIGHT. THIS RAIN MIGHT CAUSE SOME MINOR INCREASES IN STREAMFLOWS...BUT MOST OF IT WILL JUST SOAK INTO THE GROUND. MORE RAINFALL MAY OCCUR ON WEDNESDAY...BUT AGAIN IT LOOKS LIKE AMOUNTS SHOULD NOT BE MUCH MORE THAN A HALF INCH...IF THAT MUCH. AGAIN THIS RAIN WILL MOSTLY JUST SOAK INTO THE GROUND...AND NOT HAVE MUCH EFFECT ON THE RIVERS AND STREAMS. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...11 NEAR TERM...KL/KGM/11 SHORT TERM...11 LONG TERM...RCK AVIATION...RCK/KL HYDROLOGY...RCK/11
AREA FORECAST DISCUSSION
NWS ALBANY NY
1246 PM EST MON NOV 14 2011 .SYNOPSIS... A COLD FRONT IS EXPECTED TO MOVE INTO THE EASTERN GREAT LAKES REGION THIS MORNING AND THROUGH OUR REGION BY TUESDAY MORNING. THE FRONTAL BOUNDARY WILL THEN STALL OVER THE MIDDLE ATLANTIC REGION AS A WAVE OF LOW PRESSURE MOVES NORTHEAST ALONG IT ON WEDNESDAY. THIS WILL RESULT IN THE POTENTIAL FOR UNSETTLED WEATHER FOR MUCH OF THE TIME THROUGH THE MID WEEK PERIOD. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 1050 AM EST...CLOUDS HAVE INCREASED ACROSS MUCH OF THE REGION...WITH PATCHY LIGHT RAIN/SPRINKLES DEVELOPING ACROSS THE CAPITAL REGION...EXTENDING SOUTH AND WEST INTO THE SCHOHARIE VALLEY AND CATSKILLS. INCREASING MID LEVEL ISENTROPIC LIFT SHOULD SUPPORT A GENERAL EXPANSION OF LIGHT RAIN THIS AFTERNOON INTO THE CAPITAL REGION...AND EVENTUALLY AREAS N OF THE MOHAWK RIVER BY EARLY/MID AFTERNOON...WHICH IS SUPPORTED BY THE LATEST HRRR AND RUC13. THE LOW LEVELS REMAIN SOMEWHAT DRY...ESP IN THE VALLEYS...WHERE LATEST DEWPOINTS REMAINED IN THE MID TO UPPER 30S. SO...ONCE RAIN DEVELOPS...WET BULB COOLING SHOULD COMMENCE...LIMITING MUCH FURTHER RISE IN TEMPS. SO...HAVE TWEAKED MAX TEMPS DOWNWARD BY A COUPLE OF DEGREES...ALTHOUGH NORTHERN PORTIONS OF THE REGION MAY STILL EXPERIENCE A BIT MORE WARMING AS THE RAIN HOLDS OFF A BIT. PLACES SUCH AS BENNINGTON VT WILL LIKELY REACH THE MID 60S BEFORE COOLING DURING THE AFTERNOON HOURS. WE HAVE ALSO BOOSTED WINDS A BIT OVER THE NEXT 1-3 HOURS WITHIN THE IMMEDIATE HUDSON RIVER VALLEY...WHERE SOME GUSTS OF 25-30 MPH ARE POSSIBLE...ESP AS THE RAIN BEGINS...AND STRONG EVAPORATIONAL COOLING HELPS DRAG STRONGER WINDS FROM ALOFT DOWNWARD. OTHERWISE...JUST SOME MODIFICATIONS TO HOURLY TEMPS/DEWPOINTS BASED ON RECENT OBS. PREVIOUS DISCUSSION FOLLOWS... AS OF 630 AM...PARTLY TO MOSTLY CLOUDY SKIES AND VERY MILD TEMPS PREVAILED ACROSS THE FA WITH READINGS MAINLY IN THE 40S TO MID 50S. HAVE ADJUSTED SKY GRIDS TO REFLECT INCREASING CLOUDS THIS MORNING AND HAVE BACKED OFF TIMING OF ONSET OF SHOWERS BY SEVERAL HOURS AS MUCH OF LEADING EDGE OF PCPN ON MOSAIC RADAR LOOP CURRENTLY VIRGA WITH PCPN REACHING THE GROUND BACK ACROSS WESTERN PA. AS OF 4 AM...CLOUDY SKIES AND MILD TEMPS PREVAILED ACROSS THE FA WITH READINGS GENERALLY IN THE 40S AND 50S. MUCH OF THE FA WAS DRY EXCEPT FOR A FEW SPRINKLES ACROSS THE WESTERN ADIRONDACKS. THE MODEL GUIDANCE IS NOW IN BETTER AGREEMENT IN TERMS OF THE H5 TROF AXIS ACRS THE MIDDLE OF THE COUNTRY TODAY AND THE LOW PRESSURE CENTER AT THE SURFACE MOVING INTO THE EASTERN GREAT LAKES THIS EVENING. HOWEVER...SOME SIGNIFICANT DIFFERENCES EXIST IN THE QPF FIELDS ESPECIALLY CONCERNING THE AREA OF SHOWERS LIFTING EAST NORTHEAST FROM WESTERN PENNSYLVANIA EARLY THIS MORNING. THE GFS AND TO A LESSER DEGREE THE NAM HAVE QPF AMOUNTS OF A QUARTER TO A HALF INCH ACROSS SOUTHERN PORTIONS OF THE FA WITH THESE SHOWERS WHILE THE ECMWF AND THE GGEM HAVE THE SHOWERS WEAKENING AS THEY MOVE INTO THE FA WITH THE HIGHEST QPF AMOUNTS DURING THE AFTERNOON ACROSS NORTHERN AND WESTERN SECTIONS OF THE FA AHEAD OF THE LOW MOVING INTO THE EASTERN GREAT LAKES. HAVE GENERALLY GONE WITH A COMPROMISE SOLUTION ON QPF AND MAINLY CHANCE POPS AS MUCH OF THE SHOWER ACTIVITY SHOULD BE SCATTERED IN NATURE BY THE TIME IT REACHES FA STARTING LATER THIS MORNING. TEMPS ARE EXPECTED TO BE MILD TODAY WITH HIGHS GENERALLY IN THE MID 50S TO LOWER 60S AS H8 TEMPS GENERALLY IN THE +8 TO +9 C RANGE. IT WILL ALSO CONTINUE TO BE WINDY AS PRESSURE GRADIENT REMAINS FAIRLY STRONG AHEAD OF APPROACHING LOW. GENERALLY EXPECT SOUTHWEST WINDS 1O TO 20 MPH WITH GUSTS UP TO 30 MPH. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... TONIGHT...THE LOW PRESSURE SYSTEM MOVING INTO THE EASTERN GREAT LAKES WILL RESULT IN THE BULK OF THE PCPN FALLING ACROSS THE NORTHERN AND WESTERN PORTIONS OF THE FA THIS EVENING. THIS WILL BE FOLLOWED BY IMPROVING CONDITIONS LATE TONIGHT AS THE COLD FRONT WILL DROP SOUTH THROUGH THE FA IN THE WAKE OF THE LOW AND BE POSITIONED JUST SOUTH OF THE FA BY TUESDAY MORNING. FOR TONIGHT HAVE PLACED HIGHEST POPS NORTH AND WEST THIS EVENING AND LOWEST POPS SOUTH AND EAST. ALSO EXPECT THAT THERE MAY BE A RUMBLE OF THUNDER THIS EVENING AND HAVE PLACED ISOLATED THUNDERSTORMS IN THE GRIDS AS SHOWALTER INDICES FALL TO JUST BELOW ZERO ALONG WITH ML MUCAPES OF SEVERAL HUNDRED J/KG. EXPECT QPF AMOUNTS THROUGH TONIGHT TO GENERALLY BE BETWEEN A QUARTER AND A HALF INCH IN MOST PLACES WITH HIGHEST AMOUNTS NORTHWEST AND LOWEST AMOUNTS SOUTHEAST. LOWS OVERNIGHT ARE EXPECTED TO BE IN THE MID 40S TO LOWER 50S. TUESDAY LOOKS TO BE DRY AT THIS POINT AS A WEAK RIDGE OF HIGH PRESSURE WILL SETTLE ACROSS THE FA IN THE WAKE OF THE COLD FRONT WHICH IS EXPECTED TO SETTLE ACROSS THE MIDDLE ATLANTIC REGION. EXPECT THAT THERE WILL BE MORE SUN NORTH AND LESS SUN SOUTH WITH HIGHS STILL RELATIVELY MILD IN THE MID 50S TO MID 60S. FOR THE PERIOD FROM TUESDAY NIGHT THROUGH WEDNESDAY NIGHT THE MODELS DIVERGE AGAIN IN SOLUTIONS REGARDING A WAVE OR WAVES OF LOW PRESSURE TRACKING NORTHEAST ALONG THE FRONTAL BOUNDARY STALLED TO OUR SOUTH. THE NAM IS MUCH QUICKER AND HAS MUCH LESS OF AN IMPACT ON THE FA THAN THE OTHER MODELS REGARDING THIS FEATURE...WHILE THE GGEM AND GFS ARE SIMILAR WITH A MAINLY WED EVENT AND THE ECMWF IS CONSIDERABLY SLOWER WITH A FARTHER NORTH AND WEST EXTENT OF THE PCPN SHIELD AND A LATER ARRIVAL AND DEPARTURE TIME OF THE PCPN MAINLY LATE WEDNESDAY MORNING THROUGH WEDNESDAY EVENING. WILL COMPROMISE ON THESE LATER TWO SOLUTIONS AND HAVE HIGHEST POPS SOUTHEAST AND LOWEST POPS NORTHWEST FROM LATE TUESDAY NIGHT INTO WEDNESDAY EVENING. IT IS ALSO POSSIBLE THAT ANY LINGERING PCPN ACROSS SRN VT AND THE NRN BERKS WED EVENING MAY END AS A LITTLE BIT OF SNOW WITH H8 TEMPS DROPPING TO -2 TO -4 C BY 06Z THU. THE SECOND HALF OF WED NIGHT LOOKS DRY IN THE WAKE OF DEPARTING LOW. EXPECT LOWS TUESDAY NIGHT TO BE IN THE UPPER 30S TO MID 40S...HIGHS ON WEDNESDAY IN THE UPPER 40S TO MID 50S AND LOWS WEDNESDAY NIGHT IN THE MID 20S TO MID 30S. TOTAL QPF AMOUNTS FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY EVENING ARE EXPECTED TO RANGE FROM AROUND A TENTH OF AN INCH NORTHWEST TO AROUND HALF AN INCH SOUTHEAST. && .LONG TERM /THURSDAY THROUGH SUNDAY/... AT THE START OF THIS PERIOD...AN UPPER TROF WILL APPROACH THE REGION AND PASS THROUGH FAIRLY QUICKLY. BROAD RIDGING WILL BEGIN TO SET IN ON FRIDAY. BRISK WEST NORTHWEST WINDS WILL USHER IN COOLER AIR FOR THE START...ALONG WITH SOME DIURNALLY DRIVEN INSTABILITY SHOWERS...ESPECIALLY NORTH AND WEST OF THE ALBANY AREA WHERE SOME LAKE ENHANCEMENT MAY ALLOW FOR SOME RAIN AND SNOW SHOWER ACTIVITY. HIGHS WILL RANGE FROM THE UPPER 30S ACROSS THE HIGHER TERRAIN TO AROUND 50 IN THE HUDSON VALLEY SOUTH OF ALBANY...COOLER THAN RECENT DAYS WITH THE UPPER TROUGH OVERHEAD...WITH LOTS OF CLOUDS AND CHANCE POPS NORTH AND WEST DIMINISHING TO NO POPS OVER MUCH OF THE HUDSON VALLEY...OR LOWER ELEVATIONS OF WESTERN NEW ENGLAND. SOME LAKE EFFECT SNOW SHOWERS MAY LINGER ACROSS THE WESTERN ADIRONDACKS AND UPPER MOHAWK VALLEY...BUT THE REST OF THE REGION SHOULD BE DRY AND CHILLY THURSDAY NIGHT...WITH LOWS RANGING FROM THE LOWER 20S ACROSS THE HIGHER ELEVATIONS OF THE ADIRONDACKS... CATSKILLS...SOUTHERN VERMONT...AND THE BERKSHIRES TO THE MID AND UPPER 20S IN THE MOHAWK...HUDSON...AND HOUSATONIC VALLEYS...WITH CONSIDERABLE CLOUDINESS NORTH AND WEST AND MOSTLY CLEAR SKIES OVER THE HUDSON VALLEY AND FARTHER EAST. THE TROUGH EXITS OUT THE REGION AS BROAD SOUTHWEST FLOW AT 500 HPA TAKES OVER FOR FRIDAY INTO THE WEEKEND ACROSS THE REGION...WHICH WILL ALLOW FOR WARMING STARTING ON FRIDAY. WITH PARTLY TO MOSTLY SUNNY SKIES HIGHS FRIDAY WILL RANGE FROM THE UPPER 30S TO THE UPPER 40S. IT WILL NOT BE AS COLD FRIDAY NIGHT...WITH LOWS FROM THE MID 20S TO THE LOWER 30S. ON SATURDAY...ANOTHER SYSTEM MOVING OUT OF THE PLAINS INTO THE GREAT LAKES WILL BEGIN TO SPREAD SOME CLOUDINESS INTO THE REGION WITH AN APPROACHING WARM FRONT. IN SPITE OF INCREASED CLOUDINESS SATURDAY WILL BE WARMER WITH HIGHS FROM THE MID 40S TO THE LOW 50S. AS THE WARM FRONT GETS CLOSER SATURDAY NIGHT IT WILL BRING ABOUT AN INCREASING CHANCE OF SHOWERS NORTH AND WEST. IT WILL BE MILDER ON SATURDAY NIGHT WITH LOWS MOSTLY IN THE 30S. SUNDAY WILL BE MOSTLY CLOUDY WITH A POSSIBILITY OF SHOWERS...ESPECIALLY NORTH AND WEST OF THE HUDSON VALLEY. HIGHS WILL BE FROM THE MID 40S TO THE LOWER 50S...ABOUT 5 DEGREES ABOVE NORMAL. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... AS OF 1245 PM EST...LIGHT RAIN HAS DEVELOPED AT KALB...WHILE REMAINING GENERALLY NORTH OF KPOU...AND THUS FAR...SOUTH OF KGFL. HOWEVER...THE RAIN SHOULD EXPAND NORTH AND EAST DURING THE EARLY AFTERNOON HOURS...WITH OCCASIONAL LIGHT RAIN AFFECTING KALB AND KGFL THROUGH SUNSET. DESPITE THIS LIGHT RAIN...EXPECT MAINLY VFR CONDITIONS...POSSIBLY BECOMING MVFR FOR CIGS TOWARD SUNSET. AT KPOU...OTHER THAN PERHAPS A FEW SPRINKLES...EXPECT MAINLY DRY CONDITIONS THROUGH SUNSET. FOR TONIGHT...THE RAIN SHOULD BECOME MORE SHOWERY AT KALB AND KGFL...AS A WEAK WARM FRONT LIFTS NORTH. THEN...AS A COLD FRONT APPROACHES FROM THE NW...EXPECT A BAND OF SHOWERS TO GRADUALLY SETTLE SOUTHEAST ACROSS KGFL AND KALB ONCE AGAIN LATER THIS EVENING THROUGH THE OVERNIGHT HOURS. A RUMBLE OF THUNDER COULD BE EMBEDDED WITHIN THESE SHOWERS...BUT DUE TO OVERALL LOW PROBABILITY...HAVE KEPT OUT ANY MENTION AT THIS TIME. EXPECT MVFR TO ISOLATED IFR CONDITIONS OVERNIGHT. THE SHOWERS SHOULD THEN SETTLE SOUTHWARD AFTER MIDNIGHT...TAPERING OFF AT KGFL AND KALB BEFORE SUNRISE. AT KPOU...LITTLE IF ANY RAIN IS EXPECTED UNTIL TUESDAY MORNING...WITH MVFR CIGS POSSIBLE AS THE COLD FRONT MOVES THROUGH. ALL AREAS SHOULD THEN TREND INTO VFR BY MID TO LATE MORNING TUE IN THE WAKE OF THE FRONT. OUTLOOK... TUE...IFR/MVFR IMPROVING TO VFR BY AFTERNOON. TUE NGT...SUB-VFR CIG...LIKELY -SHRA. WED-WED NGT...VFR/MVFR...CHC -SHRA. THU...VFR...BREEZY. FRI-SAT...VFR...NO SIG WX. && .HYDROLOGY... NO HYDRO PROBLEMS ARE ANTICIPATED THROUGH LATE IN THE WEEK. UP TO A HALF INCH OF RAIN IS POSSIBLE THIS EVENING AND TONIGHT. THIS RAIN MIGHT CAUSE SOME MINOR INCREASES IN STREAMFLOWS...BUT MOST OF IT WILL JUST SOAK INTO THE GROUND. MORE RAINFALL MAY OCCUR ON WEDNESDAY...BUT AGAIN IT LOOKS LIKE AMOUNTS SHOULD NOT BE MUCH MORE THAN A HALF INCH...IF THAT MUCH. AGAIN THIS RAIN WILL MOSTLY JUST SOAK INTO THE GROUND...AND NOT HAVE MUCH EFFECT ON THE RIVERS AND STREAMS. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...11 NEAR TERM...KL/11 SHORT TERM...11 LONG TERM...RCK AVIATION...KL/RCK HYDROLOGY...RCK/11
AREA FORECAST DISCUSSION
NWS ALBANY NY
1053 AM EST MON NOV 14 2011 .SYNOPSIS... A COLD FRONT IS EXPECTED TO MOVE INTO THE EASTERN GREAT LAKES REGION THIS MORNING AND THROUGH OUR REGION BY TUESDAY MORNING. THE FRONTAL BOUNDARY WILL THEN STALL OVER THE MIDDLE ATLANTIC REGION AS A WAVE OF LOW PRESSURE MOVES NORTHEAST ALONG IT ON WEDNESDAY. THIS WILL RESULT IN THE POTENTIAL FOR UNSETTLED WEATHER FOR MUCH OF THE TIME THROUGH THE MID WEEK PERIOD. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 1050 AM EST...CLOUDS HAVE INCREASED ACROSS MUCH OF THE REGION...WITH PATCHY LIGHT RAIN/SPRINKLES DEVELOPING ACROSS THE CAPITAL REGION...EXTENDING SOUTH AND WEST INTO THE SCHOHARIE VALLEY AND CATSKILLS. INCREASING MID LEVEL ISENTROPIC LIFT SHOULD SUPPORT A GENERAL EXPANSION OF LIGHT RAIN THIS AFTERNOON INTO THE CAPITAL REGION...AND EVENTUALLY AREAS N OF THE MOHAWK RIVER BY EARLY/MID AFTERNOON...WHICH IS SUPPORTED BY THE LATEST HRRR AND RUC13. THE LOW LEVELS REMAIN SOMEWHAT DRY...ESP IN THE VALLEYS...WHERE LATEST DEWPOINTS REMAINED IN THE MID TO UPPER 30S. SO...ONCE RAIN DEVELOPS...WET BULB COOLING SHOULD COMMENCE...LIMITING MUCH FURTHER RISE IN TEMPS. SO...HAVE TWEAKED MAX TEMPS DOWNWARD BY A COUPLE OF DEGREES...ALTHOUGH NORTHERN PORTIONS OF THE REGION MAY STILL EXPERIENCE A BIT MORE WARMING AS THE RAIN HOLDS OFF A BIT. PLACES SUCH AS BENNINGTON VT WILL LIKELY REACH THE MID 60S BEFORE COOLING DURING THE AFTERNOON HOURS. WE HAVE ALSO BOOSTED WINDS A BIT OVER THE NEXT 1-3 HOURS WITHIN THE IMMEDIATE HUDSON RIVER VALLEY...WHERE SOME GUSTS OF 25-30 MPH ARE POSSIBLE...ESP AS THE RAIN BEGINS...AND STRONG EVAPORATIONAL COOLING HELPS DRAG STRONGER WINDS FROM ALOFT DOWNWARD. OTHERWISE...JUST SOME MODIFICATIONS TO HOURLY TEMPS/DEWPOINTS BASED ON RECENT OBS. PREVIOUS DISCUSSION FOLLOWS... AS OF 630 AM...PARTLY TO MOSTLY CLOUDY SKIES AND VERY MILD TEMPS PREVAILED ACROSS THE FA WITH READINGS MAINLY IN THE 40S TO MID 50S. HAVE ADJUSTED SKY GRIDS TO REFLECT INCREASING CLOUDS THIS MORNING AND HAVE BACKED OFF TIMING OF ONSET OF SHOWERS BY SEVERAL HOURS AS MUCH OF LEADING EDGE OF PCPN ON MOSAIC RADAR LOOP CURRENTLY VIRGA WITH PCPN REACHING THE GROUND BACK ACROSS WESTERN PA. AS OF 4 AM...CLOUDY SKIES AND MILD TEMPS PREVAILED ACROSS THE FA WITH READINGS GENERALLY IN THE 40S AND 50S. MUCH OF THE FA WAS DRY EXCEPT FOR A FEW SPRINKLES ACROSS THE WESTERN ADIRONDACKS. THE MODEL GUIDANCE IS NOW IN BETTER AGREEMENT IN TERMS OF THE H5 TROF AXIS ACRS THE MIDDLE OF THE COUNTRY TODAY AND THE LOW PRESSURE CENTER AT THE SURFACE MOVING INTO THE EASTERN GREAT LAKES THIS EVENING. HOWEVER...SOME SIGNIFICANT DIFFERENCES EXIST IN THE QPF FIELDS ESPECIALLY CONCERNING THE AREA OF SHOWERS LIFTING EAST NORTHEAST FROM WESTERN PENNSYLVANIA EARLY THIS MORNING. THE GFS AND TO A LESSER DEGREE THE NAM HAVE QPF AMOUNTS OF A QUARTER TO A HALF INCH ACROSS SOUTHERN PORTIONS OF THE FA WITH THESE SHOWERS WHILE THE ECMWF AND THE GGEM HAVE THE SHOWERS WEAKENING AS THEY MOVE INTO THE FA WITH THE HIGHEST QPF AMOUNTS DURING THE AFTERNOON ACROSS NORTHERN AND WESTERN SECTIONS OF THE FA AHEAD OF THE LOW MOVING INTO THE EASTERN GREAT LAKES. HAVE GENERALLY GONE WITH A COMPROMISE SOLUTION ON QPF AND MAINLY CHANCE POPS AS MUCH OF THE SHOWER ACTIVITY SHOULD BE SCATTERED IN NATURE BY THE TIME IT REACHES FA STARTING LATER THIS MORNING. TEMPS ARE EXPECTED TO BE MILD TODAY WITH HIGHS GENERALLY IN THE MID 50S TO LOWER 60S AS H8 TEMPS GENERALLY IN THE +8 TO +9 C RANGE. IT WILL ALSO CONTINUE TO BE WINDY AS PRESSURE GRADIENT REMAINS FAIRLY STRONG AHEAD OF APPROACHING LOW. GENERALLY EXPECT SOUTHWEST WINDS 1O TO 20 MPH WITH GUSTS UP TO 30 MPH. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... TONIGHT...THE LOW PRESSURE SYSTEM MOVING INTO THE EASTERN GREAT LAKES WILL RESULT IN THE BULK OF THE PCPN FALLING ACROSS THE NORTHERN AND WESTERN PORTIONS OF THE FA THIS EVENING. THIS WILL BE FOLLOWED BY IMPROVING CONDITIONS LATE TONIGHT AS THE COLD FRONT WILL DROP SOUTH THROUGH THE FA IN THE WAKE OF THE LOW AND BE POSITIONED JUST SOUTH OF THE FA BY TUESDAY MORNING. FOR TONIGHT HAVE PLACED HIGHEST POPS NORTH AND WEST THIS EVENING AND LOWEST POPS SOUTH AND EAST. ALSO EXPECT THAT THERE MAY BE A RUMBLE OF THUNDER THIS EVENING AND HAVE PLACED ISOLATED THUNDERSTORMS IN THE GRIDS AS SHOWALTER INDICES FALL TO JUST BELOW ZERO ALONG WITH ML MUCAPES OF SEVERAL HUNDRED J/KG. EXPECT QPF AMOUNTS THROUGH TONIGHT TO GENERALLY BE BETWEEN A QUARTER AND A HALF INCH IN MOST PLACES WITH HIGHEST AMOUNTS NORTHWEST AND LOWEST AMOUNTS SOUTHEAST. LOWS OVERNIGHT ARE EXPECTED TO BE IN THE MID 40S TO LOWER 50S. TUESDAY LOOKS TO BE DRY AT THIS POINT AS A WEAK RIDGE OF HIGH PRESSURE WILL SETTLE ACROSS THE FA IN THE WAKE OF THE COLD FRONT WHICH IS EXPECTED TO SETTLE ACROSS THE MIDDLE ATLANTIC REGION. EXPECT THAT THERE WILL BE MORE SUN NORTH AND LESS SUN SOUTH WITH HIGHS STILL RELATIVELY MILD IN THE MID 50S TO MID 60S. FOR THE PERIOD FROM TUESDAY NIGHT THROUGH WEDNESDAY NIGHT THE MODELS DIVERGE AGAIN IN SOLUTIONS REGARDING A WAVE OR WAVES OF LOW PRESSURE TRACKING NORTHEAST ALONG THE FRONTAL BOUNDARY STALLED TO OUR SOUTH. THE NAM IS MUCH QUICKER AND HAS MUCH LESS OF AN IMPACT ON THE FA THAN THE OTHER MODELS REGARDING THIS FEATURE...WHILE THE GGEM AND GFS ARE SIMILAR WITH A MAINLY WED EVENT AND THE ECMWF IS CONSIDERABLY SLOWER WITH A FARTHER NORTH AND WEST EXTENT OF THE PCPN SHIELD AND A LATER ARRIVAL AND DEPARTURE TIME OF THE PCPN MAINLY LATE WEDNESDAY MORNING THROUGH WEDNESDAY EVENING. WILL COMPROMISE ON THESE LATER TWO SOLUTIONS AND HAVE HIGHEST POPS SOUTHEAST AND LOWEST POPS NORTHWEST FROM LATE TUESDAY NIGHT INTO WEDNESDAY EVENING. IT IS ALSO POSSIBLE THAT ANY LINGERING PCPN ACROSS SRN VT AND THE NRN BERKS WED EVENING MAY END AS A LITTLE BIT OF SNOW WITH H8 TEMPS DROPPING TO -2 TO -4 C BY 06Z THU. THE SECOND HALF OF WED NIGHT LOOKS DRY IN THE WAKE OF DEPARTING LOW. EXPECT LOWS TUESDAY NIGHT TO BE IN THE UPPER 30S TO MID 40S...HIGHS ON WEDNESDAY IN THE UPPER 40S TO MID 50S AND LOWS WEDNESDAY NIGHT IN THE MID 20S TO MID 30S. TOTAL QPF AMOUNTS FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY EVENING ARE EXPECTED TO RANGE FROM AROUND A TENTH OF AN INCH NORTHWEST TO AROUND HALF AN INCH SOUTHEAST. && .LONG TERM /THURSDAY THROUGH SUNDAY/... AT THE START OF THIS PERIOD...AN UPPER TROF WILL APPROACH THE REGION AND PASS THROUGH FAIRLY QUICKLY. BROAD RIDGING WILL BEGIN TO SET IN ON FRIDAY. BRISK WEST NORTHWEST WINDS WILL USHER IN COOLER AIR FOR THE START...ALONG WITH SOME DIURNALLY DRIVEN INSTABILITY SHOWERS...ESPECIALLY NORTH AND WEST OF THE ALBANY AREA WHERE SOME LAKE ENHANCEMENT MAY ALLOW FOR SOME RAIN AND SNOW SHOWER ACTIVITY. HIGHS WILL RANGE FROM THE UPPER 30S ACROSS THE HIGHER TERRAIN TO AROUND 50 IN THE HUDSON VALLEY SOUTH OF ALBANY...COOLER THAN RECENT DAYS WITH THE UPPER TROUGH OVERHEAD...WITH LOTS OF CLOUDS AND CHANCE POPS NORTH AND WEST DIMINISHING TO NO POPS OVER MUCH OF THE HUDSON VALLEY...OR LOWER ELEVATIONS OF WESTERN NEW ENGLAND. SOME LAKE EFFECT SNOW SHOWERS MAY LINGER ACROSS THE WESTERN ADIRONDACKS AND UPPER MOHAWK VALLEY...BUT THE REST OF THE REGION SHOULD BE DRY AND CHILLY THURSDAY NIGHT...WITH LOWS RANGING FROM THE LOWER 20S ACROSS THE HIGHER ELEVATIONS OF THE ADIRONDACKS... CATSKILLS...SOUTHERN VERMONT...AND THE BERKSHIRES TO THE MID AND UPPER 20S IN THE MOHAWK...HUDSON...AND HOUSATONIC VALLEYS...WITH CONSIDERABLE CLOUDINESS NORTH AND WEST AND MOSTLY CLEAR SKIES OVER THE HUDSON VALLEY AND FARTHER EAST. THE TROUGH EXITS OUT THE REGION AS BROAD SOUTHWEST FLOW AT 500 HPA TAKES OVER FOR FRIDAY INTO THE WEEKEND ACROSS THE REGION...WHICH WILL ALLOW FOR WARMING STARTING ON FRIDAY. WITH PARTLY TO MOSTLY SUNNY SKIES HIGHS FRIDAY WILL RANGE FROM THE UPPER 30S TO THE UPPER 40S. IT WILL NOT BE AS COLD FRIDAY NIGHT...WITH LOWS FROM THE MID 20S TO THE LOWER 30S. ON SATURDAY...ANOTHER SYSTEM MOVING OUT OF THE PLAINS INTO THE GREAT LAKES WILL BEGIN TO SPREAD SOME CLOUDINESS INTO THE REGION WITH AN APPROACHING WARM FRONT. IN SPITE OF INCREASED CLOUDINESS SATURDAY WILL BE WARMER WITH HIGHS FROM THE MID 40S TO THE LOW 50S. AS THE WARM FRONT GETS CLOSER SATURDAY NIGHT IT WILL BRING ABOUT AN INCREASING CHANCE OF SHOWERS NORTH AND WEST. IT WILL BE MILDER ON SATURDAY NIGHT WITH LOWS MOSTLY IN THE 30S. SUNDAY WILL BE MOSTLY CLOUDY WITH A POSSIBILITY OF SHOWERS...ESPECIALLY NORTH AND WEST OF THE HUDSON VALLEY. HIGHS WILL BE FROM THE MID 40S TO THE LOWER 50S...ABOUT 5 DEGREES ABOVE NORMAL. && .AVIATION /16Z MONDAY THROUGH FRIDAY/... VFR FLIGHT CONDITIONS WILL PREVAIL ACROSS THE REGION THROUGH 00Z TUESDAY...BUT CONDITIONS ARE LIKELY TO DETERIORATE STARTING THIS EVENING. THERE WERE SOME HIGH AND MIDLEVEL CLOUDS OVER THE REGION EARLY THIS MONDAY MORNING. A LOW CENTER MOVING FROM THE OHIO VALLEY UP THE ST LAWRENCE VALLEY WILL SPREAD LOW CLOUDS AND SHOWERS INTO THE SOUTHERN PART OF THE REGION THIS AFTERNOON...AND FARTHER NORTH STARTING THIS EVENING. DURING THE DAY TODAY...CIGS WILL GENERALLY BE BROKEN TO OVERCAST 5000 TO 10000 FT...UNTIL MID TO LATE AFTERNOON...AFTER WHICH THEY WILL LOWER TO AROUND 3500 FT. THE MODELS ARE NOT IN GOOD AGREEMENT WITH THE PLACEMENT OR TIMING OF PRECIP. WITH WEAK FORCING IN PLACE...ANY SHOWERS WILL SCATTERED AND RATHER LIGHT IN INTENSITY. FOR NOW...WILL GO WITH A VCSH IN THE TAFS DURING MUCH OF THE DAY...WITH PRECIP MORE DEFINITE DURING THE MID AFTERNOON TO THE SOUTH AND NOT UNTIL THE LATE AFTERNOON FROM THE ALBANY AREA NORTH. FOR THE TIME BEING...LOOKS LIKE VFR SHOULD PREDOMINATE...WITH PERHAPS SOME AREAS OF MVFR CIGS ACROSS THE HIGHER TERRAIN NORTH AND WEST OF THE ALBANY AREA...EARLY AFTERNOON SOUTH OF THE ALBANY AREA AND LATE AFTERNOON FARTHER NORTH. CONDITIONS WILL BE MVFR THIS EVENING DUE TO LOW CIGS ALONG WITH VISIBILITY 4 TO 5 MILES IN RAIN AND MIST...WITH AREAS OF IFR ACROSS THE HIGHER TERRAIN. CIGS ARE LIKELY TO DETERIORATE TO IFR AFTER MIDNIGHT. WINDS WERE CALM AT KPOU AND SOUTHERLY AT KALB AND KGFL. THEY WILL CONTINUE SOUTHERLY 5 TO 10 KNOTS THROUGH MUCH OF THE DAY WITH SOMEWHAT HIGHER SPEEDS AT KALB. OUTLOOK... TUE...IFR/MVFR IMPROVING TO VFR. TUE NGT...SUB-VFR CIG...LIKELY -SHRA. WED-WED NGT...VFR/MVFR...CHC -SHRA. THU...VFR...BREEZY. FRI...VFR...NO SIG WX. && .HYDROLOGY... NO HYDRO PROBLEMS ARE ANTICIPATED THROUGH LATE IN THE WEEK. UP TO A HALF INCH OF RAIN IS POSSIBLE THIS EVENING AND TONIGHT. THIS RAIN MIGHT CAUSE SOME MINOR INCREASES IN STREAMFLOWS...BUT MOST OF IT WILL JUST SOAK INTO THE GROUND. MORE RAINFALL MAY OCCUR ON WEDNESDAY...BUT AGAIN IT LOOKS LIKE AMOUNTS SHOULD NOT BE MUCH MORE THAN A HALF INCH...IF THAT MUCH. AGAIN THIS RAIN WILL MOSTLY JUST SOAK INTO THE GROUND...AND NOT HAVE MUCH EFFECT ON THE RIVERS AND STREAMS. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...11 NEAR TERM...KL/11 SHORT TERM...11 LONG TERM...RCK AVIATION...RCK HYDROLOGY...RCK/11
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
159 AM EST MON NOV 14 2011 .SYNOPSIS... HIGH PRESSURE CENTERED OFF THE ATLANTIC COAST WILL CONTINUE TO MOVE EASTWARD INTO MONDAY. A COLD FRONT TO THE NORTHWEST WILL APPROACH THE REGION TUESDAY BRINGING AN INCREASING CHANCE FOR RAINFALL BY MID- WEEK. HIGH PRESSURE BRINGS DRIER AND COOLER AIR FOR THURSDAY. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... MAINLY HIGH AND MID-LEVEL CLOUDS ACROSS THE AREA OVERNIGHT. LIGHT WINDS...VARIABLE CLOUDINESS AND SOME INCREASE IN LOW-LEVEL MOISTURE WILL HELP TO KEEP MODERATING OVERNIGHT LOWS. EXPECT READINGS IN THE UPPER 40S BY MORNING...WITH SOME PATCHY FOG BEING POSSIBLE TOWARDS SUNRISE. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/... HIGH PRESSURE WILL BE WELL OFFSHORE BEGINNING ON MONDAY. ON THE BACKSIDE OF THE HIGH...SOUTHERLY WINDS WILL BRING WARMER AND MOISTURE AIR BACK INTO THE REGION THROUGH TUESDAY. EVEN SO...DRY CONDITIONS ARE EXPECTED TO CONTINUE THROUGH MUCH OF THE SHORT TERM PERIOD. WITH THE WARMING TREND...HIGHS ON MONDAY WILL REACH INTO THE LOWER TO MID 70S...THEN INTO THE MID TO UPPER 70S TUESDAY. LOWS MONDAY NIGHT WILL ONLY FALL INTO THE LOWER TO MID 50S. CHANGES WILL BEGIN LATER IN THE DAY TUESDAY IN REGARDS TO POP POTENTIAL. A COLD FRONT OFF TO THE NORTHWEST OF THE REGION WILL BE STRENGTHENING AND MOVING TOWARDS THE REGION LATE IN THE DAY TUESDAY. MUCH OF THE DAY TUESDAY IS EXPECTED TO BE DRY...BUT WILL CONTINUE TO GO WITH A SLIGHT CHANCE OF RAINFALL LATE IN THE AFTERNOON TUESDAY. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... MODELS IN GOOD AGREEMENT WITH SHORT WAVE TROUGH AND COLD FRONT MOVING TOWARDS THE REGION TUESDAY NIGHT AND GRADUALLY PUSHING EAST OF THE AREA WEDNESDAY. THIS WILL BRING A CHANCE OF SHOWERS BEGINNING OVERNIGHT TUESDAY NIGHT AND LINGERING WEDNESDAY. ONLY MARGINAL INSTABILITY WITH THE SYSTEM WEDNESDAY. THE SYSTEM EXITS THE AREA BY THURSDAY AS A STRONGER SHORT WAVE TROUGH MOVES THROUGH THE GREAT LAKES REGION WITH HIGH PRESSURE AND DRY WEATHER IN THE SOUTHEAST. SIGNIFICANT COOLING OF HIGH TEMPERATURES EXPECTED FROM WEDNESDAY TO THURSDAY. HIGH PRESSURE WILL COVER THE AREA THURSDAY THROUGH SATURDAY WITH DRY CONDITIONS AND COOLER TEMPERATURES. && .AVIATION /07Z MONDAY THROUGH FRIDAY/... CURRENT OBSERVATIONS SHOW A TONGUE OF SURFACE MOISTURE ADVECTING NORTH ACROSS SOUTHEAST GEORGIA INTO WEST CENTRAL SOUTH CAROLINA. HOWEVER FLOW AT THE SURFACE CONTINUES TO BE LIGHT SO SURFACE MOISTURE ADVECTION WILL BE SLOWER THAN THAT JUST ABOVE THE SURFACE AS A LOW LEVEL JET DEVELOPS...BUT PER VAD WIND PROFILES...SEEMS TO STEER THE BEST MOISTURE TO OUR WEST. HOWEVER...ELECTED TO KEEP CURRENT FORECAST INTACT FOR NOW AS EVIDENCE IS STILL TOO COMPELLING TO REMOVE THE CHANCE OF IFR CEILINGS AND MVFR VISIBILITY AT THIS TIME. FOLLOWED A COMBINATION OF THE GFS/NAM AND RUC IN MAKING THE FORECAST. CONDITIONS WILL BE VFR FOR THE REST OF THE FORECAST PERIOD. LONGWAVE RIDGE WILL REBUILD ACROSS THE SOUTHEAST UNITED STATES THIS AFTERNOON AND INTO TUESDAY...KEEPING PARTLY CLOUDY TO MOSTLY CLEAR SKIES TONIGHT...WITH ANOTHER CHANCE OF MVFR/IFR VISIBILITY/ CEILINGS TUESDAY MORNING. EXTENDED AVIATION OUTLOOK...A FRONTAL SYSTEM MOVING INTO THE AREA MAY BRING WIDESPREAD MVFR OR IFR CONDITIONS TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$ SYNOPSIS...07 NEAR TERM...07 SHORT TERM...07 LONG TERM...07 AVIATION...12
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1246 AM EST MON NOV 14 2011 .SYNOPSIS... HIGH PRESSURE CENTERED OFF THE ATLANTIC COAST WILL CONTINUE TO MOVE EASTWARD INTO MONDAY. A COLD FRONT TO THE NORTHWEST WILL APPROACH THE REGION TUESDAY BRINGING AN INCREASING CHANCE FOR RAINFALL BY MID- WEEK. HIGH PRESSURE BRINGS DRIER AND COOLER AIR FOR THURSDAY. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... MAINLY HIGH AND MID-LEVEL CLOUDS ACROSS THE AREA LATE THIS EVENING. LIGHT WINDS...VARIABLE CLOUDINESS AND SOME INCREASE IN LOW-LEVEL MOISTURE WILL HELP TO KEEP MODERATING OVERNIGHT LOWS. EXPECT READINGS IN THE UPPER 40S BY MORNING...WITH SOME PATCHY FOG BEING POSSIBLE TOWARDS SUNRISE. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/... HIGH PRESSURE WILL BE WELL OFFSHORE BEGINNING ON MONDAY. ON THE BACKSIDE OF THE HIGH...SOUTHERLY WINDS WILL BRING WARMER AND MOISTURE AIR BACK INTO THE REGION THROUGH TUESDAY. EVEN SO...DRY CONDITIONS ARE EXPECTED TO CONTINUE THROUGH MUCH OF THE SHORT TERM PERIOD. WITH THE WARMING TREND...HIGHS ON MONDAY WILL REACH INTO THE LOWER TO MID 70S...THEN INTO THE MID TO UPPER 70S TUESDAY. LOWS MONDAY NIGHT WILL ONLY FALL INTO THE LOWER TO MID 50S. CHANGES WILL BEGIN LATER IN THE DAY TUESDAY IN REGARDS TO POP POTENTIAL. A COLD FRONT OFF TO THE NORTHWEST OF THE REGION WILL BE STRENGTHENING AND MOVING TOWARDS THE REGION LATE IN THE DAY TUESDAY. MUCH OF THE DAY TUESDAY IS EXPECTED TO BE DRY...BUT WILL CONTINUE TO GO WITH A SLIGHT CHANCE OF RAINFALL LATE IN THE AFTERNOON TUESDAY. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... MODELS IN GOOD AGREEMENT WITH SHORT WAVE TROUGH AND COLD FRONT MOVING TOWARDS THE REGION TUESDAY NIGHT AND GRADUALLY PUSHING EAST OF THE AREA WEDNESDAY. THIS WILL BRING A CHANCE OF SHOWERS BEGINNING OVERNIGHT TUESDAY NIGHT AND LINGERING WEDNESDAY. ONLY MARGINAL INSTABILITY WITH THE SYSTEM WEDNESDAY. THE SYSTEM EXITS THE AREA BY THURSDAY AS A STRONGER SHORT WAVE TROUGH MOVES THROUGH THE GREAT LAKES REGION WITH HIGH PRESSURE AND DRY WEATHER IN THE SOUTHEAST. SIGNIFICANT COOLING OF HIGH TEMPERATURES EXPECTED FROM WEDNESDAY TO THURSDAY. HIGH PRESSURE WILL COVER THE AREA THURSDAY THROUGH SATURDAY WITH DRY CONDITIONS AND COOLER TEMPERATURES. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... CURRENT OBSERVATIONS SHOW A TONGUE OF SURFACE MOISTURE ADVECTING NORTH ACROSS SOUTHEAST GEORGIA INTO WEST CENTRAL SOUTH CAROLINA. HOWEVER FLOW AT THE SURFACE CONTINUES TO BE LIGHT SO SURFACE MOISTURE ADVECTION WILL BE SLOWER THAN THAT JUST ABOVE THE SURFACE AS A LOW LEVEL JET DEVELOPS...BUT PER VAD WIND PROFILES...SEEMS TO STEER THE BEST MOISTURE TO OUR WEST. HOWEVER...ELECTED TO KEEP CURRENT FORECAST INTACT FOR NOW AS EVIDENCE IS STILL TOO COMPELLING TO REMOVE THE CHANCE OF IFR CEILINGS AND MVFR VISIBILITY AT THIS TIME. FOLLOWED A COMBINATION OF THE GFS/NAM AND RUC IN MAKING THE FORECAST. CONDITIONS WILL BE VFR FOR THE REST OF THE FORECAST PERIOD. LONGWAVE RIDGE WILL REBUILD ACROSS THE SOUTHEAST UNITED STATES THIS AFTERNOON AND INTO TUESDAY...KEEPING PARTLY CLOUDY TO MOSTLY CLEAR SKIES TONIGHT...WITH ANOTHER CHANCE OF MVFR/IFR VISIBILITY/ CEILINGS TUESDAY MORNING. EXTENDED AVIATION OUTLOOK...A FRONTAL SYSTEM MOVING INTO THE AREA MAY BRING WIDESPREAD MVFR OR IFR CONDITIONS TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$ SYNOPSIS... NEAR TERM... SHORT TERM... LONG TERM... AVIATION...
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1016 PM EST TUE NOV 15 2011 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... WEATHER CONDITIONS WILL BE FLUCTUATING QUITE A BIT OVER THE NEXT SEVERAL DAYS. FIRST...ANOTHER COLD FRONT WILL MOVE ACROSS CENTRAL INDIANA TONIGHT BRINGING MUCH COLDER AIR BEHIND IT. HIGHS WILL ONLY TOP OFF IN THE 40S THE NEXT FEW DAYS DESPITE THE DRY CONDITIONS. THE NEXT CHANCE FOR PRECIP AND ISOLATED THUNDERSTORMS WILL BE LATE IN THE WEEKEND AS A RATHER STRONG SYSTEM MOVES ACROSS CENTRAL INDIANA. FURTHER OUT...HIGH PRESSURE WILL RE-ESTABLISH ITSELF OVER CENTRAL INDIANA LATE MONDAY. && .NEAR TERM /REST OF TONIGHT/... SO FAR CURRENT FORECAST SEEMS TO BE ON TRACK. PRESENTLY RAIN OCCURRING SOUTH OF OHIO RIVER...BUT RADAR LOOPS INDICATE THAT IT HAS PUSHED NORTH INTO MISSOURI BOOTHEEL AS UPPER LEVEL DISTURBANCE MOVING ACROSS ARKANSAS AND TENNESSEE. RUC BRINGS PRECIPITATION ACROSS OUR FAR SOUTH LATE TONIGHT AND EARLY WEDNESDAY...BUT NOTHING MUCH NORTH OF OUR SOUTHERN ROW OF COUNTIES. I HAVE ADJUSTED RAIN AREA SLIGHTLY SOUTH OVERNIGHT...BUT NOT ENOUGH TO UPDATE FORECAST PRODUCTS. ONE MINOR CHANGE IN GRIDS WILL BE TO SLOW DOWN FALL OF TEMPERATURES A LITTLE OVERNIGHT UNTIL SECONDARY COLD FRONT MOVES THROUGH LATE TONIGHT. BUT EVEN THERE THE OVERNIGHT LOWS STILL SEEM TO BE ON TRACK WITH MID TO UPPER 30S ACROSS OUR NORTHWEST AND LOWER TO MID 40S SOUTH. && .SHORT TERM /TOMORROW THROUGH THURSDAY/... THE MAIN FOCUS OF THE SHORT TERM IS TEMPS. MUCH COOLER TEMPS AND DRY CONDITIONS WILL PREVAIL TOMORROW IN THE WAKE OF A COLD FRONT. HIGHS WILL ONLY TOP OFF IN THE UPPER 40S/LOWER 50S ACROSS THE SOUTHERN COUNTIES...AND MID 40S TO THE NORTH. MODELS SEEM TO HAVE A GOOD HANDLE ON THE COLD ADVECTION...SO WENT WITH ALLBLEND. TOMORROW NIGHT...TRENDED ON THE WARMER SIDE OF GUIDANCE AS CLOUDS BUILD INTO THE AREA AHEAD OF A BROAD UPPER LEVEL LOW. GUIDANCE IS SHOWING LOWS IN THE MID TO UPPER 20S...SO WENT WITH UPPER 20S/LOW 30S. HOWEVER...CONFIDENCE IS LOW SINCE 850MB TEMPS ARE HINTING AT A COOLING TREND. THURSDAY...WENT ABOVE GUIDANCE SINCE WINDS WILL BE BACKING TO THE WEST THROUGH THE COURSE OF THE DAY. THIS MAY BE TOO OPTIMISTIC THOUGH...SO CONFIDENCE IS A BIT LOW. FOR NOW...HAVE HIGHS OF LOW TO MID 40S OVER THE NORTH...AND UPPER 40S ACROSS THE SOUTHERN PORTIONS OF CENTRAL INDIANA. THURSDAY NIGHT...JUST WENT WITH A BLEND OF UPPER 20S/LOW 30S. && .LONG TERM /FRIDAY THROUGH TUESDAY/... MODELS ARE HAVING TIMING DIFFICULTIES WITH A STRONG FRONTAL SYSTEM THAT IS EXPECTED TO IMPACT CENTRAL INDIANA THIS WEEKEND INTO EARLY NEXT WEEK. THE 12Z ECMWF AND 12Z GEM ARE BOTH QUITE A BIT FASTER THAN THE 12Z GFS. THE 12Z GFS ESEMBLE MEANS WERE IN BETWEEN...BUT THE ESEMBLES HAD LARGE STANDARD DEVIATIONS. SO...AT THIS POINT...A NON-GFS BLEND LOOKS GOOD. HAD TO MAKE SEVERAL CHANGES TO THE INITIALIZATION EXTENDED REGARDING TIMING OF THE RAIN. DROPPED SLIGHT CHANCE POPS NORTHWEST ON FRIDAY WITH THE FRONTAL SYSTEM WELL TO THE WEST ACROSS THE ROCKIES. OTHERWISE...THE FRONT IS EXPECTED TO SLIDE ACROSS SATURDAY NIGHT. MODELS SUGGEST SYSTEM STRONG ENOUGH TO PRODUCE A FEW THUNDERSTORMS AS WELL AS SHOWERS SATURDAY AND SATURDAY NIGHT. THE 12Z ECMWF ALSO WAS SHOWING A WAVE LIFTING NORTHEAST ALONG THE OSCILLATING FRONT NEAR THE OHIO RIVER ON MONDAY WHICH JUSTIFIES KEEPING POPS IN THROUGH THEN. FINALLY...HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT ON MONDAY NIGHT WHICH SHOULD DRY THINGS OUT BY TUESDAY AND ALLOW FOR MUCH COOLER TEMPERATURES ONLY IN THE 40S FOR AFTERNOON HIGHS IN CONTRAST TO HIGHS IN THE 50S AND POSSIBLY 60S SATURDAY IN THE RETURN FLOW AHEAD OF THE FRONT. AFTER COORDINATING WITH ADJACENT OFFICES...PULLED THE INITIALIZATION EXTENDED POPS. && .AVIATION /DISCUSSION FOR THE 16/03Z IND TAF UPDATE/... MINOR TWEAKS TO TIMING AND LOWERED CEILINGS TO SCT/TEMPO BKN012. REMAINDER OF FORECAST REMAINS UNCHANGED. PREVIOUS DISCUSSION FOLLOWS. SOME IMPROVEMENT OF CEILINGS TO LOW VFR HAS OCCURRED EARLY THIS EVENING...BUT SREF PROBABILITIES...FORECAST SOUNDINGS AND UPSTREAM OBS SUGGEST SOME ADDITIONAL MVFR WILL BUILD IN DURING THE FIRST 4-5 HOURS OF THE TAF PERIOD. BMG WILL EXPERIENCE MVFR MOST OF THE NIGHT DUE TO ITS PROXIMITY TO MOISTURE AND BOUNDARY TO OUR SOUTH. SECONDARY COLD FRONT WILL COME THROUGH OVERNIGHT AND ALLOW CONDITIONS TO IMPROVE MARKEDLY...FIRST AT LAF...THEN IND/HUF...AND FINALLY BMG IN THE MORNING. SHOWER ACTIVITY APPEARS TO BE REMAINING WELL TO OUR SOUTH...AND WHILE A SPRINKLE CANNOT BE RULED OUT...ESPECIALLY AT BMG...THIS APPEARS UNLIKELY AND NO MENTION WILL BE MADE. WINDS WILL BECOME NORTHERLY BY TOMORROW MORNING...WITH GUSTS IN THE HIGH TEENS POSSIBLE FROM MID MORNING THROUGH THE AFTERNOON. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...TDUD NEAR TERM...JH SHORT TERM...TDUD LONG TERM....50 AVIATION...NIELD
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
955 PM EST TUE NOV 15 2011 .UPDATE... NEAR TERM FOR THE REST OF TONIGHT HAS BEEN UPDATED BELOW. && .SYNOPSIS... WEATHER CONDITIONS WILL BE FLUCTUATING QUITE A BIT OVER THE NEXT SEVERAL DAYS. FIRST...ANOTHER COLD FRONT WILL MOVE ACROSS CENTRAL INDIANA TONIGHT BRINGING MUCH COLDER AIR BEHIND IT. HIGHS WILL ONLY TOP OFF IN THE 40S THE NEXT FEW DAYS DESPITE THE DRY CONDITIONS. THE NEXT CHANCE FOR PRECIP AND ISOLATED THUNDERSTORMS WILL BE LATE IN THE WEEKEND AS A RATHER STRONG SYSTEM MOVES ACROSS CENTRAL INDIANA. FURTHER OUT...HIGH PRESSURE WILL RE-ESTABLISH ITSELF OVER CENTRAL INDIANA LATE MONDAY. && .NEAR TERM /REST OF TONIGHT/... SO FAR CURRENT FORECAST SEEMS TO BE ON TRACK. PRESENTLY RAIN OCCURRING SOUTH OF OHIO RIVER...BUT RADAR LOOPS INDICATE THAT IT HAS PUSHED NORTH INTO MISSOURI BOOTHEEL AS UPPER LEVEL DISTURBANCE MOVING ACROSS ARKANSAS AND TENNESSEE. RUC BRINGS PRECIPITATION ACROSS OUR FAR SOUTH LATE TONIGHT AND EARLY WEDNESDAY...BUT NOTHING MUCH NORTH OF OUR SOUTHERN ROW OF COUNTIES. I HAVE ADJUSTED RAIN AREA SLIGHTLY SOUTH OVERNIGHT...BUT NOT ENOUGH TO UPDATE FORECAST PRODUCTS. ONE MINOR CHANGE IN GRIDS WILL BE TO SLOW DOWN FALL OF TEMPERATURES A LITTLE OVERNIGHT UNTIL SECONDARY COLD FRONT MOVES THROUGH LATE TONIGHT. BUT EVEN THERE THE OVERNIGHT LOWS STILL SEEM TO BE ON TRACK WITH MID TO UPPER 30S ACROSS OUR NORTHWEST AND LOWER TO MID 40S SOUTH. && .SHORT TERM /TOMORROW THROUGH THURSDAY/... THE MAIN FOCUS OF THE SHORT TERM IS TEMPS. MUCH COOLER TEMPS AND DRY CONDITIONS WILL PREVAIL TOMORROW IN THE WAKE OF A COLD FRONT. HIGHS WILL ONLY TOP OFF IN THE UPPER 40S/LOWER 50S ACROSS THE SOUTHERN COUNTIES...AND MID 40S TO THE NORTH. MODELS SEEM TO HAVE A GOOD HANDLE ON THE COLD ADVECTION...SO WENT WITH ALLBLEND. TOMORROW NIGHT...TRENDED ON THE WARMER SIDE OF GUIDANCE AS CLOUDS BUILD INTO THE AREA AHEAD OF A BROAD UPPER LEVEL LOW. GUIDANCE IS SHOWING LOWS IN THE MID TO UPPER 20S...SO WENT WITH UPPER 20S/LOW 30S. HOWEVER...CONFIDENCE IS LOW SINCE 850MB TEMPS ARE HINTING AT A COOLING TREND. THURSDAY...WENT ABOVE GUIDANCE SINCE WINDS WILL BE BACKING TO THE WEST THROUGH THE COURSE OF THE DAY. THIS MAY BE TOO OPTIMISTIC THOUGH...SO CONFIDENCE IS A BIT LOW. FOR NOW...HAVE HIGHS OF LOW TO MID 40S OVER THE NORTH...AND UPPER 40S ACROSS THE SOUTHERN PORTIONS OF CENTRAL INDIANA. THURSDAY NIGHT...JUST WENT WITH A BLEND OF UPPER 20S/LOW 30S. && .LONG TERM /FRIDAY THROUGH TUESDAY/... MODELS ARE HAVING TIMING DIFFICULTIES WITH A STRONG FRONTAL SYSTEM THAT IS EXPECTED TO IMPACT CENTRAL INDIANA THIS WEEKEND INTO EARLY NEXT WEEK. THE 12Z ECMWF AND 12Z GEM ARE BOTH QUITE A BIT FASTER THAN THE 12Z GFS. THE 12Z GFS ESEMBLE MEANS WERE IN BETWEEN...BUT THE ESEMBLES HAD LARGE STANDARD DEVIATIONS. SO...AT THIS POINT...A NON-GFS BLEND LOOKS GOOD. HAD TO MAKE SEVERAL CHANGES TO THE INITIALIZATION EXTENDED REGARDING TIMING OF THE RAIN. DROPPED SLIGHT CHANCE POPS NORTHWEST ON FRIDAY WITH THE FRONTAL SYSTEM WELL TO THE WEST ACROSS THE ROCKIES. OTHERWISE...THE FRONT IS EXPECTED TO SLIDE ACROSS SATURDAY NIGHT. MODELS SUGGEST SYSTEM STRONG ENOUGH TO PRODUCE A FEW THUNDERSTORMS AS WELL AS SHOWERS SATURDAY AND SATURDAY NIGHT. THE 12Z ECMWF ALSO WAS SHOWING A WAVE LIFTING NORTHEAST ALONG THE OSCILLATING FRONT NEAR THE OHIO RIVER ON MONDAY WHICH JUSTIFIES KEEPING POPS IN THROUGH THEN. FINALLY...HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT ON MONDAY NIGHT WHICH SHOULD DRY THINGS OUT BY TUESDAY AND ALLOW FOR MUCH COOLER TEMPERATURES ONLY IN THE 40S FOR AFTERNOON HIGHS IN CONTRAST TO HIGHS IN THE 50S AND POSSIBLY 60S SATURDAY IN THE RETURN FLOW AHEAD OF THE FRONT. AFTER COORDINATING WITH ADJACENT OFFICES...PULLED THE INITIALIZATION EXTENDED POPS. && .AVIATION /DISCUSSION FOR THE 16/00Z TAFS/... SOME IMPROVEMENT OF CEILINGS TO LOW VFR HAS OCCURRED EARLY THIS EVENING...BUT SREF PROBABILITIES...FORECAST SOUNDINGS AND UPSTREAM OBS SUGGEST SOME ADDITIONAL MVFR WILL BUILD IN DURING THE FIRST 4-5 HOURS OF THE TAF PERIOD. BMG WILL EXPERIENCE MVFR MOST OF THE NIGHT DUE TO ITS PROXIMITY TO MOISTURE AND BOUNDARY TO OUR SOUTH. SECONDARY COLD FRONT WILL COME THROUGH OVERNIGHT AND ALLOW CONDITIONS TO IMPROVE MARKEDLY...FIRST AT LAF...THEN IND/HUF...AND FINALLY BMG IN THE MORNING. SHOWER ACTIVITY APPEARS TO BE REMAINING WELL TO OUR SOUTH...AND WHILE A SPRINKLE CANNOT BE RULED OUT...ESPECIALLY AT BMG...THIS APPEARS UNLIKELY AND NO MENTION WILL BE MADE. WINDS WILL BECOME NORTHERLY BY TOMORROW MORNING...WITH GUSTS IN THE HIGH TEENS POSSIBLE FROM MID MORNING THROUGH THE AFTERNOON. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...TDUD NEAR TERM...JH SHORT TERM...TDUD LONG TERM....50 AVIATION...NIELD
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
553 PM EST MON NOV 14 2011 .AVIATION... 00Z TAFS...LINGERING SHOWERS AFFECTING KFWA SHOULD EXIT BEFORE 00Z WITH LOW LEVEL DRY AIR ADVECTION AFFECTING NORTHERN INDIANA TONIGHT IN THE WAKE OF PASSING SFC WAVE. WEAK NORTH WINDS BEHIND THIS TROUGH SHOULD EVENTUALLY BECOME SOUTHERLY LATER THIS EVENING AS SFC TROUGH TRACKS ACROSS THE NORTHERN PLAINS LATE TONIGHT. GRADIENT WILL TIGHTEN IN ASSOCIATION WITH THIS APPROACHING TROUGH ON TUESDAY...WITH SOME GUSTS TO 20 TO 25 KNOTS POSSIBLE LATE MORNING INTO THE AFTERNOON...ESPECIALLY AT KSBN WHERE LOW LEVEL HEIGHT GRADIENT WILL BE STRONGER. VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD WITH JUST SOME LOW COVERAGE CIRRUS THROUGH THE PERIOD. && .PREV DISCUSSION... /ISSUED 425 PM EST MON NOV 14 2011/ SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT SEVERE POTENTIAL THROUGH EARLY EVENING WILL BE THE IMMEDIATE SHORT TERM CONCERN...FOLLOWED BY TRANSITION TO COLDER TEMPERATURES AND LAKE EFFECT PRECIP POTENTIAL FOR WEDNESDAY/EARLY THURSDAY. SHORT WAVE FROM THE CENTRAL PLAINS HAS RAPIDLY TRACKED INTO THE WESTERN GREAT LAKES REGION LATE THIS AFTERNOON. SFC WAVE RIDING ALONG NORTHWARD MOVING WARM FRONT COMBINED WITH INCREASED MID/UPPER LEVEL FORCING HAS ALLOWED FOR SOLID LINE OF CONVECTION TO DEVELOP ALONG A STRONG LOW LEVEL FRONTAL CONVERGENCE ZONE. EXTREME DEEP LAYER SHEAR NOTED WITH 150 KNOT JET CORE PROGRESSING THROUGH THE SOUTHERN GREAT LAKES...WITH 0 TO 6 KM DEEP LAYER SHEAR VALUES ON THE ORDER OF 80 TO 100 KNOTS. A TIGHT INSTABILITY GRADIENT IS ACCOMPANYING THE WARM FRONT WITH 20Z SPC RUC ANALYSIS INDICATING BETWEEN 500-700 J/KG OF SFC BASED CAPE ACROSS SOUTHERN THIRD OF THE FORECAST AREA. THE WARM FRONT HAS LIKELY REACHED ITS FAR NORTHERN EXTENT BASED ON POSITIONING OF AFOREMENTIONED SURFACE WAVE. SEVERE POTENTIAL FOR THE REMAINDER OF THE EARLY EVENING HOURS CAN BE APPROXIMATELY DELINEATED BY CURRENT POSITIONING OF SHARP FRONTAL CONVERGENCE AXIS. COMBINATION OF SHEAR AND INSTABILITY IS MORE THAN AMPLE FOR CONTINUED LOW TOP SUPERCELLULAR FEATURES EMBEDDED ALONG THE LINE...WITH PERIODIC BOWING SEGMENTS GIVEN THE VERY STRONG FLOW ALOFT. THREAT OF SEVERE SHOULD SHIFT INTO EXTREME SOUTHEAST AREAS OVER NEXT HOUR OR TWO...BEFORE EXITING THE FORECAST AREA TOWARD 00Z. COLD ADVECTION BEHIND SURFACE WAVE TONIGHT IS NOT EXPECTED TO BE PARTICULARLY STRONG DUE TO MAINTENANCE OF LONG WAVE TROUGHING ACROSS MUCH OF CENTRAL CONUS. APPROACH OF NEXT SFC TROUGH FROM THE CENTRAL/NORTHERN PLAINS WILL ALLOW LOW LEVEL WINDS TO BACK AGAIN LATE TONIGHT AND ON TUESDAY...WITH STRONG WARM ADVECTION DEVELOPING ONCE AGAIN DURING THE DAY. SOME LIMITED LOW LEVEL MOISTURE RETURN IS POSSIBLE IN ADVANCE OF THIS WAVE TUESDAY NIGHT ACROSS MAINLY FAR SOUTHEAST PORTIONS OF THE AREA. IN ADDITION...APPROACHING LARGER SCALE UPPER TROUGH MAY ACT TO ENHANCE SOME WEAK TO MODERATE MID LEVEL FRONTOGENESIS. GIVEN THESE FACTORS...DID ADD SLIGHT CHANCE OF SHOWERS ACROSS EXTREME SOUTHEAST TUESDAY NIGHT...WITH GREATER CHANCES OF SHOWERS REMAINING SOUTHEAST OF THE AREA. TEMPERATURES BACK INTO THE UPPER 50S TO AROUND 60 EXPECTED ON TUESDAY AFTERNOON WITH JUST SOME PASSING MID CLOUDS EXPECTED. LONG TERM...WEDNESDAY THROUGH MONDAY FRONTAL PASSAGE LATE TUESDAY NIGHT WILL ALLOW FOR STRONG LOW LEVEL COLD ADVECTION ON WEDNESDAY. MODIFIED GFS BUFFER SOUNDINGS FOR SOUTHERN LAKE MICHIGAN CONDITIONS SUGGEST SUFFICIENT LAKE INDUCED INSTABILITY FOR SCT SNOW SHOWER/FLURRY CHANCES. WILL KEEP PRECIP TYPE AS SNOW SHOWERS FOR MAINLY EXTREME SOUTHWESTERN LOWER MICHIGAN DUE TO A FAIRLY DRY SUBCLOUD LAYER. WILL MAINTAIN SLIGHT CHANCE OF SHOWERS FURTHER INLAND ON WEDNESDAY EVENING ACROSS MUCH OF SOUTHERN LOWER MICHIGAN AS MAIN UPPER TROUGH AXIS MOVES ACROSS THE GREAT LAKES. THE THERMAL ROLLER COASTER RIDE WILL CONTINUE BY THE END OF THE WEEK AS A STRONG SOUTHWESTERLY LOW LEVEL JET WILL BRING LOW LEVEL THERMAL RIDGING BACK INTO THE REGION AND A MODERATING TEMPERATURE TREND. THE NEXT STRONG EASTERN PACIFIC JET WILL DIG INTO WESTERN CONUS FRIDAY ALLOWING FOR LONGWAVE AMPLIFICATION...WHICH WILL EVENTUALLY SUPPORT RAIN SHOWER CHANCES FOR MUCH OF NEXT WEEKEND AS THIS TROUGH LIFTS ACROSS NORTHERN TIER OF CONUS. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SHORT TERM...MARSILI LONG TERM...MARSILI AVIATION...MARSILI
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
425 PM EST MON NOV 14 2011 .SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT SEVERE POTENTIAL THROUGH EARLY EVENING WILL BE THE IMMEDIATE SHORT TERM CONCERN...FOLLOWED BY TRANSITION TO COLDER TEMPERATURES AND LAKE EFFECT PRECIP POTENTIAL FOR WEDNESDAY/EARLY THURSDAY. SHORT WAVE FROM THE CENTRAL PLAINS HAS RAPIDLY TRACKED INTO THE WESTERN GREAT LAKES REGION LATE THIS AFTERNOON. SFC WAVE RIDING ALONG NORTHWARD MOVING WARM FRONT COMBINED WITH INCREASED MID/UPPER LEVEL FORCING HAS ALLOWED FOR SOLID LINE OF CONVECTION TO DEVELOP ALONG A STRONG LOW LEVEL FRONTAL CONVERGENCE ZONE. EXTREME DEEP LAYER SHEAR NOTED WITH 150 KNOT JET CORE PROGRESSING THROUGH THE SOUTHERN GREAT LAKES...WITH 0 TO 6 KM DEEP LAYER SHEAR VALUES ON THE ORDER OF 80 TO 100 KNOTS. A TIGHT INSTABILITY GRADIENT IS ACCOMPANYING THE WARM FRONT WITH 20Z SPC RUC ANALYSIS INDICATING BETWEEN 500-700 J/KG OF SFC BASED CAPE ACROSS SOUTHERN THIRD OF THE FORECAST AREA. THE WARM FRONT HAS LIKELY REACHED ITS FAR NORTHERN EXTENT BASED ON POSITIONING OF AFOREMENTIONED SURFACE WAVE. SEVERE POTENTIAL FOR THE REMAINDER OF THE EARLY EVENING HOURS CAN BE APPROXIMATELY DELINEATED BY CURRENT POSITIONING OF SHARP FRONTAL CONVERGENCE AXIS. COMBINATION OF SHEAR AND INSTABILITY IS MORE THAN AMPLE FOR CONTINUED LOW TOP SUPERCELLULAR FEATURES EMBEDDED ALONG THE LINE...WITH PERIODIC BOWING SEGMENTS GIVEN THE VERY STRONG FLOW ALOFT. THREAT OF SEVERE SHOULD SHIFT INTO EXTREME SOUTHEAST AREAS OVER NEXT HOUR OR TWO...BEFORE EXITING THE FORECAST AREA TOWARD 00Z. COLD ADVECTION BEHIND SURFACE WAVE TONIGHT IS NOT EXPECTED TO BE PARTICULARLY STRONG DUE TO MAINTENANCE OF LONG WAVE TROUGHING ACROSS MUCH OF CENTRAL CONUS. APPROACH OF NEXT SFC TROUGH FROM THE CENTRAL/NORTHERN PLAINS WILL ALLOW LOW LEVEL WINDS TO BACK AGAIN LATE TONIGHT AND ON TUESDAY...WITH STRONG WARM ADVECTION DEVELOPING ONCE AGAIN DURING THE DAY. SOME LIMITED LOW LEVEL MOISTURE RETURN IS POSSIBLE IN ADVANCE OF THIS WAVE TUESDAY NIGHT ACROSS MAINLY FAR SOUTHEAST PORTIONS OF THE AREA. IN ADDITION...APPROACHING LARGER SCALE UPPER TROUGH MAY ACT TO ENHANCE SOME WEAK TO MODERATE MID LEVEL FRONTOGENESIS. GIVEN THESE FACTORS...DID ADD SLIGHT CHANCE OF SHOWERS ACROSS EXTREME SOUTHEAST TUESDAY NIGHT...WITH GREATER CHANCES OF SHOWERS REMAINING SOUTHEAST OF THE AREA. TEMPERATURES BACK INTO THE UPPER 50S TO AROUND 60 EXPECTED ON TUESDAY AFTERNOON WITH JUST SOME PASSING MID CLOUDS EXPECTED. .LONG TERM...WEDNESDAY THROUGH MONDAY FRONTAL PASSAGE LATE TUESDAY NIGHT WILL ALLOW FOR STRONG LOW LEVEL COLD ADVECTION ON WEDNESDAY. MODIFIED GFS BUFFER SOUNDINGS FOR SOUTHERN LAKE MICHIGAN CONDITIONS SUGGEST SUFFICIENT LAKE INDUCED INSTABILITY FOR SCT SNOW SHOWER/FLURRY CHANCES. WILL KEEP PRECIP TYPE AS SNOW SHOWERS FOR MAINLY EXTREME SOUTHWESTERN LOWER MICHIGAN DUE TO A FAIRLY DRY SUBCLOUD LAYER. WILL MAINTAIN SLIGHT CHANCE OF SHOWERS FURTHER INLAND ON WEDNESDAY EVENING ACROSS MUCH OF SOUTHERN LOWER MICHIGAN AS MAIN UPPER TROUGH AXIS MOVES ACROSS THE GREAT LAKES. THE THERMAL ROLLER COASTER RIDE WILL CONTINUE BY THE END OF THE WEEK AS A STRONG SOUTHWESTERLY LOW LEVEL JET WILL BRING LOW LEVEL THERMAL RIDGING BACK INTO THE REGION AND A MODERATING TEMPERATURE TREND. THE NEXT STRONG EASTERN PACIFIC JET WILL DIG INTO WESTERN CONUS FRIDAY ALLOWING FOR LONGWAVE AMPLIFICATION...WHICH WILL EVENTUALLY SUPPORT RAIN SHOWER CHANCES FOR MUCH OF NEXT WEEKEND AS THIS TROUGH LIFTS ACROSS NORTHERN TIER OF CONUS. && .PREV DISCUSSION... /ISSUED 126 PM EST MON NOV 14 2011/ AVIATION... 18Z TAFS...WARM FRONTAL BOUNDARY JUST TO THE SOUTH OF TERMINALS WILL CONTINUE TO LIFT SLIGHTLY NORTHWARD THROUGH THE REMAINDER OF THE AFTERNOON. LATEST SFC OBSERVATIONS INDICATING WARM FRONT HAS REACHED KFWA WITH WINDS NOW SOUTHERLY AND GUSTING TO AROUND 20 KNOTS. THIS SHARP FRONTAL BOUNDARY WILL INTERACT WITH AN APPROACHING UPPER LEVEL TROUGH TO PRODUCE WIDESPREAD SHOWERS AND THUNDERSTORMS ACROSS NORTHERN INDIANA THIS AFTERNOON. THE PRIMARY INSTABILITY AXIS WILL SET UP FROM EAST CENTRAL ILLINOIS INTO NORTHEAST INDIANA WITH KFWA MARKING THE NORTHERN FRINGE OF THIS GREATER INSTABILITY. WHILE THUNDER MAY BE MORE ISOLD OR SCT AT KSBN...BEST POTENTIAL FOR THUNDER AT KSBN SHOULD BE OVER THE NEXT HOUR OR TWO. WITH STRONG BACKGROUND WIND SHEAR AND PLACEMENT OF INSTABILITY...STORMS WILL LIKELY BE STRONG/SEVERE AND DID INDICATE WIND GUSTS OF 45 TO 50 KNOTS IN TEMPO TSRA GROUP FOR FWA. THREAT OF PRECIP SHOULD END AT EARLY THIS EVENING AS COLD FRONT TRACKS EASTWARD THROUGH THE AREA. CONFIDENCE IN WINDS DIMINISHES LATE THIS AFTERNOON WITH UNCERTAINTY AS TO EXACT PLACEMENT OF WARM FRONTAL BOUNDARY...BUT WINDS SHOULD EVENTUALLY FAVOR SOUTHWEST LATER TONIGHT BEHIND THE COLD FRONT AS ANOTHER TROUGH OF LOW PRESSURE TRACKS ACROSS THE NORTHERN GREAT LAKES. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SHORT TERM...MARSILI LONG TERM...MARSILI AVIATION...MARSILI
AREA FORECAST DISCUSSION...UPDATED
NWS PADUCAH KY
1214 PM CST MON NOV 14 2011 .UPDATE... SHORT TERM /REST OF TODAY/ FORECAST UPDATE AND 18Z MONDAY ROUTINE TAF ISSUANCE DISCUSSION. && .DISCUSSION... THE CURRENT SEVERE CONVECTIVE ACTIVITY CLOSELY MATCHES THE 4KM NAM-WRF NMM REFLECTIVITY FIELDS...AS OF 18Z MONDAY. AT THIS TIME...ADJUSTED POP/WEATHER FIELDS TO REFLECT HIGHER CHANCES FOR SIGNIFICANT SHOWERS AND THUNDERSTORMS OVER SOUTHERN ILLINOIS AND INTO SOUTHWEST INDIANA THIS AFTERNOON. GIVEN THE SHARP SURFACE PRESSURE GRADIENT AND DOWNWARD MIXING OF LOW LEVEL WINDS...A MENTION OF GUSTY WINDS WAS ADDED TO THE ZONE OF THE HIGHEST POPS OVER THE INTERSTATE 64 CORRIDOR OVER SOUTHEAST IL/SOUTHWEST INDIANA EARLY THIS AFTERNOON AND THEN WORKING SOUTHWEST INTO PARTS OF SOUTHEAST MISSOURI AND THE REMAINDER OF SOUTHERN ILLINOIS. THE 13KM RUC AND 12KM NAM-WRF GUIDANCE STILL SUGGEST THAT ANY SIGNIFICANT /SEVERE WEATHER POTENTIAL/ THUNDERSTORM ACTIVITY COULD DEVELOP INTO PARTS OF SOUTHEAST ILLINOIS FROM 18Z-20Z...WORKING ACROSS SOUTHWEST INDIANA IN THE 19Z-21Z TIME FRAME. THERE ARE ALSO SOME INDICATIONS THAT THE LOW LEVEL LAPSE RATES WILL BECOME FAVORABLE FOR CONVECTIVE ACTIVITY TO LIGHT UP FURTHER SOUTHWEST INTO SOUTHEAST MISSOURI IN THE 22Z-01Z TIME FRAME...SO RAISED POP/WEATHER ACROSS THIS AREA LATE THIS AFTERNOON. /PREVIOUSLY ISSUED AT 236 AM CST MON NOV 14 2011/ BIGGEST CHALLENGES WITH THIS PACKAGE CONTINUE TO BE POPS AND QPF FROM TONIGHT INTO WEDNESDAY MORNING...THEN PRECIP CHANCES LATE IN THE PERIOD. A SURFACE LOW WILL SCOOT BY TO THE NORTH AND WEST OF OUR CWA TODAY. SIMILAR TO SUNDAY...THIS WILL CAUSE THE PRESSURE GRADIENT TO TIGHTEN BETWEEN THE LOW AND AN AREA OF HIGH PRESSURE CENTERED OVER THE SOUTHEAST US. THE BOTTOM LINE WILL BE ANOTHER GUSTY DAY OUT OF THE SOUTH SOUTHWEST...BUT TODAY WIND SPEEDS SHOULD REMAIN BELOW ADVISORY LEVELS. THE FRONT ASSOCIATED WITH THE AFOREMENTIONED LOW IS FORECAST TO MOVE INTO OUR CWA AND BECOME QUASI-STATIONARY ACROSS THE SOUTHEAST HALF OF OUR CWA BY TUESDAY MORNING. THE PRESENCE OF THE FRONT COMBINED WITH DEEPENING MOISTURE AND WEAK IMPULSES OF ENERGY ALOFT WILL INCREASE PRECIP CHANCES TODAY INTO TONIGHT...ESPECIALLY OVER THE SOUTHEAST HALF OF THE CWA TONIGHT. EVEN THOUGH INSTABILITY IS MODEST AT BEST...DEEP LAYER SHEAR...ESPECIALLY EAST OF A LINE FROM PINCKNEYVILLE ILLINOIS TO HICKMAN KENTUCKY...COULD CAUSE A FEW STORMS TO BECOME SEVERE THIS AFTERNOON WITH THE MAIN THREAT BEING DAMAGING WINDS BUT ALSO WITH A REMOTE CHANCE FOR ISOLATED TORNADOES...MAINLY OVER SOUTHWEST INDIANA. TUESDAY AS A SHARP H5 TROF LIFTS NORTHEAST OUT OF THE SOUTHERN PLAINS...IT WILL SERVE TO LIFT THE QUASI-STATIONARY FRONT AND MOISTURE FIELDS SLIGHTLY FARTHER NORTH...BUT THE HIGHEST POPS AND QPF ARE STILL EXPECTED TO REMAIN OVER THE SOUTHEAST HALF OF THE CWA. THIS SCENARIO IS EXPECTED TO CONTINUE THROUGH TUESDAY NIGHT. PRECIP WILL RAPIDLY DIMINISH FROM WEST TO EAST ON WEDNESDAY AS THE STORM SYSTEM FINALLY PULLS OFF TO THE EAST. STORM TOTAL PRECIP AT THIS TIME IS EXPECTED TO RANGE FROM .25-.50 INCHES OVER THE NORTHWEST SECTIONS OF THE CWA TO 2.75-3.0 INCHES OVER THE SOUTHEAST SECTIONS. MODELS HAVE BECOME MORE CONSISTENT HANDLING THE TRACK...TIMING...AND DURATION OF THIS SYSTEM...BUT THE SLIGHTEST SHIFT OF THE BOUNDARY OR ANY OF THE OTHER PRIMARY SYNOPTIC PARAMETERS COULD SIGNIFICANTLY AFFECT THE OUTCOME. IN THE WAKE OF THIS SYSTEM HIGH PRESSURE SHOULD KEEP THE REGION DRY AND COOLER THROUGH SATURDAY. BEYOND THAT THE NEXT STORM SYSTEM WILL BEGIN TO MOVE OUT OF THE PLAINS AND INTERACT WITH AVAILABLE MOISTURE PRODUCING PRECIP CHANCES THROUGH THE END OF THE FORECAST CYCLE. && .AVIATION... CURRENT 18Z TAF ISSUANCE SLIGHTLY DELAYED DUE TO SEVERE WEATHER PREPARATIONS. THE 12Z MONDAY TAF FORECAST ISSUANCE INITIALIZED FAIRLY WELL WITH WINDS AND CEILINGS...SO DID NOT MAKE ANY MEASURABLE CHANGES TO ONGOING FORECAST. THE MAIN ADJUSTMENT WAS MADE AS THE COLD FRONT STALLS ACROSS THE WFO PAH TAF SITES THIS EVENING AND INTO TUESDAY MORNING. THE KCGI TAF SITE WAS DISPLACED A LITTLE FARTHER AWAY FROM THE FRONTAL BOUNDAY...SO INTRODUCED MVFR VISIBILITIES/CEILINGS IN THE 11Z-14Z TUESDAY TIME FRAME. THE WORST CONDITIONS...LIFR CEILINGS AND MVFR VISIBILITIES WILL LIKELY HOLD NEAR KPAH...WITH SLIGHTLY HIGHER IFR CEILINGS EXPECTED TO DEVELOP AT KEVV AND KOWB. THE LOWER CEILINGS AND VISIBILITIES WILL LIKELY LAST INTO THE 18Z TUESDAY AND 00Z WEDNESDAY TIME FRAME FOR THE NEXT FORECAST ISSUANCE. && .PAH WATCHES/WARNINGS/ADVISORIES... KY...NONE. MO...NONE. IL...NONE. IN...NONE. && $$ AVIATION/NEAR TERM...SMITH
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
755 PM EST TUE NOV 15 2011 .SYNOPSIS... HIGH PRESSURE WILL CONTINUE OVER THE REGION THROUGH WEDNESDAY. A COLD FRONT OVER THE MIDWEST WILL SLIDE EASTWARD BRINGING SHOWERS AND A CHANCE OF THUNDERSTORMS OVERNIGHT WEDNESDAY INTO THURSDAY. MUCH COOLER AND DRIER AIR WILL FOLLOW ON THURSDAY AND FRIDAY. HIGH PRESSURE WILL MOVE OVERHEAD WITH TEMPERATURES MODERATING DURING THE WEEKEND. A SECOND FRONT WILL SHIFT TOWARD THE AREA ON TUESDAY. && .NEAR TERM /THROUGH WEDNESDAY/... AS OF 755 PM TUESDAY...THE ZONES BORDERING THE IMMEDIATE COASTAL WATERS WILL HAVE A CONTINUED THREAT OF SEA FOG OCCASIONALLY MOVING ONSHORE. THIS A RESULT OF SFC WINDS BOUNCING FROM 180-210 DEGREES. AS WINDS BECOME THE DOMINANT 210-230 DIRECTION AFTER DAYBREAK WEDNESDAY...THE THREAT FOR SEA FOG MOVING ONSHORE WILL DIMINISH. THE OCCURRENCE OF ISOLATED/SCATTERED -SHRA THIS EVENING WILL ALSO KEEP THE FOG AT BAY. THE LATEST AVAILABLE SST MAP OF THE WATERS OFF THE SE U.S. COAST USING AVHRR DATA FOR THE 2 DAYS ENDING ON NOV 14TH...INDICATED 2 PATCHES OF NOTEWORTHY COOL SHELF WATERS OFF THE CAROLINAS...WITH 12 BETWEEN SURF CITY AND CAPE FEAR...TO NEARLY OUT TO THE FRYING PAN SHOALS BUOY...41013. AND THE SECOND PATCH LYING ACROSS THE COASTAL WATERS BETWEEN NORTH MYRTLE BEACH TO SOUTH SANTEE RIVER. THIS 2ND ONE NOT AS PRONOUNCED AS THE 1ST. WITH SFC DEWPOINTS IN THE MID 60S TO NEAR 70 ADVECTING ACROSS THESE COOLER SHELF WATERS OVERNIGHT INTO WED...SEA FOG WILL CONTINUE TO DEVELOP AND AFFECT THE IMMEDIATE COAST BORDERING THE AFOREMENTIONED COLL SHELF WATER AREAS. A FEW LOCAL SURF CAMS HAVE ALSO SHOWCASED THE EXISTENCE OF THE SEA FOG AT TIMES. PREVIOUS MIN FORECAST FOR TONIGHT LOOKING ON TARGET AND SEE NO REASON TO ALTER AT THIS POINT. PREVIOUS DISCUSSION................................................ AS OF 300 PM...SURFACE HIGH PRESSURE COVERS THE WESTERN ATLANTIC AND IS LARGELY RESPONSIBLE FOR ADVECTING TROPICAL AIR NORTHWARD ALONG THE U.S. EAST COAST. THE UPPER LEVEL HIGH HAS PUSHED EAST OF THE BAHAMAS AND DEEP-LAYER SOUTHWEST FLOW COVERS THE CAROLINAS. IT TOOK NEARLY 5 HOURS FOR THIS MORNING`S LOW STRATUS ACROSS EASTERN SOUTH CAROLINA TO MIX OUT...HOWEVER THIS MOISTURE STILL EXISTS AND SHOULD RESULT IN THE DEVELOPMENT OF A NEW AND PERHAPS MORE EXPANSIVE STRATUS DECK OVERNIGHT. SHOWERS DEVELOPED THIS MORNING ALONG THE WESTERN EDGE OF THE GULF STREAM AND HAVE SO FAR REMAINED 20-60 MILES FROM SHORE. A CLUSTER OF SHOWERS HAS DEVELOPED CLOSER TO SHORE ALONG THE GEORGIA COAST AND MAY PUSH UP TOWARD THE CAPE FEAR WATERS EARLY THIS EVENING. GFS AND NAM MODELS SHOW SOME SYNOPTIC JET SUPPORT FOR REDEVELOPMENT OF ADDITIONAL SHOWERS NEAR CAPE FEAR OVERNIGHT. WE ARE UNSURE IF THESE SHOWERS WILL REMAIN OFFSHORE AND AFFECT LAND AREAS AS WELL...SO WE ARE MAINTAINING ONLY SMALL POPS ACROSS BRUNSWICK...NEW HANOVER AND PENDER COUNTIES...AND HAVE EXPANDED TO THE GRAND STRAND. LOWS TONIGHT ARE FORECAST TO RUN WELL ABOVE NORMALS GIVEN THE WARM AIRMASS...CLOUD COVER...A 30 KT LOW LEVEL JET...AND HIGH DEWPOINTS. LOWS SHOULD RANGE FROM 62-66...WARMEST ALONG THE NC COAST WHERE ONSHORE FLOW WILL BE STRONGEST. NWS CHARLESTON ALERTED US TO THE DEVELOPMENT OF SEA FOG OVER A PORTION OF THEIR FORECAST AREA THIS AFTERNOON. AS DEWPOINTS CONTINUE TO RISE...CONDITIONS HAVE BECOME CONDUCIVE FOR SEA FOG ALONG THE GRAND STRAND AND THE CAPE FEAR VICINITY. && .SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/... AS OF 3 PM TUESDAY...A LARGE SCALE UPPER LEVEL TROUGH OVER THE WESTERN UNITED STATES WILL SHIFT EASTWARD BY WEDNESDAY NIGHT AND THIS WILL PROVIDE GOOD SYNOPTIC LIFT FOR THE REGION. AT THE SURFACE A FRONTAL BOUNDARY WILL ACT AS THE LOW LEVEL LIFTING MECHANISM FOR SHOWERS AND ISOLATED THUNDERSTORMS. INSTABILITY IS FORECAST BY THE MODEL TO BE VERY LOW AND THE LOW-LEVEL 0 TO 2.5 KM BULK SHEAR MAGNITUDE REACHES ALMOST 40 KNOTS. THE LOW-LEVEL HELICITY MAXIMUM APPEARS TO BE SHIFTING FARTHER NORTH WITH THIS MODEL RUN AND IS RUNNING AHEAD OF THE MODEL CONVECTION...SO CONFIDENCE ON ISOLATED TORNADOES IS NOT VERY HIGH AT THIS TIME. MAXIMUM TEMPERATURES ARE EXPECTED TO REACH IN THE UPPER 70S INLAND ON WEDNESDAY AND WITH THE FRONTAL BOUNDARY PASSAGE HIGHS ARE EXPECTED TO ONLY REACH IN THE LOWER TO MIDDLE 60S ON THURSDAY. && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 3 PM TUESDAY...COLD SURFACE HIGH BUILDS INTO THE REGION FRI BEFORE QUICKLY SHIFTING NORTHEAST FRI NIGHT INTO SAT. WEAK COASTAL TROUGH DEVELOPS SAT WITH LOW LEVEL EAST TO NORTHEAST FLOW INCREASING MOISTURE IN THE LOWEST 3K FT OR SO. CURRENT FORECAST IS DEVOID OF PRECIP HOWEVER THE INCREASE IN LOW LEVEL MOISTURE COMBINED WITH DEVELOPING RETURN FLOW JUST ABOVE THE SURFACE LATER IN THE DAY SAT COULD PRODUCE SOME LIGHT PATCHY OF RAIN. WOULD NOT EXPECT MUCH QPF SHOULD SOMETHING DEVELOP WITH COASTAL NC THE MOST LIKELY AREA TO SEE SOMETHING. AT THE VERY LEAST ANTICIPATE AN INCREASE IN CLOUD COVER SAT INTO SUN. COASTAL TROUGH DISSIPATES SUN AS SURFACE RIDGE AXIS SHIFTS EAST OF THE AREA. ALTHOUGH DEVELOPING SOUTHERLY FLOW HELPS INCREASE LOW LEVEL MOISTURE SUN AND MON DRY MID LEVELS AND WEAK CAP...A RESULT OF BUILDING WEAK MID LEVEL RIDGE...WILL PREVENT ANY PRECIP. WEAK COLD FRONT STALLED NORTH OF THE AREA TUE WILL TRY AND DROP SOUTH DURING THE DAY. IF FRONT MOVES ACROSS THE AREA DO NOT THINK IT WOULD HAVE MUCH PRECIP ASSOCIATED WITH IT. THE FRONT IS STRETCHED OUT WITH THE DYNAMICS WELL OFF TO THE NORTHEAST. TEMPERATURES WILL RANGE FROM WELL BELOW CLIMO AT THE START OF THE PERIOD TO ABOVE CLIMO EARLY NEXT WEEK. THE TRANSITION FROM BELOW CLIMO TO ABOVE WILL BE QUICK...BY SAT NIGHT TEMPS SHOULD BE ABOVE CLIMO. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... AS OF 00Z...EXPECT CONTINUED AREAS OF PATCHY SEA FOG TO ADVECT ONSHORE AT KCRE/KMYR OVER THE NEXT COUPLE OF HOURS...REDUCING VSBYS OFF AND ON TO MVFR BEFORE FLOW FROM VEERING WINDS STEER FOG AWAY FROM TERMINALS AFTER DAYBREAK. FOR KILM...CURRENT RADAR DEPICTS SOME -SHRA OFFSHORE. CANNOT RULE OUT A LIGHT SHOWER TO WRAP AROUND TO TERMINAL...AND POSSIBLY THE TWO OTHER COASTAL SITES...THUS HAVE OPTED TO INCLUDE VCSH FOR A FEW HOURS. ELSEWHERE...VFR WILL PREVAIL THROUGH ROUGHLY 06Z WITH SOUTH- SOUTHWEST WINDS AROUND 5-8KTS. WITH MODELS IN GENERAL AGREEMENT...ANTICIPATE CIGS AND VSBYS AT ALL SITES DETERIORATE AFTER 07Z DUE TO ADVECTION FOG/STRATUS. FOR NOW...ANTICIPATE LIFR/IFR CIGS...AND IFR/MVFR FOG THROUGH WEDNESDAY MORNING. SOON AFTER DAYBREAK...EXPECT CONDITIONS TO SLOWLY IMPROVE TO VFR...WITH TIGHTENED PRESSURE GRADIENT CREATING GUSTY WINDS 18-22KTS ACROSS THE ENTIRE AREA. WINDS THROUGHOUT THE PERIOD WILL REMAIN SOUTH- SOUTHWEST. TOWARDS THE END OF THE VALID PERIOD INTO THE NEXT...CONDITIONS WILL SLOWLY BEGIN TO DETERIORATE AGAIN AS A COLD FRONT BRINGS ANTICIPATED SHRA AND ISOLATED TSRA. EXTENDED OUTLOOK...COLD FRONT MOVING ACROSS THE AREA WEDNESDAY EVENING THROUGH THURSDAY MORNING COULD CREATE ISOLATED TSRA AND IFR. EXPECT VFR FRIDAY AND SATURDAY...WITH LOWERED CONFIDENCE FOR POTENTIAL IFR FOG/STRATUS SUNDAY MORNING. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 755 PM TUESDAY...THIS UPDATE HAS FOCUSED ON THE REFINEMENT AND PLACEMENT OF THE SEA FOG THREAT ACROSS THE ILM WATERS. FROM THE UPDATE EARLIER...WILL CONTINUE TO INDICATE PATCHY/AREAS OF SEA FOG ACROSS THE ILM WATERS THROUGH OR JUST AFTER DAYBREAK WEDNESDAY. WITH THE LATEST AVAILABLE SST MAP OF THE ILM WATERS USING AVHRR DATA FOR THE 2 DAYS ENDING ON NOV 14TH...HAVING INDICATED 2 PATCHES OF NOTEWORTHY COOL SHELF WATERS...IE LOW TO MID 60S...WITH 1 BETWEEN SURF CITY AND CAPE FEAR...AND OUT TO NEARLY THE FRYING PAN SHOALS BUOY...41013. AND THE 2ND...LYING ACROSS THE WATERS BETWEEN NORTH MYRTLE BEACH TO SOUTH SANTEE RIVER. THIS 2ND ONE NOT NEARLY AS PRONOUNCED AS THE 1ST. SFC DEWPOINTS IN THE MID 60S TO NEAR 70 WILL CONTINUE TO ADVECT ACROSS THESE COOLER SHELF WATERS OVERNIGHT INTO WED. THIS WILL RESULT WITH AN INCREASED POTENTIAL FOR SEA FOG TO DEVELOP AND AFFECT THE ILM WATERS...PARTICULAR ACROSS THOSE COOL WATERS. A FEW LOCAL SURF CAMS HAVE EVEN SHOWCASED THE EXISTENCE OF THE SEA FOG. AS SYNOPTIC WINDS SLOWLY VEER FROM 190-230 OVERNIGHT INTO WED...THE THREAT FOR SEA FOG WILL SLOWLY DIMINISH OR ATLEAST KEEP THE FOG FROM ADVECTING ONSHORE/INLAND. WILL INDICATE VSBY REDUCING TO 1NM OR LESS. IF ANY RECEIVED REPORTS AND/OR OBS INDICATE 1/2 NM OR LESS VSBYS...WILL THEN UPDATE AND ADVERTISE DENSE FOG. HAVE MAINTAINED THE WINDS AND SEAS FORECAST FROM THE PREVIOUS FORECAST...WITH THE LATEST HRRR KEEPING WINDS AND SEAS ON THE LOWER SIDE OF MODEL GUIDANCE. PREVIOUS DISCUSSION................................................. AS OF 300 PM TUESDAY...HIGH PRESSURE IS MOVING FARTHER OFF THE EAST COAST WITH A VERY MOIST SOUTHWEST FLOW CONTINUING. MODELS ARE PAINTING VERY DIFFERENT SCENARIOS FOR WIND SPEEDS TONIGHT DEPENDING ON THE BEHAVIOR OF SHOWERS ALONG THE WESTERN WALL OF THE GULF STREAM. THE 12Z GFS AND NAM MODELS SHOW SYNOPTIC WINDS INCREASING TO 15-18 KT TONIGHT WHICH WOULD SUPPORT SEAS BUILDING TO NEARLY 5 FT NEAR AND EAST OF CAPE FEAR. TWO EXPERIMENTAL NAM RUNS UTILIZING DIFFERENT MODEL PHYSICS MAINTAIN EXTENSIVE SHOWERS AND THUNDERSTORMS ALONG THE WESTERN EDGE OF THE GULF STREAM OVERNIGHT WHICH DISRUPTS THE WIND FIELDS ALONG THE CAROLINA COAST AND RESULTS IN MUCH LOWER WIND SPEEDS. GIVEN THE PERSISTENCE OF CONVECTION SO FAR TODAY ALONG THE WEST WALL OF THE GULF STREAM OUR FORECAST SPLITS THE DIFFERENCE BETWEEN THOSE TWO SCENARIOS AND HAS WINDS BUILDING TO 12-15 KT OVERNIGHT WITH SEAS BUILDING TO NO HIGHER THAN 4 FT AT 20 MILES FROM SHORE. NWS CHARLESTON ALERTED US TO THE DEVELOPMENT OF SEA FOG NEAR TYBEE ISLAND...HILTON HEAD AND EDISTO BEACH THIS AFTERNOON. WITH PLENTY OF LOW-LEVEL MOISTURE EXPECTED OVERNIGHT SEA FOG MAY DEVELOP ALONG OUR PORTION OF THE SOUTH CAROLINA COAST AS WELL. WE ARE INCLUDING PATCHY FOG IN THE FORECAST WITHIN 5 MILES OF SHORE TONIGHT ALONG THE GRAND STRAND AND NEAR GEORGETOWN. SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 3 PM TUESDAY...A COLD FRONT WILL BE APPROACHING THE WATERS LATE WEDNESDAY INTO THURSDAY. SOUTHWEST WINDS WILL INCREASE THROUGH OUT THE DAY ON WEDNESDAY AND THE LOCAL SWAN MODEL IS INDICATING THE SEAS WILL REACH SMALL CRAFT CONDITIONS AROUND MIDNIGHT WEDNESDAY NIGHT-THURSDAY MORNING. AS THE FRONT PUSHES THROUGH THE COLD AIR ADVECTION WILL HELP PROVIDE AN ENVIRONMENT FOR 20 TO 25 KNOT OFF SHORE WINDS ON THURSDAY. LONG TERM /FRIDAY THROUGH SATURDAY/... AS OF 3 PM TUESDAY...POST FRONT COLD SURGE IN THE 15 TO 20 KT RANGE FRI WILL DROP CLOSER TO 10 KT BY SAT MORNING AS GRADIENT. WEAK COASTAL TROF TAKING SHAPE WILL INDUCE A MORE EASTERLY COMPONENT TO LOW LEVEL FLOW. GRADIENT REMAINS WEAK THROUGH THE END OF THE PERIOD WITH WINDS BECOMING EAST TO SOUTHEAST LATE SAT NIGHT AND SUN AS ELONGATED RIDGE AXIS SHIFTS OFFSHORE. ADVISORY WORTHY SEAS AT THE START OF THE PERIOD WILL DROP TO 3 TO 4 FT BY FRI NIGHT AND REMAIN IN THE 3 TO 4 FT RANGE THROUGH SUN. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...HAWKINS NEAR TERM...DOUGH/ARMSTRONG SHORT TERM...HAWKINS LONG TERM...III AVIATION...LACORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
515 PM EST MON NOV 14 2011 .SYNOPSIS... LOW PRESSURE MOVING ALONG THE LOWER GREAT LAKES WILL PUSH A FRONT SOUTHWARD ACROSS THE REGION TONIGHT. THE FRONT WILL STALL AROUND OR JUST TO THE SOUTH OF THE MARYLAND BORDER. ANOTHER WAVE OF LOW PRESSURE WILL ROLL ALONG THE FRONT BUT TO THE SOUTH OF THE AREA ON WEDNESDAY. THE UNSEASONABLY MILD TEMPERATURES WILL DROP BACK TO NORMALS LATER THIS WEEK AS A NOTICEABLY COLDER AIR MASS SETTLES IN. && .NEAR TERM /UNTIL 11 PM THIS EVENING/... SFC LOW TRACKING NE OVR LK ERIE THIS EVENING. LL JET TRANSPORTING INCREASINGLY MOIST/UNSTABLE AIR INTO NW PA SETTING THE STAGE FOR A ROUND OF TSRA LATER THIS EVENING AS TRAILING COLD FRONT ARRIVES OVR THE NW MTNS. MDL SIMULATED REFLECTIVITY INDICATES LINE OF TSRA WILL ARRIVE OVR WARREN COUNTY ARND 00Z. LATEST RUC SOUNDINGS INDICATE SUFFICIENT INSTABILITY WILL BE PRESENT ACROSS THE NW MTNS...COMBINED WITH PLENTY OF SHEAR...TO PRODUCE A SVR WX POTENTIAL THRU ARND MIDNIGHT. LATEST MDL DATA INDICATES MUCH OF CENTRAL AND SOUTHERN PA WILL REMAIN DRY THIS EVENING...SO HAVE REMOVED MENTION OF PRECIP. && .SHORT TERM /11 PM THIS EVENING THROUGH 6 PM TUESDAY/... FRONT PROGRESSES SOUTHWARD TONIGHT...AND WILL HOLD ONTO MENTIONS OF THUNDER FOR THE EARLY NIGHTTIME IN THE WEST. GUSTY WINDS ARE POSSIBLE WITH DEEP-ER CONVECTION. EXPECT ANY STORMS TO BE SHORT...BUT SVR WINDS NOT MORE THAN 3KFT OFF THE DECK EARLY TONIGHT. DRY IS THE WORD FOR THE BEGINNING OF THE PD IN THE SOUTH...AND MOISTURE AND FORCING BOTH DECREASE TONIGHT AS THE FRONT DIPS THROUGH THE AREA. SFC WINDS GO LIGHT AND AMBIENT MOISTURE COULD CREATE PATCHY FOG BUT NOT BAD/WIDESPREAD ENOUGH TO MENTION IN THE GRIDS. FRONT LOSES GOOD/VISIBLE WIND SHIFT AND LITTLE P-GRAD FOUND LATER TONIGHT AND TUES AM. THUS...IT MAY BE TOUGH TO PINPOINT WHERE THE HIGHER CHCS FOR PRECIP WILL BE TUES...BUT WILL BEND TOWARD THE SREF MEAN PRECIP FIELDS AND PAINT HIGHEST NUMBERS IN THE LAURELS WHERE UPSLOPE SHOULD HELP SQUEEZE SOME MOISTURE OUT...BUT DOWNSLOPE AND MORE-DISTANCE FROM THE WEAK MOISTURE FEED WILL MAKE IT A TOUGH FCST FOR PRECIP /NO OR YES/ IN THE LOWER SUSQ. HAVE KEPT HIGH POPS IN FOR THE DAYTIME BUT EXPECT QPF TO BE LOW LIKE TODAY/MONDAY HAS BEEN IN THE N. LOTS OF RADAR ECHOES LIKELY...BUT ONLY MINOR ACCUMS. MEAGER POS CAPES LATER TONIGHT AND TUES...BUT STABILITY INCREASES RATHER QUICKLY AFTER MIDNIGHT AND LASTS THRU ALL OF TUES. MAXES ON TUES WILL BE MILD AGAIN...BUT NOT AS TOASTY AS TODAY IN THE SOUTH WHERE THE CLOUDS WILL BE THICKEST. ALMOST UNIFORM 55-60F MAXES ARE EXPECTED. THESE ARE STILL 5-10F ABOVE NORMAL. && .LONG TERM /TUESDAY NIGHT THROUGH MONDAY/... BROAD SOUTHWESTERLY FLOW ALOFT IS FORECAST TO DOMINATE THE EASTERN US THROUGH MUCH OF THE PERIOD. A COLD FRONT IS FORECAST TO PUSH THROUGH THE OHIO VALLEY TUESDAY AND THE MIDDLE ATLANTIC REGION ON WEDNESDAY. THE PERIOD WILL START WET WITH RAINS ALONG THE FRONT THEN TURN DRY AS SFC HIGH PRESSURE BUILDS INTO THE REGION BEHIND THE FRONT. IN THE WAKE OF A COLD FRONT...IT WILL TURN MUCH COLDER LATER WEDNESDAY INTO THURSDAY...WITH 850 HPA TEMPERATURES DIPPING TO ABOUT 1 SD BELOW NORMAL. THE SOUTHERN EDGE OF A BROAD AREA OF STEEPER MID LEVEL LAPSE RATES WILL MOVE ACROSS NW AND NORTH CENTRAL PENN WED NIGHT AND THURSDAY LEADING TO NUMEROUS SNOW SHOWERS ACROSS THE NW MTNS...WITH SCATTERED SNOW SHOWERS FURTHER SOUTH AND EAST ACROSS THE ALLEGHENY PLATEAU. 850 HPA TEMPS ARE -6C BY WED NIGHT AND FALL FARTHER TO -8C...WITH A TROUGH OF VERY COLD 700 MB TEMPS NEAR -20C SLIDING ACROSS NRN PENN ON THURSDAY. IN ADDITION TO THE SNOW SHOWER THREAT...THE WINDS SHOULD PICK UP...PUSHING THE WIND CHILLS THROUGH THE 20S...AND INTO THE TEENS LATE THURSDAY AND THUR NIGHT. SOME ENSEMBLE MEMBERS AND MEDIUM RANGE MODEL GUIDANCE IMPLIES 1-3 INCHES OF SNOWFALL IS POSSIBLE ACROSS THE PERENNIAL SNOWBELT NEAR...AND TO THE WEST OF KBFD...WITH AN INCH OR LESS ELSEWHERE ACROSS THE HIGHER TERRAIN OF THE NORTH AND WEST. FOR THE SOUTHEAST HALF OF THE CWA...PARTLY TO MOSTLY CLOUDY SKIES WILL OCCUR IN THE WAKE OF THE CFRONT...WITH NOTHING MORE THAN A FEW LIGHT SNOW SHOWERS ACROSS THE CENTRAL RIDGE AND VALLEY REGION. TEMPERATURES MODERATE BACK TOWARD NORMAL THURSDAY NIGHT INTO FRIDAY...THAT PESKY RIDGE IN THE SOUTHEAST AND OVER THE WESTERN ATLANTIC WILL LIMIT THE SOUTHWARD PENETRATION OF THE FRONT. THE PW VALUES DROP BELOW NORMAL LATE WED AND STAY NORMAL OR BELOW NORMAL FROM THU-SUNDAY. THIS PERIOD SHOULD BE UNSEASONABLY DRY. WILL CONTINUE WITH BELOW NORMAL POPS FOR ALL OF THE REGION DURING THE THURSDAY NIGHT THROUGH SATURDAY PERIOD. AS THE TROUGH BUILDS OVER THE WESTERN US LATER THIS WEEK...THE SOUTHEASTERN RIDGE SHOULD PUSH WARMER AIR INTO OUR REGION SATURDAY. THE 850 HPA TEMPERATURES ARE PREDICTED TO BE 1SD ABOVE NORMAL LATE SATURDAY ACROSS THE NW PART OF THE STATE...AND AREA-WIDE ON SUNDAY. ANOTHER COLD FRONT APPROACHES WITH THE NEXT CHC FOR SHOWERS LATER SUNDAY INTO MONDAY. && .AVIATION /22Z MONDAY THROUGH SATURDAY/... TAFS UPDATED AT 21Z FOR CURRENT ACTIVITY. FOR THE TIME BEING... CONVECTION N OF PA. WILL KEEP THIS SHORT AND CONTINUE TO MONITOR THE RADAR ETC. EARLIER DISCUSSION BELOW. STABILITY MAY DIP ENOUGH TO PRODUCE ISOLD TSRA LATE THIS AFTN/EARLY EVENING IN THE WEST...BUT WILL ONLY KEEP A MENTION OF CB IN THOSE TAFS FOR NOW. CONFIDENCE OF THUNDER AT ANY POINT ALMOST NIL. PER LATEST MESO MDLS AND RADAR TRENDS...THE CURR AREA OF SHOWERS SHOULD LIFT OUT BY 22Z...AND A BREAK MAY OCCUR BEFORE A LINE OF STORMS COULD FORM ALONG THE FRONT VCTY OF LK ERIE. STRONG WINDS OF 40-50KT JUST 2-3KT ALOFT WILL MAKE LLWS AND MECH TURBULENCE THE GREATEST THREATS TO AVIATION THIS EVENING AND OVERNIGHT. BUT THESE WINDS MAY ALSO MIX DOWN IF ANY CONVECTION CAN DEVELOP AND GET DEEP ENOUGH. THE LINE OF STORMS WOULD MOST LIKELY BE ON THE FRONT AS IT PRESSES SOUTHWARD. VFR TO MVFR CONDS SHOULD PREVAIL FOR THE MOST PART WITH POST-FNTL IFR CIGS POSSIBLE AT BFD AFT 06Z...THEN KJST AFTER 09Z. LINGERING RAIN ON TUESDAY WILL PROBABLY KEEP THE CIGS AND VSBY IN MVFR FOR MOST SITES. KBFD MIGHT BE THE NICEST LOCATION. WINDS WILL BE LESS THAN 10KTS TUES AND THE STRONG WINDS ALOFT WILL ALSO SLACK OFF TO ONLY 30KT OR SO AT 2KFT. WILL CONTINUE TO CARRY LLWS FOR ALL SITES FOR MOST OF THE TAF VALID PD THOUGH. OUTLOOK... TUES NIGHT-WED...MVFR TO IFR IN PDS OF RAIN...ESP SOUTH. THU...MVFR TO IFR CIGS WEST WITH -SHSN. VFR TO MVFR EAST. FRI-SAT...NO SIG WX EXPECTED. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DANGELO NEAR TERM...DANGELO/FITZGERALD SHORT TERM...DANGELO LONG TERM...LAMBERT/GARTNER AVIATION...DANGELO/FITZGERALD/MARTIN
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1031 AM MST MON NOV 14 2011 .UPDATE...LATEST ANALYSIS SHOWS NORTHWEST FLOW CONTINUES OVER THE REGION WITH ISOLATED -SHRASN IN A NARROW BAND FROM SOUTHEASTERN MONTANA TO NEAR PIERRE IN CENTARL SD. EXPECT LAPSE RATES TO STEEPEN AGAIN DUE TO DIURNAL HEATING...WHICH WILL INCREASE THE COVERAGE OF SHOWERS AND CLOUDS THIS AFTERNOON. && .AVIATION...18Z TAF FCST ISOLD/SCT SHSN OR SHRA WILL BE POSSIBLE THROUGH THE FORECAST PERIOD OVER NERN WY AND WRN SD. BRIEF PERIODS OF LCL IFR VIS WILL BE POSSIBLE IN HEAVIER SHSN. OTHERWISE...VFR CONDITIONS ARE EXPECTED. && PREV DISCUSSION... /ISSUED 250 AM MST MON NOV 14 2011/ DISCUSSION...09Z SURFACE ANALYSIS HAS NORTHWEST FLOW OVER THE CWA. REGIONAL RADAR LOOPS HAD ISOLATED -SHSN FROM MT INTO SD IN A REGIME DOMINATED BY VERY STEEP LAPSE RATES...SEE 00Z KUNR SOUNDING...AND A BIT OF MLCAPE PER LATEST RUC ANALYSIS. WATER VAPOUR HAD MEAN LONGWAVE TROUGH OVER CENTRAL NORTH AMERICAN WITH DRY NORTHWEST FLOW FROM THE NORTHERN PLAINS INTO WESTERN CANADA. TODAY THROUGH TUESDAY...DIRTY NORTHWEST FLOW ALOFT WITH CONTINUE WITH VERY STEEP LAPSE RATES FROM 850-600MB. MOISTURE WILL BE LIMITED. HOWEVER...A PARADE OF SHORTWAVES WITH RATHER COLD 500MB AIR WILL TRAVERSE THE CWA. SHOULD SEE ISOLATED SHOWERS THROUGH TUESDAY NIGHT ACROSS THE AREA. A COLDER PUSH OF AIR DROPS IN TONIGHT WITH THE BEST 850-700MB FRONTOGENESIS. 850MB WINDS WILL BE 20-35KTS THROUGH THE PERIOD AND THAT COMBINED WITH DEEP MIXING WILL SUPPORT WINDY/GUSTY WEST/NORTHWEST WINDS. PRECIPITATION TYPE SHOULD LEAN STRONGLY TOWARD -SHSN TONIGHT INTO TUESDAY NIGHT GIVEN LOWER TROPOSPHERIC THERMAL PROFILES. CHILLY DAY EXPECTED TUESDAY. WEDNESDAY...UPPER FLOW SLOWLY BECOME LESS CYCLONIC WITH UPPER RIDGE BUILDING OVER THE ROCKIES. STILL COLD THOUGH GIVEN 850-700MB TEMPERATURES. EXTENDED...UPPER RIDGE SLIDES ACROSS THE NORTHERN PLAINS ON THURSDAY...WITH ABOVE AVERAGE TEMPS AND DRY CONDITIONS EXPECTED. STRONG UPPER TROF PUSHES THROUGH THE WEST COAST FRIDAY...WITH UPPER FLOW SHIFTING SOUTHWEST OVER OUR AREA. WEAK ENERGY WILL EJECT OVER THE AREA AHEAD OF THE TROF AS IT SLOWLY APPROACHES...BRINGING CHANCES FOR PRECIP LATE FRIDAY. BETTER CHANCES FOR PRECIP WILL OCCUR OVER THE WEEKEND AS UPPER TROF SLIDES ACROSS THE NORTHERN PLAINS. TEMPERATURES WILL FALL TO BELOW AVERAGE FROM FRIDAY INTO THE WEEKEND. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...NONE. WY...NONE. && $$
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
505 AM MST MON NOV 14 2011 .AVIATION...12Z TAFS SFC WINDS WILL REMAIN MOSTLY WESTERLY AT 10-20 KTS THROUGH THIS MORNING...AND INCREASE TO 15 TO 25 KTS THIS AFTERNOON. ISOLATED TO SCATTERED -SHRA/SHSN WILL CONTINUE TO CROSS NERN WY AND WRN SD FROM WEST TO EAST THROUGH THE DAY...PRODUCING LOCALIZED MVFR CONDITIONS. && .PREV DISCUSSION... /ISSUED 250 AM MST MON NOV 14 2011/ DISCUSSION...09Z SURFACE ANALYSIS HAS NORTHWEST FLOW OVER THE CWA. REGIONAL RADAR LOOPS HAD ISOLATED -SHSN FROM MT INTO SD IN A REGIME DOMINATED BY VERY STEEP LAPSE RATES...SEE 00Z KUNR SOUNDING...AND A BIT OF MLCAPE PER LATEST RUC ANALYSIS. WATER VAPOUR HAD MEAN LONGWAVE TROUGH OVER CENTRAL NORTH AMERICAN WITH DRY NORTHWEST FLOW FROM THE NORTHERN PLAINS INTO WESTERN CANADA. TODAY THROUGH TUESDAY...DIRTY NORTHWEST FLOW ALOFT WITH CONTINUE WITH VERY STEEP LAPSE RATES FROM 850-600MB. MOISTURE WILL BE LIMITED. HOWEVER...A PARADE OF SHORTWAVES WITH RATHER COLD 500MB AIR WILL TRAVERSE THE CWA. SHOULD SEE ISOLATED SHOWERS THROUGH TUESDAY NIGHT ACROSS THE AREA. A COLDER PUSH OF AIR DROPS IN TONIGHT WITH THE BEST 850-700MB FRONTOGENESIS. 850MB WINDS WILL BE 20-35KTS THROUGH THE PERIOD AND THAT COMBINED WITH DEEP MIXING WILL SUPPORT WINDY/GUSTY WEST/NORTHWEST WINDS. PRECIPITATION TYPE SHOULD LEAN STRONGLY TOWARD -SHSN TONIGHT INTO TUESDAY NIGHT GIVEN LOWER TROPOSPHERIC THERMAL PROFILES. CHILLY DAY EXPECTED TUESDAY. WEDNESDAY...UPPER FLOW SLOWLY BECOME LESS CYCLONIC WITH UPPER RIDGE BUILDING OVER THE ROCKIES. STILL COLD THOUGH GIVEN 850-700MB TEMPERATURES. EXTENDED...UPPER RIDGE SLIDES ACROSS THE NORTHERN PLAINS ON THURSDAY...WITH ABOVE AVERAGE TEMPS AND DRY CONDITIONS EXPECTED. STRONG UPPER TROF PUSHES THROUGH THE WEST COAST FRIDAY...WITH UPPER FLOW SHIFTING SOUTHWEST OVER OUR AREA. WEAK ENERGY WILL EJECT OVER THE AREA AHEAD OF THE TROF AS IT SLOWLY APPROACHES...BRINGING CHANCES FOR PRECIP LATE FRIDAY. BETTER CHANCES FOR PRECIP WILL OCCUR OVER THE WEEKEND AS UPPER TROF SLIDES ACROSS THE NORTHERN PLAINS. TEMPERATURES WILL FALL TO BELOW AVERAGE FROM FRIDAY INTO THE WEEKEND. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...NONE. WY...NONE. && $$ SHORT TERM...HELGESON LONG TERM....15 AVIATION...15
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
250 AM MST MON NOV 14 2011 .DISCUSSION...09Z SURFACE ANALYSIS HAS NORTHWEST FLOW OVER THE CWA. REGIONAL RADAR LOOPS HAD ISOLATED -SHSN FROM MT INTO SD IN A REGIME DOMINATED BY VERY STEEP LAPSE RATES...SEE 00Z KUNR SOUNDING...AND A BIT OF MLCAPE PER LATEST RUC ANALYSIS. WATER VAPOUR HAD MEAN LONGWAVE TROUGH OVER CENTRAL NORTH AMERICAN WITH DRY NORTHWEST FLOW FROM THE NORTHERN PLAINS INTO WESTERN CANADA. TODAY THROUGH TUESDAY...DIRTY NORTHWEST FLOW ALOFT WITH CONTINUE WITH VERY STEEP LAPSE RATES FROM 850-600MB. MOISTURE WILL BE LIMITED. HOWEVER...A PARADE OF SHORTWAVES WITH RATHER COLD 500MB AIR WILL TRAVERSE THE CWA. SHOULD SEE ISOLATED SHOWERS THROUGH TUESDAY NIGHT ACROSS THE AREA. A COLDER PUSH OF AIR DROPS IN TONIGHT WITH THE BEST 850-700MB FRONTOGENESIS. 850MB WINDS WILL BE 20-35KTS THROUGH THE PERIOD AND THAT COMBINED WITH DEEP MIXING WILL SUPPORT WINDY/GUSTY WEST/NORTHWEST WINDS. PRECIPITATION TYPE SHOULD LEAN STRONGLY TOWARD -SHSN TONIGHT INTO TUESDAY NIGHT GIVEN LOWER TROPOSPHERIC THERMAL PROFILES. CHILLY DAY EXPECTED TUESDAY. WEDNESDAY...UPPER FLOW SLOWLY BECOME LESS CYCLONIC WITH UPPER RIDGE BUILDING OVER THE ROCKIES. STILL COLD THOUGH GIVEN 850-700MB TEMPERATURES. EXTENDED...UPPER RIDGE SLIDES ACROSS THE NORTHERN PLAINS ON THURSDAY...WITH ABOVE AVERAGE TEMPS AND DRY CONDITIONS EXPECTED. STRONG UPPER TROF PUSHES THROUGH THE WEST COAST FRIDAY...WITH UPPER FLOW SHIFTING SOUTHWEST OVER OUR AREA. WEAK ENERGY WILL EJECT OVER THE AREA AHEAD OF THE TROF AS IT SLOWLY APPROACHES...BRINGING CHANCES FOR PRECIP LATE FRIDAY. BETTER CHANCES FOR PRECIP WILL OCCUR OVER THE WEEKEND AS UPPER TROF SLIDES ACROSS THE NORTHERN PLAINS. TEMPERATURES WILL FALL TO BELOW AVERAGE FROM FRIDAY INTO THE WEEKEND. && .AVIATION...06Z TAF UPDATE SFC WINDS WILL REMAIN MOSTLY WESTERLY AT 10-20 KTS THROUGH THIS MORNING...AND INCREASE TO 15 TO 25 KTS THIS AFTERNOON. ISOLATED TO SCATTERED -SHRA/SHSN WILL CONTINUE TO CROSS NERN WY AND WRN SD FROM WEST TO EAST THROUGH THE DAY...PRODUCING LOCALIZED MVFR CONDITIONS. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...NONE. WY...NONE. && $$ SHORT TERM...HELGESON LONG TERM....15 AVIATION...15
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
926 PM CST TUE NOV 15 2011 .AVIATION/06Z TAFS/... VFR/MOSTLY CLEAR THROUGH THE TAF FORECAST PERIOD. THE COLD FRONT HAS PUSHED EAST AND INCREASING WEST TO NORTHWEST WINDS CAN BE EXPECTED. SFC WINDS TONIGHT WILL BE DECOUPLED FROM THE STRONGER WINDS ABOUT 1KFT AGL. THUS WILL CONTINUE LOW LEVEL WIND SHEER IN THE TAFS THROUGH ABOUT 12-13Z WEDNESDAY. WINDS WILL INCREASE QUICKLY TO ABOUT 35KTS AT 1KFT. && .PREV DISCUSSION... /ISSUED 328 PM CST TUE NOV 15 2011/ TONIGHT AND WEDNESDAY...FORECAST CONFIDENCE HIGH. SURFACE LOW PRESSURE TRACKING FROM NORTHERN WI TO LAKE SUPERIOR WILL DRAG A COLD FRONT ACROSS SOUTHERN WISCONSIN THIS EVENING. SURFACE WINDS WILL SHIFT FROM SOUTHWEST TO WEST EARLY THIS EVENING IN MADISON...LATER THIS EVENING IN MILWAUKEE. WINDS WILL THEN VEER TO THE WNW AFTER MIDNIGHT. TEMPERATURES WILL BE SLOW TO COOL THIS EVENING...BUT THEN DROP RAPIDLY AFTER MIDNIGHT WITH THE COLD AIR ADVECTION BEHIND THE SFC TROUGH/FRONT. LOWS EXPECTED IN THE MID TO UPPER 20S...WARMEST NEAR THE LAKE. 850MB TEMPS WILL BE AROUND -8 TO -10C OVERNIGHT...POSSIBLY THE COLDEST SO FAR THIS SEASON. WINDS SHOULD DECOUPLE THIS EVENING WITH AN INVERSION SETTING UP...THEN HAVE A BETTER POTENTIAL TO GUST AFTER MIDNIGHT...BUT ESPECIALLY EARLY WED MORNING...WITH THE COLD AIR ADVECTION. THE NAM SNDGS SHOW A STRONGER INVERSION THAN THE RUC AND GFS...BUT MAKE SENSE. EXPECT WNW WINDS THROUGH THE DAY ON WEDNESDAY...WITH GUSTS UP TO 25 KNOTS LIKELY...ESPECIALLY IN THE MORNING. THE PRESSURE GRADIENT WILL SLOWLY RELAX WED AFTERNOON AS HIGH PRESSURE RIDGES INTO SOUTHERN WI. SHORT TERM...WEDNESDAY NIGHT THROUGH FRIDAY...FORECAST CONFIDENCE MEDIUM TO HIGH. SECONDARY COLD FRONT SHIFTS SOUTHEAST THROUGH THE AREA WEDNESDAY NIGHT...WITH SOME MORE COLD AIR ADVECTION IN ITS WAKE. PASSING VORTICITY MAXIMUM FIGHTING SOMEWHAT DRY AIRMASS OVER THE AREA...SO LEFT OUT MENTION OF FLURRIES. COLDER TEMPERATURES EXPECTED TO CONTINUE...WITH LOWS IN THE LOWER TO MID 20S PER 925MB TEMPERATURES OF 5 TO 9 BELOW ZERO. WARM AIR ADVECTION BEGINS THURSDAY...AND CONTINUES THURSDAY NIGHT AND FRIDAY ACROSS THE AREA. THURSDAY SHOULD STILL REMAIN COLD...WITH HIGHS ONLY IN THE MID TO UPPER 30S. TEMPERATURES WILL WARM THURSDAY NIGHT AND FRIDAY...AS WINDS SHIFT SOUTH/SOUTHWEST AND BECOME GUSTY WITH A TIGHTENING PRESSURE GRADIENT. HIGHS SHOULD RISE INTO THE MID TO UPPER 40S FRIDAY...WITH THE FAIRLY DRY AIRMASS LINGERING WITH CONTINUED WARM AIR ADVECTION. LONG TERM...FRIDAY NIGHT THROUGH TUESDAY...FORECAST CONFIDENCE MEDIUM. STRONG LOW PRESSURE WILL FORM IN THE CENTRAL PLAINS FRIDAY NIGHT...THEN SHIFT NORTHEAST INTO THE REGION SATURDAY...THEN NORTHEAST OF THE AREA SATURDAY NIGHT. THE GFS/CANADIAN/00Z ECMWF DIFFER SOMEWHAT WITH TIMING AND PLACEMENT OF THE LOW. THE CANADIAN IS QUICKEST NORTHEAST INTO THE AREA...ACROSS CENTRAL WISCONSIN BY 00Z SUNDAY. THE GFS/00Z ECMWF ARE SLOWER AND OVER NORTH CENTRAL/NORTHEAST IOWA AT 00Z SUNDAY. ALL MODELS BRING FOCUSED WARM AIR ADVECTION AND FRONTOGENESIS RESPONSE THROUGH THE REGION SATURDAY...WITH AREA THEN GETTING INTO THE WARM SECTOR. COLD FRONT THEN SHIFTS EAST THROUGH THE AREA SATURDAY NIGHT. MAIN SHORTWAVE TROUGH STAYS NORTHWEST OF THE AREA DURING THIS TIME. KEPT HIGH END CHANCE POPS FOR SATURDAY...THEN TRENDED DOWNWARD SATURDAY NIGHT. KEPT SLIGHT CHANCES FOR THUNDER SATURDAY WITHIN WARM SECTOR AND WEAK INSTABILITY IN LOW LEVELS WITH STRONG DYNAMICS...AND SATURDAY NIGHT ACROSS THE SOUTHEAST COUNTIES. COLDER AIR QUICKLY WRAPS INTO THE BACKSIDE OF SYSTEM LATER SATURDAY NIGHT...SO MENTIONED CHANCES FOR A MIX OF RAIN AND SNOW SHOWERS IN THE NORTHWEST HALF OF THE AREA. MAY HAVE TO RAISE POPS IN SUBSEQUENT FORECASTS IF MODELS CONTINUE TO SHOW GENERAL AGREEMENT WITH THIS SYSTEMS. MODELS THEN IN FAIR AGREEMENT WITH HIGH PRESSURE MOVING INTO THE REGION SUNDAY...THEN SLOWLY EAST SOUTHEAST ACROSS THE REGION THROUGH TUESDAY. THEY ALSO SHOW A SHORTWAVE TROUGH MOVING THROUGH THE REGION MONDAY...WITH THE GFS ABOUT SIX HOURS SLOWER THAN THE 00Z ECMWF. SOME QUESTION AS TO THE AMOUNT OF MOISTURE AVAILABLE WITH THIS FEATURE. FOR NOW...WILL MAINTAIN SLIGHT CHANCE POPS FOR LIGHT RAIN AND SNOW SHOWERS. THE REST OF THIS PERIOD APPEARS TO BE DRY. COOL TEMPERATURES SHOULD LINGER DURING THIS PERIOD AS WELL. AVIATION/00Z TAFS/... SURFACE LOW PRESSURE WILL TRACK FROM NORTHERN WISCONSIN TO LAKE SUPERIOR THIS EVENING...AND DRAG A COLD FRONT ACROSS SOUTHERN WI. VFR CONDITIONS THROUGH THE PERIOD. WINDS WILL GRADUALLY VEER WEST THIS THIS EVENING...THEN WNW AND INCREASE AFTER MIDNIGHT WITH COLDER AIR WORKING INTO THE REGION BEHIND THE FRONT. LOW LEVEL WIND SHEAR EXPECTED AFTER MIDNIGHT AT ALL TAF SITES. WIND GUSTS WILL INCREASE TOWARD WED MORNING AS THE INVERSION ERODES AWAY WITH COLD AIR ADVECTION. BRISK DAY ON WED...WITH GUSTS TO 25 KNOTS POSSIBLE. MARINE... SMALL CRAFT ADVISORY IN EFFECT THROUGH WEDNESDAY AFTERNOON AS LOW PRESSURE TRACKS FROM NORTHERN WI THROUGH LAKE SUPERIOR AND INTO ONTARIO. THERE WILL BE A LULL IN THE WINDS THIS EVENING AS THE SURFACE TROUGH CROSSES LAKE MICHIGAN...THEN WINDS WILL INCREASE TOWARD WEDNESDAY MORNING AS COLD AIR WORKS INTO THE AREA BEHIND THE FRONT. WINDS WILL EASE IN THE AFTERNOON...FALLING BELOW SMALL CRAFT ADVISORY CRITERIA BY EVENING. SURFACE HIGH PRESSURE WILL BUILD INTO SOUTHERN WI AND LAKE MICHIGAN ON THURSDAY. THE PRESSURE GRADIENT WILL INCREASE ONCE AGAIN BETWEEN THE HIGH IN THE SOUTHERN U.S. AND LOW PRESSURE MOVING THROUGH THE UPPER MIDWEST. SMALL CRAFT ADVY POTENTIAL ONCE AGAIN ON FRIDAY. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...SMALL CRAFT ADVISORY UNTIL 6 PM CST WEDNESDAY FOR LMZ643>646. && $$ UPDATE...DAVIS TONIGHT/WEDNESDAY AND AVIATION/MARINE...MRC WEDNESDAY NIGHT THROUGH TUESDAY...WOOD
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
958 AM MST MON NOV 14 2011 .UPDATE...STRONG DOWNSLOPING WINDS OFF THE LARAMIE RANGE HAS CAUSED DEWPOINTS TO REALLY BEGIN TO DRY OUT THIS MORNING ACROSS THE SOUTHERN PANHANDLE. LATEST HRRR FORECAST SHOWING TDS DROPPING INTO THE SINGLE DIGITS OUT THAT WAY THIS AFTERNOON WITH AFTERNOON MIN HUMIDITIES DROPPING INTO THE LOW TEENS. WENT AHEAD AND ISSUED A RED FLAG WARNING FOR FIRE WEATHER ZONE 313 IN THE SOUTHERN PANHANDLE TO ACCOUNT FOR THE LOW HUMIDITIES AND STRONG WINDS. UPDATES HAVE BEEN SENT. CLAYCOMB && AVIATION...18Z TAFS. VFR OVER ALL TERMINALS THROUGH TUESDAY BUT SOME HIGHER MTN OBSCURATIONS EXPECTED. STRONG AND GUSTY WINDS EXPECTED OVER MAINLY SE WY TERMINALS THROUGH THIS AFTERNOON THEN EASING SOME THIS EVENING. && PREV DISCUSSION... /ISSUED 358 AM MST MON NOV 14 2011/ SHORT TERM...TODAY THROUGH WEDNESDAY... WATER VAPOR IMAGERY SHOWED A BROAD UPPER TROUGH ENCOMPASSING MUCH OF THE CONUS. A SHORTWAVE TROUGH WAS MOVING EAST ACROSS WESTERN COLORADO AND ANOTHER THROUGH THE DAKOTAS. THE REGIONAL SURFACE ANALYSIS DEPICTED A COLD FRONT FROM A LOW NORTHEAST OF FARGO SOUTHWESTWARD INTO WEST CENTRAL NEBRASKA. HIGH PRESSURE PREVAILED OVER SOUTHERN WYOMING AND NORTHERN COLORADO. WESTERLY SURFACE WINDS WERE GUSTING BETWEEN 35 AND 55 MPH OVER MUCH OF SOUTHEAST WYOMING COURTESY OF A TIGHT PRESSURE GRADIENT AND 50-60 KT 700 MB WINDS. TEMPERATURES AT 3 AM WERE IN THE 20S AND 30S. THE 00Z SHORT RANGE NUMERICAL MODEL GUIDANCE OUTPUT REVEALED GOOD RUN-TO-RUN CONSISTENCY. IT MAINTAINS THE BROAD UPPER TROUGH ACROSS MUCH OF NORTH AMERICA DURING THE SHORT TERM...WITH THE NORTH TO SOUTH AXIS OVER THE GREAT PLAINS. THIS PATTERN WILL PROVIDE A FAST NORTHWEST FLOW ALOFT WITH SEVERAL EMBEDDED SHORTWAVES. ONE WAVE MOVES SOUTHEAST FROM MONTANA INTO NORTHERN AND EASTERN WYOMING TONIGHT AND THE DAKOTAS ON TUESDAY. MOISTURE WILL BE LIMITED... BUT DYNAMICS AND STEEP LAPSE RATES WILL BE SUFFICIENT TO SQUEEZE OUT SOME LIGHT SNOW OR FLURRIES TONIGHT FOR AREAS NORTH OF A LINE FROM DOUGLAS TO CHADRON. WILL SEE A RETURN OF SCATTERED SNOW SHOWERS TO THE SNOWY AND SIERRA MOUNTAIN RANGES TONIGHT AND LASTING INTO TUESDAY NIGHT DUE TO NORTHWEST FLOW... WEAK INSTABILITY AND OROGRAPHICS. TODAY/S CONCERN WILL BE THE STRONG WESTERLY WINDS AS 700 MB WINDS RANGE FROM 50 TO 60 KT ACROSS SOUTHEAST WYOMING...RESULTING IN SURFACE WIND GUSTS OF 55 TO 70 MPH ALONG THE INTERSTATE 80 AND 25 WIND CORRIDORS. THE HIGH WIND WARNING REMAINS IN EFFECT UNTIL 6 PM MST FOR THESE AREAS. FURTHER EAST ACROSS THE WESTERN NEBRASKA PANHANDLE...SUSTAINED WINDS TODAY WILL BE CLOSE TO ADVISORY CRITERIA AT 20 TO 30 MPH WITH GUSTS TO 40 MPH. THE WINDS WILL SLOWLY START TO DIMINISH TONIGHT AS THE PRESSURE GRADIENT BEGINS TO RELAX A BIT. GUSTS OF 45 TO 55 MPH ARE EXPECTED ACROSS SOUTHEAST WYOMING TONIGHT. THE DECREASING WIND TREND WILL CONTINUE TUESDAY THROUGH WEDNESDAY AS WINDS ALOFT WEAKEN AND PRESSURE GRADIENT RELAXES FURTHER. HIGH TEMPERATURES TODAY WILL REMAIN 5 TO 10 DEGREES ABOVE NORMAL WITH UPPER 40S AND 50S. THE NEXT COLD FRONT TO AFFECT THE CWA WILL PUSHING SOUTH THROUGH MONTANA AND NORTH DAKOTA LATER TODAY...CENTRAL WYOMING AND NORTHERN NEBRASKA TONIGHT...AND EASTERN COLORADO AND CENTRAL KANSAS TUESDAY MORNING. HIGH TEMPERATURES ON TUESDAY WILL BE 5 TO 10 DEGREES COOLER...ESPECIALLY ALONG AND EAST OF THE LARAMIE RANGE IN THE POST-FRONTAL AIRMASS. ANOTHER SHORTWAVE IS FORECAST TO MOVE SOUTHEAST ACROSS EASTERN WYOMING AND THE DAKOTAS TUESDAY NIGHT WITH ISOLATED SNOW SHOWERS DEVELOPING FROM THE NORTHERN LARAMIE RANGE EAST INTO THE NORTHERN NEBRASKA PANHANDLE. THE FLOW ALOFT WEDNESDAY BECOMES LESS CYCLONIC WITH THE DEPARTURE OF THE SHORTWAVE TROUGH TO THE EAST AND WEAK RIDGING UPSTREAM. A SURFACE RIDGE BUILDS INTO THE REGION...PROMOTING DRY AND STABLE CONDITIONS. HIGH TEMPERATURES WEDNESDAY WILL BE A FEW DEGREES COOLER THAN TUESDAY FOLLOWING THE PASSAGE OF ANOTHER COLD FRONT. LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY. 14/00Z NAM...GFS AND ECMWF SIMILAR WITH THEIR 500 MB SYNOPTIC PATTERNS...THUS HIGH CONFIDENCE IN THEIR RESPECTIVE MODEL SOLUTIONS. WEDNESDAY NIGHT/THURSDAY...FLOW ALOFT BACKS TO ZONAL...WEST TO EAST... THUS INDUCING A DECENT WARMING TREND AS SURFACE LEE TROUGHING BECOMES WELL ESTABLISHED FROM EASTERN MONTANA THROUGH EASTERN WYOMING TO EASTERN COLORADO. DRY WITH LACK OF LOW AND MID LEVEL MOISTURE. BREEZY TO WINDY WITH PROGGED UNIDIRECTIONAL SURFACE THROUGH 700 MB GRADIENTS. MAXIMUM TEMPERATURES 40S WEST AND 50S EAST WITH 1000-500 MB THICKNESSES NEAR 5520 METERS. FRIDAY...FLOW ALOFT BACKS EVEN FURTHER TO SOUTHWEST IN ADVANCE OF APPROACHING TROUGH FROM THE GREAT BASIN STATES. GFS HINTS AT A BACKDOOR COLD FRONT ENTERING OUR NORTHEAST COUNTIES FROM DOUGLAS TO KIMBALL...THOUGH STILL TOO EARLY TO TELL WHERE THIS FRONTAL BOUNDARY WILL END UP. ALTHOUGH THE BULK OF PRECIPITATION WILL FALL OVER WESTERN WYOMING...WILL MESH WITH OUR RIVERTON NEIGHBORS TO THE WEST AND INCLUDE SOME LOW CHANCE POPS WEST OF A DOUGLAS TO LARAMIE LINE WITH DEEPENING LOW AND MID LEVEL MOISTURE LIFTED BY OROGRAPHICS AND DYNAMICS. SATURDAY...INITIAL SHORTWAVE TROUGH ALOFT MOVES ACROSS WYOMING SPREADING SNOWFALL ACROSS OUR COUNTIES AND BRINGING IN A COLDER AIRMASS IN THE WAKE OF THE SHORTWAVE TROUGHS ASSOCIATED COLD FRONT. SUNDAY...UNSETTLED PATTERN CONTINUES WITH LOW AMPLITUDE TROUGHING ACROSS MONTANA AND WYOMING AND MOIST WEST FLOW ALOFT ACROSS WYOMING PRODUCING OROGRAPHIC SNOWS ACROSS OUR SIERRA MADRE AND SNOWY RANGES WITH MOSTLY DRY WEATHER ELSEWHERE. FIRE WEATHER... STRONG WINDS ALOFT AND A TIGHT PRESSURE GRADIENT WILL CONTINUE TO GENERATE WINDY CONDITIONS TODAY. WINDS WILL GUST FROM 55 TO 70 MPH ACROSS SOUTHEAST WYOMING...AND 30 TO 40 MPH FOR THE WESTERN NEBRASKA PANHANDLE. THE WINDS WILL GRADUALLY DIMINISH TONIGHT AND TUESDAY WITH THE RELAXING GRADIENT. MINIMUM RELATIVE HUMIDITIES TODAY WILL RANGE BETWEEN 25 AND 35 PERCENT EAST OF THE LARAMIE RANGE...AND 30 TO 40 PERCENT TUESDAY. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...HIGH WIND WARNING UNTIL 6 PM MONDAY FOR WYZ103-WYZ104-WYZ105- WYZ106-WYZ109-WYZ110-WYZ113-WYZ115-WYZ116-WYZ117-WYZ118. NE...RED FLAG WARNING UNTIL 5 PM MONDAY FOR NEZ019-NEZ020-NEZ021- NEZ054-NEZ055. && $$ SHORT TERM...JAMSKI LONG TERM/AVIATION...RUBIN
AREA FORECAST DISCUSSION
NWS DENVER CO
1149 PM MST TUE NOV 15 2011 .UPDATE... && .SHORT TERM...WINDS IN THE DENVER METRO AREA JUST SHIFTED TO A NORTHERLY DIRECTION WITH PASSAGE OF A WEAK FRONTAL BOUNDARY WHICH IS BEING PUSHED SOUTHWARD BY 2-3MB PRESSURE RISE COUPLET ALONG THE COLORADO/WYOMING BORDER. WIND SPEEDS IMMEDIATELY BEHIND THIS BOUNDARY IN THE 10-20KT RANGE. WIND SHIFT/SURGE NOT HANDLED WELL BY THE MODELS EXCEPT FOR THE RUC. ALTHOUGH THE RUC WAS A BIT PREMATURE TO MOVE THIS WIND SHIFT THROUGH THE METRO AREA. AT ANY RATE...UPDATED WIND AND WIND GUST GRIDS OUT TO 18Z USING THE LATEST RUC AND HRRR MODEL RUNS TO ACCOUNT FOR THE CURRENT WIND SHIFT AND TO REFLECT THE NORTHERLY WIND PATTERN EXPECTED ON THE PLAINS DURING THE DAY. .AVIATION...JUST UPDATED DENVER AREA TERMINAL FORECASTS TO REFLECT THE SHIFT THE NORTHERLY WINDS WITH PASSAGE OF A WEAK FRONTAL BOUNDARY. NEXT FEW HOURS SHOULD SEE WINDS IN THE METRO AREA ASSUMING A SOMEWHAT TYPICAL DRAINING PATTERN...ONLY TO SWING AROUND TO A NORTHERLY COMPONENT AROUND MID-MORNING WITH HEATING AND MIXING. && .PREV DISCUSSION... /ISSUED 952 PM MST TUE NOV 15 2011/ UPDATE... SHORT TERM...JET RELATED LIFT HAS RESOLVED INTO TWO SHOWER BANDS. THE MAIN ONE IS NOW FROM SOUTHERN SUMMIT COUNTY OUT TO WASHINGTON COUNTY WHILE A WEAKER ONE HAS DEVELOPED ON THE BACK EDGE OF THE CLOUD DECK FROM NEAR STEAMBOAT SPRINGS INTO LARIMER COUNTY. DOWNSLOPE WINDS ARE STILL ENOUGH TO KILL THE SHOWERS ALONG THE EAST SLOPES...AND LOW LEVELS ARE STILL PRETTY DRY TOO...SO I EXPECT THAT WE ARE SEEING MAINLY FLURRIES ON THE PLAINS AND JUST LIGHT SHOWERS IN THE MOUNTAINS. COULD SEE AN INCH OR TWO WHERE THE SHOWERS ARE TRAINING I SUPPOSE. INCOMING AIR WAS A BIT COLDER/DRIER THAN EXPECTED SO DROPPED TEMPS ABOUT 4 DEGREES TONIGHT. AREAS THAT CLEARED EARLIER WILL HAVE CLOUDS FOR A WHILE...BUT COULD STILL DROP EVEN COLDER IN THE NORTHERN/WESTERN PARTS OF THE AREA IF IT CLEARS AGAIN BEFORE MORNING. AVIATION...VFR CONDITIONS AS WEAK SHOWERS STAY AWAY FROM THE DENVER AREA...NO CHANGES NEEDED. PREV DISCUSSION... /ISSUED 305 PM MST TUE NOV 15 2011/ SHORT TERM...LATEST Q-G ANALYSIS SHOWS DEEP BUT WEAK LIFT OVER THE FORECAST AREA. SOME OF THIS LIFT IS LIKELY ASSOCIATED WITH THE RIGHT REAR ENTRANCE REGION OF THE DEPARTING UPPER LEVEL JET. MEANWHILE...ANOTHER SPEED MAX WAS MOVING TOWARD THE FOUR CORNERS AREA AND THERE IS ALSO A MODEST AMOUNT OF FRONTOGENESIS DEPICTED ACROSS THE EASTERN PLAINS TONIGHT. THIS SHOULD KEEP AT LEAST WEAK LIFT GOING THROUGH THE NIGHT. AT THE SAME TIME...AIRMASS WILL SLOWLY DESTABILIZE WITH COLD ADVECTION ALOFT. WE ARE STILL A LITTLE SKEPTICAL OF THE MOISTURE SHOWN...ESPECIALLY WITH THE GFS WHICH SEEMS TO AGGRESSIVE WITH AVAILABLE MOISTURE AND THUS PRECIPITATION AMOUNTS OVER THE PLAINS. WE WILL LEAN TOWARD THE NAM AND LATEST RUC SOLUTIONS TONIGHT WHICH ARE MORE CONSERVATIVE OVER EAST CENTRAL COLORADO. WE ALSO KEEP THE CHANCE OF PRECIPITATION CONFINED TO THE PALMER DIVIDE AREA EASTWARD TOWARD AKRON AND LIMON TONIGHT BASED ON THIS AREA BEING UNDER THE BEST LIFT...MID LEVEL CONVERGENCE...AND FRONTOGENESIS. IN THE MOUNTAINS...SNOW SHOWERS WILL CONTINUE TONIGHT BUT MOISTURE DEPTH IS QUITE LIMITED. A FEW SPOTS HAVE PICKED UP AN INCH OR TWO TODAY BASED ON THE SNOTEL DATA...AND EXPECT SIMILAR AMOUNTS TONIGHT. BY WEDNESDAY...AIRMASS WILL BE DRYING WITH SNOW SHOWERS COMING TO AN END IN THE MOUNTAINS. MOSTLY SUNNY SKIES SHOULD PREVAIL ON THE PLAINS WITH LARGE SCALE SUBSIDENCE IN PLACE. WINDS WILL ALSO BE LIGHTER IN MOST LOCATIONS. LONG TERM...FAST ZONAL FLOW LOOKS LIKE IT WILL CONTINUE ACROSS THE COUNTRY FOR MOST OF THE UPCOMING WEEK. THE POLAR JET STREAM WILL MIGRATE BACK AND FORTH OVER THE STATE AT TIMES THROUGH THE FORECAST PERIOD AS THE ZONAL FLOW ALOFT CONTINUES. RIPPLES EMBEDDED IN THE ZONAL FLOW WILL BRING PERIODS OF SNOW TO THE MOUNTAINS AND GUSTY WINDS OVER THE CONTINENTAL DIVIDE AND EAST SLOPES. THE FIRST MAIN JET WILL BE PASSING OVERHEAD WEDNESDAY NIGHT...BRINGING THE FIRST EPISODE OF GUSTY WINDS TO THE FOOTHILLS TOMORROW NIGHT. STRONG WINDS ARE EXPECTED TO REMAIN UP OVER THE HIGHER TERRAIN SINCE HIGH PRESSURE OVER KANSAS WILL INITIALLY PRODUCE SOUTHEASTERLY FLOW ACROSS THE NORTHEAST COLORADO PLAINS. SPEEDS ALSO APPEAR TO NOT BE STRONG ENOUGH TO WARRANT ANY HIGHLIGHTS FOR NOW. ON THURSDAY NIGHT...THE RIGHT EXIT REGION OF ANOTHER UPPER JET WILL BE MOVING IN FROM THE WEST. THIS WILL PRODUCE ANOTHER PERIOD OF GUSTY WINDS WHICH MIGHT WORK THEIR WAY DOWN THE EASTERN FOOTHILL SLOPES. BY FRIDAY...THE ECMWF AND GFS SHOW A SHORT WAVE TROUGH APPROACHING COLORADO WHICH WILL SPREAD SNOW INTO THE MOUNTAINS. THIS TROUGH WILL BE ACCOMPANIED BY A COMPLICATED UPPER LEVEL JET STRUCTURE...HELPING TO ENHANCE SNOWFALL OVER THE NORTHWEST PART OF THE STATE. BY SATURDAY MORNING...THE MODELS SHOW THIS TROUGH SHEARING OUT OVER THE CENTRAL PART OF THE STATE BEFORE PRODUCING ANY PRECIPITATION OVER THE NORTHEAST COLORADO PLAINS. THE STATE WILL CONTINUE UNDER STRONG SOUTHWESTERLY FLOW ALOFT THROUGH THE REST OF THE WEEKEND AS AN UPPER LOW CUTS OFF ALONG THE CALIFORNIA COAST. THIS UPPER LOW IS FORECAST TO BE MOVING TOWARDS COLORADO BY TUESDAY...WITH MOST OF ITS PRECIPITATION OCCURRING OVER NEW MEXICO AND SOUTHERN COLORADO. ALL IN ALL...AN ACTIVE WEATHER PATTERN BUT WITHOUT ENOUGH WIND OR PRECIPITATION TO WARRANT ANY HIGHLIGHTS FOR NOW. AVIATION...ANTICYCLONIC LOW LEVEL FLOW IS STILL MAKING FOR A TRICKY WIND FORECAST THIS EVENING...ALTHOUGH WINDS WILL TREND MORE EAST/SOUTHEASTERLY AND EVENTUALLY RETURN TO NORMAL DIURNAL SOUTHERLY FLOW AFT 06Z TONIGHT. THERE IS JUST A SLIGHT RISK OF A PASSING SNOW SHOWER IN THE AREA BUT AT THIS TIME MAIN CHANCE WOULD REMAIN TO THE SOUTH AND EAST OF THE FRONT RANGE AIRPORTS AND AFFECT THE SOUTHEAST APPROACH GATES AROUND LIMON FROM 01Z-10Z. VISUAL LANDING CONDITIONS SHOULD PREVAIL WITH ONLY A SLIGHT RISK OF CEILINGS DROPPING BELOW 6000 FT AGL BETWEEN 00Z AND 06Z. ON WEDNESDAY...LOOK FOR ONLY FEW-SCT CLOUDS ABOVE 7000 FT AND WINDS BECOMING NORTH/NORTHEAST 10-15 KTS AROUND 18Z. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...BAKER/GIMMESTAD/BARJENBRUCH LONG TERM....DANKERS AVIATION...BAKER/GIMMESTAD/BARJENBRUCH
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1202 AM EST WED NOV 16 2011 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... WEATHER CONDITIONS WILL BE FLUCTUATING QUITE A BIT OVER THE NEXT SEVERAL DAYS. FIRST...ANOTHER COLD FRONT WILL MOVE ACROSS CENTRAL INDIANA TONIGHT BRINGING MUCH COLDER AIR BEHIND IT. HIGHS WILL ONLY TOP OFF IN THE 40S THE NEXT FEW DAYS DESPITE THE DRY CONDITIONS. THE NEXT CHANCE FOR PRECIP AND ISOLATED THUNDERSTORMS WILL BE LATE IN THE WEEKEND AS A RATHER STRONG SYSTEM MOVES ACROSS CENTRAL INDIANA. FURTHER OUT...HIGH PRESSURE WILL RE-ESTABLISH ITSELF OVER CENTRAL INDIANA LATE MONDAY. && .NEAR TERM /REST OF TONIGHT/... SO FAR CURRENT FORECAST SEEMS TO BE ON TRACK. PRESENTLY RAIN OCCURRING SOUTH OF OHIO RIVER...BUT RADAR LOOPS INDICATE THAT IT HAS PUSHED NORTH INTO MISSOURI BOOTHEEL AS UPPER LEVEL DISTURBANCE MOVING ACROSS ARKANSAS AND TENNESSEE. RUC BRINGS PRECIPITATION ACROSS OUR FAR SOUTH LATE TONIGHT AND EARLY WEDNESDAY...BUT NOTHING MUCH NORTH OF OUR SOUTHERN ROW OF COUNTIES. I HAVE ADJUSTED RAIN AREA SLIGHTLY SOUTH OVERNIGHT...BUT NOT ENOUGH TO UPDATE FORECAST PRODUCTS. ONE MINOR CHANGE IN GRIDS WILL BE TO SLOW DOWN FALL OF TEMPERATURES A LITTLE OVERNIGHT UNTIL SECONDARY COLD FRONT MOVES THROUGH LATE TONIGHT. BUT EVEN THERE THE OVERNIGHT LOWS STILL SEEM TO BE ON TRACK WITH MID TO UPPER 30S ACROSS OUR NORTHWEST AND LOWER TO MID 40S SOUTH. && .SHORT TERM /TOMORROW THROUGH THURSDAY/... THE MAIN FOCUS OF THE SHORT TERM IS TEMPS. MUCH COOLER TEMPS AND DRY CONDITIONS WILL PREVAIL TOMORROW IN THE WAKE OF A COLD FRONT. HIGHS WILL ONLY TOP OFF IN THE UPPER 40S/LOWER 50S ACROSS THE SOUTHERN COUNTIES...AND MID 40S TO THE NORTH. MODELS SEEM TO HAVE A GOOD HANDLE ON THE COLD ADVECTION...SO WENT WITH ALLBLEND. TOMORROW NIGHT...TRENDED ON THE WARMER SIDE OF GUIDANCE AS CLOUDS BUILD INTO THE AREA AHEAD OF A BROAD UPPER LEVEL LOW. GUIDANCE IS SHOWING LOWS IN THE MID TO UPPER 20S...SO WENT WITH UPPER 20S/LOW 30S. HOWEVER...CONFIDENCE IS LOW SINCE 850MB TEMPS ARE HINTING AT A COOLING TREND. THURSDAY...WENT ABOVE GUIDANCE SINCE WINDS WILL BE BACKING TO THE WEST THROUGH THE COURSE OF THE DAY. THIS MAY BE TOO OPTIMISTIC THOUGH...SO CONFIDENCE IS A BIT LOW. FOR NOW...HAVE HIGHS OF LOW TO MID 40S OVER THE NORTH...AND UPPER 40S ACROSS THE SOUTHERN PORTIONS OF CENTRAL INDIANA. THURSDAY NIGHT...JUST WENT WITH A BLEND OF UPPER 20S/LOW 30S. && .LONG TERM /FRIDAY THROUGH TUESDAY/... MODELS ARE HAVING TIMING DIFFICULTIES WITH A STRONG FRONTAL SYSTEM THAT IS EXPECTED TO IMPACT CENTRAL INDIANA THIS WEEKEND INTO EARLY NEXT WEEK. THE 12Z ECMWF AND 12Z GEM ARE BOTH QUITE A BIT FASTER THAN THE 12Z GFS. THE 12Z GFS ESEMBLE MEANS WERE IN BETWEEN...BUT THE ESEMBLES HAD LARGE STANDARD DEVIATIONS. SO...AT THIS POINT...A NON-GFS BLEND LOOKS GOOD. HAD TO MAKE SEVERAL CHANGES TO THE INITIALIZATION EXTENDED REGARDING TIMING OF THE RAIN. DROPPED SLIGHT CHANCE POPS NORTHWEST ON FRIDAY WITH THE FRONTAL SYSTEM WELL TO THE WEST ACROSS THE ROCKIES. OTHERWISE...THE FRONT IS EXPECTED TO SLIDE ACROSS SATURDAY NIGHT. MODELS SUGGEST SYSTEM STRONG ENOUGH TO PRODUCE A FEW THUNDERSTORMS AS WELL AS SHOWERS SATURDAY AND SATURDAY NIGHT. THE 12Z ECMWF ALSO WAS SHOWING A WAVE LIFTING NORTHEAST ALONG THE OSCILLATING FRONT NEAR THE OHIO RIVER ON MONDAY WHICH JUSTIFIES KEEPING POPS IN THROUGH THEN. FINALLY...HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT ON MONDAY NIGHT WHICH SHOULD DRY THINGS OUT BY TUESDAY AND ALLOW FOR MUCH COOLER TEMPERATURES ONLY IN THE 40S FOR AFTERNOON HIGHS IN CONTRAST TO HIGHS IN THE 50S AND POSSIBLY 60S SATURDAY IN THE RETURN FLOW AHEAD OF THE FRONT. AFTER COORDINATING WITH ADJACENT OFFICES...PULLED THE INITIALIZATION EXTENDED POPS. && .AVIATION /DISCUSSION FOR THE 16/06Z TAFS/... CEILINGS AT SOME LOCATIONS /HUF AND BMG ESPECIALLY/ HAVE AT LEAST TEMPORARILY DROPPED INTO IFR CATEGORY...AND MAY REMAIN THERE UNTIL THE SECONDARY FRONT PASSES EARLY THIS MORNING. SREF PROBABILITIES INDICATE MVFR/IFR SHOULD END AT HUF/IND AROUND 09Z...LASTING AT BMG THROUGH MID MORNING. SOME CONCERN ABOUT FOG OR LIFR CEILINGS WITH SLOW MOVING BOUNDARY IN PROXIMITY TO SITES...AND SOME UNSETTLINGLY LOW TEMP/DEWPOINT SPREADS...BUT NO GUIDANCE INDICATES THIS AS A SIGNIFICANT POTENTIAL...AND WITH BOUNDARY MAKING SLOW BUT STEADY PROGRESS...WILL LEAVE OUT. WILL REQUIRE MONITORING...ESPECIALLY NEAR SUNRISE AT ALL SITES. WINDS FROM MID MORNING THROUGH THIS EVENING WILL BE NORTHERLY...AND GUSTY INTO THE MID TO HIGH TEENS. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...TDUD NEAR TERM...JH SHORT TERM...TDUD LONG TERM....50 AVIATION...NIELD/50
AREA FORECAST DISCUSSION
NWS GOODLAND KS
301 AM MST WED NOV 16 2011 .DISCUSSION... 301 AM MST WED NOV 16 2011 FORECAST PROBLEMS WILL BE TODAY...AND THEN HOW FAST IS THE TEMPERATURE RECOVERY INTO FRIDAY. SATELLITE SHOWING SOME AMPLIFICATION TO THE FLOW FROM THE WESTERN PACIFIC INTO CENTRAL NORTH AMERICA. UPPER TROUGH IS STILL HANGING AROUND OVER THE CENTRAL PORTION OF THE COUNTRY WITH NUMEROUS SHORTWAVE TROUGHS MOVING THROUGH IT. COLD FRONT THAT WENT THROUGH EARLIER TODAY EXTENDS FROM THE SOUTHERN PLAINS TO ALONG THE FRONT RANGE OF COLORADO. MODELS INITIALIZED FINE AT JET LEVEL. MODELS INITIALIZED FINE AT MID LEVELS EXCEPT THE GFS WAS TOO MOIST. THE MODELS TENDED TO BE SLIGHTLY TOO FAR EAST AND SOUTH WITH THE SURFACE RIDGE AND THE LEE SURFACE TROUGH. HOWEVER...THE NAM WAS PRETTY CLOSE AND SLIGHTLY BETTER THAN THE ECMWF. ON THE LOW LEVEL THERMAL FIELD OVERALL...THE CANADIAN...GFS AND UKMET WERE ABOUT THE SAME AND A LITTLE BETTER WITH THE NAM NOT TOO FAR BEHIND AND MAYBE BETTER TO THE NORTH OF THE AREA. TODAY/TONIGHT...INITIAL PROBLEM WILL BE COVERAGE AND DURATION OF SNOWFALL THIS MORNING AS A SHORTWAVE TROUGH AND LIFT FROM THE UPPER JET MOVE THROUGH. GOING BY THE DNR 00Z SOUNDING...THE BEST MOISTURE IS ABOVE 700 MB AND REALITY IS SUPPORTING THAT. SO FAR VISIBILITIES/OBSERVATIONS AND CAMERAS SHOW LITTLE IF ANY ACCUMULATION...EVEN UNDER THE MOST INTENSE BAND THAT IS ALONG THE KANSAS AND NEBRASKA BORDER. TEMPERATURE AND DEWPOINT SPREADS ARE LARGE...ESPECIALLY IN THE NORTH WHERE THE RADAR SAYS THE MOST INTENSE PRECIPITATION IS. MOST OF THE MODELS SAY THAT MEASURABLE SHOULD BE OCCURRING AT THIS TIME WITH RUC HAVING THE LEAST MEASURABLE AND LOOKING THE BEST AT THIS TIME. RIGHT REAR QUADRANT SHOULD BE EAST OF THE AREA BY 12Z. 7-5H SHORTWAVE LOOKS TO BE ENTERING THE WESTERN PORTION OF THE FORECAST AREA AT THIS TIME. SOME PV MOVES ACROSS EARLY WITH THE BRUNT OF IT NORTH. DOWNGLIDE ALSO MOVES IN RATHER QUICKLY THIS MORNING. WILL CONTINUE TO WATCH TRENDS FOR CHANGES BUT PLAN ON TAKING THE MEASURABLE OUT AND HAVE FLURRIES OVER MOST OF THE AREA THIS MORNING WITH MAYBE A LITTLE LINGERING IN THE FAR EAST INTO THE EARLY AFTERNOON. QUESTION THEN BECOMES HOW FAST WE CLEAR OUT AND ITS AFFECT ON HIGH TEMPERATURES. STRONG JET ON THE BACKSIDE OF THE UPPER TROUGH DOES NOT GET CLOSE TO THE AREA UNTIL LATE IN THE DAY. BASED ON SATELLITE...WE SHOULD CLEAR OUT RATHER QUICKLY WITH THE MODELS LOOKING LIKE THEY ARE HANGING ONTO CLOUDS A LITTLE TOO LONG. CURRENTLY TEMPERATURES ARE RUNNING A LITTLE WARMER THAN DEPICTED BUT CLEARING AND TEMPERATURES UPSTREAM SUPPORT MINS GETTING NEAR WHAT IS CALLED FOR. MODEL GUIDANCE IS SIMILAR IN ITS DEPICTION AND MADE SLIGHT ADJUSTMENTS BASED ON LATEST TRENDS/GUIDANCE. ANOTHER CONCERN WILL BE WINDS ON THE BACKSIDE OF THE SYSTEM AS IT EXITS. LOOKS LIKE WILL HAVE GOOD SUBSIDENCE AND ADIABATIC LAPSE RATES. SO IT LOOKS LIKE WE WILL SEE A BRIEF PERIOD OF AT LEAST BREEZY AND GUSTY WINDS THIS AFTERNOON BUT DO NOT SEE ANYTHING GETTING OUT OF HAND. JET AXIS MOVES ACROSS THE AREA DURING THE NIGHT...AND AFFECTS THE NORTHEAST HALF OF THE AREA BY 12Z. THAT AND ANOTHER SHORTWAVE WILL INCREASE THE CLOUDS AFTER 06Z. NEXT QUESTION WILL BE HOW FAST THE SURFACE MOVES THROUGH AND HOW FAST DO THE WINDS INCREASE. LIKE THE SLIGHTLY SLOWER EVOLUTION AND THINK THE GFS IS TOO FAST. AT THIS TIME...IT LOOKS LIKE TEMPERATURES WILL BOTTOM OUT EARLY... ESPECIALLY IN THE WEST AND THEN REMAIN STEADY AFTER THAT. THURSDAY/THURSDAY NIGHT...RIGHT REAR QUADRANT OF THE JET REMAINS NEAR OR OVER THE AREA THROUGH THE DAY. SOME DIFFERENCE IN THE AMOUNT OF CLOUD COVER WITH MOST OF THE MODELS SHOWING A MOSTLY SUNNY TO A PARTLY SUNNY DAY. AS HAS BEEN THE CASE IN THIS FLOW...CLOUDS MAY BE A LITTLE MORE THAN CURRENTLY THINK. SHOULD START OFF WITH DOWNSLOPE WINDS BUT THEN THEY SHIFT TO THE SOUTH AS LEE TROUGH STRENGTHENS. MODELS DO NOT LOOK AS STRONG ON THE WINDS AS YESTERDAY AS MIXING AND GRADIENT ARE NOT AS STRONG AS PREVIOUSLY DEPICTED. STRONGEST WINDS WILL BE IN THE EAST. SOME DIFFERENCES IN THE DEPICTED MAXES. THE 06Z NAM HAS COOLED THINGS OFF A LITTLE FROM 00Z. AT THIS TIME...WILL TREND TOWARD THE WARMER SIDE OF THE GUIDANCE. FRIDAY/FRIDAY NIGHT...COMPLEX JET SETUP BEGINS DURING THE DAY. NORTHERN STREAM REMAINS WELL NORTHWEST OF THE AREA THROUGH THE DAY. HOWEVER...LEFT FRONT QUADRANT OF A SOUTHERN JET DEVELOPS OR STRENGTHENS OVER THE AREA THROUGH THE DAY...ESPECIALLY IN THE AFTERNOON. THERE LOOKS TO BE SOME INCREASING HIGH CLOUDS IN THE AFTERNOON. CONSIDERING WHAT THE JET IS DOING AND THE STRONG SOUTHWESTERLY FLOW...LIKE WHAT THE NAM AND ECMWF ARE SHOWING WITH A STRENGTHENING AND FURTHER WEST LEE TROUGH. THIS MEANS LESS OF A DOWNSLOPE COMPONENT AND IF MODELS ARE CORRECT MORE OF AN EASTERLY COMPONENT AS THE DAY WHERES ON. SO WILL TREND TOWARD THE COOLER SIDE OF GUIDANCE. AS A SIDE NOTE...DUE TO A MORE EASTERLY WIND AND HIGHER DEWPOINTS... BELIEVE SHOULD NOT SEE ANY FIRE WEATHER CONCERNS DESPITE THE WARMER TEMPERATURES. BULLER FOR THE PERIOD SATURDAY THROUGH TUESDAY...SHORTWAVE WILL EJECT ACROSS THE CENTRAL PLAINS SATURDAY FROM BASE OF WEST COAST MEAN TROUGH. TRACK OF THE UPPER SYSTEM AND MOISTURE PROFILES SUGGEST FROPA WILL BE DRY. THERE MAY BE A PERIOD OF GUSTY NORTH WINDS BEHIND THE FRONT SOMETIME ON SATURDAY. COLDER TEMPERATURES WILL FOLLOW ON SUNDAY...LOW TO MIDDLE 40S FOR HIGHS...WHICH IS AROUND 10 DEGREES BELOW NORMAL. RETURN FLOW GETS UNDER WAY FOR MONDAY UNDER SHORTWAVE RIDGING ALOFT WITH TEMPERATURES WARMING TO NEAR NORMAL AND CONTINUED DRY. REMNANTS OF WEST COAST SYSTEM COMES ACROSS SOUTHERN ROCKIES ON TUESDAY BRINGING A CHANCE OF MAINLY RAIN...BEST CHANCES WILL BE SOUTH. JK THANKS TO ALL THAT COLLABORATED. && .AVIATION... 1047 PM MST TUE NOV 15 2011 CLOUD COVER WILL INCREASE WITH CEILINGS BECOMING LOWER AS A FAST MOVING DISTURBANCE MOVES ACROSS THE CENTRAL HIGH PLAINS OVERNIGHT. CONDITIONS WILL START OUT VFR TONIGHT...BUT WILL LIKELY SEE A DROP TO MVFR AS CEILINGS LOWER BETWEEN 09 AND 17Z AT KGLD. THERE WILL ALSO BE THE POSSIBILITY OF LIGHT SNOW MAINLY BETWEEN 09 AND 14 Z AT KGLD. KMCK WILL SEE A DROP TO MVFR AFTER 11Z THAT CONTINUES THROUGH 19Z. LIGHT SNOW IS POSSIBLE AT KMCK, BUT IT SEEMS SLIGHTLY LESS LIKELY THAN KGLD AND LEFT IT OUT. CEILINGS WILL RISE AGAIN WITH A RETURN TO VFR CONDITIONS AS WINDS TURN NORTHWESTERLY AND BECOME GUSTY AFTER ABOUT 19Z AS THE SYSTEM BEGINS TO MOVE OUT OF THE AREA. WINDS WILL DIMINISH AND TURN SOUTHWESTERLY AFTER 00Z ALONG WITH SKIES CLEARING OUT. LOCKHART && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. NE...NONE. CO...NONE. && $$
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
427 AM EST WED NOV 16 2011 .SYNOPSIS... A WEAK STATIONARY FRONT WILL REMAIN OVER THE MID ATLANTIC REGION EARLY TODAY AS A COLD FRONT APPROACHES FROM THE WEST. THE COLD FRONT PASSES THROUGH TONIGHT...WITH HIGH PRESSURE RETURNING LATE THURSDAY AND INTO THE WEEKEND. ANOTHER COLD FRONT APPROACHES SUNDAY NIGHT INTO MONDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... WEAK STATIONARY FRONT OVER THE MID ATLANTIC IS EXPECTED TO SLOWLY NUDGE NORTH THIS MORNING...ALLOWING FOR SW WARM AND MOIST FLOW TO CONTINUE OVER THE LOCAL AREA. CYCLONIC FLOW ALOFT AND DECENT MID-LEVEL MOISTURE ADVECTION WILL LEAD TO MOSTLY CLOUDY SKIES...WITH SOME BREAKS POSSIBLE ESP TO THE S. PRECIP CURRENTLY OVER WESTERN VIRGINIA IS EXPECTED TO CLIP NORTHERN PORTIONS OF THE FA LATER THIS MORNING. LOWER CHANCES FOR RAIN FURTHER S WHERE THE BEST FORCING AND DEEP MOISTURE WILL HOLD OFF UNTIL LATER TODAY AND TONIGHT. A COLD FRONT APPROACHING FROM THE OHIO VALLEY AND A DEVELOPING SFC WAVE (IN RESPONSE TO A POTENT S/W OVER THE TN VALLEY EMBEDDED WITHIN THE SW UPPER FLOW) WILL ALSO INCREASE THE RAIN POTENTIAL STARTING LATE THIS AFTERNOON. CHANCE OF THUNDERSTORMS REMAINS IN THE FORECAST...W/ STRONG LOW-TOPPED CONVECTION (LOW CAPE AND HIGH SHEAR) POSSIBLE...ESP FOR NE NORTH CAROLINA AND EXTREME SE VIRGINIA (SPC HAS A SLIGHT RISK) WHERE INSTABILITY WILL BE GREATEST. MAIN THREAT WOULD BE DAMAGING WINDS (40 KT OF 0-3 KM SHEAR AND DCAPE>1000 J/KG). ALSO...SOME STORMS MAY EXHIBIT ROTATION AS RUC AND NAM BOTH PROGGING 0-1 KM HELICITIES GREATER THAN 200 M2/S2. EXPECTING ABOVE NORMAL HIGHS AGAIN TODAY DUE TO THE COLD FROPA BEING DELAYED UNTIL TONIGHT...HIGHS IN THE L-M70S OVER THE NW AND M-U70S OVER THE SE. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/... BEST PROBABILITY FOR RAIN (CATEGORICAL POPS) COMES TONIGHT DUE TO A COMBO OF ISENTROPIC LIFT AND STRONG LOW/MID LEVEL CONVERGENCE ASSOCIATED W/ COLD FRONT. RAIN WILL BE HEAVY AT TIMES AND SOME AREAS MAY RECEIVE OVER AN INCH TOTAL W/ THIS SYSTEM (ESP NORTHERN AREAS). NO SIGNIFICANT FLOODING IS ANTICIPATED ATTM DUE TO FLASH FLOOD GUIDANCE BEING VERY HIGH. THE RAIN TAPERS OFF FROM W TO E THUR MIDDAY/AFTERNOON. DECREASING CLOUDS FOR THE REST OF THE DAY AND NIGHT. COOL N FLOW AT THE SFC WILL ONLY YIELD HIGHS IN THE L-M50S THUR. STRONG HIGH PRESSURE BUILDS OVER THE MID ATLANTIC FRI LEADING TO DRY WX AND SUNNY SKIES. TEMPS WILL ONLY MAX OUT IN THE U40S-L50S AFTER A CHILLY START IN THE U20S-M30S. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... LONG RANGE MODELS ARE IN GOOD AGREEMENT WITH SHOWING A SOUTHWEST UPPER LEVEL FLOW DEVELOPING SATURDAY AS HIGH PRESSURE BECOMES ANCHORED OVER THE MID ATLANTIC STATES THROUGH SUNDAY. SOME CLOUDINESS IS POSSIBLE IN NORTHEAST NC AND EXTREME SOUTHEAST VA ON SATURDAY AS TROPICAL MOISTURE ROTATES AROUND A MID-LEVEL HIGH OFF THE SOUTHEAST U.S. COAST AND MOVES NEAR THIS AREA. OTHERWISE...A DRYING AND WARMING TREND IS ANTICIPATED UNDER THIS FLOW REGIME...WITH HIGH TEMPS REBOUNDING BACK INTO THE 60S BY SUNDAY. LOWS SHOULD BE NEAR FREEZING SATURDAY MORNING DUE TO PRIME COOLING CONDITIONS UNDER MOSTLY CLEAR SKIES WITH VERY LIGHT WINDS...THEN REBOUND TOWARD THE LOW 50S BY EARLY NEXT WEEK AS CLOUDS INCREASE AHEAD OF THE NEXT WEATHER DISTURBANCE. BY LATE SUNDAY...A WEAK COLD FRONT IS EXPECTED TO SAG SOUTHWARD AND STALL OVER THE MID ATLANTIC REGION THROUGH TUESDAY. 12Z MODEL RUNS TODAY ARE HINTING AT SLOWING THE SOUTHERN MOVEMENT OF THIS BOUNDARY UNTIL LATE MONDAY...WHICH WOULD DELAY THE ONSET OF PRECIPITATION UNTIL THAT TIMEFRAME. HAVE TRENDED THE ONGOING FORECAST TOWARD SLOWING THE PASSAGE OF THE FRONT UNTIL LATE MONDAY...WITH PRECIPITATION BEING INTRODUCED LATE SUNDAY/EARLY MONDAY. && .AVIATION /09Z WEDNESDAY THROUGH SUNDAY/... COLD FRNT WILL APPROACH THE AREA THRU THIS MORNG...THEN DROP ACRS THE REGION THIS AFTN THRU TNGT. CIGS/VSBYS WILL QUICKLY LWR TO MVFR THEN IFR (LIFR?) DURING THIS MORNG WITH -DZ OR SCTD -SHRAS MOVNG INTO NRN AND WRN AREAS. CIGS/VSBYS WILL LIKELY LIFT TO MVFR AND VFR CONDITIONS LATER THIS MORNG AND AFTN...AS SW WNDS INCRS IN ADVANCE OF FRNT...WITH ISLTD TO SCTD SHRAS AHEAD OF AND ALNG THE FRNTL BNDRY INTO THIS EVENG. DURING THIS EVENG INTO THU MORNG...IFR (LIFR?) CONDITIONS WITH -RA EXPECTED BEHIND THE FRNT. VFR AND DRY CONDITIONS WILL RETURN THU AFTN THRU SUN. && .MARINE... HAVE EXTENDED THE SCA HEADLINE FOR ALL THE WTRS THRU LATE THU NGT...AS NNW WNDS (CAA) WILL CONTINUE AT 15 TO 25 KT AND WAVES/SEAS WILL STAY UP. SE OR S WNDS 10 KT OR LESS ERLY THIS MORNG...WILL BECOME SW AND INCRS TO 15 TO 20 KT THIS AFTN IN ADVANCE OF COLD FRNT. CUD BE GUSTS TO 25 KT. WNDS WILL SHIFT TO THE NW OR N THIS EVENG INTO ERLY THU MORNG BEHIND THE FRNT. THIS CAA SURGE WILL THEN CONTINUE FOR THE REMAINDER OF THU AND THU NGT. MORE BENIGN MARINE CONDITIONS THEN EXPECTED FRI INTO SUN...AS HI PRES BLDS OVR THE WTRS FM THE W. && .CLIMATE... RECORD HIGH TEMPS FOR NOV 16TH (WED): RIC...85 IN 1955 ORF...83 IN 1955 SBY...78 IN 1928 ECG...85 IN 1993 && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY FROM NOON TODAY TO 6 AM EST FRIDAY FOR ANZ630>634-650-652-654-656-658. && $$ SYNOPSIS...MAS NEAR TERM...MAS SHORT TERM...MAS LONG TERM...BMD AVIATION...TMG MARINE...TMG CLIMATE...AKQ
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
400 AM EST WED NOV 16 2011 .SYNOPSIS... A WEAK STATIONARY FRONT WILL REMAIN OVER THE MID ATLANTIC REGION EARLY TODAY AS A COLD FRONT APPROACHES FROM THE WEST. THE COLD FRONT PASSES THROUGH TONIGHT...WITH HIGH PRESSURE RETURNING LATE THURSDAY AND INTO THE WEEKEND. ANOTHER COLD FRONT APPROACHES SUNDAY NIGHT INTO MONDAY. && .NEAR TERM /THROUGH TODAY/... WEAK STATIONARY FRONT OVER THE MID ATLANTIC IS EXPECTED TO SLOWLY NUDGE NORTH THIS MORNING...ALLOWING FOR SW WARM AND MOIST FLOW TO CONTINUE OVER THE LOCAL AREA. CYCLONIC FLOW ALOFT AND DECENT MID-LEVEL MOISTURE ADVECTION WILL LEAD TO MOSTLY CLOUDY SKIES...WITH SOME BREAKS POSSIBLE ESP TO THE S. PRECIP CURRENTLY OVER WESTERN VIRGINIA IS EXPECTED TO CLIP NORTHERN PORTIONS OF THE FA LATER THIS MORNING. LOWER CHANCES FOR RAIN FURTHER S WHERE THE BEST FORCING AND DEEP MOISTURE WILL HOLD OFF UNTIL LATER TODAY AND TONIGHT. A COLD FRONT APPROACHING FROM THE OHIO VALLEY AND A DEVELOPING SFC WAVE (IN RESPONSE TO A POTENT S/W OVER THE TN VALLEY EMBEDDED WITHIN THE SW UPPER FLOW) WILL ALSO INCREASE THE RAIN POTENTIAL STARTING LATE THIS AFTERNOON. CHANCE OF THUNDERSTORMS REMAINS IN THE FORECAST...W/ STRONG LOW-TOPPED CONVECTION (LOW CAPE AND HIGH SHEAR) POSSIBLE...ESP FOR NE NORTH CAROLINA AND EXTREME SE VIRGINIA (SPC HAS A SLIGHT RISK) WHERE INSTABILITY WILL BE GREATEST. MAIN THREAT WOULD BE DAMAGING WINDS (40 KT OF 0-3 KM SHEAR AND DCAPE>1000 J/KG). ALSO...SOME STORMS MAY EXHIBIT ROTATION AS RUC AND NAM BOTH PROGGING 0-1 KM HELICITIES GREATER THAN 200 M2/S2. EXPECTING ABOVE NORMAL HIGHS AGAIN TODAY DUE TO THE COLD FROPA BEING DELAYED UNTIL TONIGHT...HIGHS IN THE L-M70S OVER THE NW AND M-U70S OVER THE SE. && .SHORT TERM /TONIGHT THROUGH FRIDAY/... BEST PROBABILITY FOR RAIN (CATEGORICAL POPS) COMES TONIGHT DUE TO A COMBO OF ISENTROPIC LIFT AND STRONG LOW/MID LEVEL CONVERGENCE ASSOCIATED W/ COLD FRONT. RAIN WILL BE HEAVY AT TIMES AND SOME AREAS MAY RECEIVE OVER AN INCH TOTAL W/ THIS SYSTEM (ESP NORTHERN AREAS). NO SIGNIFICANT FLOODING IS ANTICIPATED ATTM DUE TO FLASH FLOOD GUIDANCE BEING VERY HIGH. THE RAIN TAPERS OFF FROM W TO E THUR MIDDAY/AFTERNOON. DECREASING CLOUDS FOR THE REST OF THE DAY AND NIGHT. COOL N FLOW AT THE SFC WILL ONLY YIELD HIGHS IN THE L-M50S THUR. STRONG HIGH PRESSURE BUILDS OVER THE MID ATLANTIC FRI LEADING TO DRY WX AND SUNNY SKIES. TEMPS WILL ONLY MAX OUT IN THE U40S-L50S AFTER A CHILLY START IN THE U20S-M30S. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... LONG RANGE MODELS ARE IN GOOD AGREEMENT WITH SHOWING A SOUTHWEST UPPER LEVEL FLOW DEVELOPING SATURDAY AS HIGH PRESSURE BECOMES ANCHORED OVER THE MID ATLANTIC STATES THROUGH SUNDAY. SOME CLOUDINESS IS POSSIBLE IN NORTHEAST NC AND EXTREME SOUTHEAST VA ON SATURDAY AS TROPICAL MOISTURE ROTATES AROUND A MID-LEVEL HIGH OFF THE SOUTHEAST U.S. COAST AND MOVES NEAR THIS AREA. OTHERWISE...A DRYING AND WARMING TREND IS ANTICIPATED UNDER THIS FLOW REGIME...WITH HIGH TEMPS REBOUNDING BACK INTO THE 60S BY SUNDAY. LOWS SHOULD BE NEAR FREEZING SATURDAY MORNING DUE TO PRIME COOLING CONDITIONS UNDER MOSTLY CLEAR SKIES WITH VERY LIGHT WINDS...THEN REBOUND TOWARD THE LOW 50S BY EARLY NEXT WEEK AS CLOUDS INCREASE AHEAD OF THE NEXT WEATHER DISTURBANCE. BY LATE SUNDAY...A WEAK COLD FRONT IS EXPECTED TO SAG SOUTHWARD AND STALL OVER THE MID ATLANTIC REGION THROUGH TUESDAY. 12Z MODEL RUNS TODAY ARE HINTING AT SLOWING THE SOUTHERN MOVEMENT OF THIS BOUNDARY UNTIL LATE MONDAY...WHICH WOULD DELAY THE ONSET OF PRECIPITATION UNTIL THAT TIMEFRAME. HAVE TRENDED THE ONGOING FORECAST TOWARD SLOWING THE PASSAGE OF THE FRONT UNTIL LATE MONDAY...WITH PRECIPITATION BEING INTRODUCED LATE SUNDAY/EARLY MONDAY. && .AVIATION /08Z WEDNESDAY THROUGH SUNDAY/... COLD FRNT WILL APPROACH THE AREA THRU THIS MORNG...THEN DROP ACRS THE REGION THIS AFTN THRU TNGT. CIGS/VSBYS WILL QUICKLY LWR TO MVFR THEN IFR (LIFR?) DURING THIS MORNG WITH -DZ OR SCTD -SHRAS MOVNG INTO NRN AND WRN AREAS. CIGS/VSBYS WILL LIKELY LIFT TO MVFR AND VFR CONDITIONS LATER THIS MORNG AND AFTN...AS SW WNDS INCRS IN ADVANCE OF FRNT...WITH ISLTD TO SCTD SHRAS AHEAD OF AND ALNG THE FRNTL BNDRY INTO THIS EVENG. DURING THIS EVENG INTO THU MORNG...IFR (LIFR?) CONDITIONS WITH -RA EXPECTED BEHIND THE FRNT. VFR AND DRY CONDITIONS WILL RETURN THU AFTN THRU SUN. && .MARINE... LATEST OBS REFLECTING TIGHTENING PRESSURE GRADIENT BETWEEN HIGH PRESSURE CENTERED OFF THE SE COAST AND THE COLD FRONT SLOWLY PUSHING SE FROM THE OHIO VALLEY INTO THE MID-ATLANTIC. THIS TIGHTENING GRADIENT HAS RESULTED IN SW WINDS 10-15 KT OVER BAY AND ~15-20KT OVER ATLANTIC COASTAL WATERS. WINDS SHOULD REMAIN SUB- SCA THIS EVENING AND OVERNIGHT INTO EARLY WED WITH THE BUILDING SOUTH FLOW FROM SW TO NE WED MORN AHEAD OF APPROACHING COLD FRONT FROM THE NW...WHICH DROPS ACROSS THE REGION WED EVENING. SCA FLAGS HAVE BEEN HOISTED FOR ENTIRE MARINE AREA W/PRE-FRONTAL SW FLOW WED AFTN...CONTINUING WITH THE POST-FRONTAL CAA SURGE THU MORNING INTO THU AFTN. MORE BENIGN MARINE CONDITIONS EXPECTED BY LATE IN THE WEEK INTO THE WEEKEND AS HIGH PRESSURE BUILDS OVER THE WATERS FROM THE WEST. HOWEVER...SCA`S FOR HAZARDOUS SEAS MAY BE NEEDED INTO THE WEEKEND OVER THE COASTAL WATERS WITH GUIDANCE INDICATING POTENTIAL FOR SEAS TO LINGER IN THE 5-6 FOOT RANGE COURTESY OF ONSHORE FLOW/LINGERING E-SE SWELL. && .CLIMATE... RECORD HIGH TEMPS FOR NOV 16TH (WED): RIC...85 IN 1955 ORF...83 IN 1955 SBY...78 IN 1928 ECG...85 IN 1993 && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY FROM NOON TODAY TO 6 PM EST THURSDAY FOR ANZ630>634-650-652-654-656-658. && $$ SYNOPSIS...MAS NEAR TERM...MAS SHORT TERM...MAS LONG TERM...BMD AVIATION...TMG MARINE...TMG CLIMATE...
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
347 AM CST WED NOV 16 2011 .DISCUSSION... A COLD WEST-NORTHWEST FLOW OF AIR WILL COVER THE REGION INTO THURSDAY. A SHORT WAVE OVER NORTH DAKOTA WILL PROGRESS TO THE WESTERN GREAT LAKES BY TONIGHT. SOME CLOUDINESS OVER CENTRAL MN AND WEST CENTRAL WI EARLY THIS MORNING WILL PART FOR A TIME BEFORE ANOTHER SURGE OF LOW CLOUDINESS ARRIVES FOR THE AFTERNOON AND EVENING HOURS. OUR LOCAL MODEL AND THE RUC PAINT SOME LIGHT ECHOES ACROSS CENTRAL MN AND WEST CENTRAL WI DURING THE AFTERNOON AND EVENING HOURS...SO KEPT THE MENTION OF FLURRIES TO THESE AREAS. THERE SHOULD BE A GOOD DEAL OF SUNSHINE ACROSS SOUTHERN MN TODAY. THE MIX-DOWN TD TOOL POINTS TO DEW POINT LOWERING TO AROUND 5 DEG C DURING THE AFTERNOON. WE ARE CURRENTLY SEEING SOME SINGLE DIGIT DEW POINTS NEAR THE SD/NE EARLY THIS MORNING. THE ARW/NMM WRFS ALSO INDICATE DINGLE DIGIT DEW POINT IN THE SOUTH THIS AFTERNOON. HENCE...BLENDED IN THE MIX DOWN DPS WITH CONSENSUS FOR THE AFTERNOON AND EVENING HOURS. TRENDED A FEW DEGREES HIGHER ON HIGH TEMPERATURES TODAY OVER THE SOUTHERN HALF OF THE CWA VERSUS MET/MAV MOS DUE TO MORE SUNSHINE AND WHAT THE MIX DOWN MAX T WAS SHOWING. FLURRIES/CLOUDS WILL DIMINISH TONIGHT OVER THE NORTHERN AND EASTERN CWA AS HIGH PRESSURE MOVES IN LATE IN THE NIGHT. THE RIDGE WILL MOVE ACROSS THE CWA ON THURSDAY WITH FLOW BECOMING MORE SOUTHERLY. IT WILL STILL BE A COOL DAY WITH HIGHS ONLY IN THE 30S. AS THE RIDGE MOVES EAST THURSDAY NIGHT...A WARM FRONT WILL DEVELOP AND MOVE NORTHEAST ACROSS THE CWA. ONLY SOME CLOUDS EXPECTED WITH THE WARM FRONT. THIS WILL LEAD TO A WARMER FRIDAY WITH HIGHS REACHING WELL INTO THE 40S IN MOST AREAS WITH SOME 50S IN THE SOUTH. THE LOW PRESSURE SYSTEM AND PRECIPITATION EVENT FOR SATURDAY AND SATURDAY NIGHT REMAINS ON TRACK. THE GEM AND ECMWF ARE IN STEP WITH THIS SYSTEM WHILE THE GFS LAGS BY ABOUT 6 HOURS. THE GFS ENSEMBLE IS EVEN SLOWER BY ABOUT ANOTHER 6 HOURS. STILL EXPECT A LOW TO TRACK FROM EASTERN NEBRASKA SATURDAY MORNING TO EASTERN WI BY SATURDAY NIGHT. ALL SOLUTIONS INDICATE THE LOW SLOWLY FILLING DURING THIS PERIOD WHICH IS NOTE GOOD FOR A HEAVY SNOW EVENT. WE ALSO CONTINUE TO SEE AN OPEN WAVE ALOFT WHICH SPEAKS FOR THE QUICKNESS WITH THIS SYSTEM. LOOKING AT SOME OF THE MID/UPPER LEVEL FEATURES SHOWS THE H5 HEIGHT FALL TRACK FROM YELLOW MEDICINE COUNTY TO BURNETT COUNTY. THE -15 DEG C OMEGA IS ON THE LEFT SIDE OF THIS TRACK WITH THE DEPTH OF THE DENDRITIC GROWTH ZONE BEING ABOUT 1100M. THE WARM POCKET AT H2 ALSO TRACKS ALONG THE AFOREMENTIONED AXIS WITH 10 DEG OF WARMING NOTED. THE 295K THETA SURFACE PLACES 700 MB ABOUT IN THIS GENERAL AREA AS WELL WITH PLENTY OF SATURATION AND ADIABATIC OMEGA NOTED TO THE NORTH AND WEST. THE MIX RATIO CONTINUES TO RUN BETWEEN 2 AND 3 G/KG AND IS ALIGNED WITH THE -FN VECTOR DIVERGENCE. THIS ALL POINTS TO A BAND OF 4 TO LOCALLY 6 INCHES FROM WEST CENTRAL MN ON NORTHEAST TO DULUTH AND HAYWARD. THE CARIBOU SNOW TOOL USING THE GFS AGREES PRETTY WELL WITH THIS SCENARIO. ALSO INTERESTING IS THE 16/00Z CIPS DATA...BASED ON THE TOP 15 ANALOGS...WHICH SHOWS MEAN SNOWFALL OF 4 TO 6 FROM WEST CENTRAL MN THROUGH THE ARROWHEAD AND FAR NORTHERN AREAS OF WI WITH 2 TO 3 INCHES FROM SOUTHWEST MN THROUGH THE METRO AND ACROSS MUCH OF WEST CENTRAL WI. IN THE WAKE OF THE LOW PRESSURE SYSTEM...A RATHER SUBSTANTIAL HIGH WILL BUILD OVER THE REGION FROM SUNDAY THROUGH TUESDAY WITH DRY WEATHER AND BELOW NORMAL TEMPERATURES OCCURRING. && .AVIATION... /06Z TAF ISSUANCE/ BKN040 WILL AFFECT MOST TAFS BUT RWF FOR A TIME DURING THE NEXT 4-6 HOURS AS NW FLOW BRINGS DOWN CLOUDS IN WAKE OF STRONG VORT NOW VCNTY OF DULUTH. UPSTREAM VORT IN SASK WILL MOVE ACROSS N MN ON WEDNESDAY SENDING ANOTHER CDFNT ACROSS AREA WITH MORE VFR CLDS. GRADIENT REMAINS FAIRLY STRONG OVERNITE...SO WINDS SHUD REMAIN IN 12 TO 15 KT RANGE. WNW WINDS BECOMING GUSTY AGAIN DURING THE DAY WED WITH GUSTS 20 TO 25 KTS BY AROUND 18Z. KMSP...SHUD SEE A PERIOD OF BKN040 BETWEEN 06Z-10Z AS CLOUDS SKIRT ACROSS CENTRAL MN. GUSTINESS HAS SLOWLY BEEN DIMINISHING LAST COUPLE OF HOURS AND THIS TREND WILL CONTINUE OVERNITE...SUSTAINED WINDS SHUD REMAIN IN THE 12-15 KT RANGE MOST OF NITE. GUSTS 20-25 KT RETURNING BY 18Z WED. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ RAH/BAP
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
333 AM CST WED NOV 16 2011 .DISCUSSION... A COLD WEST-NORTHWEST FLOW OF AIR WILL COVER THE REGION INTO THURSDAY. A SHORT WAVE OVER NORTH DAKOTA WILL PROGRESS TO THE WESTERN GREAT LAKES BY TONIGHT. SOME CLOUDINESS OVER CENTRAL MN AND WEST CENTRAL WI EARLY THIS MORNING WILL PART FOR A TIME BEFORE ANOTHER SURGE OF LOW CLOUDINESS ARRIVES FOR THE AFTERNOON AND EVENING HOURS. OUR LOCAL MODEL AND THE RUC PAINT SOME LIGHT ECHOES ACROSS CENTRAL MN AND WEST CENTRAL WI DURING THE AFTERNOON AND EVENING HOURS...SO KEPT THE MENTION OF FLURRIES TO THESE AREAS. THERE SHOULD BE A GOOD DEAL OF SUNSHINE ACROSS SOUTHERN MN TODAY. THE MIX-DOWN TD TOOL POINTS TO DEW POINT LOWERING TO AROUND 5 DEG C DURING THE AFTERNOON. WE ARE CURRENTLY SEEING SOME SINGLE DIGIT DEW POINTS NEAR THE SD/NE EARLY THIS MORNING. THE ARW/NMM WRFS ALSO INDICATE DINGLE DIGIT DEW POINT IN THE SOUTH THIS AFTERNOON. HENCE...BLENDED IN THE MIX DOWN DPS WITH CONSENSUS FOR THE AFTERNOON AND EVENING HOURS. TRENDED A FEW DEGREES HIGHER ON HIGH TEMPERATURES TODAY OVER THE SOUTHERN HALF OF THE CWA VERSUS MET/MAV MOS DUE TO MORE SUNSHINE AND WHAT THE MIX DOWN MAX T WAS SHOWING. FLURRIES/CLOUDS WILL DIMINISH TONIGHT OVER THE NORTHERN AND EASTERN CWA AS HIGH PRESSURE MOVES IN LATE IN THE NIGHT. THE RIDGE WILL MOVE ACROSS THE CWA ON THURSDAY WITH FLOW BECOMING MORE SOUTHERLY. IT WILL STILL BE A COOL DAY WITH HIGHS ONLY IN THE 30S. AS THE RIDGE MOVES EAST THURSDAY NIGHT...A WARM FRONT WILL DEVELOP AND MOVE NORTHEAST ACROSS THE CWA. ONLY SOME CLOUDS EXPECTED WITH THE WARM FRONT. THIS WILL LEAD TO A WARMER FRIDAY WITH HIGHS REACHING WELL INTO THE 40S IN MOST AREAS WITH SOME 50S IN THE SOUTH. THE LOW PRESSURE SYSTEM AND PRECIPITATION EVENT FOR SATURDAY AND SATURDAY NIGHT REMAINS ON TRACK. THE GEM AND ECMWF ARE IN STEP WITH THIS SYSTEM WHILE THE GFS LAGS BY ABOUT 6 HOURS. THE GFS ENSEMBLE IS EVEN SLOWER BY ABOUT ANOTHER 6 HOURS. STILL EXPECT A LOW TO TRACK FROM EASTERN NEBRASKA SATURDAY MORNING TO EASTERN WI BY SATURDAY NIGHT. ALL SOLUTIONS INDICATE THE LOW SLOWLY FILLING DURING THIS PERIOD WHICH IS NOTE GOOD FOR A HEAVY SNOW EVENT. WE ALSO CONTINUE TO SEE AN OPEN WAVE ALOFT WHICH SPEAKS FOR THE QUICKNESS WITH THIS SYSTEM. LOOKING AT SOME OF THE MID/UPPER LEVEL FEATURES SHOWS THE H5 HEIGHT FALL TRACK FROM YELLOW MEDICINE COUNTY TO BURNETT COUNTY. THE -15 DEG C OMEGA IS ON THE LEFT SIDE OF THIS TRACK WITH THE DEPTH OF THE DENDRITIC GROWTH ZONE BEING ABOUT 1100M. THE WARM POCKET AT H2 ALSO TRACKS ALONG THE AFOREMENTIONED AXIS WITH 10 DEG OF WARMING NOTED. THE 295K THETA SURFACE PLACES 700 MB ABOUT IN THIS GENERAL AREA AS WELL WITH PLENTY OF SATURATION AND ADIABATIC OMEGA NOTED TO THE NORTH AND WEST. THE MIX RATIO CONTINUES TO RUN BETWEEN 2 AND 3 G/KG AND IS ALIGNED WITH THE -FN VECTOR DIVERGENCE. THIS ALL POINTS TO A BAND OF 4 TO LOCALLY 6 INCHES FROM WEST CENTRAL MN ON NORTHEAST TO DULUTH AND HAYWARD. THE CARIBOU SNOW TOOL USING THE GFS AGREES WITH THIS SCENARIO. SNOW AMOUNTS TO THE SOUTHEAST OF THIS AREA WILL BE MORE IN THE 1 TO 3 INCH RANGE AS IT CURRENTLY STANDS. THE SMALLER TOTALS WOULD BE FROM ALBERT LEA TO EAU CLAIRE WHERE RAIN WILL DOMINATE FOR MUCH OF THE PERIOD. A RATHER SUBSTANTIAL HIGH PRESSURE SYSTEM WILL BUILD OVER THE REGION FROM SUNDAY THROUGH TUESDAY WITH DRY WEATHER AND BELOW NORMAL TEMPERATURES OCCURRING. && .AVIATION... /06Z TAF ISSUANCE/ BKN040 WILL AFFECT MOST TAFS BUT RWF FOR A TIME DURING THE NEXT 4-6 HOURS AS NW FLOW BRINGS DOWN CLOUDS IN WAKE OF STRONG VORT NOW VCNTY OF DULUTH. UPSTREAM VORT IN SASK WILL MOVE ACROSS N MN ON WEDNESDAY SENDING ANOTHER CDFNT ACROSS AREA WITH MORE VFR CLDS. GRADIENT REMAINS FAIRLY STRONG OVERNITE...SO WINDS SHUD REMAIN IN 12 TO 15 KT RANGE. WNW WINDS BECOMING GUSTY AGAIN DURING THE DAY WED WITH GUSTS 20 TO 25 KTS BY AROUND 18Z. KMSP...SHUD SEE A PERIOD OF BKN040 BETWEEN 06Z-10Z AS CLOUDS SKIRT ACROSS CENTRAL MN. GUSTINESS HAS SLOWLY BEEN DIMINISHING LAST COUPLE OF HOURS AND THIS TREND WILL CONTINUE OVERNITE...SUSTAINED WINDS SHUD REMAIN IN THE 12-15 KT RANGE MOST OF NITE. GUSTS 20-25 KT RETURNING BY 18Z WED. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ RAH/BAP
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
300 AM EST WED NOV 16 2011 .SYNOPSIS... A COLD FRONT OVER THE TENNESSEE VALLEY WILL SLIDE EASTWARD BRINGING SHOWERS AND A CHANCE OF THUNDERSTORMS THROUGH THURSDAY MORNING. MUCH COOLER AND DRIER AIR WILL FOLLOW LATE THURSDAY AND FRIDAY. HIGH PRESSURE WILL MOVE OVERHEAD WITH TEMPERATURES MODERATING DURING THE WEEKEND. ANOTHER FRONT WILL SHIFT TOWARD THE AREA EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... AS OF 3:00 AM WEDNESDAY...MORNING LOW STRATUS WILL BURN OFF DURING THE MID TO LATE MORNING HOURS. PATCHY SEA FOG OFFSHORE MAY ENCROACH ONTO THE BEACHES AND NEARBY ENVIRONS FOR AT LEAST THE FIRST HALF OF THE DAY. VISIBILITIES MAY BE REDUCED TO A MILE OR LESS IN A FEW PLACES. SOME HIGHER CLOUDS WILL BE IN PLACE THROUGH THE DAY. AS WE MIX DRIER AIR TO THE SURFACE...SKIES WILL BECOME AT LEAST PARTLY CLOUDY. WINDS ALOFT WILL BE SW AT 30 TO 40 KT AND AS WE MIX TO A DEPTH OF AROUND 3 KFT...WE WILL EXPERIENCE WIND GUSTS OF NEAR 30 MPH LATE MORNING AND THROUGH THE AFTERNOON AND EVE. A STRONG COLD FRONT WILL BE APPROACHING FROM THE NW TODAY. A SERIES OF SURFACE LOWS WILL TRAVERSE THIS BOUNDARY. THE FRONT IS EXPECTED TO REACH THE I-95 CORRIDOR DURING THE LATE EVE AND THEN MOVE ACROSS THE FORECAST AREA DURING THE EARLY MORNING HOURS OF THU...AND FINALLY OFF THE COAST DURING THU MORNING. DEEP SW FLOW WILL ALLOW PRECIPITABLE WATER VALUES TO RISE TO AROUND ONE AND A HALF INCHES. SUFFICIENT FORCING TO GENERATE PRECIPITATION MAY NOT ARRIVE TO WELL AFTER DARK. LOW LEVEL JET WILL INCREASE TO AROUND 50 KT OVERNIGHT. MODELS ARE INDICATING AN INVERSION AROUND 1400 FT TONIGHT AND THIS WILL MAKE IT DIFFICULT FOR HIGHER WINDS ALOFT TO REACH THE GROUND. HOWEVER...ONE AREA OF LOW PRESSURE WILL LIKELY BE MOVING ALONG AND N OF OUR INLAND ZONES OVERNIGHT. BULK SHEAR VALUES ARE FORECAST TO BE NEAR OR OVER 60 KT DURING THE LATE NIGHT AND EARLY MORNING HOURS...HIGHEST NEAR THE TRACK OF THE SURFACE LOW. LCLS WILL BE DROPPING DURING THIS TIME. THIS SUPPORTS AN ISOLATED RISK FOR TORNADOES. SPC HAS A PORTION OF THE FORECAST AREA IN A SLIGHT RISK FOR SEVERE WEATHER...INCLUDING TORNADOES. CURRENTLY THE RISK AREA IS ACROSS THE PEE DEE REGION OF SOUTH CAROLINA AND FROM NEAR FAIR BLUFF TO BURGAW IN NORTH CAROLINA AND POINTS NORTH. THIS AREA MAY SHIFT THROUGH THE DAY...BUT AT THIS TIME IT IS REASONABLE TO EXPECT SOME RISK OF ISOLATED TORNADOES OR DAMAGING WIND GUSTS ACROSS A MAJORITY OF THE AREA. POPS WILL BE HIGHEST LATE TONIGHT...CATEGORICAL NW ZONES TO LIKELY AS YOU APPROACH THE COAST WITH CONVECTION LINGERING ALONG THE COAST THROUGH THU MORNING. CURRENT PRECIPITATION FORECAST INCLUDES AMOUNTS IN THE ONE-HALF INCH TO ONE-INCH RANGE...BUT AMOUNTS SHOULD BE HIGHLY VARIABLE AS YOU MOVE FROM ONE COMMUNITY TO THE NEXT. FORECAST TEMPS WILL BE WELL ABOVE NORMAL WITH HIGHS IN THE UPPER 70S TO LOWER 80S EXCEPT ALONG THE IMMEDIATE COAST WHERE THE COMPARATIVELY COOL MARINE ENVIRONMENT WILL KEEP READINGS IN THE LOWER TO PERHAPS MID 70S. TEMPS TONIGHT WILL BE IN THE BALMY 70S FOR MOST OF THE EVE WITH MINIMUMS ACROSS MOST OF THE AREA PROJECTED TO FALL ONLY TO THE LOWER TO MID 60S BY SUNRISE THU. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY EVENING/... AS OF 3:00 AM WEDNESDAY...FORECAST MODELS HAVE SLOWED DOWN THE PROGRESSION OF THE COLD FRONT EVER SO SLIGHTLY AND HAVE THEREFORE EXTENDED POPS ACROSS THE BOARD INTO THE LATE MORNING HOURS...ESPECIALLY COASTAL AREAS. OTHERWISE INTERESTING TEMPERATURE FORECAST FOR THURSDAY HIGHS AS THE MAV NUMBERS SHOW NO WARMING IN WILMINGTON WITH LITTLE ELSEWHERE. WITH THE DOWNSLOPE FLOW AND COLD AIR ADVECTION NOT THAT IMPRESSIVE...DID ADD A DEGREE OR TWO TO THE MAV NUMBERS. FOR FRIDAY MORNING WINDS DECOUPLE INLAND WHILE REMAINING UP SLIGHTLY ALONG THE COAST AND ADJUSTED MOS NUMBERS ACCORDINGLY. COOL DAY FRIDAY WITH MOST AREAS REMAINING BELOW 60. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 3:00 AM WEDNESDAY...EXTENDED FORECAST IS RATHER UNEVENTFUL AS THE PATTERN QUICKLY EVOLVES FROM ZONAL TO RIDGING ACROSS THE SOUTHEAST...SIMILAR TO THE PATTERN WE HAVE EXPERIENCED THE PAST FEW DAYS. HPC IS FAVORING A BLEND OF THE GFS/ECMWF AND UKMET. REALLY THE ONLY FORECAST CHALLENGES INVOLVE LIGHT COASTAL TROUGH QPF SATURDAY AND A BACKDOOR FRONT TUESDAY. AS FOR THE FORMER...MAINTAINED A DRY FORECAST AS THE MODELS ARE USUALLY OVERDONE WITH THE QPF AND IN REALITY IT IS GENERALLY A STRATUS LAYER. REGARDING THE FRONT...THE LATEST GFS IS MORE BULLISH IN PUSHING THE FRONT SOUTH WITH THE EFFECTS ONLY BEING AN AIRMASS CHANGE. THE 0000 UTC ECMWF HAS BACKED OFF A FURTHER SOUTH SOLUTION. OTHERWISE...AS WE JUST EXPERIENCED...ABOVE NORMAL TO DOWN RIGHT BALMY CONDITIONS FOR LATE IN THE WEEKEND AND EARLY NEXT WEEK. && .AVIATION /08Z WEDNESDAY THROUGH SUNDAY/... AS OF 06Z...HIGH CONFIDENCE IFR CEILINGS OR LOWER WILL DOMINATE THROUGH THE FIRST 6 TO 9 HOURS AT ALL THE TERMINALS. VISIBILITY WILL FLUCTUATE FROM MVFR TO IFR OR LOWER IN FOG. EARLIER LIGHT RAIN AT KILM HAS ENDED AS SHOWERS CONTINUE TO PULL AWAY FROM THE CAPE FEAR REGION. PATCHY SEA FOG WILL CONTINUE OFFSHORE AND MAY COME ONTO THE COAST BRINGING BOUTS OF LOWER VISIBILITY TO THE COASTAL TERMINALS BEFORE WINDS VEER MORE SOLIDLY SW BY/AFTER SUNRISE. CONDITIONS WILL SLOWLY IMPROVE TO VFR MID-MORNING THROUGH MIDDAY. TIGHTENING PRESSURE GRADIENT AHEAD OF COLD FRONT WILL CREATE GUSTY SW WINDS...18-22KTS AT ALL TAF SITES LATE MORNING AND THROUGH THE AFTERNOON AND EARLY EVE. TOWARD THE END OF THE VALID PERIOD AND THEREAFTER...CONDITIONS WILL SLOWLY BEGIN TO DETERIORATE AGAIN AS A COLD FRONT BRINGS SHRA AND ISOLATED TSRA LATE TONIGHT AND THU MORNING. EXTENDED OUTLOOK...COLD FRONT MOVING ACROSS THE AREA OVERNIGHT INTO THURSDAY MORNING COULD CREATE ISOLATED IFR IN TSRA. EXPECT VFR FRIDAY AND SATURDAY...WITH LOWERED CONFIDENCE FOR POTENTIAL IFR FOG/STRATUS SUNDAY MORNING. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1055 PM TUESDAY...THE SEA FOG THREAT CONTINUES ACROSS THE ILM WATERS. WILL CONTINUE TO INDICATE PATCHY/AREAS OF SEA FOG ACROSS THE ILM WATERS THROUGH OR JUST AFTER DAYBREAK WEDNESDAY. WITH THE LATEST AVAILABLE SST MAP OF THE ILM WATERS USING AVHRR DATA FOR THE 2 DAYS ENDING ON NOV 14TH...2 NOTEWORTHY PATCHES OF COOLER SHELF WATERS IN THE LOW 60S WERE SHOWN. ONE PATCH BETWEEN SURF CITY AND CAPE FEAR...AND OUT TO NEARLY THE FRYING PAN SHOALS BUOY...41013. AND THE 2ND PATCH...LYING ACROSS THE WATERS BETWEEN NORTH MYRTLE BEACH TO SOUTH SANTEE RIVER. THIS 2ND ONE NOT NEARLY AS PRONOUNCED AS THE 1ST. SFC DEWPOINTS IN THE MID 60S TO NEAR 70 WILL CONTINUE TO ADVECT ACROSS THESE COOLER SHELF WATERS OVERNIGHT INTO WED. THIS WILL RESULT WITH AN INCREASED POTENTIAL FOR SEA FOG TO DEVELOP AND AFFECT THE ILM WATERS...PARTICULAR ACROSS THOSE COOL WATERS. A FEW LOCAL SURF CAMS HAVE SHOWCASED THE EXISTENCE OF THE SEA FOG. AS SYNOPTIC WINDS SLOWLY VEER FROM 190-230 OVERNIGHT INTO WED...THE THREAT FOR SEA FOG WILL SLOWLY DIMINISH OR AT LEAST KEEP THE FOG FROM ADVECTING ONSHORE/INLAND. WILL INDICATE VSBY REDUCING TO 1NM OR LESS. IF ANY RECEIVED REPORTS AND/OR OBS INDICATE 1/2 NM OR LESS VSBYS...WILL THEN UPDATE AND ADVERTISE DENSE FOG. A MARINE WEATHER STATEMENT HAS BEEN ISSUED TO HIGHLIGHT THE INCREASED POTENTIAL FOR SEA FOG. HAVE MAINTAINED THE WINDS AND SEAS FORECAST FROM THE PREVIOUS FORECAST...WITH THE LATEST HRRR KEEPING WINDS ON THE LOWER SIDE OF MODEL GUIDANCE. WHICH IN TURN...PRODUCING SLIGHTLY LOWER SEAS THAN ORIGINALLY THOUGHT. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 3:00 AM WEDNESDAY...MAIN FORECAST CHALLENGE WILL BE WHEN TO CONCLUDE THE SMALL CRAFT ADVISORY LATE THURSDAY EVENING. A PERIOD OF STRONG NORTHERLY WINDS WILL FOLLOW THE FRONT THURSDAY INTO THURSDAY EVENING. FOR NOW WITH THE TIMING STILL OUT FOUR PERIODS...WILL NOT TWEAK BUT ISSUE THE DISCLAIMER THE HEADLINE MAY HAVE TO BE EXTENDED A FEW HOURS. WINDS VEER TO NORTHEASTERLY FRIDAY AND DIMINISH SOMEWHAT TO A MANAGEABLE RANGE OF 15-20 KNOTS MAINLY TO THE LOWER END. HIGH SEAS EARLY GET CONFINED TO THE OUTER WATERS WITH THE WIND SHIFT AND REMAIN THERE FOR THE MOST PART. SOME FIVE TO SIX FOOTERS MAY LINGER ACROSS THE OUTER WATERS GIVING THE FRIDAY. LONG TERM /SATURDAY THROUGH SUNDAY/... AS OF 3:00 AM WEDNESDAY...NORTHEAST FLOW INITIALLY WILL QUICKLY VEER TO SOUTHEAST AS HIGH PRESSURE WEAKENS AND LEAVES THE WIND FIELD TO BE FORCED BY LOCAL EFFECTS IE...THE SEABREEZE. THIS WILL OCCUR LATE SATURDAY AND SUNDAY AS WINDS DROP TO BELOW 10 KNOTS. SEAS FOLLOW A SIMILAR TREND WITH 2-4 FEET INITIALLY DROPPING TO 2-3 FEET. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...SMALL CRAFT ADVISORY FROM NOON TODAY TO MIDNIGHT EST THURSDAY NIGHT FOR AMZ250-252-254-256. && $$ SYNOPSIS...SHK NEAR TERM...RJD SHORT TERM...SHK LONG TERM...SHK AVIATION...SGL/RJD
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1222 AM EST WED NOV 16 2011 .SYNOPSIS... HIGH PRESSURE WILL CONTINUE OVER THE REGION THROUGH WEDNESDAY. A COLD FRONT OVER THE MIDWEST WILL SLIDE EASTWARD BRINGING SHOWERS AND A CHANCE OF THUNDERSTORMS OVERNIGHT WEDNESDAY INTO THURSDAY. MUCH COOLER AND DRIER AIR WILL FOLLOW ON THURSDAY AND FRIDAY. HIGH PRESSURE WILL MOVE OVERHEAD WITH TEMPERATURES MODERATING DURING THE WEEKEND. A SECOND FRONT WILL SHIFT TOWARD THE AREA ON TUESDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1045 PM TUESDAY...SPORADIC ONSHORE MOVEMENT OF PATCHY OR AREAS OF SEA FOG WILL CONTINUE OVERNIGHT. THIS A RESULT OF SFC WINDS BOUNCING FROM 180-210 DEGREES. AS WINDS BECOME DOMINANT 210-230 DEGREE DIRECTION AFTER DAYBREAK WEDNESDAY...THE THREAT FOR SEA FOG MOVING ONSHORE WILL DIMINISH GREATLY. SCATTERED -SHRA LATE THIS EVENING AND OVERNIGHT DUE TO A WEAK LOW-MID LEVEL IMPULSE TRACKING NE...AS WELL AS LOW LEVEL WIND SPEED CONVERGENCE FROM 15-25 KT S-SW WINDS OFFSHORE QUICKLY DROPPING TO 10 KT OR LESS OVER THE COOLER SHELF WATERS...AS WELL AS WEAK WIND DIRECTION CONVERGENCE FROM SW INLAND TO S-SSW ALONG THE IMMEDIATE COAST. AS FOR SEA FOG...THE LATEST AVAILABLE SST MAP OF THE WATERS OFF THE SOUTHEAST U.S. COAST USING AVHRR DATA FOR THE 2 DAYS ENDING ON NOV 14TH...INDICATED 2 PATCHES OF NOTEWORTHY COOL SHELF WATERS OFF THE CAROLINAS...WITH 1 PATCH BETWEEN SURF CITY AND CAPE FEAR...TO NEARLY OUT TO THE FRYING PAN SHOALS BUOY...41013. AND THE SECOND PATCH LYING ACROSS THE COASTAL WATERS BETWEEN NORTH MYRTLE BEACH TO SOUTH SANTEE RIVER. THIS 2ND ONE NOT AS PRONOUNCED AS THE 1ST. WITH SFC DEWPOINTS IN THE MID 60S TO NEAR 70 ADVECTING ACROSS THESE COOLER SHELF WATERS OVERNIGHT INTO WED...SEA FOG WILL CONTINUE TO DEVELOP AND AFFECT THE IMMEDIATE COAST BORDERING THE AFOREMENTIONED COLL SHELF WATER AREAS. A FEW LOCAL SURF CAMS HAVE ALSO SHOWCASED THE EXISTENCE OF THE SEA FOG AT TIMES. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 3 PM TUESDAY...A LARGE SCALE UPPER LEVEL TROUGH OVER THE WESTERN UNITED STATES WILL SHIFT EASTWARD BY WEDNESDAY NIGHT AND THIS WILL PROVIDE GOOD SYNOPTIC LIFT FOR THE REGION. AT THE SURFACE A FRONTAL BOUNDARY WILL ACT AS THE LOW LEVEL LIFTING MECHANISM FOR SHOWERS AND ISOLATED THUNDERSTORMS. INSTABILITY IS FORECAST BY THE MODEL TO BE VERY LOW AND THE LOW-LEVEL 0 TO 2.5 KM BULK SHEAR MAGNITUDE REACHES ALMOST 40 KNOTS. THE LOW-LEVEL HELICITY MAXIMUM APPEARS TO BE SHIFTING FARTHER NORTH WITH THIS MODEL RUN AND IS RUNNING AHEAD OF THE MODEL CONVECTION...SO CONFIDENCE ON ISOLATED TORNADOES IS NOT VERY HIGH AT THIS TIME. MAXIMUM TEMPERATURES ARE EXPECTED TO REACH IN THE UPPER 70S INLAND ON WEDNESDAY AND WITH THE FRONTAL BOUNDARY PASSAGE HIGHS ARE EXPECTED TO ONLY REACH IN THE LOWER TO MIDDLE 60S ON THURSDAY. && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 3 PM TUESDAY...COLD SURFACE HIGH BUILDS INTO THE REGION FRI BEFORE QUICKLY SHIFTING NORTHEAST FRI NIGHT INTO SAT. WEAK COASTAL TROUGH DEVELOPS SAT WITH LOW LEVEL EAST TO NORTHEAST FLOW INCREASING MOISTURE IN THE LOWEST 3K FT OR SO. CURRENT FORECAST IS DEVOID OF PRECIP HOWEVER THE INCREASE IN LOW LEVEL MOISTURE COMBINED WITH DEVELOPING RETURN FLOW JUST ABOVE THE SURFACE LATER IN THE DAY SAT COULD PRODUCE SOME LIGHT PATCHY OF RAIN. WOULD NOT EXPECT MUCH QPF SHOULD SOMETHING DEVELOP WITH COASTAL NC THE MOST LIKELY AREA TO SEE SOMETHING. AT THE VERY LEAST ANTICIPATE AN INCREASE IN CLOUD COVER SAT INTO SUN. COASTAL TROUGH DISSIPATES SUN AS SURFACE RIDGE AXIS SHIFTS EAST OF THE AREA. ALTHOUGH DEVELOPING SOUTHERLY FLOW HELPS INCREASE LOW LEVEL MOISTURE SUN AND MON DRY MID LEVELS AND WEAK CAP...A RESULT OF BUILDING WEAK MID LEVEL RIDGE...WILL PREVENT ANY PRECIP. WEAK COLD FRONT STALLED NORTH OF THE AREA TUE WILL TRY AND DROP SOUTH DURING THE DAY. IF FRONT MOVES ACROSS THE AREA DO NOT THINK IT WOULD HAVE MUCH PRECIP ASSOCIATED WITH IT. THE FRONT IS STRETCHED OUT WITH THE DYNAMICS WELL OFF TO THE NORTHEAST. TEMPERATURES WILL RANGE FROM WELL BELOW CLIMO AT THE START OF THE PERIOD TO ABOVE CLIMO EARLY NEXT WEEK. THE TRANSITION FROM BELOW CLIMO TO ABOVE WILL BE QUICK...BY SAT NIGHT TEMPS SHOULD BE ABOVE CLIMO. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... AS OF 06Z...HIGH CONFIDENCE IFR CEILINGS OR LOWER WILL DOMINATE THROUGH THE FIRST 6 TO 9 HOURS AT ALL THE TERMINALS. VISIBILITY WILL FLUCTUATE FROM MVFR TO IFR OR LOWER IN FOG. EARLIER LIGHT RAIN AT KILM HAS ENDED AS SHOWERS CONTINUE TO PULL AWAY FROM THE CAPE FEAR REGION. PATCHY SEA FOG WILL CONTINUE OFFSHORE AND MAY COME ONTO THE COAST BRINGING BOUTS OF LOWER VISIBILITY TO THE COASTAL TERMINALS BEFORE WINDS VEER MORE SOLIDLY SW BY/AFTER SUNRISE. CONDITIONS WILL SLOWLY IMPROVE TO VFR MID-MORNING THROUGH MIDDAY. TIGHTENING PRESSURE GRADIENT AHEAD OF COLD FRONT WILL CREATE GUSTY SW WINDS...18-22KTS AT ALL TAF SITES LATE MORNING AND THROUGH THE AFTERNOON AND EARLY EVE. TOWARD THE END OF THE VALID PERIOD AND THEREAFTER...CONDITIONS WILL SLOWLY BEGIN TO DETERIORATE AGAIN AS A COLD FRONT BRINGS SHRA AND ISOLATED TSRA LATE TONIGHT AND THU MORNING. EXTENDED OUTLOOK...COLD FRONT MOVING ACROSS THE AREA OVERNIGHT INTO THURSDAY MORNING COULD CREATE ISOLATED IFR IN TSRA. EXPECT VFR FRIDAY AND SATURDAY...WITH LOWERED CONFIDENCE FOR POTENTIAL IFR FOG/STRATUS SUNDAY MORNING. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1055 PM TUESDAY...THE SEA FOG THREAT CONTINUES ACROSS THE ILM WATERS. WILL CONTINUE TO INDICATE PATCHY/AREAS OF SEA FOG ACROSS THE ILM WATERS THROUGH OR JUST AFTER DAYBREAK WEDNESDAY. WITH THE LATEST AVAILABLE SST MAP OF THE ILM WATERS USING AVHRR DATA FOR THE 2 DAYS ENDING ON NOV 14TH...2 NOTEWORTHY PATCHES OF COOLER SHELF WATERS IN THE LOW 60S WERE SHOWN. ONE PATCH BETWEEN SURF CITY AND CAPE FEAR...AND OUT TO NEARLY THE FRYING PAN SHOALS BUOY...41013. AND THE 2ND PATCH...LYING ACROSS THE WATERS BETWEEN NORTH MYRTLE BEACH TO SOUTH SANTEE RIVER. THIS 2ND ONE NOT NEARLY AS PRONOUNCED AS THE 1ST. SFC DEWPOINTS IN THE MID 60S TO NEAR 70 WILL CONTINUE TO ADVECT ACROSS THESE COOLER SHELF WATERS OVERNIGHT INTO WED. THIS WILL RESULT WITH AN INCREASED POTENTIAL FOR SEA FOG TO DEVELOP AND AFFECT THE ILM WATERS...PARTICULAR ACROSS THOSE COOL WATERS. A FEW LOCAL SURF CAMS HAVE SHOWCASED THE EXISTENCE OF THE SEA FOG. AS SYNOPTIC WINDS SLOWLY VEER FROM 190-230 OVERNIGHT INTO WED...THE THREAT FOR SEA FOG WILL SLOWLY DIMINISH OR ATLEAST KEEP THE FOG FROM ADVECTING ONSHORE/INLAND. WILL INDICATE VSBY REDUCING TO 1NM OR LESS. IF ANY RECEIVED REPORTS AND/OR OBS INDICATE 1/2 NM OR LESS VSBYS...WILL THEN UPDATE AND ADVERTISE DENSE FOG. A MARINE WEATHER STATEMENT HAS BEEN ISSUED TO HIGHLIGHT THE INCREASED POTENTIAL FOR SEA FOG. HAVE MAINTAINED THE WINDS AND SEAS FORECAST FROM THE PREVIOUS FORECAST...WITH THE LATEST HRRR KEEPING WINDS ON THE LOWER SIDE OF MODEL GUIDANCE. WHICH IN TURN...PRODUCING SLIGHTLY LOWER SEAS THAN ORIGINALLY THOUGHT. SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 3 PM TUESDAY...A COLD FRONT WILL BE APPROACHING THE WATERS LATE WEDNESDAY INTO THURSDAY. SOUTHWEST WINDS WILL INCREASE THROUGH OUT THE DAY ON WEDNESDAY AND THE LOCAL SWAN MODEL IS INDICATING THE SEAS WILL REACH SMALL CRAFT CONDITIONS AROUND MIDNIGHT WEDNESDAY NIGHT-THURSDAY MORNING. AS THE FRONT PUSHES THROUGH THE COLD AIR ADVECTION WILL HELP PROVIDE AN ENVIRONMENT FOR 20 TO 25 KNOT OFF SHORE WINDS ON THURSDAY. LONG TERM /FRIDAY THROUGH SUNDAY/... AS OF 3 PM TUESDAY...POST FRONT COLD SURGE IN THE 15 TO 20 KT RANGE FRI WILL DROP CLOSER TO 10 KT BY SAT MORNING AS GRADIENT. WEAK COASTAL TROF TAKING SHAPE WILL INDUCE A MORE EASTERLY COMPONENT TO LOW LEVEL FLOW. GRADIENT REMAINS WEAK THROUGH THE END OF THE PERIOD WITH WINDS BECOMING EAST TO SOUTHEAST LATE SAT NIGHT AND SUN AS ELONGATED RIDGE AXIS SHIFTS OFFSHORE. ADVISORY WORTHY SEAS AT THE START OF THE PERIOD WILL DROP TO 3 TO 4 FT BY FRI NIGHT AND REMAIN IN THE 3 TO 4 FT RANGE THROUGH SUN. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...HAWKINS NEAR TERM...DOUGH SHORT TERM...HAWKINS LONG TERM...III AVIATION...RJD/LACORTE
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1045 PM EST TUE NOV 15 2011 .SYNOPSIS... HIGH PRESSURE WILL CONTINUE OVER THE REGION THROUGH WEDNESDAY. A COLD FRONT OVER THE MIDWEST WILL SLIDE EASTWARD BRINGING SHOWERS AND A CHANCE OF THUNDERSTORMS OVERNIGHT WEDNESDAY INTO THURSDAY. MUCH COOLER AND DRIER AIR WILL FOLLOW ON THURSDAY AND FRIDAY. HIGH PRESSURE WILL MOVE OVERHEAD WITH TEMPERATURES MODERATING DURING THE WEEKEND. A SECOND FRONT WILL SHIFT TOWARD THE AREA ON TUESDAY. && .NEAR TERM /THROUGH WEDNESDAY/... AS OF 1045 PM TUESDAY...SPORADIC ONSHORE MOVEMENT OF PATCHY OR AREAS OF SEA FOG WILL CONTINUE OVERNIGHT. THIS A RESULT OF SFC WINDS BOUNCING FROM 180-210 DEGREES. AS WINDS BECOME DOMINANT 210-230 DEGREE DIRECTION AFTER DAYBREAK WEDNESDAY...THE THREAT FOR SEA FOG MOVING ONSHORE WILL DIMINISH GREATLY. SCATTERED -SHRA LATE THIS EVENING AND OVERNIGHT DUE TO A WEAK LOW-MID LEVEL IMPULSE TRACKING NE...AS WELL AS LOW LEVEL WINDSPEED CONVERGENCE FROM 15-25 KT S-SW WINDS OFFSHORE QUICKLY DROPPING TO 10 KT OR LESS OVER THE COOLER SHELF WATERS...AS WELL AS WEAK WIND DIRECTION CONVERGENCE FROM SW INLAND TO S-SSW ALONG THE IMMEDIATE COAST. AS FOR SEA FOG...THE LATEST AVAILABLE SST MAP OF THE WATERS OFF THE SOUTHEAST U.S. COAST USING AVHRR DATA FOR THE 2 DAYS ENDING ON NOV 14TH...INDICATED 2 PATCHES OF NOTEWORTHY COOL SHELF WATERS OFF THE CAROLINAS...WITH 1 PATCH BETWEEN SURF CITY AND CAPE FEAR...TO NEARLY OUT TO THE FRYING PAN SHOALS BUOY...41013. AND THE SECOND PATCH LYING ACROSS THE COASTAL WATERS BETWEEN NORTH MYRTLE BEACH TO SOUTH SANTEE RIVER. THIS 2ND ONE NOT AS PRONOUNCED AS THE 1ST. WITH SFC DEWPOINTS IN THE MID 60S TO NEAR 70 ADVECTING ACROSS THESE COOLER SHELF WATERS OVERNIGHT INTO WED...SEA FOG WILL CONTINUE TO DEVELOP AND AFFECT THE IMMEDIATE COAST BORDERING THE AFOREMENTIONED COLL SHELF WATER AREAS. A FEW LOCAL SURF CAMS HAVE ALSO SHOWCASED THE EXISTENCE OF THE SEA FOG AT TIMES. PREVIOUS MIN FORECAST FOR TONIGHT STILL LOOKING AOK WITH ANY TWEAKS NEEDED WOULD BE ON THE ORDER TO INCREASE LOWS CLOSER TO THE IMMEDIATE COAST. && .SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/... AS OF 3 PM TUESDAY...A LARGE SCALE UPPER LEVEL TROUGH OVER THE WESTERN UNITED STATES WILL SHIFT EASTWARD BY WEDNESDAY NIGHT AND THIS WILL PROVIDE GOOD SYNOPTIC LIFT FOR THE REGION. AT THE SURFACE A FRONTAL BOUNDARY WILL ACT AS THE LOW LEVEL LIFTING MECHANISM FOR SHOWERS AND ISOLATED THUNDERSTORMS. INSTABILITY IS FORECAST BY THE MODEL TO BE VERY LOW AND THE LOW-LEVEL 0 TO 2.5 KM BULK SHEAR MAGNITUDE REACHES ALMOST 40 KNOTS. THE LOW-LEVEL HELICITY MAXIMUM APPEARS TO BE SHIFTING FARTHER NORTH WITH THIS MODEL RUN AND IS RUNNING AHEAD OF THE MODEL CONVECTION...SO CONFIDENCE ON ISOLATED TORNADOES IS NOT VERY HIGH AT THIS TIME. MAXIMUM TEMPERATURES ARE EXPECTED TO REACH IN THE UPPER 70S INLAND ON WEDNESDAY AND WITH THE FRONTAL BOUNDARY PASSAGE HIGHS ARE EXPECTED TO ONLY REACH IN THE LOWER TO MIDDLE 60S ON THURSDAY. && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 3 PM TUESDAY...COLD SURFACE HIGH BUILDS INTO THE REGION FRI BEFORE QUICKLY SHIFTING NORTHEAST FRI NIGHT INTO SAT. WEAK COASTAL TROUGH DEVELOPS SAT WITH LOW LEVEL EAST TO NORTHEAST FLOW INCREASING MOISTURE IN THE LOWEST 3K FT OR SO. CURRENT FORECAST IS DEVOID OF PRECIP HOWEVER THE INCREASE IN LOW LEVEL MOISTURE COMBINED WITH DEVELOPING RETURN FLOW JUST ABOVE THE SURFACE LATER IN THE DAY SAT COULD PRODUCE SOME LIGHT PATCHY OF RAIN. WOULD NOT EXPECT MUCH QPF SHOULD SOMETHING DEVELOP WITH COASTAL NC THE MOST LIKELY AREA TO SEE SOMETHING. AT THE VERY LEAST ANTICIPATE AN INCREASE IN CLOUD COVER SAT INTO SUN. COASTAL TROUGH DISSIPATES SUN AS SURFACE RIDGE AXIS SHIFTS EAST OF THE AREA. ALTHOUGH DEVELOPING SOUTHERLY FLOW HELPS INCREASE LOW LEVEL MOISTURE SUN AND MON DRY MID LEVELS AND WEAK CAP...A RESULT OF BUILDING WEAK MID LEVEL RIDGE...WILL PREVENT ANY PRECIP. WEAK COLD FRONT STALLED NORTH OF THE AREA TUE WILL TRY AND DROP SOUTH DURING THE DAY. IF FRONT MOVES ACROSS THE AREA DO NOT THINK IT WOULD HAVE MUCH PRECIP ASSOCIATED WITH IT. THE FRONT IS STRETCHED OUT WITH THE DYNAMICS WELL OFF TO THE NORTHEAST. TEMPERATURES WILL RANGE FROM WELL BELOW CLIMO AT THE START OF THE PERIOD TO ABOVE CLIMO EARLY NEXT WEEK. THE TRANSITION FROM BELOW CLIMO TO ABOVE WILL BE QUICK...BY SAT NIGHT TEMPS SHOULD BE ABOVE CLIMO. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... AS OF 00Z...EXPECT CONTINUED AREAS OF PATCHY SEA FOG TO ADVECT ONSHORE AT KCRE/KMYR OVER THE NEXT COUPLE OF HOURS...REDUCING VSBYS OFF AND ON TO MVFR BEFORE FLOW FROM VEERING WINDS STEER FOG AWAY FROM TERMINALS AFTER DAYBREAK. FOR KILM...CURRENT RADAR DEPICTS SOME -SHRA OFFSHORE. CANNOT RULE OUT A LIGHT SHOWER TO WRAP AROUND TO TERMINAL...AND POSSIBLY THE TWO OTHER COASTAL SITES...THUS HAVE OPTED TO INCLUDE VCSH FOR A FEW HOURS. ELSEWHERE...VFR WILL PREVAIL THROUGH ROUGHLY 06Z WITH SOUTH- SOUTHWEST WINDS AROUND 5-8KTS. WITH MODELS IN GENERAL AGREEMENT...ANTICIPATE CIGS AND VSBYS AT ALL SITES DETERIORATE AFTER 07Z DUE TO ADVECTION FOG/STRATUS. FOR NOW...ANTICIPATE LIFR/IFR CIGS...AND IFR/MVFR FOG THROUGH WEDNESDAY MORNING. SOON AFTER DAYBREAK...EXPECT CONDITIONS TO SLOWLY IMPROVE TO VFR...WITH TIGHTENED PRESSURE GRADIENT CREATING GUSTY WINDS 18-22KTS ACROSS THE ENTIRE AREA. WINDS THROUGHOUT THE PERIOD WILL REMAIN SOUTH- SOUTHWEST. TOWARDS THE END OF THE VALID PERIOD INTO THE NEXT...CONDITIONS WILL SLOWLY BEGIN TO DETERIORATE AGAIN AS A COLD FRONT BRINGS ANTICIPATED SHRA AND ISOLATED TSRA. EXTENDED OUTLOOK...COLD FRONT MOVING ACROSS THE AREA WEDNESDAY EVENING THROUGH THURSDAY MORNING COULD CREATE ISOLATED TSRA AND IFR. EXPECT VFR FRIDAY AND SATURDAY...WITH LOWERED CONFIDENCE FOR POTENTIAL IFR FOG/STRATUS SUNDAY MORNING. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1055 PM TUESDAY...THE SEA FOG THREAT CONTINUES ACROSS THE ILM WATERS. WILL CONTINUE TO INDICATE PATCHY/AREAS OF SEA FOG ACROSS THE ILM WATERS THROUGH OR JUST AFTER DAYBREAK WEDNESDAY. WITH THE LATEST AVAILABLE SST MAP OF THE ILM WATERS USING AVHRR DATA FOR THE 2 DAYS ENDING ON NOV 14TH...2 NOTEWORTHY PATCHES OF COOLER SHELF WATERS IN THE LOW 60S WERE SHOWN. ONE PATCH BETWEEN SURF CITY AND CAPE FEAR...AND OUT TO NEARLY THE FRYING PAN SHOALS BUOY...41013. AND THE 2ND PATCH...LYING ACROSS THE WATERS BETWEEN NORTH MYRTLE BEACH TO SOUTH SANTEE RIVER. THIS 2ND ONE NOT NEARLY AS PRONOUNCED AS THE 1ST. SFC DEWPOINTS IN THE MID 60S TO NEAR 70 WILL CONTINUE TO ADVECT ACROSS THESE COOLER SHELF WATERS OVERNIGHT INTO WED. THIS WILL RESULT WITH AN INCREASED POTENTIAL FOR SEA FOG TO DEVELOP AND AFFECT THE ILM WATERS...PARTICULAR ACROSS THOSE COOL WATERS. A FEW LOCAL SURF CAMS HAVE SHOWCASED THE EXISTENCE OF THE SEA FOG. AS SYNOPTIC WINDS SLOWLY VEER FROM 190-230 OVERNIGHT INTO WED...THE THREAT FOR SEA FOG WILL SLOWLY DIMINISH OR ATLEAST KEEP THE FOG FROM ADVECTING ONSHORE/INLAND. WILL INDICATE VSBY REDUCING TO 1NM OR LESS. IF ANY RECEIVED REPORTS AND/OR OBS INDICATE 1/2 NM OR LESS VSBYS...WILL THEN UPDATE AND ADVERTISE DENSE FOG. A MARINE WEATHER STATEMENT HAS BEEN ISSUED TO HIGHLIGHT THE INCREASED POTENTIAL FOR SEA FOG. HAVE MAINTAINED THE WINDS AND SEAS FORECAST FROM THE PREVIOUS FORECAST...WITH THE LATEST HRRR KEEPING WINDS ON THE LOWER SIDE OF MODEL GUIDANCE. WHICH IN TURN...PRODUCING SLIGHTLY LOWER SEAS THAN ORIGINALLY THOUGHT. SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 3 PM TUESDAY...A COLD FRONT WILL BE APPROACHING THE WATERS LATE WEDNESDAY INTO THURSDAY. SOUTHWEST WINDS WILL INCREASE THROUGH OUT THE DAY ON WEDNESDAY AND THE LOCAL SWAN MODEL IS INDICATING THE SEAS WILL REACH SMALL CRAFT CONDITIONS AROUND MIDNIGHT WEDNESDAY NIGHT-THURSDAY MORNING. AS THE FRONT PUSHES THROUGH THE COLD AIR ADVECTION WILL HELP PROVIDE AN ENVIRONMENT FOR 20 TO 25 KNOT OFF SHORE WINDS ON THURSDAY. LONG TERM /FRIDAY THROUGH SATURDAY/... AS OF 3 PM TUESDAY...POST FRONT COLD SURGE IN THE 15 TO 20 KT RANGE FRI WILL DROP CLOSER TO 10 KT BY SAT MORNING AS GRADIENT. WEAK COASTAL TROF TAKING SHAPE WILL INDUCE A MORE EASTERLY COMPONENT TO LOW LEVEL FLOW. GRADIENT REMAINS WEAK THROUGH THE END OF THE PERIOD WITH WINDS BECOMING EAST TO SOUTHEAST LATE SAT NIGHT AND SUN AS ELONGATED RIDGE AXIS SHIFTS OFFSHORE. ADVISORY WORTHY SEAS AT THE START OF THE PERIOD WILL DROP TO 3 TO 4 FT BY FRI NIGHT AND REMAIN IN THE 3 TO 4 FT RANGE THROUGH SUN. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...HAWKINS NEAR TERM...DOUGH SHORT TERM...HAWKINS LONG TERM...III AVIATION...LACORTE
AREA FORECAST DISCUSSION
NWS GOODLAND KS
604 AM MST WED NOV 16 2011 .UPDATE... 601 AM MST WED NOV 16 2011 JUST COMPLETED AN UPDATE. PERSISTENT BANDS CONTINUE OVER NORTHERN AND EASTERN SECTIONS...AND ARE PRODUCING MORE THAN FLURRIES. MOST INTENSE BAND IS OVER NORTHERN SECTIONS AT THIS TIME. SO INCREASED POPS IN THOSE AREAS. ALSO INCREASED CLOUD COVER PER LATEST SATELLITE AND UPDATED HOURLY TEMPERATURE...DEWPOINT...AND WIND GRIDS FOR THIS MORNING. BULLER && .DISCUSSION... 301 AM MST WED NOV 16 2011 FORECAST PROBLEMS WILL BE TODAY...AND THEN HOW FAST IS THE TEMPERATURE RECOVERY INTO FRIDAY. SATELLITE SHOWING SOME AMPLIFICATION TO THE FLOW FROM THE WESTERN PACIFIC INTO CENTRAL NORTH AMERICA. UPPER TROUGH IS STILL HANGING AROUND OVER THE CENTRAL PORTION OF THE COUNTRY WITH NUMEROUS SHORTWAVE TROUGHS MOVING THROUGH IT. COLD FRONT THAT WENT THROUGH EARLIER TODAY EXTENDS FROM THE SOUTHERN PLAINS TO ALONG THE FRONT RANGE OF COLORADO. MODELS INITIALIZED FINE AT JET LEVEL. MODELS INITIALIZED FINE AT MID LEVELS EXCEPT THE GFS WAS TOO MOIST. THE MODELS TENDED TO BE SLIGHTLY TOO FAR EAST AND SOUTH WITH THE SURFACE RIDGE AND THE LEE SURFACE TROUGH. HOWEVER...THE NAM WAS PRETTY CLOSE AND SLIGHTLY BETTER THAN THE ECMWF. ON THE LOW LEVEL THERMAL FIELD OVERALL...THE CANADIAN...GFS AND UKMET WERE ABOUT THE SAME AND A LITTLE BETTER WITH THE NAM NOT TOO FAR BEHIND AND MAYBE BETTER TO THE NORTH OF THE AREA. TODAY/TONIGHT...INITIAL PROBLEM WILL BE COVERAGE AND DURATION OF SNOWFALL THIS MORNING AS A SHORTWAVE TROUGH AND LIFT FROM THE UPPER JET MOVE THROUGH. GOING BY THE DNR 00Z SOUNDING...THE BEST MOISTURE IS ABOVE 700 MB AND REALITY IS SUPPORTING THAT. SO FAR VISIBILITIES/OBSERVATIONS AND CAMERAS SHOW LITTLE IF ANY ACCUMULATION...EVEN UNDER THE MOST INTENSE BAND THAT IS ALONG THE KANSAS AND NEBRASKA BORDER. TEMPERATURE AND DEWPOINT SPREADS ARE LARGE...ESPECIALLY IN THE NORTH WHERE THE RADAR SAYS THE MOST INTENSE PRECIPITATION IS. MOST OF THE MODELS SAY THAT MEASURABLE SHOULD BE OCCURRING AT THIS TIME WITH RUC HAVING THE LEAST MEASURABLE AND LOOKING THE BEST AT THIS TIME. RIGHT REAR QUADRANT SHOULD BE EAST OF THE AREA BY 12Z. 7-5H SHORTWAVE LOOKS TO BE ENTERING THE WESTERN PORTION OF THE FORECAST AREA AT THIS TIME. SOME PV MOVES ACROSS EARLY WITH THE BRUNT OF IT NORTH. DOWNGLIDE ALSO MOVES IN RATHER QUICKLY THIS MORNING. WILL CONTINUE TO WATCH TRENDS FOR CHANGES BUT PLAN ON TAKING THE MEASURABLE OUT AND HAVE FLURRIES OVER MOST OF THE AREA THIS MORNING WITH MAYBE A LITTLE LINGERING IN THE FAR EAST INTO THE EARLY AFTERNOON. QUESTION THEN BECOMES HOW FAST WE CLEAR OUT AND ITS AFFECT ON HIGH TEMPERATURES. STRONG JET ON THE BACKSIDE OF THE UPPER TROUGH DOES NOT GET CLOSE TO THE AREA UNTIL LATE IN THE DAY. BASED ON SATELLITE...WE SHOULD CLEAR OUT RATHER QUICKLY WITH THE MODELS LOOKING LIKE THEY ARE HANGING ONTO CLOUDS A LITTLE TOO LONG. CURRENTLY TEMPERATURES ARE RUNNING A LITTLE WARMER THAN DEPICTED BUT CLEARING AND TEMPERATURES UPSTREAM SUPPORT MINS GETTING NEAR WHAT IS CALLED FOR. MODEL GUIDANCE IS SIMILAR IN ITS DEPICTION AND MADE SLIGHT ADJUSTMENTS BASED ON LATEST TRENDS/GUIDANCE. ANOTHER CONCERN WILL BE WINDS ON THE BACKSIDE OF THE SYSTEM AS IT EXITS. LOOKS LIKE WILL HAVE GOOD SUBSIDENCE AND ADIABATIC LAPSE RATES. SO IT LOOKS LIKE WE WILL SEE A BRIEF PERIOD OF AT LEAST BREEZY AND GUSTY WINDS THIS AFTERNOON BUT DO NOT SEE ANYTHING GETTING OUT OF HAND. JET AXIS MOVES ACROSS THE AREA DURING THE NIGHT...AND AFFECTS THE NORTHEAST HALF OF THE AREA BY 12Z. THAT AND ANOTHER SHORTWAVE WILL INCREASE THE CLOUDS AFTER 06Z. NEXT QUESTION WILL BE HOW FAST THE SURFACE MOVES THROUGH AND HOW FAST DO THE WINDS INCREASE. LIKE THE SLIGHTLY SLOWER EVOLUTION AND THINK THE GFS IS TOO FAST. AT THIS TIME...IT LOOKS LIKE TEMPERATURES WILL BOTTOM OUT EARLY... ESPECIALLY IN THE WEST AND THEN REMAIN STEADY AFTER THAT. THURSDAY/THURSDAY NIGHT...RIGHT REAR QUADRANT OF THE JET REMAINS NEAR OR OVER THE AREA THROUGH THE DAY. SOME DIFFERENCE IN THE AMOUNT OF CLOUD COVER WITH MOST OF THE MODELS SHOWING A MOSTLY SUNNY TO A PARTLY SUNNY DAY. AS HAS BEEN THE CASE IN THIS FLOW...CLOUDS MAY BE A LITTLE MORE THAN CURRENTLY THINK. SHOULD START OFF WITH DOWNSLOPE WINDS BUT THEN THEY SHIFT TO THE SOUTH AS LEE TROUGH STRENGTHENS. MODELS DO NOT LOOK AS STRONG ON THE WINDS AS YESTERDAY AS MIXING AND GRADIENT ARE NOT AS STRONG AS PREVIOUSLY DEPICTED. STRONGEST WINDS WILL BE IN THE EAST. SOME DIFFERENCES IN THE DEPICTED MAXES. THE 06Z NAM HAS COOLED THINGS OFF A LITTLE FROM 00Z. AT THIS TIME...WILL TREND TOWARD THE WARMER SIDE OF THE GUIDANCE. FRIDAY/FRIDAY NIGHT...COMPLEX JET SETUP BEGINS DURING THE DAY. NORTHERN STREAM REMAINS WELL NORTHWEST OF THE AREA THROUGH THE DAY. HOWEVER...LEFT FRONT QUADRANT OF A SOUTHERN JET DEVELOPS OR STRENGTHENS OVER THE AREA THROUGH THE DAY...ESPECIALLY IN THE AFTERNOON. THERE LOOKS TO BE SOME INCREASING HIGH CLOUDS IN THE AFTERNOON. CONSIDERING WHAT THE JET IS DOING AND THE STRONG SOUTHWESTERLY FLOW...LIKE WHAT THE NAM AND ECMWF ARE SHOWING WITH A STRENGTHENING AND FURTHER WEST LEE TROUGH. THIS MEANS LESS OF A DOWNSLOPE COMPONENT AND IF MODELS ARE CORRECT MORE OF AN EASTERLY COMPONENT AS THE DAY WHERES ON. SO WILL TREND TOWARD THE COOLER SIDE OF GUIDANCE. AS A SIDE NOTE...DUE TO A MORE EASTERLY WIND AND HIGHER DEWPOINTS... BELIEVE SHOULD NOT SEE ANY FIRE WEATHER CONCERNS DESPITE THE WARMER TEMPERATURES. BULLER FOR THE PERIOD SATURDAY THROUGH TUESDAY...SHORTWAVE WILL EJECT ACROSS THE CENTRAL PLAINS SATURDAY FROM BASE OF WEST COAST MEAN TROUGH. TRACK OF THE UPPER SYSTEM AND MOISTURE PROFILES SUGGEST FROPA WILL BE DRY. THERE MAY BE A PERIOD OF GUSTY NORTH WINDS BEHIND THE FRONT SOMETIME ON SATURDAY. COLDER TEMPERATURES WILL FOLLOW ON SUNDAY...LOW TO MIDDLE 40S FOR HIGHS...WHICH IS AROUND 10 DEGREES BELOW NORMAL. RETURN FLOW GETS UNDER WAY FOR MONDAY UNDER SHORTWAVE RIDGING ALOFT WITH TEMPERATURES WARMING TO NEAR NORMAL AND CONTINUED DRY. REMNANTS OF WEST COAST SYSTEM COMES ACROSS SOUTHERN ROCKIES ON TUESDAY BRINGING A CHANCE OF MAINLY RAIN...BEST CHANCES WILL BE SOUTH. 024 THANKS TO ALL THAT COLLABORATED. && .AVIATION... 427 AM MST WED NOV 16 2011 FLURRIES WILL MOVE THROUGH THE REGION THIS MORNING BUT NOT EXPECTED TO IMPACT FLIGHT CATEGORIES AT EITHER KGLD OR KMCK. NORTHWEST WINDS WILL INCREASE BY THE AFTERNOON BEHIND DEPARTING SYSTEM WITH A FEW GUSTS TO 25KTS BEFORE DIMINISHING AT SUNSET. 024 && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. NE...NONE. CO...NONE. && $$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
427 AM MST WED NOV 16 2011 .DISCUSSION... 301 AM MST WED NOV 16 2011 FORECAST PROBLEMS WILL BE TODAY...AND THEN HOW FAST IS THE TEMPERATURE RECOVERY INTO FRIDAY. SATELLITE SHOWING SOME AMPLIFICATION TO THE FLOW FROM THE WESTERN PACIFIC INTO CENTRAL NORTH AMERICA. UPPER TROUGH IS STILL HANGING AROUND OVER THE CENTRAL PORTION OF THE COUNTRY WITH NUMEROUS SHORTWAVE TROUGHS MOVING THROUGH IT. COLD FRONT THAT WENT THROUGH EARLIER TODAY EXTENDS FROM THE SOUTHERN PLAINS TO ALONG THE FRONT RANGE OF COLORADO. MODELS INITIALIZED FINE AT JET LEVEL. MODELS INITIALIZED FINE AT MID LEVELS EXCEPT THE GFS WAS TOO MOIST. THE MODELS TENDED TO BE SLIGHTLY TOO FAR EAST AND SOUTH WITH THE SURFACE RIDGE AND THE LEE SURFACE TROUGH. HOWEVER...THE NAM WAS PRETTY CLOSE AND SLIGHTLY BETTER THAN THE ECMWF. ON THE LOW LEVEL THERMAL FIELD OVERALL...THE CANADIAN...GFS AND UKMET WERE ABOUT THE SAME AND A LITTLE BETTER WITH THE NAM NOT TOO FAR BEHIND AND MAYBE BETTER TO THE NORTH OF THE AREA. TODAY/TONIGHT...INITIAL PROBLEM WILL BE COVERAGE AND DURATION OF SNOWFALL THIS MORNING AS A SHORTWAVE TROUGH AND LIFT FROM THE UPPER JET MOVE THROUGH. GOING BY THE DNR 00Z SOUNDING...THE BEST MOISTURE IS ABOVE 700 MB AND REALITY IS SUPPORTING THAT. SO FAR VISIBILITIES/OBSERVATIONS AND CAMERAS SHOW LITTLE IF ANY ACCUMULATION...EVEN UNDER THE MOST INTENSE BAND THAT IS ALONG THE KANSAS AND NEBRASKA BORDER. TEMPERATURE AND DEWPOINT SPREADS ARE LARGE...ESPECIALLY IN THE NORTH WHERE THE RADAR SAYS THE MOST INTENSE PRECIPITATION IS. MOST OF THE MODELS SAY THAT MEASURABLE SHOULD BE OCCURRING AT THIS TIME WITH RUC HAVING THE LEAST MEASURABLE AND LOOKING THE BEST AT THIS TIME. RIGHT REAR QUADRANT SHOULD BE EAST OF THE AREA BY 12Z. 7-5H SHORTWAVE LOOKS TO BE ENTERING THE WESTERN PORTION OF THE FORECAST AREA AT THIS TIME. SOME PV MOVES ACROSS EARLY WITH THE BRUNT OF IT NORTH. DOWNGLIDE ALSO MOVES IN RATHER QUICKLY THIS MORNING. WILL CONTINUE TO WATCH TRENDS FOR CHANGES BUT PLAN ON TAKING THE MEASURABLE OUT AND HAVE FLURRIES OVER MOST OF THE AREA THIS MORNING WITH MAYBE A LITTLE LINGERING IN THE FAR EAST INTO THE EARLY AFTERNOON. QUESTION THEN BECOMES HOW FAST WE CLEAR OUT AND ITS AFFECT ON HIGH TEMPERATURES. STRONG JET ON THE BACKSIDE OF THE UPPER TROUGH DOES NOT GET CLOSE TO THE AREA UNTIL LATE IN THE DAY. BASED ON SATELLITE...WE SHOULD CLEAR OUT RATHER QUICKLY WITH THE MODELS LOOKING LIKE THEY ARE HANGING ONTO CLOUDS A LITTLE TOO LONG. CURRENTLY TEMPERATURES ARE RUNNING A LITTLE WARMER THAN DEPICTED BUT CLEARING AND TEMPERATURES UPSTREAM SUPPORT MINS GETTING NEAR WHAT IS CALLED FOR. MODEL GUIDANCE IS SIMILAR IN ITS DEPICTION AND MADE SLIGHT ADJUSTMENTS BASED ON LATEST TRENDS/GUIDANCE. ANOTHER CONCERN WILL BE WINDS ON THE BACKSIDE OF THE SYSTEM AS IT EXITS. LOOKS LIKE WILL HAVE GOOD SUBSIDENCE AND ADIABATIC LAPSE RATES. SO IT LOOKS LIKE WE WILL SEE A BRIEF PERIOD OF AT LEAST BREEZY AND GUSTY WINDS THIS AFTERNOON BUT DO NOT SEE ANYTHING GETTING OUT OF HAND. JET AXIS MOVES ACROSS THE AREA DURING THE NIGHT...AND AFFECTS THE NORTHEAST HALF OF THE AREA BY 12Z. THAT AND ANOTHER SHORTWAVE WILL INCREASE THE CLOUDS AFTER 06Z. NEXT QUESTION WILL BE HOW FAST THE SURFACE MOVES THROUGH AND HOW FAST DO THE WINDS INCREASE. LIKE THE SLIGHTLY SLOWER EVOLUTION AND THINK THE GFS IS TOO FAST. AT THIS TIME...IT LOOKS LIKE TEMPERATURES WILL BOTTOM OUT EARLY... ESPECIALLY IN THE WEST AND THEN REMAIN STEADY AFTER THAT. THURSDAY/THURSDAY NIGHT...RIGHT REAR QUADRANT OF THE JET REMAINS NEAR OR OVER THE AREA THROUGH THE DAY. SOME DIFFERENCE IN THE AMOUNT OF CLOUD COVER WITH MOST OF THE MODELS SHOWING A MOSTLY SUNNY TO A PARTLY SUNNY DAY. AS HAS BEEN THE CASE IN THIS FLOW...CLOUDS MAY BE A LITTLE MORE THAN CURRENTLY THINK. SHOULD START OFF WITH DOWNSLOPE WINDS BUT THEN THEY SHIFT TO THE SOUTH AS LEE TROUGH STRENGTHENS. MODELS DO NOT LOOK AS STRONG ON THE WINDS AS YESTERDAY AS MIXING AND GRADIENT ARE NOT AS STRONG AS PREVIOUSLY DEPICTED. STRONGEST WINDS WILL BE IN THE EAST. SOME DIFFERENCES IN THE DEPICTED MAXES. THE 06Z NAM HAS COOLED THINGS OFF A LITTLE FROM 00Z. AT THIS TIME...WILL TREND TOWARD THE WARMER SIDE OF THE GUIDANCE. FRIDAY/FRIDAY NIGHT...COMPLEX JET SETUP BEGINS DURING THE DAY. NORTHERN STREAM REMAINS WELL NORTHWEST OF THE AREA THROUGH THE DAY. HOWEVER...LEFT FRONT QUADRANT OF A SOUTHERN JET DEVELOPS OR STRENGTHENS OVER THE AREA THROUGH THE DAY...ESPECIALLY IN THE AFTERNOON. THERE LOOKS TO BE SOME INCREASING HIGH CLOUDS IN THE AFTERNOON. CONSIDERING WHAT THE JET IS DOING AND THE STRONG SOUTHWESTERLY FLOW...LIKE WHAT THE NAM AND ECMWF ARE SHOWING WITH A STRENGTHENING AND FURTHER WEST LEE TROUGH. THIS MEANS LESS OF A DOWNSLOPE COMPONENT AND IF MODELS ARE CORRECT MORE OF AN EASTERLY COMPONENT AS THE DAY WHERES ON. SO WILL TREND TOWARD THE COOLER SIDE OF GUIDANCE. AS A SIDE NOTE...DUE TO A MORE EASTERLY WIND AND HIGHER DEWPOINTS... BELIEVE SHOULD NOT SEE ANY FIRE WEATHER CONCERNS DESPITE THE WARMER TEMPERATURES. BULLER FOR THE PERIOD SATURDAY THROUGH TUESDAY...SHORTWAVE WILL EJECT ACROSS THE CENTRAL PLAINS SATURDAY FROM BASE OF WEST COAST MEAN TROUGH. TRACK OF THE UPPER SYSTEM AND MOISTURE PROFILES SUGGEST FROPA WILL BE DRY. THERE MAY BE A PERIOD OF GUSTY NORTH WINDS BEHIND THE FRONT SOMETIME ON SATURDAY. COLDER TEMPERATURES WILL FOLLOW ON SUNDAY...LOW TO MIDDLE 40S FOR HIGHS...WHICH IS AROUND 10 DEGREES BELOW NORMAL. RETURN FLOW GETS UNDER WAY FOR MONDAY UNDER SHORTWAVE RIDGING ALOFT WITH TEMPERATURES WARMING TO NEAR NORMAL AND CONTINUED DRY. REMNANTS OF WEST COAST SYSTEM COMES ACROSS SOUTHERN ROCKIES ON TUESDAY BRINGING A CHANCE OF MAINLY RAIN...BEST CHANCES WILL BE SOUTH. 024 THANKS TO ALL THAT COLLABORATED. && .AVIATION... 427 AM MST WED NOV 16 2011 FLURRIES WILL MOVE THROUGH THE REGION THIS MORNING BUT NOT EXPECTED TO IMPACT FLIGHT CATEGORIES AT EITHER KGLD OR KMCK. NORTHWEST WINDS WILL INCREASE BY THE AFTERNOON BEHIND DEPARTING SYSTEM WITH A FEW GUSTS TO 25KTS BEFORE DIMINISHING AT SUNSET. 024 && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. NE...NONE. CO...NONE. && $$
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
646 AM EST WED NOV 16 2011 .SYNOPSIS... A WEAK STATIONARY FRONT WILL REMAIN OVER THE MID ATLANTIC REGION EARLY TODAY AS A COLD FRONT APPROACHES FROM THE WEST. THE COLD FRONT PASSES THROUGH TONIGHT...WITH HIGH PRESSURE RETURNING LATE THURSDAY AND INTO THE WEEKEND. ANOTHER COLD FRONT APPROACHES SUNDAY NIGHT INTO MONDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... WEAK STATIONARY FRONT OVER THE MID ATLANTIC IS EXPECTED TO SLOWLY NUDGE NORTH THIS MORNING...ALLOWING FOR SW WARM AND MOIST FLOW TO CONTINUE OVER THE LOCAL AREA. CYCLONIC FLOW ALOFT AND DECENT MID-LEVEL MOISTURE ADVECTION WILL LEAD TO MOSTLY CLOUDY SKIES...WITH SOME BREAKS POSSIBLE ESP TO THE S. PRECIP CURRENTLY OVER WESTERN VIRGINIA IS EXPECTED TO CLIP NORTHERN PORTIONS OF THE FA LATER THIS MORNING. LOWER CHANCES FOR RAIN FURTHER S WHERE THE BEST FORCING AND DEEP MOISTURE WILL HOLD OFF UNTIL LATER TODAY AND TONIGHT. A COLD FRONT APPROACHING FROM THE OHIO VALLEY AND A DEVELOPING SFC WAVE (IN RESPONSE TO A POTENT S/W OVER THE TN VALLEY EMBEDDED WITHIN THE SW UPPER FLOW) WILL ALSO INCREASE THE RAIN POTENTIAL STARTING LATE THIS AFTERNOON. CHANCE OF THUNDERSTORMS REMAINS IN THE FORECAST...W/ STRONG LOW-TOPPED CONVECTION (LOW CAPE AND HIGH SHEAR) POSSIBLE...ESP FOR NE NORTH CAROLINA AND EXTREME SE VIRGINIA (SPC HAS A SLIGHT RISK) WHERE INSTABILITY WILL BE GREATEST. MAIN THREAT WOULD BE DAMAGING WINDS (>40 KT OF 0-3 KM SHEAR AND DCAPE>1000 J/KG). ALSO...SOME STORMS MAY EXHIBIT ROTATION AS RUC AND NAM BOTH PROG 0-1 KM HELICITIES>300 M2/S2. MAIN LIMITING FACTOR MAY BE LACK OF INSTABILITY DUE TO MOSTLY CLOUDY SKIES. EXPECT ABOVE NORMAL HIGHS AGAIN TODAY SINCE COLD FROPA HOLDS OFF UNTIL EVENING...HIGHS IN THE L-M70S OVER THE NW AND M-U70S OVER THE SE. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/... BEST PROBABILITY FOR RAIN (CATEGORICAL POPS) COMES TONIGHT DUE TO A COMBO OF ISENTROPIC LIFT AND STRONG LOW/MID LEVEL CONVERGENCE ASSOCIATED W/ COLD FRONT. RAIN WILL BE HEAVY AT TIMES AND SOME AREAS MAY RECEIVE OVER AN INCH TOTAL W/ THIS SYSTEM (ESP N PART OF FA). NO SIGNIFICANT FLOODING IS ANTICIPATED ATTM DUE TO FLASH FLOOD GUIDANCE BEING HIGH. THE RAIN TAPERS OFF FROM W TO E THUR MIDDAY/AFTERNOON. DECREASING CLOUDS FOR THE REST OF THE DAY AND NIGHT. COOL N FLOW AT THE SFC WILL ONLY YIELD HIGHS IN THE L-M50S THUR. STRONG HIGH PRESSURE BUILDS OVER THE MID ATLANTIC FRI LEADING TO DRY WX AND SUNNY SKIES. TEMPS WILL ONLY MAX OUT IN THE U40S-L50S AFTER A CHILLY START IN THE U20S-M30S. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... LONG RANGE MODELS ARE IN GOOD AGREEMENT WITH SHOWING A SOUTHWEST UPPER LEVEL FLOW DEVELOPING SATURDAY AS HIGH PRESSURE BECOMES ANCHORED OVER THE MID ATLANTIC STATES THROUGH SUNDAY. SOME CLOUDINESS IS POSSIBLE IN NORTHEAST NC AND EXTREME SOUTHEAST VA ON SATURDAY AS TROPICAL MOISTURE ROTATES AROUND A MID-LEVEL HIGH OFF THE SOUTHEAST U.S. COAST AND MOVES NEAR THIS AREA. OTHERWISE...A DRYING AND WARMING TREND IS ANTICIPATED UNDER THIS FLOW REGIME...WITH HIGH TEMPS REBOUNDING BACK INTO THE 60S BY SUNDAY. LOWS SHOULD BE NEAR FREEZING SATURDAY MORNING DUE TO PRIME COOLING CONDITIONS UNDER MOSTLY CLEAR SKIES WITH VERY LIGHT WINDS...THEN REBOUND TOWARD THE LOW 50S BY EARLY NEXT WEEK AS CLOUDS INCREASE AHEAD OF THE NEXT WEATHER DISTURBANCE. BY LATE SUNDAY...A WEAK COLD FRONT IS EXPECTED TO SAG SOUTHWARD AND STALL OVER THE MID ATLANTIC REGION THROUGH TUESDAY. 12Z MODEL RUNS TODAY ARE HINTING AT SLOWING THE SOUTHERN MOVEMENT OF THIS BOUNDARY UNTIL LATE MONDAY...WHICH WOULD DELAY THE ONSET OF PRECIPITATION UNTIL THAT TIMEFRAME. HAVE TRENDED THE ONGOING FORECAST TOWARD SLOWING THE PASSAGE OF THE FRONT UNTIL LATE MONDAY...WITH PRECIPITATION BEING INTRODUCED LATE SUNDAY/EARLY MONDAY. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... COLD FRNT WILL APPROACH THE AREA THRU THIS MORNG...THEN DROP ACRS THE REGION THIS AFTN THRU TNGT. CIGS/VSBYS WILL QUICKLY LWR TO MVFR THEN IFR (LIFR?) DURING THIS MORNG WITH -DZ OR SCTD -SHRAS MOVNG INTO NRN AND WRN AREAS. CIGS/VSBYS WILL LIKELY LIFT TO MVFR AND VFR CONDITIONS LATER THIS MORNG AND AFTN...AS SW WNDS INCRS IN ADVANCE OF FRNT...WITH ISLTD TO SCTD SHRAS AHEAD OF AND ALNG THE FRNTL BNDRY INTO THIS EVENG. DURING THIS EVENG INTO THU MORNG...IFR (LIFR?) CONDITIONS WITH -RA EXPECTED BEHIND THE FRNT. VFR AND DRY CONDITIONS WILL RETURN THU AFTN THRU SUN. && .MARINE... HAVE EXTENDED THE SCA HEADLINE FOR ALL THE WTRS THRU LATE THU NGT...AS NNW WNDS (CAA) WILL CONTINUE AT 15 TO 25 KT AND WAVES/SEAS WILL STAY UP. SE OR S WNDS 10 KT OR LESS ERLY THIS MORNG...WILL BECOME SW AND INCRS TO 15 TO 20 KT THIS AFTN IN ADVANCE OF COLD FRNT. CUD BE GUSTS TO 25 KT. WNDS WILL SHIFT TO THE NW OR N THIS EVENG INTO ERLY THU MORNG BEHIND THE FRNT. THIS CAA SURGE WILL THEN CONTINUE FOR THE REMAINDER OF THU AND THU NGT. MORE BENIGN MARINE CONDITIONS THEN EXPECTED FRI INTO SUN...AS HI PRES BLDS OVR THE WTRS FM THE W. && .CLIMATE... RECORD HIGH TEMPS FOR NOV 16TH (WED): RIC...85 IN 1955 ORF...83 IN 1955 SBY...78 IN 1928 ECG...85 IN 1993 && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY FROM NOON TODAY TO 6 AM EST FRIDAY FOR ANZ630>634-650-652-654-656-658. && $$ SYNOPSIS...MAS NEAR TERM...MAS SHORT TERM...MAS LONG TERM...BMD AVIATION...TMG MARINE...TMG CLIMATE...
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
632 AM EST WED NOV 16 2011 .SYNOPSIS... A WEAK STATIONARY FRONT WILL REMAIN OVER THE MID ATLANTIC REGION EARLY TODAY AS A COLD FRONT APPROACHES FROM THE WEST. THE COLD FRONT PASSES THROUGH TONIGHT...WITH HIGH PRESSURE RETURNING LATE THURSDAY AND INTO THE WEEKEND. ANOTHER COLD FRONT APPROACHES SUNDAY NIGHT INTO MONDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... WEAK STATIONARY FRONT OVER THE MID ATLANTIC IS EXPECTED TO SLOWLY NUDGE NORTH THIS MORNING...ALLOWING FOR SW WARM AND MOIST FLOW TO CONTINUE OVER THE LOCAL AREA. CYCLONIC FLOW ALOFT AND DECENT MID-LEVEL MOISTURE ADVECTION WILL LEAD TO MOSTLY CLOUDY SKIES...WITH SOME BREAKS POSSIBLE ESP TO THE S. PRECIP CURRENTLY OVER WESTERN VIRGINIA IS EXPECTED TO CLIP NORTHERN PORTIONS OF THE FA LATER THIS MORNING. LOWER CHANCES FOR RAIN FURTHER S WHERE THE BEST FORCING AND DEEP MOISTURE WILL HOLD OFF UNTIL LATER TODAY AND TONIGHT. A COLD FRONT APPROACHING FROM THE OHIO VALLEY AND A DEVELOPING SFC WAVE (IN RESPONSE TO A POTENT S/W OVER THE TN VALLEY EMBEDDED WITHIN THE SW UPPER FLOW) WILL ALSO INCREASE THE RAIN POTENTIAL STARTING LATE THIS AFTERNOON. CHANCE OF THUNDERSTORMS REMAINS IN THE FORECAST...W/ STRONG LOW-TOPPED CONVECTION (LOW CAPE AND HIGH SHEAR) POSSIBLE...ESP FOR NE NORTH CAROLINA AND EXTREME SE VIRGINIA (SPC HAS A SLIGHT RISK) WHERE INSTABILITY WILL BE GREATEST. MAIN THREAT WOULD BE DAMAGING WINDS (>40 KT OF 0-3 KM SHEAR AND DCAPE>1000 J/KG). ALSO...SOME STORMS MAY EXHIBIT ROTATION AS RUC AND NAM BOTH PROG 0-1 KM HELICITIES>300 M2/S2. EXPECT ABOVE NORMAL HIGHS AGAIN TODAY DUE TO THE COLD FROPA BEING DELAYED UNTIL TONIGHT...HIGHS IN THE L-M70S OVER THE NW AND M-U70S OVER THE SE. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/... BEST PROBABILITY FOR RAIN (CATEGORICAL POPS) COMES TONIGHT DUE TO A COMBO OF ISENTROPIC LIFT AND STRONG LOW/MID LEVEL CONVERGENCE ASSOCIATED W/ COLD FRONT. RAIN WILL BE HEAVY AT TIMES AND SOME AREAS MAY RECEIVE OVER AN INCH TOTAL W/ THIS SYSTEM (ESP N PART OF FA). NO SIGNIFICANT FLOODING IS ANTICIPATED ATTM DUE TO FLASH FLOOD GUIDANCE BEING HIGH. THE RAIN TAPERS OFF FROM W TO E THUR MIDDAY/AFTERNOON. DECREASING CLOUDS FOR THE REST OF THE DAY AND NIGHT. COOL N FLOW AT THE SFC WILL ONLY YIELD HIGHS IN THE L-M50S THUR. STRONG HIGH PRESSURE BUILDS OVER THE MID ATLANTIC FRI LEADING TO DRY WX AND SUNNY SKIES. TEMPS WILL ONLY MAX OUT IN THE U40S-L50S AFTER A CHILLY START IN THE U20S-M30S. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... LONG RANGE MODELS ARE IN GOOD AGREEMENT WITH SHOWING A SOUTHWEST UPPER LEVEL FLOW DEVELOPING SATURDAY AS HIGH PRESSURE BECOMES ANCHORED OVER THE MID ATLANTIC STATES THROUGH SUNDAY. SOME CLOUDINESS IS POSSIBLE IN NORTHEAST NC AND EXTREME SOUTHEAST VA ON SATURDAY AS TROPICAL MOISTURE ROTATES AROUND A MID-LEVEL HIGH OFF THE SOUTHEAST U.S. COAST AND MOVES NEAR THIS AREA. OTHERWISE...A DRYING AND WARMING TREND IS ANTICIPATED UNDER THIS FLOW REGIME...WITH HIGH TEMPS REBOUNDING BACK INTO THE 60S BY SUNDAY. LOWS SHOULD BE NEAR FREEZING SATURDAY MORNING DUE TO PRIME COOLING CONDITIONS UNDER MOSTLY CLEAR SKIES WITH VERY LIGHT WINDS...THEN REBOUND TOWARD THE LOW 50S BY EARLY NEXT WEEK AS CLOUDS INCREASE AHEAD OF THE NEXT WEATHER DISTURBANCE. BY LATE SUNDAY...A WEAK COLD FRONT IS EXPECTED TO SAG SOUTHWARD AND STALL OVER THE MID ATLANTIC REGION THROUGH TUESDAY. 12Z MODEL RUNS TODAY ARE HINTING AT SLOWING THE SOUTHERN MOVEMENT OF THIS BOUNDARY UNTIL LATE MONDAY...WHICH WOULD DELAY THE ONSET OF PRECIPITATION UNTIL THAT TIMEFRAME. HAVE TRENDED THE ONGOING FORECAST TOWARD SLOWING THE PASSAGE OF THE FRONT UNTIL LATE MONDAY...WITH PRECIPITATION BEING INTRODUCED LATE SUNDAY/EARLY MONDAY. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... COLD FRNT WILL APPROACH THE AREA THRU THIS MORNG...THEN DROP ACRS THE REGION THIS AFTN THRU TNGT. CIGS/VSBYS WILL QUICKLY LWR TO MVFR THEN IFR (LIFR?) DURING THIS MORNG WITH -DZ OR SCTD -SHRAS MOVNG INTO NRN AND WRN AREAS. CIGS/VSBYS WILL LIKELY LIFT TO MVFR AND VFR CONDITIONS LATER THIS MORNG AND AFTN...AS SW WNDS INCRS IN ADVANCE OF FRNT...WITH ISLTD TO SCTD SHRAS AHEAD OF AND ALNG THE FRNTL BNDRY INTO THIS EVENG. DURING THIS EVENG INTO THU MORNG...IFR (LIFR?) CONDITIONS WITH -RA EXPECTED BEHIND THE FRNT. VFR AND DRY CONDITIONS WILL RETURN THU AFTN THRU SUN. && .MARINE... HAVE EXTENDED THE SCA HEADLINE FOR ALL THE WTRS THRU LATE THU NGT...AS NNW WNDS (CAA) WILL CONTINUE AT 15 TO 25 KT AND WAVES/SEAS WILL STAY UP. SE OR S WNDS 10 KT OR LESS ERLY THIS MORNG...WILL BECOME SW AND INCRS TO 15 TO 20 KT THIS AFTN IN ADVANCE OF COLD FRNT. CUD BE GUSTS TO 25 KT. WNDS WILL SHIFT TO THE NW OR N THIS EVENG INTO ERLY THU MORNG BEHIND THE FRNT. THIS CAA SURGE WILL THEN CONTINUE FOR THE REMAINDER OF THU AND THU NGT. MORE BENIGN MARINE CONDITIONS THEN EXPECTED FRI INTO SUN...AS HI PRES BLDS OVR THE WTRS FM THE W. && .CLIMATE... RECORD HIGH TEMPS FOR NOV 16TH (WED): RIC...85 IN 1955 ORF...83 IN 1955 SBY...78 IN 1928 ECG...85 IN 1993 && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY FROM NOON TODAY TO 6 AM EST FRIDAY FOR ANZ630>634-650-652-654-656-658. && $$ SYNOPSIS...MAS NEAR TERM...MAS SHORT TERM...MAS LONG TERM...BMD AVIATION...TMG MARINE...TMG CLIMATE...
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
651 AM EST WED NOV 16 2011 UPDATED AVIATION DISCUSSION FOR 12Z TAFS .SYNOPSIS... WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW BROAD CYCLONIC FLOW ACROSS MOST OF THE CONUS WITH AXIS ROUGHLY OVER THE WRN PLAINS. A VIGOROUS LOOKING SHORTWAVE IS TRACKING THRU THE UPPER GREAT LAKES ATTM. LIKE ITS PREDECESSOR 24-30HRS AGO...THIS SYSTEM PRODUCED SOME LIGHTNING STRIKES ACROSS LAKE SUPERIOR EARLIER IN THE NIGHT. THE MORE SIGNIFICANT PCPN WITH WAVE HAS PASSED MOSTLY N OF UPPER MI... JUST N OF THE VORT TRACK ACROSS NRN UPPER MI/SRN LAKE SUPERIOR. UPSTREAM...850MB TEMPS RANGE FROM -7C AT KINL TO -10C KBIS AND -12C AT CYQD. WHILE 00Z KBIS SOUNDING SHOWED DRYNESS IN THE BOUNDARY LAYER...KINL AND CQYD SOUNDINGS SHOWED DEEP MOISTURE...ESPECIALLY CYQD. THIS UPSTREAM COMBINATION OF COLD AIR/DEEP MOISTURE SUGGESTS AN ACTIVE LES PERIOD SHOULD BE ON THE WAY OVER THE NEXT 36HRS AS TROF AXIS TO THE W SHIFTS E. && .DISCUSSION... FCST CONCERNS INVOLVE LES LOCATION/INTENSITY AND SNOW ACCUMULATIONS THRU THURSDAY AND THEN POSSIBLE WINTER STORM FOR THE WEEKEND. GIVEN FAVORABLE INSTABILITY/MOISTURE...SOMEWHAT PUZZLED BY THE RELATIVELY LIGHT PCPN INDICATED BY THE NAM/GFS FOR THE LES TODAY THRU THU...BUT THERE MAY BE A REASON. WHILE DEEPER MOISTURE EVIDENT ON CYQD/KINL SOUNDINGS WILL REACH THE AREA...THE FLOW IN THE LOW-LEVELS IS MORE WRLY...WHICH MAY SUPPORT SOMEWHAT DRIER AIR IN THE BOUNDARY LAYER AS SUGGESTED BY THE KBIS SOUNDING. BOTH THE NAM AND GFS HINT AT THAT...BUT THE NAM/GFS SOUNDINGS AREN`T REALLY THAT DRY. WITH DEEP MOISTURE UWPARDS OF 8-10KFT AND DGZ DESCENDING MORE FIRMLY INTO THE CONVECTIVE LAYER UNDER CAA REGIME...HAVE TO BELIEVE LES WILL BE MORE SIGNIFICANT THAN THE NAM/GFS INDICATE. REGIONAL GEM IS MUCH MORE AGGRESSIVE WITH PCPN AMOUNTS. WHILE THE NAM HAS 12Z WED-00Z FRI PCPN AMOUNTS UP TO 0.4 INCHES NW TO 0.5 INCHES ALONG SHORE E OF MUNISING...THE REGIONAL GEM IS UPWARDS OF 0.8 INCHES NW TO OVER 2 INCHES E OF MUNISING. SOMETHING BTWN THE TWO EXTREMES IS PROBABLY REASONABLE...THOUGH THE REGIONAL GEM LOOKS QUITE EXCESSIVE OVER THE E. AT THIS POINT...WILL KEEP 12-24HR SNOW AMOUNTS JUST UNDER LES WARNING THRESHOLDS NW DUE TO UNCERTAINTY IN BOUNDARY LAYER MOISTURE. WITH LOW-LEVEL WINDS ESSENTIALLY W...LES WILL TARGET AREAS FROM ONTONAGON COUNTY THRU THE KEWEENAW. TO THE E...SLIGHT VEERING OF WINDS HIGHER IN THE CONVECTIVE LAYER SHOULD TEND TO FOCUS THE SRN LES BAND ALONG TO JUST INLAND FROM THE SHORE FROM PICTURED ROCKS EASTWARD. TYPICALLY...THE SRN MOST BAND YIELDS HEAVIEST SNOW RATES DUE TO LAND BREEZE CONVERGENCE AND THE OVERALL LONG FETCH ACROSS THE LAKE...ONLY INTERRUPTED BRIEFLY BY THE KEWEENAW. THUS...POTENTIAL EXISTS FOR VERY IMPRESSIVE SNOW ACCUMULATIONS OVER A SMALL AREA OF THE E CLOSE TO LAKE SUPERIOR...PROVIDED LES BAND DOES NOT SHIFT OFFSHORE FREQUENTLY. ALSO...DEEP/VIGOROUS CONVECTION AND RELATIVELY WARM EARLY SEASON WATER/BOUNDARY LAYER MAY LEAD TO MORE GRAUPEL/SNOW PELLET TYPE PCPN RATHER THAN LARGE SNOWFLAKES...WHICH WILL REDUCE SNOW ACCUMULATIONS OVER WHAT COULD BE EXPECTED. HAVE OPTED TO ISSUE A LAKE EFFECT SNOW WATCH FOR ALGER/LUCE...EMPHASIZING THE AREAS FROM AROUND GRAND MARAIS EASTWARD. AWAY FROM LES...DRY WEATHER WILL GENERALLY PREVAIL THRU THU. LES WILL WIND DOWN/END LATER THU/THU NIGHT AS MID/UPPER TROF SHIFTS E OF THE AREA AND FLOW BEGINS TO BACK IN ADVANCE OF TROF AMPLIFICATION OVER THE WRN CONUS. LEAD WAVE AHEAD OF THE WRN TROF AMPLIFICATION COMBINED WITH STRONG WAA COULD LEAD TO SOME LIGHT PCPN LATER THU NIGHT/FRI MORNING. LACK OF MOISTURE MAY RESULT IN PCPN OCCURRING FARTHER N IN THE COLDER AIR WHERE SATURATION THRU THE COLUMN CAN OCCUR. SHORTWAVE WILL LIFT OUT OF THE WRN TROF EARLY IN THE WEEKEND. FOR SEVERAL DAYS...MODELS HAVE SHOWN UNUSUALLY GOOD CONTINUITY ON SFC LOW TRACK DESPITE BEING WAY OUT IN THE FCST CYCLE. THERE HAVE BEEN THE EXPECTED INTENSITY/PLACEMENT ISSUES...BUT THEY WERE MINOR WHEN CONSIDERING THE TIME RANGE INTO THE FCST RUN. FOR 90 TO 108HRS INTO THE MODEL RUN...TODAYS 00Z ROUND OF MEDIUM RANGE GUIDANCE REMAINS WELL CLUSTERED ON A LOW TRACK FROM KS TO THE UPPER GREAT LAKES... SOMEWHERE BTWN CNTRL UPPER MI AND FAR NRN LWR MI/STRAITS AREA. ALL SUGGEST A HEADLINE SNOW EVENT FOR SOME PART OF THE FCST AREA... PROBABLY HIGH END ADVY TYPE. THE WRN MOST LOW TRACK (GFS) WOULD PROVIDE HEAVIEST SNOW OVER NW UPPER MI WHILE THE ERN TRACKS (GLOBAL GEM/ECMWF) WOULD SPREAD HEAVIEST SNOW OVER MOSTLY THE CNTRL PORTION OF UPPER MI. && .AVIATION /FOR THE 12Z TAF ISSUANCE/ COLD AIR MOVING INTO THE REGION ON WEST NORTHWEST WINDS BEHIND A SHORTWAVE TROUGH AND SFC LOW WILL SUPPORT LAKE EFFECT SNOW THROUGH THE PERIOD AT CMX. FOR THE MAJORITY OF THE TIME AT CMX...EXPECT LOWER MVFR CIGS WITH MAINLY IFR VSBY. MEANWHILE AT IWD AND SAW...WESTERLY LOW LEVEL WINDS ARE NOT FAVORABLE FOR LAKE EFFECT SNOW...SO LITTLE IN WAY OF VSBY REDUCTION IS EXPECTED. COULD SEE OCCASIONAL CIGS AT OR NEAR MVFR AT IWD AND SAW THOUGH. && .MARINE /FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE/... EXPECT WESTERLY GALES TO DIMINISH BY THIS EVENING OVR LK SUPERIOR AS SFC LOW JUST EAST OF LK SUPERIOR HEADS INTO QUEBEC. WINDS REMAIN OUT OF THE W/NW UP TO 30 KTS THURSDAY INTO THURSDAY NIGHT...THEN BECOME MORE SOUTHERLY ON FRIDAY AS LOW PRESSURE SYSTEM PASSES TO NORTH OF LK SUPERIOR. COULD BE MARGINAL SRLY GALES OVR FAR EASTERN SECTIONS FRIDAY. ACTIVE PATTERN CONTINUES INTO THE UPCOMING WEEKEND AS ANOTHER LOW OVR THE PLAINS ON SATURDAY TRACKS ACROSS THE LAKE SUPERIOR REGION SATURDAY NIGHT. NE WINDS COULD REACH GALE FORCE OVR WESTERN SECTIONS SATURDAY WITH NW GALES THEN POSSIBLE LATE SATURDAY NIGHT INTO SUNDAY MORNING AS THE LOW PULLS AWAY FM THE REGION. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... WINTER WEATHER ADVISORY UNTIL 5 PM EST THURSDAY FOR MIZ001>003- 084. LAKE EFFECT SNOW WATCH FROM THIS EVENING THROUGH THURSDAY AFTERNOON FOR MIZ006-007. LAKE SUPERIOR... GALE WARNING UNTIL 10 PM EST THIS EVENING FOR LSZ248>251-265>267. GALE WARNING UNTIL 4 PM EST /3 PM CST/ THIS AFTERNOON FOR LSZ162- 241>243-263-264. GALE WARNING UNTIL 1 PM EST THIS AFTERNOON FOR LSZ244-245. LAKE MICHIGAN... GALE WARNING UNTIL 10 AM EST THIS MORNING FOR LMZ221-250. && $$ SYNOPSIS...ROLFSON DISCUSSION...ROLFSON AVIATION...JLA MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
549 AM EST WED NOV 16 2011 .SYNOPSIS... WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW BROAD CYCLONIC FLOW ACROSS MOST OF THE CONUS WITH AXIS ROUGHLY OVER THE WRN PLAINS. A VIGOROUS LOOKING SHORTWAVE IS TRACKING THRU THE UPPER GREAT LAKES ATTM. LIKE ITS PREDECESSOR 24-30HRS AGO...THIS SYSTEM PRODUCED SOME LIGHTNING STRIKES ACROSS LAKE SUPERIOR EARLIER IN THE NIGHT. THE MORE SIGNIFICANT PCPN WITH WAVE HAS PASSED MOSTLY N OF UPPER MI... JUST N OF THE VORT TRACK ACROSS NRN UPPER MI/SRN LAKE SUPERIOR. UPSTREAM...850MB TEMPS RANGE FROM -7C AT KINL TO -10C KBIS AND -12C AT CYQD. WHILE 00Z KBIS SOUNDING SHOWED DRYNESS IN THE BOUNDARY LAYER...KINL AND CQYD SOUNDINGS SHOWED DEEP MOISTURE...ESPECIALLY CYQD. THIS UPSTREAM COMBINATION OF COLD AIR/DEEP MOISTURE SUGGESTS AN ACTIVE LES PERIOD SHOULD BE ON THE WAY OVER THE NEXT 36HRS AS TROF AXIS TO THE W SHIFTS E. && .DISCUSSION... FCST CONCERNS INVOLVE LES LOCATION/INTENSITY AND SNOW ACCUMULATIONS THRU THURSDAY AND THEN POSSIBLE WINTER STORM FOR THE WEEKEND. GIVEN FAVORABLE INSTABILITY/MOISTURE...SOMEWHAT PUZZLED BY THE RELATIVELY LIGHT PCPN INDICATED BY THE NAM/GFS FOR THE LES TODAY THRU THU...BUT THERE MAY BE A REASON. WHILE DEEPER MOISTURE EVIDENT ON CYQD/KINL SOUNDINGS WILL REACH THE AREA...THE FLOW IN THE LOW-LEVELS IS MORE WRLY...WHICH MAY SUPPORT SOMEWHAT DRIER AIR IN THE BOUNDARY LAYER AS SUGGESTED BY THE KBIS SOUNDING. BOTH THE NAM AND GFS HINT AT THAT...BUT THE NAM/GFS SOUNDINGS AREN`T REALLY THAT DRY. WITH DEEP MOISTURE UWPARDS OF 8-10KFT AND DGZ DESCENDING MORE FIRMLY INTO THE CONVECTIVE LAYER UNDER CAA REGIME...HAVE TO BELIEVE LES WILL BE MORE SIGNIFICANT THAN THE NAM/GFS INDICATE. REGIONAL GEM IS MUCH MORE AGGRESSIVE WITH PCPN AMOUNTS. WHILE THE NAM HAS 12Z WED-00Z FRI PCPN AMOUNTS UP TO 0.4 INCHES NW TO 0.5 INCHES ALONG SHORE E OF MUNISING...THE REGIONAL GEM IS UPWARDS OF 0.8 INCHES NW TO OVER 2 INCHES E OF MUNISING. SOMETHING BTWN THE TWO EXTREMES IS PROBABLY REASONABLE...THOUGH THE REGIONAL GEM LOOKS QUITE EXCESSIVE OVER THE E. AT THIS POINT...WILL KEEP 12-24HR SNOW AMOUNTS JUST UNDER LES WARNING THRESHOLDS NW DUE TO UNCERTAINTY IN BOUNDARY LAYER MOISTURE. WITH LOW-LEVEL WINDS ESSENTIALLY W...LES WILL TARGET AREAS FROM ONTONAGON COUNTY THRU THE KEWEENAW. TO THE E...SLIGHT VEERING OF WINDS HIGHER IN THE CONVECTIVE LAYER SHOULD TEND TO FOCUS THE SRN LES BAND ALONG TO JUST INLAND FROM THE SHORE FROM PICTURED ROCKS EASTWARD. TYPICALLY...THE SRN MOST BAND YIELDS HEAVIEST SNOW RATES DUE TO LAND BREEZE CONVERGENCE AND THE OVERALL LONG FETCH ACROSS THE LAKE...ONLY INTERRUPTED BRIEFLY BY THE KEWEENAW. THUS...POTENTIAL EXISTS FOR VERY IMPRESSIVE SNOW ACCUMULATIONS OVER A SMALL AREA OF THE E CLOSE TO LAKE SUPERIOR...PROVIDED LES BAND DOES NOT SHIFT OFFSHORE FREQUENTLY. ALSO...DEEP/VIGOROUS CONVECTION AND RELATIVELY WARM EARLY SEASON WATER/BOUNDARY LAYER MAY LEAD TO MORE GRAUPEL/SNOW PELLET TYPE PCPN RATHER THAN LARGE SNOWFLAKES...WHICH WILL REDUCE SNOW ACCUMULATIONS OVER WHAT COULD BE EXPECTED. HAVE OPTED TO ISSUE A LAKE EFFECT SNOW WATCH FOR ALGER/LUCE...EMPHASIZING THE AREAS FROM AROUND GRAND MARAIS EASTWARD. AWAY FROM LES...DRY WEATHER WILL GENERALLY PREVAIL THRU THU. LES WILL WIND DOWN/END LATER THU/THU NIGHT AS MID/UPPER TROF SHIFTS E OF THE AREA AND FLOW BEGINS TO BACK IN ADVANCE OF TROF AMPLIFICATION OVER THE WRN CONUS. LEAD WAVE AHEAD OF THE WRN TROF AMPLIFICATION COMBINED WITH STRONG WAA COULD LEAD TO SOME LIGHT PCPN LATER THU NIGHT/FRI MORNING. LACK OF MOISTURE MAY RESULT IN PCPN OCCURRING FARTHER N IN THE COLDER AIR WHERE SATURATION THRU THE COLUMN CAN OCCUR. SHORTWAVE WILL LIFT OUT OF THE WRN TROF EARLY IN THE WEEKEND. FOR SEVERAL DAYS...MODELS HAVE SHOWN UNUSUALLY GOOD CONTINUITY ON SFC LOW TRACK DESPITE BEING WAY OUT IN THE FCST CYCLE. THERE HAVE BEEN THE EXPECTED INTENSITY/PLACEMENT ISSUES...BUT THEY WERE MINOR WHEN CONSIDERING THE TIME RANGE INTO THE FCST RUN. FOR 90 TO 108HRS INTO THE MODEL RUN...TODAYS 00Z ROUND OF MEDIUM RANGE GUIDANCE REMAINS WELL CLUSTERED ON A LOW TRACK FROM KS TO THE UPPER GREAT LAKES... SOMEWHERE BTWN CNTRL UPPER MI AND FAR NRN LWR MI/STRAITS AREA. ALL SUGGEST A HEADLINE SNOW EVENT FOR SOME PART OF THE FCST AREA... PROBABLY HIGH END ADVY TYPE. THE WRN MOST LOW TRACK (GFS) WOULD PROVIDE HEAVIEST SNOW OVER NW UPPER MI WHILE THE ERN TRACKS (GLOBAL GEM/ECMWF) WOULD SPREAD HEAVIEST SNOW OVER MOSTLY THE CNTRL PORTION OF UPPER MI. && .AVIATION /FOR THE 06Z TAF ISSUANCE/ COLD AIR MOVING INTO THE REGION ON WEST NORTHWEST WINDS BEHIND A SHORTWAVE TROUGH AND LOW WILL SUPPORT LAKE ENHANCED SNOW OVER IWD AND CMX...WITH CIGS DROPPING INTO THE MVFR RANGE AND OCNL IFR VSBY. EXPECT SOME IMPROVEMENT AT IWD TOWARDS MID DAY AS MORE WESTERLY FLOW PUSHES THE BEST SNOW ACTIVITY NORTH OF THE TAF SITE. AT KCMX...MORE PERSISTENT LOWER MVFR OR NEAR IFR CONDITIONS ARE EXPECTED AS THE LAKE EFFECT/ENHANCED SNOW CONTINUES. LOW LEVEL WINDS TOWARD KSAW WILL BE LESS FAVORABLE FOR LAKE EFFECT PCPN...BUT MAY SEE CIGS AT OR NEAR MVFR. && .MARINE /FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE/... EXPECT WESTERLY GALES TO DIMINISH BY THIS EVENING OVR LK SUPERIOR AS SFC LOW JUST EAST OF LK SUPERIOR HEADS INTO QUEBEC. WINDS REMAIN OUT OF THE W/NW UP TO 30 KTS THURSDAY INTO THURSDAY NIGHT...THEN BECOME MORE SOUTHERLY ON FRIDAY AS LOW PRESSURE SYSTEM PASSES TO NORTH OF LK SUPERIOR. COULD BE MARGINAL SRLY GALES OVR FAR EASTERN SECTIONS FRIDAY. ACTIVE PATTERN CONTINUES INTO THE UPCOMING WEEKEND AS ANOTHER LOW OVR THE PLAINS ON SATURDAY TRACKS ACROSS THE LAKE SUPERIOR REGION SATURDAY NIGHT. NE WINDS COULD REACH GALE FORCE OVR WESTERN SECTIONS SATURDAY WITH NW GALES THEN POSSIBLE LATE SATURDAY NIGHT INTO SUNDAY MORNING AS THE LOW PULLS AWAY FM THE REGION. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... WINTER WEATHER ADVISORY UNTIL 5 PM EST THURSDAY FOR MIZ001>003- 084. LAKE EFFECT SNOW WATCH FROM THIS EVENING THROUGH THURSDAY AFTERNOON FOR MIZ006-007. LAKE SUPERIOR... GALE WARNING UNTIL 10 PM EST THIS EVENING FOR LSZ248>251-265>267. GALE WARNING UNTIL 4 PM EST /3 PM CST/ THIS AFTERNOON FOR LSZ162- 241>243-263-264. GALE WARNING UNTIL 1 PM EST THIS AFTERNOON FOR LSZ244-245. LAKE MICHIGAN... GALE WARNING UNTIL 10 AM EST THIS MORNING FOR LMZ221-250. && $$ SYNOPSIS...ROLFSON DISCUSSION...ROLFSON AVIATION...JLB MARINE...JLA
AREA FORECAST DISCUSSION...UPDATED
NWS TWIN CITIES/CHANHASSEN MN
610 AM CST WED NOV 16 2011 .UPDATE... UPDATED FOR THE 12Z AVIATION DISCUSSION BELOW. .DISCUSSION... A COLD WEST-NORTHWEST FLOW OF AIR WILL COVER THE REGION INTO THURSDAY. A SHORT WAVE OVER NORTH DAKOTA WILL PROGRESS TO THE WESTERN GREAT LAKES BY TONIGHT. SOME CLOUDINESS OVER CENTRAL MN AND WEST CENTRAL WI EARLY THIS MORNING WILL PART FOR A TIME BEFORE ANOTHER SURGE OF LOW CLOUDINESS ARRIVES FOR THE AFTERNOON AND EVENING HOURS. OUR LOCAL MODEL AND THE RUC PAINT SOME LIGHT ECHOES ACROSS CENTRAL MN AND WEST CENTRAL WI DURING THE AFTERNOON AND EVENING HOURS...SO KEPT THE MENTION OF FLURRIES TO THESE AREAS. THERE SHOULD BE A GOOD DEAL OF SUNSHINE ACROSS SOUTHERN MN TODAY. THE MIX-DOWN TD TOOL POINTS TO DEW POINT LOWERING TO AROUND 5 DEG C DURING THE AFTERNOON. WE ARE CURRENTLY SEEING SOME SINGLE DIGIT DEW POINTS NEAR THE SD/NE EARLY THIS MORNING. THE ARW/NMM WRFS ALSO INDICATE DINGLE DIGIT DEW POINT IN THE SOUTH THIS AFTERNOON. HENCE...BLENDED IN THE MIX DOWN DPS WITH CONSENSUS FOR THE AFTERNOON AND EVENING HOURS. TRENDED A FEW DEGREES HIGHER ON HIGH TEMPERATURES TODAY OVER THE SOUTHERN HALF OF THE CWA VERSUS MET/MAV MOS DUE TO MORE SUNSHINE AND WHAT THE MIX DOWN MAX T WAS SHOWING. FLURRIES/CLOUDS WILL DIMINISH TONIGHT OVER THE NORTHERN AND EASTERN CWA AS HIGH PRESSURE MOVES IN LATE IN THE NIGHT. THE RIDGE WILL MOVE ACROSS THE CWA ON THURSDAY WITH FLOW BECOMING MORE SOUTHERLY. IT WILL STILL BE A COOL DAY WITH HIGHS ONLY IN THE 30S. AS THE RIDGE MOVES EAST THURSDAY NIGHT...A WARM FRONT WILL DEVELOP AND MOVE NORTHEAST ACROSS THE CWA. ONLY SOME CLOUDS EXPECTED WITH THE WARM FRONT. THIS WILL LEAD TO A WARMER FRIDAY WITH HIGHS REACHING WELL INTO THE 40S IN MOST AREAS WITH SOME 50S IN THE SOUTH. THE LOW PRESSURE SYSTEM AND PRECIPITATION EVENT FOR SATURDAY AND SATURDAY NIGHT REMAINS ON TRACK. THE GEM AND ECMWF ARE IN STEP WITH THIS SYSTEM WHILE THE GFS LAGS BY ABOUT 6 HOURS. THE GFS ENSEMBLE IS EVEN SLOWER BY ABOUT ANOTHER 6 HOURS. STILL EXPECT A LOW TO TRACK FROM EASTERN NEBRASKA SATURDAY MORNING TO EASTERN WI BY SATURDAY NIGHT. ALL SOLUTIONS INDICATE THE LOW SLOWLY FILLING DURING THIS PERIOD WHICH IS NOTE GOOD FOR A HEAVY SNOW EVENT. WE ALSO CONTINUE TO SEE AN OPEN WAVE ALOFT WHICH SPEAKS FOR THE QUICKNESS WITH THIS SYSTEM. LOOKING AT SOME OF THE MID/UPPER LEVEL FEATURES SHOWS THE H5 HEIGHT FALL TRACK FROM YELLOW MEDICINE COUNTY TO BURNETT COUNTY. THE -15 DEG C OMEGA IS ON THE LEFT SIDE OF THIS TRACK WITH THE DEPTH OF THE DENDRITIC GROWTH ZONE BEING ABOUT 1100M. THE WARM POCKET AT H2 ALSO TRACKS ALONG THE AFOREMENTIONED AXIS WITH 10 DEG OF WARMING NOTED. THE 295K THETA SURFACE PLACES 700 MB ABOUT IN THIS GENERAL AREA AS WELL WITH PLENTY OF SATURATION AND ADIABATIC OMEGA NOTED TO THE NORTH AND WEST. THE MIX RATIO CONTINUES TO RUN BETWEEN 2 AND 3 G/KG AND IS ALIGNED WITH THE -FN VECTOR DIVERGENCE. THIS ALL POINTS TO A BAND OF 4 TO LOCALLY 6 INCHES FROM WEST CENTRAL MN ON NORTHEAST TO DULUTH AND HAYWARD. THE CARIBOU SNOW TOOL USING THE GFS AGREES PRETTY WELL WITH THIS SCENARIO. ALSO INTERESTING IS THE 16/00Z CIPS DATA...BASED ON THE TOP 15 ANALOGS...WHICH SHOWS MEAN SNOWFALL OF 4 TO 6 FROM WEST CENTRAL MN THROUGH THE ARROWHEAD AND FAR NORTHERN AREAS OF WI WITH 2 TO 3 INCHES FROM SOUTHWEST MN THROUGH THE METRO AND ACROSS MUCH OF WEST CENTRAL WI. IN THE WAKE OF THE LOW PRESSURE SYSTEM...A RATHER SUBSTANTIAL HIGH WILL BUILD OVER THE REGION FROM SUNDAY THROUGH TUESDAY WITH DRY WEATHER AND BELOW NORMAL TEMPERATURES OCCURRING. && .AVIATION.../12Z TAF ISSUANCE/ CURRENT 3000-4500FT CEILINGS BEING OBSERVED THIS MORNING IN PORTIONS OF NORTHERN WISCONSIN AND CENTRAL WILL LARGEST SLIDE EAST WITH TIME AND BYPASS MOST OF THE TAF SITES. A SECOND WEAKER WAVE WILL PASS THROUGH THE AREA TODAY AND COULD SHAKE OUT A FEW SNOW FLURRIES AS WELL. LIKE THE PAST COUPLE DAYS...THE WIND WILL REMAIN QUITE STRONG OUT OF THE WEST/NORTHWEST AND FINALLY BEGIN TO SUBSIDE THIS EVENING. KMSP...VERY LITTLE RISK FOR ANY WEATHER IMPACTS TO AVIATION OUTSIDE THE WIND...WHICH WILL AGAIN BE QUITE GUSTY BY THIS AFTERNOON. SUSTAINED WINDS NEAR 15KTS WITH GUSTS TO 25KTS ARE EXPECTED ACROSS EASTERN MN. SHOULD SEE MORE SUN THAN CLOUD TODAY AND THE WINDS WILL FINALLY RELAX THIS EVENING AND REMAIN LIGHT THROUGH THURSDAY MORNING. OUTLOOK...FAIRLY QUIET WEATHER OVER THE NEXT COUPLE DAYS. CEILING AND VISIBILITY RESTRICTIONS ARE EXPECTED SATURDAY NIGHT WHEN A SYSTEM BRINGS ACCUMULATING SNOW TO MN/WI. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ 99/99
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1052 AM EST WED NOV 16 2011 .SYNOPSIS... A COLD FRONT OVER THE TENNESSEE VALLEY WILL SLIDE EASTWARD BRINGING SHOWERS AND A CHANCE OF THUNDERSTORMS...INCLUDING SEVERE WEATHER...TONIGHT INTO THROUGH THURSDAY MORNING. MUCH COOLER AND DRIER AIR WILL FOLLOW LATE THURSDAY AND FRIDAY. HIGH PRESSURE WILL MOVE OVERHEAD WITH TEMPERATURES MODERATING DURING THE WEEKEND. ANOTHER FRONT WILL SHIFT TOWARD THE AREA EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1030 AM WEDNESDAY...WARM MOIST SOUTHWEST FLOW CONTINUES OVER THE CAROLINAS TODAY IN ADVANCE OF A STRONG COLD FRONT NOW LOCATED IN EASTERN TENNESSEE...NORTHERN ALABAMA...AND MISSISSIPPI. TODAY SHOULD BE THE WARMEST DAY OF THIS ENTIRE STRING OF MILD WEATHER DATING BACK TO SUNDAY...WITH THIS AFTERNOON`S HIGHS REACHING THE LOWER 80S INLAND AWAY FROM MARINE INFLUENCES. 850 MB TEMPS IN THE +15C TO +16C RANGE WOULD BE MORE AT HOME IN JUNE THAN IN NOVEMBER...AND WILL SUPPORT THESE VERY MILD READINGS. RECORD HIGHS FOR TODAY ARE IN THE MID TO UPPER 80S ARE SHOULD REMAIN UNTOUCHED. DEWPOINTS IN THE UPPER 60S PLUS A LONG WIND FETCH ACROSS THE COLD NEARSHORE COASTAL WATERS IS PRODUCING AREAS OF FOG AND VERY LOW STRATUS CLOUDS OVER THE OCEAN AND SOME OF THE BEACHES. VISIBILITIES IN THE 0.25 TO 1 MILE RANGE ARE COMMON ON THE BEACHES AND OUT OVER THE COASTAL WATERS. AS LONG AS THE SUN IS SHINING TODAY THIS FOG SHOULD HAVE LITTLE SUCCESS MAKING IT MORE THAN 1 MILE INLAND OR SO...BUT ANY REMAINING FOG THIS EVENING COULD PUSH FARTHER INLAND. FIRST WE HAVE TRIMMED BACK POPS TODAY WITH ALL SHORT-TERM GUIDANCE SUGGESTING WE WILL SEE LITTLE IF ANY SHOWER ACTIVITY OVER OUR FORECAST AREA BEFORE DARK. WE DID LEAVE A SMALL 20 POP WEST OF I-95 LATE THIS AFTERNOON WHERE ONE OF THE PREVIOUS THREE HRRR RUNS SHOWS SOME SHOWERS POSSIBLE. THERE IS INSTABILITY (CAPE AROUND 1000 J/KG) FORECAST TO DEVELOP THIS AFTERNOON BUT TRIGGERS FOR CONVECTION ARE LARGELY ABSENT. THE BIG STORY IS THE POTENTIAL FOR SEVERE WEATHER AHEAD OF THE FRONT TONIGHT. ALTHOUGH SURFACE-BASED CAPE/INSTABILITY IS NOT IMPRESSIVE AFTER SUNSET THERE IS RATHER LARGE ELEVATED CAPE WHEN PARCELS AT 950/925 MB ARE CONSIDERED. RATHER STEEP LAPSE RATES THROUGH ALL THE MID AND UPPER LEVELS OF THE ATMOSPHERE WILL BE SUPPORTIVE OF DEEP CONVECTION. SYNOPTIC FACTORS SUPPORTIVE OF LIFT INCLUDE A FAVORABLY-POSITIONED JET STREAK MOVING THROUGH THE MID-ATLANTIC REGION TONIGHT PLACING THE CAROLINAS SQUARELY IN THE FAVORED RIGHT-ENTRANCE REGION...STRONG AND SLIGHTLY BACKED LOW LEVEL WINDS RELATIVE TO THE MID AND UPPER LEVEL FLOW PRODUCING 0-6 KM BULK SHEAR VALUES ON THE ORDER OF 50-70 KT...AND SEVERAL 500 MB VORTICITY CENTERS PASSING OVER OR JUST NORTH OF OUR FORECAST AREA. THE LATEST SPC CONVECTIVE OUTLOOK INCREASED SEVERE WEATHER PROBABILITIES FOR WIND AND TORNADOES...AND WE WOULD NOT BE AT ALL SURPRISED TO SEE TORNADO WATCHES FOR PORTIONS OF OUR FORECAST AREA THIS EVENING AND OVERNIGHT. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 3 AM WEDNESDAY...FORECAST MODELS HAVE SLOWED DOWN THE PROGRESSION OF THE COLD FRONT EVER SO SLIGHTLY AND HAVE THEREFORE EXTENDED POPS ACROSS THE BOARD INTO THE LATE MORNING HOURS...ESPECIALLY COASTAL AREAS. OTHERWISE INTERESTING TEMPERATURE FORECAST FOR THURSDAY HIGHS AS THE MAV NUMBERS SHOW NO WARMING IN WILMINGTON WITH LITTLE ELSEWHERE. WITH THE DOWNSLOPE FLOW AND COLD AIR ADVECTION NOT THAT IMPRESSIVE...DID ADD A DEGREE OR TWO TO THE MAV NUMBERS. FOR FRIDAY MORNING WINDS DECOUPLE INLAND WHILE REMAINING UP SLIGHTLY ALONG THE COAST AND ADJUSTED MOS NUMBERS ACCORDINGLY. COOL DAY FRIDAY WITH MOST AREAS REMAINING BELOW 60. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 3 AM WEDNESDAY...EXTENDED FORECAST IS RATHER UNEVENTFUL AS THE PATTERN QUICKLY EVOLVES FROM ZONAL TO RIDGING ACROSS THE SOUTHEAST...SIMILAR TO THE PATTERN WE HAVE EXPERIENCED THE PAST FEW DAYS. HPC IS FAVORING A BLEND OF THE GFS/ECMWF AND UKMET. REALLY THE ONLY FORECAST CHALLENGES INVOLVE LIGHT COASTAL TROUGH QPF SATURDAY AND A BACKDOOR FRONT TUESDAY. AS FOR THE FORMER...MAINTAINED A DRY FORECAST AS THE MODELS ARE USUALLY OVERDONE WITH THE QPF AND IN REALITY IT IS GENERALLY A STRATUS LAYER. REGARDING THE FRONT...THE LATEST GFS IS MORE BULLISH IN PUSHING THE FRONT SOUTH WITH THE EFFECTS ONLY BEING AN AIRMASS CHANGE. THE 0000 UTC ECMWF HAS BACKED OFF A FURTHER SOUTH SOLUTION. OTHERWISE...AS WE JUST EXPERIENCED...ABOVE NORMAL TO DOWN RIGHT BALMY CONDITIONS FOR LATE IN THE WEEKEND AND EARLY NEXT WEEK. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... AS OF 12Z...SATELLITE AND OBSERVATIONS SHOW IFR/LIFR CONDITIONS ENTRENCHED OVER MUCH OF THE CWA...A MIXTURE OF STRATUS AND ADVECTION SEA FOG. EXPECT IFR CONDITIONS TO CONTINUE THROUGH THE MORNING HOURS...LIFTING OR SCATTERING AROUND 16Z...AS SOUTHWEST FLOW INCREASES AHEAD OF A COLD FRONT. EXPECT MVFR/NEAR VFR CONDITIONS FOR THE AFTERNOON HOURS...ONLY TO LOWER TO IFR SHORTLY AFTER 00Z. TONIGHT...DEEP MOISTURE ASSOCIATED WITH THE COLD FRONT WILL CROSS THE CWA...REACHING THE COAST BY 09Z. SHOWERS WILL BE SCATTERED TO NUMEROUS ALONG AND AHEAD OF THE FRONT. LOW PRESSURE ALONG THE COLD FRONT MAY ACTUALLY HAVE A DRY SLOT WITH IT...BUT CONFIDENCE IS LOW. EXTENDED OUTLOOK...SHOWERS LINGERING THURSDAY MORNING WILL LIFT OUT BY LATE MORNING WITH CONDITIONS IMPROVING TO VFR. EXPECT VFR FRIDAY AND SATURDAY...WITH LOWERED CONFIDENCE FOR POTENTIAL IFR FOG/STRATUS SUNDAY MORNING. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1030 AM WEDNESDAY...SATELLITE IMAGERY...SURF CAMS...AND OBSERVATIONS FROM NORTH MYRTLE BEACH AND SOUTHPORT CONTINUE TO INDICATE EXPANSIVE AREAS OF DENSE SEA FOG THIS MORNING. WE WILL LIKELY HAVE TO EXTEND THE TIME OF THE DENSE FOG ADVISORY LATER THIS MORNING AS THE MOIST SOUTHWESTERLY FLOW IS EXPECTED TO CONTINUE THROUGH TODAY AND INTO THIS EVENING. THERE IS QUITE A THERMAL GRADIENT ACROSS THE AREA WITH THE FRYING PAN SHOALS BUOY REPORTING AN AIR TEMP OF 75...WHILE 66-67 DEGREE TEMPS ARE BEING REPORTED ON THE BEACHES NEAR CAPE FEAR. SOUTHWESTERLY WINDS AROUND 15 KT WILL INCREASE FURTHER TONIGHT AS THE GRADIENT TIGHTENS AHEAD OF THE INCOMING STRONG COLD FRONT. SHOWERS AND THUNDERSTORMS WILL ALSO INCREASE IN COVERAGE TONIGHT. THE SMALL CRAFT ADVISORY REMAINS IN PLACE FOR THE ROUGHER CONDITIONS NEAR AND AHEAD OF THE FRONT. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 3 AM WEDNESDAY...MAIN FORECAST CHALLENGE WILL BE WHEN TO CONCLUDE THE SMALL CRAFT ADVISORY LATE THURSDAY EVENING. A PERIOD OF STRONG NORTHERLY WINDS WILL FOLLOW THE FRONT THURSDAY INTO THURSDAY EVENING. FOR NOW WITH THE TIMING STILL OUT FOUR PERIODS...WILL NOT TWEAK BUT ISSUE THE DISCLAIMER THE HEADLINE MAY HAVE TO BE EXTENDED A FEW HOURS. WINDS VEER TO NORTHEASTERLY FRIDAY AND DIMINISH SOMEWHAT TO A MANAGEABLE RANGE OF 15-20 KNOTS MAINLY TO THE LOWER END. HIGH SEAS EARLY GET CONFINED TO THE OUTER WATERS WITH THE WIND SHIFT AND REMAIN THERE FOR THE MOST PART. SOME FIVE TO SIX FOOTERS MAY LINGER ACROSS THE OUTER WATERS GIVING THE FRIDAY. LONG TERM /SATURDAY THROUGH SUNDAY/... AS OF 3 AM WEDNESDAY...NORTHEAST FLOW INITIALLY WILL QUICKLY VEER TO SOUTHEAST AS HIGH PRESSURE WEAKENS AND LEAVES THE WIND FIELD TO BE FORCED BY LOCAL EFFECTS IE...THE SEABREEZE. THIS WILL OCCUR LATE SATURDAY AND SUNDAY AS WINDS DROP TO BELOW 10 KNOTS. SEAS FOLLOW A SIMILAR TREND WITH 2-4 FEET INITIALLY DROPPING TO 2-3 FEET. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...DENSE FOG ADVISORY UNTIL NOON EST TODAY FOR AMZ250-252- 254-256. SMALL CRAFT ADVISORY FROM NOON TODAY TO MIDNIGHT EST THURSDAY NIGHT FOR AMZ250-252-254-256. && $$ NEAR TERM...TRA SHORT TERM...SHK LONG TERM...SHK AVIATION...43
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1010 AM MST WED NOV 16 2011 .DISCUSSION... 301 AM MST WED NOV 16 2011 FORECAST PROBLEMS WILL BE TODAY...AND THEN HOW FAST IS THE TEMPERATURE RECOVERY INTO FRIDAY. SATELLITE SHOWING SOME AMPLIFICATION TO THE FLOW FROM THE WESTERN PACIFIC INTO CENTRAL NORTH AMERICA. UPPER TROUGH IS STILL HANGING AROUND OVER THE CENTRAL PORTION OF THE COUNTRY WITH NUMEROUS SHORTWAVE TROUGHS MOVING THROUGH IT. COLD FRONT THAT WENT THROUGH EARLIER TODAY EXTENDS FROM THE SOUTHERN PLAINS TO ALONG THE FRONT RANGE OF COLORADO. MODELS INITIALIZED FINE AT JET LEVEL. MODELS INITIALIZED FINE AT MID LEVELS EXCEPT THE GFS WAS TOO MOIST. THE MODELS TENDED TO BE SLIGHTLY TOO FAR EAST AND SOUTH WITH THE SURFACE RIDGE AND THE LEE SURFACE TROUGH. HOWEVER...THE NAM WAS PRETTY CLOSE AND SLIGHTLY BETTER THAN THE ECMWF. ON THE LOW LEVEL THERMAL FIELD OVERALL...THE CANADIAN...GFS AND UKMET WERE ABOUT THE SAME AND A LITTLE BETTER WITH THE NAM NOT TOO FAR BEHIND AND MAYBE BETTER TO THE NORTH OF THE AREA. TODAY/TONIGHT...INITIAL PROBLEM WILL BE COVERAGE AND DURATION OF SNOWFALL THIS MORNING AS A SHORTWAVE TROUGH AND LIFT FROM THE UPPER JET MOVE THROUGH. GOING BY THE DNR 00Z SOUNDING...THE BEST MOISTURE IS ABOVE 700 MB AND REALITY IS SUPPORTING THAT. SO FAR VISIBILITIES/OBSERVATIONS AND CAMERAS SHOW LITTLE IF ANY ACCUMULATION...EVEN UNDER THE MOST INTENSE BAND THAT IS ALONG THE KANSAS AND NEBRASKA BORDER. TEMPERATURE AND DEWPOINT SPREADS ARE LARGE...ESPECIALLY IN THE NORTH WHERE THE RADAR SAYS THE MOST INTENSE PRECIPITATION IS. MOST OF THE MODELS SAY THAT MEASURABLE SHOULD BE OCCURRING AT THIS TIME WITH RUC HAVING THE LEAST MEASURABLE AND LOOKING THE BEST AT THIS TIME. RIGHT REAR QUADRANT SHOULD BE EAST OF THE AREA BY 12Z. 7-5H SHORTWAVE LOOKS TO BE ENTERING THE WESTERN PORTION OF THE FORECAST AREA AT THIS TIME. SOME PV MOVES ACROSS EARLY WITH THE BRUNT OF IT NORTH. DOWNGLIDE ALSO MOVES IN RATHER QUICKLY THIS MORNING. WILL CONTINUE TO WATCH TRENDS FOR CHANGES BUT PLAN ON TAKING THE MEASURABLE OUT AND HAVE FLURRIES OVER MOST OF THE AREA THIS MORNING WITH MAYBE A LITTLE LINGERING IN THE FAR EAST INTO THE EARLY AFTERNOON. QUESTION THEN BECOMES HOW FAST WE CLEAR OUT AND ITS AFFECT ON HIGH TEMPERATURES. STRONG JET ON THE BACKSIDE OF THE UPPER TROUGH DOES NOT GET CLOSE TO THE AREA UNTIL LATE IN THE DAY. BASED ON SATELLITE...WE SHOULD CLEAR OUT RATHER QUICKLY WITH THE MODELS LOOKING LIKE THEY ARE HANGING ONTO CLOUDS A LITTLE TOO LONG. CURRENTLY TEMPERATURES ARE RUNNING A LITTLE WARMER THAN DEPICTED BUT CLEARING AND TEMPERATURES UPSTREAM SUPPORT MINS GETTING NEAR WHAT IS CALLED FOR. MODEL GUIDANCE IS SIMILAR IN ITS DEPICTION AND MADE SLIGHT ADJUSTMENTS BASED ON LATEST TRENDS/GUIDANCE. ANOTHER CONCERN WILL BE WINDS ON THE BACKSIDE OF THE SYSTEM AS IT EXITS. LOOKS LIKE WILL HAVE GOOD SUBSIDENCE AND ADIABATIC LAPSE RATES. SO IT LOOKS LIKE WE WILL SEE A BRIEF PERIOD OF AT LEAST BREEZY AND GUSTY WINDS THIS AFTERNOON BUT DO NOT SEE ANYTHING GETTING OUT OF HAND. JET AXIS MOVES ACROSS THE AREA DURING THE NIGHT...AND AFFECTS THE NORTHEAST HALF OF THE AREA BY 12Z. THAT AND ANOTHER SHORTWAVE WILL INCREASE THE CLOUDS AFTER 06Z. NEXT QUESTION WILL BE HOW FAST THE SURFACE MOVES THROUGH AND HOW FAST DO THE WINDS INCREASE. LIKE THE SLIGHTLY SLOWER EVOLUTION AND THINK THE GFS IS TOO FAST. AT THIS TIME...IT LOOKS LIKE TEMPERATURES WILL BOTTOM OUT EARLY... ESPECIALLY IN THE WEST AND THEN REMAIN STEADY AFTER THAT. THURSDAY/THURSDAY NIGHT...RIGHT REAR QUADRANT OF THE JET REMAINS NEAR OR OVER THE AREA THROUGH THE DAY. SOME DIFFERENCE IN THE AMOUNT OF CLOUD COVER WITH MOST OF THE MODELS SHOWING A MOSTLY SUNNY TO A PARTLY SUNNY DAY. AS HAS BEEN THE CASE IN THIS FLOW...CLOUDS MAY BE A LITTLE MORE THAN CURRENTLY THINK. SHOULD START OFF WITH DOWNSLOPE WINDS BUT THEN THEY SHIFT TO THE SOUTH AS LEE TROUGH STRENGTHENS. MODELS DO NOT LOOK AS STRONG ON THE WINDS AS YESTERDAY AS MIXING AND GRADIENT ARE NOT AS STRONG AS PREVIOUSLY DEPICTED. STRONGEST WINDS WILL BE IN THE EAST. SOME DIFFERENCES IN THE DEPICTED MAXES. THE 06Z NAM HAS COOLED THINGS OFF A LITTLE FROM 00Z. AT THIS TIME...WILL TREND TOWARD THE WARMER SIDE OF THE GUIDANCE. FRIDAY/FRIDAY NIGHT...COMPLEX JET SETUP BEGINS DURING THE DAY. NORTHERN STREAM REMAINS WELL NORTHWEST OF THE AREA THROUGH THE DAY. HOWEVER...LEFT FRONT QUADRANT OF A SOUTHERN JET DEVELOPS OR STRENGTHENS OVER THE AREA THROUGH THE DAY...ESPECIALLY IN THE AFTERNOON. THERE LOOKS TO BE SOME INCREASING HIGH CLOUDS IN THE AFTERNOON. CONSIDERING WHAT THE JET IS DOING AND THE STRONG SOUTHWESTERLY FLOW...LIKE WHAT THE NAM AND ECMWF ARE SHOWING WITH A STRENGTHENING AND FURTHER WEST LEE TROUGH. THIS MEANS LESS OF A DOWNSLOPE COMPONENT AND IF MODELS ARE CORRECT MORE OF AN EASTERLY COMPONENT AS THE DAY WHERES ON. SO WILL TREND TOWARD THE COOLER SIDE OF GUIDANCE. AS A SIDE NOTE...DUE TO A MORE EASTERLY WIND AND HIGHER DEWPOINTS... BELIEVE SHOULD NOT SEE ANY FIRE WEATHER CONCERNS DESPITE THE WARMER TEMPERATURES. BULLER FOR THE PERIOD SATURDAY THROUGH TUESDAY...SHORTWAVE WILL EJECT ACROSS THE CENTRAL PLAINS SATURDAY FROM BASE OF WEST COAST MEAN TROUGH. TRACK OF THE UPPER SYSTEM AND MOISTURE PROFILES SUGGEST FROPA WILL BE DRY. THERE MAY BE A PERIOD OF GUSTY NORTH WINDS BEHIND THE FRONT SOMETIME ON SATURDAY. COLDER TEMPERATURES WILL FOLLOW ON SUNDAY...LOW TO MIDDLE 40S FOR HIGHS...WHICH IS AROUND 10 DEGREES BELOW NORMAL. RETURN FLOW GETS UNDER WAY FOR MONDAY UNDER SHORTWAVE RIDGING ALOFT WITH TEMPERATURES WARMING TO NEAR NORMAL AND CONTINUED DRY. REMNANTS OF WEST COAST SYSTEM COMES ACROSS SOUTHERN ROCKIES ON TUESDAY BRINGING A CHANCE OF MAINLY RAIN...BEST CHANCES WILL BE SOUTH. 024 THANKS TO ALL THAT COLLABORATED. && .AVIATION... 1010 AM MST WED NOV 16 2011 FOR THE 18Z TAFS...VFR CONDITIONS EXPECTED TO PREVAIL THROUGH THE EFFECTIVE TAF PERIOD AT BOTH KGLD AND KMCK. MVFR CIGS/VIS ASSOCIATED WITH LINGERING LIGHT SNOW OVER KMCK CURRENTLY EXPECTED TO IMPROVE TO VFR BY 18Z BASED ON CURRENT RADAR/SATELLITE TRENDS. WILL CONTINUE TO MONITOR TRENDS UP TO TAF ISSUANCE IN THE EVENT SNOW IS SLOWER TO MOVE EAST OF THE TERMINAL. GUSTY NORTHWEST WINDS STILL EXPECTED TO DEVELOP THIS AFTERNOON BEHIND DEPARTING SHORTWAVE TROUGH...BEFORE DECREASING AROUND 00Z AS SURFACE HIGH PRESSURE SETTLES IN OVER THE REGION AND DAYTIME MIXING COMES TO AN END. WINDS WILL INCREASE TO 12-14KT FROM THE WEST TO THE EAST 09-12Z THU IN RESPONSE TO LEE TROUGH DEVELOPMENT OVER EASTERN COLORADO. DR && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. NE...NONE. CO...NONE. && $$
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
149 PM EST WED NOV 16 2011 .SYNOPSIS... A WEAK STATIONARY FRONT WILL REMAIN OVER THE NORTHERN MID ATLANTIC REGION THIS AFTERNOON AS A COLD FRONT APPROACHES FROM THE WEST. THE COLD FRONT PASSES THROUGH TONIGHT...WITH HIGH PRESSURE RETURNING LATE THURSDAY AND INTO THE WEEKEND. ANOTHER COLD FRONT APPROACHES SUNDAY NIGHT INTO MONDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... WEAK STATIONARY FRONT IS SITUATED WSW TO ENE ACRS THE CWA...FROM ABOUT FARMVILLE TO ASHLAND INTO THE MD EASTERN SHORE. STRONG TEMPERATURE GRADIENT IN PLACE...AS WELL AS PRECIPITATION CHANCES OVER THE NEXT FEW HRS. WILL CARRY CAT POPS N/NW ZONES THIS AFTN...TAPERED TO JUST 20% OVER FAR SE VA/ NE NC. HAVE ADJUSTED HIGHS A BIT TO SHARPEN THE GRADIENT AS IT WILL TEND TO STAY IN THE 60S OVER THE MD EASTERN SHORE AND TO THE NW OF RICHMOND...WHILE HIGHS AROUND 80 CAN BE EXPECTED IN A FEW SPOTS IN THE SE. WHILE A CHANCE OF THUNDERSTORMS REMAINS IN THE FORECAST FOR THIS AFTN...THINK THAT BEST CHANCE FOR SEVERE WX WILL NOT ARRIVE UNTIL THE EVENING HRS...PRIMARILY ACRS SE VA/NE NC. DOWN THAT WAY IS WHERE BEST COMBINATION OF MODEST SFC-BASED INSTABILITY (~500 J/KG) WILL CO- EXIST WITH HIGH SHEAR (0-6 KM BULK SHEAR 60 KT+) . MAIN THREAT WOULD BE DAMAGING WINDS (>40 KT OF 0-3 KM SHEAR AND DCAPE>1000 J/KG). ALSO...SOME STORMS MAY EXHIBIT ROTATION AS RUC AND NAM BOTH PROG 0-1 KM HELICITIES>300 M2/S2 AS THE BOUNDARY DROPS THROUGH BETWEEN 02-06Z. MAIN LIMITING FACTOR MAY BE LACK OF INSTABILITY DUE TO THE TIMEFRAME BEING AFTER SUNSET ALTHOUGH SFC TEMPS WILL LIKELY BE AROUND 70 F...WITH DEW PTS IN THE 60S. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/... BEST PROBABILITY FOR RAIN (CATEGORICAL POPS) COMES TONIGHT DUE TO A COMBO OF ISENTROPIC LIFT AND STRONG LOW/MID LEVEL CONVERGENCE ASSOCIATED W/ COLD FRONT. RAIN WILL BE HEAVY AT TIMES AND SOME AREAS MAY RECEIVE OVER AN INCH TOTAL W/ THIS SYSTEM (ESP N PART OF FA). NO SIGNIFICANT FLOODING IS ANTICIPATED ATTM DUE TO FLASH FLOOD GUIDANCE BEING HIGH. THU...BOTH THE NAM AND THE GFS CONTINUE TO SHOW THE MID/UPPER LEVEL TROUGH NOT CROSSING THE REGION UNTIL AFTER 18Z. COMBINED WITH A NNE FLOW IN THE LOW LEVELS AND THE RRQ OF THE UPPER JET...RAIN WILL BE SLOW TO TAPER OFF AND HAVE BUMPED POPS TO CATEGORICAL FOR ALL ZONES THROUGH THE MORNING/EARLY AFTN HRS. SHARPLY COLDER AIRMASS WILL BE IN PLACE AS WELL...MAKING FOR A RAW AND CHILLY DAY WITH TEMPERATURES MAINLY IN THE 40S (AFTER EARLY AM HIGHS IN THE 50S). DECREASING CLOUDS FROM W TO E LATE (SO THAT COASTAL ZONES MAY STAY CLOUDY ALL DAY). DIMINISHING WINDS AND CLEARING SKIES WILL ALLOW FOR MINS INTO THE UPPER 20S WEST OF I-95 THU NIGHT...30-35 FARTHER EAST. STRONG HIGH PRESSURE BUILDS OVER THE MID ATLANTIC FRI LEADING TO DRY WX AND SUNNY SKIES. TEMPS WILL ONLY MAX OUT IN THE U40S-L50S. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... LONG RANGE MODELS ARE IN GOOD AGREEMENT WITH SHOWING A SOUTHWEST UPPER LEVEL FLOW DEVELOPING SATURDAY AS HIGH PRESSURE BECOMES ANCHORED OVER THE MID ATLANTIC STATES THROUGH SUNDAY. SOME CLOUDINESS IS POSSIBLE IN NORTHEAST NC AND EXTREME SOUTHEAST VA ON SATURDAY AS TROPICAL MOISTURE ROTATES AROUND A MID-LEVEL HIGH OFF THE SOUTHEAST U.S. COAST AND MOVES NEAR THIS AREA. OTHERWISE...A DRYING AND WARMING TREND IS ANTICIPATED UNDER THIS FLOW REGIME...WITH HIGH TEMPS REBOUNDING BACK INTO THE 60S BY SUNDAY. LOWS SHOULD BE NEAR FREEZING SATURDAY MORNING DUE TO PRIME COOLING CONDITIONS UNDER MOSTLY CLEAR SKIES WITH VERY LIGHT WINDS...THEN REBOUND TOWARD THE LOW 50S BY EARLY NEXT WEEK AS CLOUDS INCREASE AHEAD OF THE NEXT WEATHER DISTURBANCE. BY LATE SUNDAY...A WEAK COLD FRONT IS EXPECTED TO SAG SOUTHWARD AND STALL OVER THE MID ATLANTIC REGION THROUGH TUESDAY. 12Z MODEL RUNS TODAY ARE HINTING AT SLOWING THE SOUTHERN MOVEMENT OF THIS BOUNDARY UNTIL LATE MONDAY...WHICH WOULD DELAY THE ONSET OF PRECIPITATION UNTIL THAT TIMEFRAME. HAVE TRENDED THE ONGOING FORECAST TOWARD SLOWING THE PASSAGE OF THE FRONT UNTIL LATE MONDAY...WITH PRECIPITATION BEING INTRODUCED LATE SUNDAY/EARLY MONDAY. && .AVIATION /19Z WEDNESDAY THROUGH MONDAY/... WEAK SFC BOUNDARY LYING ACROSS THE REGION WITH SHORT WAVE ENERGY MOVG FROM SOUTHWEST TO NORTHEAST ACROSS THE FORECAST AREA. MOST OF THE RAIN HAS MOVED ACROSS CENTRAL VA AND THE EASTERN SHORE THIS MORNING BUT WILL OVERSPREAD SE VA AND NC INTO TONIGHT. RADAR SHOWING SOME EMBEDDED CONVECTION IN THE RAIN WHICH WILL BRING BRIEF PERIODS OF HEAVY RAIN AND GUSTY WINDS. CEILINGS HAVE BEEN MOSTLY MVFR/IFR THIS MORNING AND THIS WILL GENERALLY PERSIST THRU THE AFTERNOON AND INTO THE EVENING. ANOTHER BOUNDARY (COLD FRONT) WILL MOVE THRU THE FORECAST AREA BEGINNING EARLY TONIGHT AND SHOULD BE PUSHED OFF THE COAST BY THU MORNING. MODELS SUGGEST THAT AREAS OF LOW PRESSURE WILL FORM ALONG THE FRONT AS IT MOVES THRU THE REGION AND THIS WILL HELP TO ENHANCE CHANCE OF HEAVY RAIN OR ISOLD TSTMS FOR THE OVERNIGHT PERIOD. EXPECT MOSTLY MVFR CONDITIONS WITH TEMPO IFR THRU THE OVERNIGHT. HIGH PRESSURE WILL BUILD IN LATE THU AND WILL SETTLE OVER THE AREA THU NIGHT INTO FRI. VFR AND DRY CONDITIONS WILL PREVAIL THRU THE WEEKEND. && .MARINE... HAVE EXTENDED THE SCA HEADLINE FOR ALL THE WTRS THRU LATE THU NGT...AS NNW WNDS (CAA) WILL CONTINUE AT 15 TO 25 KT AND WAVES/SEAS WILL STAY UP. SE OR S WNDS 10 KT OR LESS ERLY THIS MORNG...WILL BECOME SW AND INCRS TO 15 TO 20 KT THIS AFTN IN ADVANCE OF COLD FRNT. CUD BE GUSTS TO 25 KT. WNDS WILL SHIFT TO THE NW OR N THIS EVENG INTO ERLY THU MORNG BEHIND THE FRNT. THIS CAA SURGE WILL THEN CONTINUE FOR THE REMAINDER OF THU AND THU NGT. MORE BENIGN MARINE CONDITIONS THEN EXPECTED FRI INTO SUN...AS HI PRES BLDS OVR THE WTRS FM THE W. && .CLIMATE... RECORD HIGH TEMPS FOR NOV 16TH (WED): RIC...85 IN 1955 ORF...83 IN 1955 SBY...78 IN 1928 ECG...85 IN 1993 && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ630>634-650- 652-654-656-658. && $$ SYNOPSIS...MAS NEAR TERM...LKB SHORT TERM...LKB/MAS LONG TERM...BMD AVIATION...JEF MARINE...TMG CLIMATE...
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
1145 AM EST WED NOV 16 2011 .SYNOPSIS... A WEAK STATIONARY FRONT WILL REMAIN OVER THE NORTHERN MID ATLANTIC REGION THIS AFTERNOON AS A COLD FRONT APPROACHES FROM THE WEST. THE COLD FRONT PASSES THROUGH TONIGHT...WITH HIGH PRESSURE RETURNING LATE THURSDAY AND INTO THE WEEKEND. ANOTHER COLD FRONT APPROACHES SUNDAY NIGHT INTO MONDAY. && .NEAR TERM /UNTIL MIDNIGHT/... WEAK STATIONARY FRONT IS SITUATED WSW TO ENE ACRS THE CWA...FROM ABOUT FARMVILLE TO ASHLAND INTO THE MD EASTERN SHORE. STRONG TEMPERATURE GRADIENT IN PLACE...AS WELL AS PRECIPITATION CHANCES OVER THE NEXT FEW HRS. WILL CARRY CAT POPS N/NW ZONES THIS AFTN...TAPERED TO JUST 20% OVER FAR SE VA/ NE NC. HAVE ADJUSTED HIGHS A BIT TO SHARPEN THE GRADIENT AS IT WILL TEND TO STAY IN THE 60S OVER THE MD EASTERN SHORE AND TO THE NW OF RICHMOND...WHILE HIGHS AROUND 80 CAN BE EXPECTED IN A FEW SPOTS IN THE SE. WHILE A CHANCE OF THUNDERSTORMS REMAINS IN THE FORECAST FOR THIS AFTN...THINK THAT BEST CHANCE FOR SEVERE WX WILL NOT ARRIVE UNTIL THE EVENING HRS...PRIMARILY ACRS SE VA/NE NC. DOWN THAT WAY IS WHERE BEST COMBINATION OF MODEST SFC-BASED INSTABILITY (~500 J/KG) WILL CO- EXIST WITH HIGH SHEAR (0-6 KM BULK SHEAR 60 KT+) . MAIN THREAT WOULD BE DAMAGING WINDS (>40 KT OF 0-3 KM SHEAR AND DCAPE>1000 J/KG). ALSO...SOME STORMS MAY EXHIBIT ROTATION AS RUC AND NAM BOTH PROG 0-1 KM HELICITIES>300 M2/S2 AS THE BOUNDARY DROPS THROUGH BETWEEN 02-06Z. MAIN LIMITING FACTOR MAY BE LACK OF INSTABILITY DUE TO THE TIMEFRAME BEING AFTER SUNSET ALTHOUGH SFC TEMPS WILL LIKELY BE AROUND 70 F...WITH DEW PTS IN THE 60S. && .SHORT TERM /MIDNIGHT THROUGH FRIDAY/... BEST PROBABILITY FOR RAIN (CATEGORICAL POPS) COMES TONIGHT DUE TO A COMBO OF ISENTROPIC LIFT AND STRONG LOW/MID LEVEL CONVERGENCE ASSOCIATED W/ COLD FRONT. RAIN WILL BE HEAVY AT TIMES AND SOME AREAS MAY RECEIVE OVER AN INCH TOTAL W/ THIS SYSTEM (ESP N PART OF FA). NO SIGNIFICANT FLOODING IS ANTICIPATED ATTM DUE TO FLASH FLOOD GUIDANCE BEING HIGH. THU...BOTH THE NAM AND THE GFS CONTINUE TO SHOW THE MID/UPPER LEVEL TROUGH NOT CROSSING THE REGION UNTIL AFTER 18Z. COMBINED WITH A NNE FLOW IN THE LOW LEVELS AND THE RRQ OF THE UPPER JET...RAIN WILL BE SLOW TO TAPER OFF AND HAVE BUMPED POPS TO CATEGORICAL FOR ALL ZONES THROUGH THE MORNING/EARLY AFTN HRS. SHARPLY COLDER AIRMASS WILL BE IN PLACE AS WELL...MAKING FOR A RAW AND CHILLY DAY WITH TEMPERATURES MAINLY IN THE 40S (AFTER EARLY AM HIGHS IN THE 50S). DECREASING CLOUDS FROM W TO E LATE (SO THAT COASTAL ZONES MAY STAY CLOUDY ALL DAY). DIMINISHING WINDS AND CLEARING SKIES WILL ALLOW FOR MINS INTO THE UPPER 20S WEST OF I-95 THU NIGHT...30-35 FARTHER EAST. STRONG HIGH PRESSURE BUILDS OVER THE MID ATLANTIC FRI LEADING TO DRY WX AND SUNNY SKIES. TEMPS WILL ONLY MAX OUT IN THE U40S-L50S. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... LONG RANGE MODELS ARE IN GOOD AGREEMENT WITH SHOWING A SOUTHWEST UPPER LEVEL FLOW DEVELOPING SATURDAY AS HIGH PRESSURE BECOMES ANCHORED OVER THE MID ATLANTIC STATES THROUGH SUNDAY. SOME CLOUDINESS IS POSSIBLE IN NORTHEAST NC AND EXTREME SOUTHEAST VA ON SATURDAY AS TROPICAL MOISTURE ROTATES AROUND A MID-LEVEL HIGH OFF THE SOUTHEAST U.S. COAST AND MOVES NEAR THIS AREA. OTHERWISE...A DRYING AND WARMING TREND IS ANTICIPATED UNDER THIS FLOW REGIME...WITH HIGH TEMPS REBOUNDING BACK INTO THE 60S BY SUNDAY. LOWS SHOULD BE NEAR FREEZING SATURDAY MORNING DUE TO PRIME COOLING CONDITIONS UNDER MOSTLY CLEAR SKIES WITH VERY LIGHT WINDS...THEN REBOUND TOWARD THE LOW 50S BY EARLY NEXT WEEK AS CLOUDS INCREASE AHEAD OF THE NEXT WEATHER DISTURBANCE. BY LATE SUNDAY...A WEAK COLD FRONT IS EXPECTED TO SAG SOUTHWARD AND STALL OVER THE MID ATLANTIC REGION THROUGH TUESDAY. 12Z MODEL RUNS TODAY ARE HINTING AT SLOWING THE SOUTHERN MOVEMENT OF THIS BOUNDARY UNTIL LATE MONDAY...WHICH WOULD DELAY THE ONSET OF PRECIPITATION UNTIL THAT TIMEFRAME. HAVE TRENDED THE ONGOING FORECAST TOWARD SLOWING THE PASSAGE OF THE FRONT UNTIL LATE MONDAY...WITH PRECIPITATION BEING INTRODUCED LATE SUNDAY/EARLY MONDAY. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... COLD FRNT WILL APPROACH THE AREA THRU THIS MORNG...THEN DROP ACRS THE REGION THIS AFTN THRU TNGT. CIGS/VSBYS WILL QUICKLY LWR TO MVFR THEN IFR (LIFR?) DURING THIS MORNG WITH -DZ OR SCTD -SHRAS MOVNG INTO NRN AND WRN AREAS. CIGS/VSBYS WILL LIKELY LIFT TO MVFR AND VFR CONDITIONS LATER THIS MORNG AND AFTN...AS SW WNDS INCRS IN ADVANCE OF FRNT...WITH ISLTD TO SCTD SHRAS AHEAD OF AND ALNG THE FRNTL BNDRY INTO THIS EVENG. DURING THIS EVENG INTO THU MORNG...IFR (LIFR?) CONDITIONS WITH -RA EXPECTED BEHIND THE FRNT. VFR AND DRY CONDITIONS WILL RETURN THU AFTN THRU SUN. && .MARINE... HAVE EXTENDED THE SCA HEADLINE FOR ALL THE WTRS THRU LATE THU NGT...AS NNW WNDS (CAA) WILL CONTINUE AT 15 TO 25 KT AND WAVES/SEAS WILL STAY UP. SE OR S WNDS 10 KT OR LESS ERLY THIS MORNG...WILL BECOME SW AND INCRS TO 15 TO 20 KT THIS AFTN IN ADVANCE OF COLD FRNT. CUD BE GUSTS TO 25 KT. WNDS WILL SHIFT TO THE NW OR N THIS EVENG INTO ERLY THU MORNG BEHIND THE FRNT. THIS CAA SURGE WILL THEN CONTINUE FOR THE REMAINDER OF THU AND THU NGT. MORE BENIGN MARINE CONDITIONS THEN EXPECTED FRI INTO SUN...AS HI PRES BLDS OVR THE WTRS FM THE W. && .CLIMATE... RECORD HIGH TEMPS FOR NOV 16TH (WED): RIC...85 IN 1955 ORF...83 IN 1955 SBY...78 IN 1928 ECG...85 IN 1993 && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ630>634-650- 652-654-656-658. && $$ SYNOPSIS...MAS NEAR TERM...LKB SHORT TERM...LKB/MAS LONG TERM...BMD AVIATION...TMG MARINE...TMG CLIMATE...AKQ
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
422 PM EST WED NOV 16 2011 .SHORT TERM /TONIGHT AND THURSDAY/... POTENT SHORTWAVE THAT MOVED THROUGH THE CWA LAST NIGHT WILL CONTINUE NE THROUGH QUEBEC TONIGHT...LEAVING THE AREA UNDER AN UPPER TROUGH FOR MUCH OF THE SHORT TERM PERIOD. LOW/MID LVL MOISTURE BEHIND THE WAVE HAS SETTLED OVER THE NE HALF OF THE CWA TODAY AND IS EXPECTED TO REMAIN THROUGH THE FIRST HALF OF THURS. THIS HAS AIDED SOME SHOWER DEVELOPMENT OVER THE ERN LK THROUGH THE DAY. THESE BANDS HAVE A NW TO SE APPEARANCE DUE TO THE NW WINDS ALOFT...BUT THE LLVL WINDS W TO WNW WINDS HAVE BEEN GRADUALLY PUSHING THEM E. DRIER LLVL AIR OVER WRN LK SUPERIOR HAS TRIED TO LIMIT LES EXTENT OVER THE WRN U.P...BUT AN ADDITIONAL AREA OF LOW/MID LVL MOISTURE OVER NRN MN /PRODUCING SCATTERED SHSN/ SHOULD BEGIN TO MOVE INTO THE AREA THIS EVENING. WITH THE AREA BETWEEN THE HIGH TO THE SW AND THE EXITING LOW IN QUEBEC...EXPECT WNW FLOW TO CONTINUE THROUGH THURS. A LINGERING TROUGH FROM THE EXITING LOW OVER ERN LK SUPERIOR FOR TONIGHT INTO THURSDAY WILL HELP TO FOCUS WINDS A LITTLE MORE OUT OF THE NW OVER NRN LUCE AND FAR ERN ALGER COUNTY AND INCREASE THE LLVL CONVERGENCE IN THAT AREA. RUC ANALYSIS OF H850 TEMPS SHOWS VALUES RANGING FROM -11C OVER WRN LK SUPERIOR TO -8C OVER ERN LK SUPERIOR. THESE TEMPS SHOULD FALL A COUPLE DEGREES BY 12Z THURS WITH THE SECONDARY SURGE OF COLD AIR BEHIND A WEAK H850 TROUGH AND REMAIN THROUGH THE DAY THURS. THIS CREATES DELTA-T VALUES IN THE UPPER TEENS ACROSS THE LK THROUGH THE PERIOD. OVER THE W...PARAMETERS HAVE REALLY COME TOGETHER FOR MODERATE TO POTENTIALLY HEAVY LES TONIGHT INTO TOMORROW MORNING. WITH THE SLIGHTLY COLDER H850 TEMPS THERE...EXPECT MUCH OF THE LK INDUCED FORCING TO BE RIGHT IN THE DGZ. MODELS STILL HINTING AT LLVL DRY AIR OVER THE WRN CWA KEEPING CLOUD BASES NEAR 3KFT THROUGH THIS EVENING...WHICH WILL LIMIT THE DEPTH OF THE CLOUD WITH EQL VALUES FROM 7-10KFT. BUT H925-850 MOISTURE CURRENTLY LOCATED OVER NRN MN SHOULD PUSH OVER WRN LK SUPERIOR AND THE WRN CWA OVERNIGHT TONIGHT AND INTO TOMORROW MORNING. THIS SHOULD PROVIDED ADDITIONAL LLVL MOISTURE TO REALLY ENHANCE THE LES IN THE WNW FAVORED LOCATIONS. LES PARAMETER IS SHOWING THIS WELL...WITH A DIMINISHING TREND LATE THIS AFTN AND INTO THE EVENING...BEFORE GREATLY INCREASING OVERNIGHT AND INTO THURS MORNING. BIGGEST CONCERN IS THE WHAT THE EQL WILL BE. BUFKIT SOUNDINGS DO HAVE SOME VARIABILITY ON IF THE EQL/S WILL RISE TOWARDS 12-15KFT OVERNIGHT INTO THURS MORNING...WHICH DEPENDS ON A DEGREE F OR TWO DIFFERENCE IN THE LK TEMPS. IF THAT OCCURS...COULD SEE SNOW AMOUNTS BEING HIGHER THAN EXPECTED. FELT THE CURRENT FORECAST WAS ON TRACK WITH HIGH END ADVISORY AMOUNTS WHERE THERE WILL LIKELY BE ENHANCED CONVERGENCE OVER NRN ONTONAGON AND CENTRAL HOUGHTON COUNTIES. THE EVENING SHIFT WILL NEED TO MONITOR TRENDS AND IF THE SNOW BECOMES HEAVY EARLIER THAN EXPECTED...MAY NEED TO BUMP UP THE ADVY TO A WARNING. OVER THE E...WITH THE DEEPER MOISTURE AND EQL NEAR 15KFT FROM THE EXITING WAVE...LES PARAMETERS ARE MUCH BETTER IN THIS AREA AND SHOWING POTENTIAL FOR MODERATE TO HEAVY SNOW. THERE POTENTIALLY TWO LIMITING FACTORS ON SNOW AMOUNTS REACHING WARNING CRITERIA. FIRST...PREVIOUS SHIFT MENTIONED THE POTENTIAL FOR SNOW PELLETS OR GRAUPEL AT TIMES TONIGHT...WHICH SEEMS REASONABLE THIS EVENING WITH THE SLIGHTLY WARMER H850 TEMPS KEEPING THE BEST OMEGA BELOW THE DGZ. BUT...AS TEMPS COOL OVERNIGHT BEHIND THE H850 TROUGH...EXPECT A TRANSITION TO MAINLY SNOW. SECOND...THE WIND DIRECTION REMAINS A CONCERN FOR TONIGHT. WITH NW WINDS SHIFTING MORE WRLY THROUGH THE DAY TODAY...THE MAIN PCPN HAS BEEN RUNNING NEARLY PARALLEL TO SHORE THIS AFTN. MODELS SHOW A SLIGHT WNW SHIFT TO THE H925 WINDS THIS EVENING...BUT NOT SURE IF THIS WILL BE ENOUGH TO SLIDE THE DOMINATE BAND ONSHORE FROM GRAND MARAIS EAST ALONG THE LUCE COUNTY SHORELINE. WITH THE GEM/ECMWF/GFS AND LOCAL WRF SHOWING THE LINGERING SFC TROUGH TIGHTENING UP OVER THE FAR ERN LK OVERNIGHT TONIGHT AND DROPPING SE THURS MORNING...EXPECT THIS TO SHIFT THE WINDS NW ENOUGH TO PUSH THE DOMINATE BAND INTO LUCE COUNTY. THUS...WITH MODERATE/HEAVY SNOW...ALONG WITH GUSTY WINDS UP TO 30MPH...HAVE SWITCHED THE LES WATCH OVER TO A WARNING FOR LUCE. WITH THE UNCERTAINTY ON THE EXACT LOCATION OF THE BAND FOR THE GRAND MARAIS AREA OF ALGER...HAVE SWITCHED THAT WATCH OVER TO AN LES ADVY...BUT THERE REMAINS SOME BUST POTENTIAL BOTH WAYS. EXPECT THIS PERIOD OF HEAVY SNOW TO CONTINUE THROUGH THURS MORNING UNDER THE NW WINDS. CURRENT FORECAST HAS SNOWFALL AMOUNTS EXCEEDING A FOOT FOR PORTIONS OF NRN LUCE COUNTY BY 00Z FRI. DRIER MID LVL AIR BEGINS TO MOVE OVER THE SW HALF OF THE CWA THURS AFTN...LOWERING THE EQL/S TOWARDS 5-6KFT BY 00Z FRI. THIS WILL DIMINISH THE INTENSITY OF THE SHOWERS OVER THE W. OVER THE E...THESE LESS FAVORABLE LES CONDITIONS DON/T ARRIVE UNTIL LATE THURS AFTN AND INTO THURS EVENING AND HAVE ENDED THE WARNING AT 00Z. .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/... THE SFC MAP AT 00Z STRONG HIGH PRESSURE ACROSS THE TN VALLEY WILL EXTEND A RIDGE ACROSS WI AND WESTERN LAKE SUPERIOR...WITH A WEAK SFC TROUGH EXTENDING FROM THE MAIN LOW OVER FAR EASTERN CANADA TO JUST EAST OF LAKE SUPERIOR. THIS WILL ALLOW THE FOCUS FOR HEAVIER SNOW TO DIMINISH ACROSS LAKE SUPERIOR...WITH NW WINDS BECOMING MORE AND MORE WESTERLY AS THE EVENING PROGRESSES. THE HIGH AMPLITUDE 500MB RIDGE OVER THE PACIFIC NORTHWEST AND WESTERN CANADA WILL FLATTEN AS IT SLIDES ACROSS THE NORTHERN PLAINS AND SOUTHERN MANITOBA BY 00Z FRIDAY. IT WILL STILL BE ENOUGH TO AT LEAST TEMPORARILY SWEEP THE TROUGHS EAST OF THE AREA THURSDAY NIGHT THROUGH THE START OF THE WEEKEND. HOWEVER...THE MAIN CULPRIT WILL BUDGE LITTLE OVER THE SECOND HALF OF THE WORK WEEK...THAT BEING THE 500MB LOW SPINNING NEAR HUDSON BAY. THE FAST SOUTHWESTERLY FLOW WILL RETURN...WITH THE APEX OF THE RIDGE EXITING THE UPPER GREAT LAKES FRIDAY AFTERNOON/EVENING. ONE TROUGH OVER NORTHERN MANITOBA AT 00Z SATURDAY SHOULD CROSS ONTARIO SATURDAY AFTERNOON/EVENING. BEHIND THIS FEATURE A MORE DISTINCT TROUGH WILL WASH OUT ALONG THE CANADIAN/U.S. BORDER...WITH A BROAD TROUGH EXPECTED ACROSS LAKE SUPERIOR AND UPPER MI SATURDAY EVENING THROUGH NEXT TUESDAY NIGHT. THE RESULT AT THE SFC WILL BE THE WEAKENING OF THE 995MB SFC LOW CENTERED ACROSS SOUTHERN SASKATCHEWAN AT 00Z FRIDAY...TO 1003MB BY 00Z SATURDAY JUST NW OF LAKE SUPERIOR. EVEN WITH THE WEAKENING OF THIS SYSTEM THE TIGHTENING PRESSURE GRADIENT WILL RESULT IN STRONGER SW WINDS AT THE SFC FRIDAY INTO EARLY FRIDAY EVENING...MAINLY ACROSS THE EASTERN HALF OF THE CWA. THE RESULT WILL BE A TROUGH OF LOW PRESSURE AT THE SFC EXTENDING BETWEEN 2 STRONGER LOW OVER HUDSON BAY AND KANSAS AT 12Z SATURDAY OVER THE EAST HALF. LOOK FOR A LOW TO PUSH NORTHEASTWARD ALONG THIS TROUGH FROM THE CENTRAL TO SOUTHERN PLAINS. MODELS CONTINUE TO PLAY THE LOW TRACKING NEAR THE STRAITS AROUND 06Z SUNDAY...WITH THE NAM FARTHEST NORTH...AND THE ECMWF ON THE SOUTHERN END OF THE FORECAST ENVELOP. THE CANADIAN LOOKS TO BE ABOUT 6 HOURS SLOW. MODERATE TO HEAVY SNOW ACCUMULATIONS REMAIN POSSIBLE OVER THE WESTERN HALF OF UPPER MI UNTIL HIGH PRESSURE BUILDS IN FROM THE WEST SUNDAY AFTERNOON. LOOKING A BIT FARTHER OUT...THERE ARE A COUPLE OF 500MB WAVES WITHIN THE BROAD TROUGH /WESTERLY FLOW/ THAT ARE DIFFICULT TO FORECAST. THE FIRST WAVE FOR MONDAY IS MORE DISTINCT OFF THE 16/12Z RUN OF THE GFS...BUT IS SIMILAR TIMING WISE...BUT IS MUCH WEAKER THAN WHAT IS SHOWN OFF THE 16/00Z ECMWF. THE CANADIAN IS OUT OF PHASE WITH THE GFS AND ECMWF STARTING AROUND 12Z MONDAY...OR ABOUT 6 HOURS SLOWER. A SIMILAR TREND WAS NOTED WITH THE TUESDAY AFTERNOON/EVENING WEAK TROUGH...WHERE THE GFS TIGHTENED UP THE TROUGH A BIT MORE THAN THE ECMWF. FORECAST MODELS ARE ABOVE NORMAL CONSISTENCY WISE FOR NEXT WEDNESDAY...WITH A LARGE 500MB RIDGE BUILDING IN FROM THE PLAINS STATES. && .AVIATION /FOR THE 18Z TAF ISSUANCE/... COLD AIR MOVING ACROSS LAKE SUPERIOR WILL PRODUCE CLOUDS AND LAKE EFFECT SNOW FOR THE WEST TO NORTHWEST WIND SNOW BELTS FOR THE TAF PERIOD. THIS WILL LARGELY AFFECT KCMX WITH PERIODS OF MVFR CIGS AND IFR VSBYS. WITH KIWD NOT BEING UNDER FAVORABLE FLOW FOR SNOW...HAVE LEFT OUT MENTION...BUT DID KEEP MVFR CIGS FOR THE OVERNIGHT PERIOD FROM MOISTURE CURRENTLY IN NRN MN. KSAW WILL MAINLY SEE VFR CONDITIONS...BUT COULD SEE SOME BRIEF MVFR CIGS LATE TONIGHT INTO TOMORROW MORNING FROM STRONGER LAKE EFFECT SNOW BANDS OVER NORTHERN ONTONAGON COUNTY. && .MARINE /FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE/... LOW PRESSURE ACROSS CENTRAL ONTARIO WILL KEEP A WEAK TROUGH ACROSS EASTERN LS OVERNIGHT...WHICH WILL ASSIST IN FOCUSING THE STRONGER GALE FORCE WINDS OF 35KTS OVER THE EASTERN HALF OF LS THROUGH THIS EVENING. LOOK FOR A RIDGE OF HIGH PRESSURE TO BUILD IN THURSDAY INTO THURSDAY NIGHT...WITH GUSTS CONTINUING 20 TO 30KTS. LOW PRESSURE ACROSS SOUTHERN SASKATCHEWAN THURSDAY NIGHT WILL FILL SLIGHTLY JUST NORTH OF LS FRIDAY NIGHT. AHEAD OF THIS FEATURE...STRONG SW WINDS FRIDAY INTO FRIDAY NIGHT MAY RESULT IN A FEW GALE FORCE GUSTS ACROSS EASTERN LS. EXPECT A NEARLY STATIONARY TROUGH OVER EASTERN LS ON SATURDAY. LOW PRESSURE OVER THE CENTRAL PLAINS SATURDAY WILL MOVE ALONG THE TROUGH...FILLING SLIGHTLY ACROSS NORTHERN LOWER MICHIGAN BY SATURDAY NIGHT...WITH A BRIEF PERIOD OF NE GALES TO 35KT SATURDAY AFTERNOON THAT MAY TRANSITION ACROSS THE ENTIRE LAKE AS WINDS TURN MORE NORTHWESTERLY AS THE LOW EXITS NE. HIGH PRESSURE SHOULD SLIDE IN FROM THE WEST SUNDAY...BEFORE SLOWLY DIPPING TO THE LOWER GREAT LAKES ON MONDAY. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... LAKE EFFECT SNOW ADVISORY UNTIL 5 PM EST THURSDAY FOR MIZ001>003- 084. LAKE EFFECT SNOW WARNING FROM 10 PM THIS EVENING TO 7 PM EST THURSDAY FOR MIZ007. LAKE EFFECT SNOW ADVISORY FROM 10 PM THIS EVENING TO 5 PM EST THURSDAY FOR MIZ006. LAKE SUPERIOR... GALE WARNING UNTIL 10 PM EST THIS EVENING FOR LSZ248>251-265>267. LAKE MICHIGAN... NONE. && $$ SHORT TERM...SRF LONG TERM...KF AVIATION...SRF MARINE...SRF/SF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1233 PM EST WED NOV 16 2011 UPDATED AVIATION DISCUSSION FOR 18Z TAFS .SYNOPSIS... WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW BROAD CYCLONIC FLOW ACROSS MOST OF THE CONUS WITH AXIS ROUGHLY OVER THE WRN PLAINS. A VIGOROUS LOOKING SHORTWAVE IS TRACKING THRU THE UPPER GREAT LAKES ATTM. LIKE ITS PREDECESSOR 24-30HRS AGO...THIS SYSTEM PRODUCED SOME LIGHTNING STRIKES ACROSS LAKE SUPERIOR EARLIER IN THE NIGHT. THE MORE SIGNIFICANT PCPN WITH WAVE HAS PASSED MOSTLY N OF UPPER MI... JUST N OF THE VORT TRACK ACROSS NRN UPPER MI/SRN LAKE SUPERIOR. UPSTREAM...850MB TEMPS RANGE FROM -7C AT KINL TO -10C KBIS AND -12C AT CYQD. WHILE 00Z KBIS SOUNDING SHOWED DRYNESS IN THE BOUNDARY LAYER...KINL AND CQYD SOUNDINGS SHOWED DEEP MOISTURE...ESPECIALLY CYQD. THIS UPSTREAM COMBINATION OF COLD AIR/DEEP MOISTURE SUGGESTS AN ACTIVE LES PERIOD SHOULD BE ON THE WAY OVER THE NEXT 36HRS AS TROF AXIS TO THE W SHIFTS E. && .DISCUSSION... FCST CONCERNS INVOLVE LES LOCATION/INTENSITY AND SNOW ACCUMULATIONS THRU THURSDAY AND THEN POSSIBLE WINTER STORM FOR THE WEEKEND. GIVEN FAVORABLE INSTABILITY/MOISTURE...SOMEWHAT PUZZLED BY THE RELATIVELY LIGHT PCPN INDICATED BY THE NAM/GFS FOR THE LES TODAY THRU THU...BUT THERE MAY BE A REASON. WHILE DEEPER MOISTURE EVIDENT ON CYQD/KINL SOUNDINGS WILL REACH THE AREA...THE FLOW IN THE LOW-LEVELS IS MORE WRLY...WHICH MAY SUPPORT SOMEWHAT DRIER AIR IN THE BOUNDARY LAYER AS SUGGESTED BY THE KBIS SOUNDING. BOTH THE NAM AND GFS HINT AT THAT...BUT THE NAM/GFS SOUNDINGS AREN`T REALLY THAT DRY. WITH DEEP MOISTURE UWPARDS OF 8-10KFT AND DGZ DESCENDING MORE FIRMLY INTO THE CONVECTIVE LAYER UNDER CAA REGIME...HAVE TO BELIEVE LES WILL BE MORE SIGNIFICANT THAN THE NAM/GFS INDICATE. REGIONAL GEM IS MUCH MORE AGGRESSIVE WITH PCPN AMOUNTS. WHILE THE NAM HAS 12Z WED-00Z FRI PCPN AMOUNTS UP TO 0.4 INCHES NW TO 0.5 INCHES ALONG SHORE E OF MUNISING...THE REGIONAL GEM IS UPWARDS OF 0.8 INCHES NW TO OVER 2 INCHES E OF MUNISING. SOMETHING BTWN THE TWO EXTREMES IS PROBABLY REASONABLE...THOUGH THE REGIONAL GEM LOOKS QUITE EXCESSIVE OVER THE E. AT THIS POINT...WILL KEEP 12-24HR SNOW AMOUNTS JUST UNDER LES WARNING THRESHOLDS NW DUE TO UNCERTAINTY IN BOUNDARY LAYER MOISTURE. WITH LOW-LEVEL WINDS ESSENTIALLY W...LES WILL TARGET AREAS FROM ONTONAGON COUNTY THRU THE KEWEENAW. TO THE E...SLIGHT VEERING OF WINDS HIGHER IN THE CONVECTIVE LAYER SHOULD TEND TO FOCUS THE SRN LES BAND ALONG TO JUST INLAND FROM THE SHORE FROM PICTURED ROCKS EASTWARD. TYPICALLY...THE SRN MOST BAND YIELDS HEAVIEST SNOW RATES DUE TO LAND BREEZE CONVERGENCE AND THE OVERALL LONG FETCH ACROSS THE LAKE...ONLY INTERRUPTED BRIEFLY BY THE KEWEENAW. THUS...POTENTIAL EXISTS FOR VERY IMPRESSIVE SNOW ACCUMULATIONS OVER A SMALL AREA OF THE E CLOSE TO LAKE SUPERIOR...PROVIDED LES BAND DOES NOT SHIFT OFFSHORE FREQUENTLY. ALSO...DEEP/VIGOROUS CONVECTION AND RELATIVELY WARM EARLY SEASON WATER/BOUNDARY LAYER MAY LEAD TO MORE GRAUPEL/SNOW PELLET TYPE PCPN RATHER THAN LARGE SNOWFLAKES...WHICH WILL REDUCE SNOW ACCUMULATIONS OVER WHAT COULD BE EXPECTED. HAVE OPTED TO ISSUE A LAKE EFFECT SNOW WATCH FOR ALGER/LUCE...EMPHASIZING THE AREAS FROM AROUND GRAND MARAIS EASTWARD. AWAY FROM LES...DRY WEATHER WILL GENERALLY PREVAIL THRU THU. LES WILL WIND DOWN/END LATER THU/THU NIGHT AS MID/UPPER TROF SHIFTS E OF THE AREA AND FLOW BEGINS TO BACK IN ADVANCE OF TROF AMPLIFICATION OVER THE WRN CONUS. LEAD WAVE AHEAD OF THE WRN TROF AMPLIFICATION COMBINED WITH STRONG WAA COULD LEAD TO SOME LIGHT PCPN LATER THU NIGHT/FRI MORNING. LACK OF MOISTURE MAY RESULT IN PCPN OCCURRING FARTHER N IN THE COLDER AIR WHERE SATURATION THRU THE COLUMN CAN OCCUR. SHORTWAVE WILL LIFT OUT OF THE WRN TROF EARLY IN THE WEEKEND. FOR SEVERAL DAYS...MODELS HAVE SHOWN UNUSUALLY GOOD CONTINUITY ON SFC LOW TRACK DESPITE BEING WAY OUT IN THE FCST CYCLE. THERE HAVE BEEN THE EXPECTED INTENSITY/PLACEMENT ISSUES...BUT THEY WERE MINOR WHEN CONSIDERING THE TIME RANGE INTO THE FCST RUN. FOR 90 TO 108HRS INTO THE MODEL RUN...TODAYS 00Z ROUND OF MEDIUM RANGE GUIDANCE REMAINS WELL CLUSTERED ON A LOW TRACK FROM KS TO THE UPPER GREAT LAKES... SOMEWHERE BTWN CNTRL UPPER MI AND FAR NRN LWR MI/STRAITS AREA. ALL SUGGEST A HEADLINE SNOW EVENT FOR SOME PART OF THE FCST AREA... PROBABLY HIGH END ADVY TYPE. THE WRN MOST LOW TRACK (GFS) WOULD PROVIDE HEAVIEST SNOW OVER NW UPPER MI WHILE THE ERN TRACKS (GLOBAL GEM/ECMWF) WOULD SPREAD HEAVIEST SNOW OVER MOSTLY THE CNTRL PORTION OF UPPER MI. && .AVIATION /FOR THE 18Z TAF ISSUANCE/... COLD AIR MOVING ACROSS LAKE SUPERIOR WILL PRODUCE CLOUDS AND LAKE EFFECT SNOW FOR THE WEST TO NORTHWEST WIND SNOW BELTS FOR THE TAF PERIOD. THIS WILL LARGELY AFFECT KCMX WITH PERIODS OF MVFR CIGS AND IFR VSBYS. WITH KIWD NOT BEING UNDER FAVORABLE FLOW FOR SNOW...HAVE LEFT OUT MENTION...BUT DID KEEP MVFR CIGS FOR THE OVERNIGHT PERIOD FROM MOISTURE CURRENTLY IN NRN MN. KSAW WILL MAINLY SEE VFR CONDITIONS...BUT COULD SEE SOME BRIEF MVFR CIGS LATE TONIGHT INTO TOMORROW MORNING FROM STRONGER LAKE EFFECT SNOW BANDS OVER NORTHERN ONTONAGON COUNTY. && .MARINE /FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE/... EXPECT WESTERLY GALES TO DIMINISH BY THIS EVENING OVR LK SUPERIOR AS SFC LOW JUST EAST OF LK SUPERIOR HEADS INTO QUEBEC. WINDS REMAIN OUT OF THE W/NW UP TO 30 KTS THURSDAY INTO THURSDAY NIGHT...THEN BECOME MORE SOUTHERLY ON FRIDAY AS LOW PRESSURE SYSTEM PASSES TO NORTH OF LK SUPERIOR. COULD BE MARGINAL SRLY GALES OVR FAR EASTERN SECTIONS FRIDAY. ACTIVE PATTERN CONTINUES INTO THE UPCOMING WEEKEND AS ANOTHER LOW OVR THE PLAINS ON SATURDAY TRACKS ACROSS THE LAKE SUPERIOR REGION SATURDAY NIGHT. NE WINDS COULD REACH GALE FORCE OVR WESTERN SECTIONS SATURDAY WITH NW GALES THEN POSSIBLE LATE SATURDAY NIGHT INTO SUNDAY MORNING AS THE LOW PULLS AWAY FM THE REGION. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... WINTER WEATHER ADVISORY UNTIL 5 PM EST THURSDAY FOR MIZ001>003- 084. LAKE EFFECT SNOW WATCH FROM 7 PM EST THIS EVENING THROUGH THURSDAY AFTERNOON FOR MIZ006-007. LAKE SUPERIOR... GALE WARNING UNTIL 10 PM EST THIS EVENING FOR LSZ248>251-265>267. GALE WARNING UNTIL 1 PM EST /NOON CST/ THIS AFTERNOON FOR LSZ162- 244-245. GALE WARNING UNTIL 4 PM EST /3 PM CST/ THIS AFTERNOON FOR LSZ241>243-263-264. LAKE MICHIGAN... NONE. && $$ SYNOPSIS...ROLFSON DISCUSSION...ROLFSON AVIATION...SRF MARINE...JLA
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
303 PM CST WED NOV 16 2011 .DISCUSSION... VERY COLD UPPER TROUGH SWINGING THROUGH THE AREA NOW. H5 TEMPS AROUND -40 THIS MORNING ABR TO GGW. VERY DRY AIR WITH SINGLE DIGIT DEW POINTS CURRENTLY OVER OUR SOUTHERN CWA. WILL NEED TO LOWER MIN TEMPS A BIT TONIGHT. IT DOES LOOK LIKE THERE IS A BACK EDGE TO THE COLD AIR CU/SC OVER EASTERN ND WITH MUCH OF THE CLOUD DECK OVER OUR AREA MAINLY CUFORM. THE TREND TOWARD CLEARING LOOKS GOOD THIS EVENING GIVING A GOOD START TO THE COLD OVERNIGHT MINS. LOOKS LIKE A COLD DAY FOR THURSDAY..BUT UNDER SUNNY SKIES DUE TO VERY DRY AIR OVER THE AREA. ATTENTION THEN TURNS TO THE SYSTEM FOR FRIDAY. SOME DECENT MODERATION AHEAD OF THE NORTHERN STREAM WAVE AND FRONT CROSSING THE AREA THURSDAY NIGHT AND FRIDAY. THIS SHOULD ALLOW RECOVERY TO TEMPS NEAR 50 OVER SOUTHERN MN ON FRIDAY. THE COLD FRONT SHOULD MOVE THROUGH THE AREAS FRIDAY NIGHT AND THEN STALL JUST TO OUR SOUTH. A TIGHT TEMP GRADIENT WILL SET UP ACROSS THE AREA ON SATURDAY. THERE HAS BEEN GENERAL CONSISTENCY IN FOCUSING THE BEST FORCING ACROSS CENTRAL MN INTO THE NORTHERN PART OF OUR WI AREA. THIS TREND CONTINUING AT LEAST WITH THE GFS AND ECMWF. THE NAM SEEMS A LITTLE TOO FAR TO THE NORTHWEST. WITH A SNOW COVER NOW DEVELOPING ACROSS CANADA INTO ND AND PARTS OF N MN...IT WILL BE INTERESTING TO SEE HOW FAR SOUTH THE FRONT ENDS UP LATE FRIDAY AND FRIDAY NIGHT. THE COLD LOW LEVEL TEMP STRUCTURE COULD BE PROBLEMATIC WITH PTYPE..WITH THE OUTSIDE CHANCE OF FZRA IN A FEW AREAS OF THE SOUTH. WILL NOT TRY TO PIN THAT DOWN AT THIS POINT...BUT KEEP THE ZONE OF RASN. HAVE BROUGHT SOME SNOW POTENTIAL A LITTLE FARTHER SOUTH BUT THE NORTH HALF OF THE CWA STILL SEEMS TO HAVE THE BEST CHANCE. THE SREF PROBS OB THE BEST DENDRITIC ZONE IS IN NORTHERN MN BUT THIS IS OUT AT THE LAST FEW TIME STEPS OF THE RUN. IT DOES LOOK LIKE AN FGEN DRIVEN EVENT WITH THE OPEN WAVE...SO THERE WILL BE POTENTIAL FOR A SHARP CUT OFF TO PRECIP. AFTER A COLD PERIOD FOLLOWING THE SYSTEM..IT LOOKS LIKE WE WILL BE BACK TO A MAINLY MILD PATTERN WITH THE DEEP MEAN TROUGH OVER AK. THE LATEST NAEFS IS SHOWING A LARGE AREA OF PROBS OF ABOVE NORMAL TEMPS IN THE EASTERN HALF OF THE COUNTRY..EAST OF THE MO RIVER. && .AVIATION.../18Z TAF ISSUANCE/ MVFR CIGS HAVE DEVELOPED ALONG THE LEADING EDGE OF DEEPER MOISTURE MOVING ACROSS WC MN...AND CENTRAL MN. MOST OF THE CLDS ARE ASSOCIATED WITH A DIURNAL TREND WHICH SHOULD ABATE AFT SUNSET. HOWEVER...THICKER CLD CVR ACROSS SC ND...AND INTO NE SD MAY ALLOW FOR THE CLDS TO LINGER INTO THE EVENING. THIS IS THE MAIN AVIATION CONCERN IN THE SHORT TERM...WITH THE COMMON DIURNAL TREND OF THE GUSTY W/NW WNDS THIS AFTN. BASED ON UPSTREAM OBS IN SD/ND AND ACROSS PORTIONS OF WC/C MN...WILL CONTINUE THE HIGH END MVFR CIGS FOR AXN...AND POSSIBLY STC IF CONDITIONS WARRANT. MOST OF THE OTHER MPX TAF SITES WILL REMAIN VFR OR AT LEAST HAVE CIGS ABV 3K. SOME -SN HAS DEVELOPED IN THE PORTIONS OF SC/SE ND WHERE DEEPER MOISTURE AND ASSOCIATED DENDRITIC ZONE HAS ALLOWED FOR -SN...BUT COVERAGE WILL REMAIN TOO LOW FOR ANY TYPE OF -SN IN THE AFTN TAF. WILL MONITOR IF CONDITIONS BECOME MORE SCATTERED/WIDESPREAD AS THE LATEST RUC IS HINTING ON THIS. WNDS WILL BECOME MORE W/SW OVERNIGHT...THEN SW/S BY THU MORNING. MSP...SCT/BKN CLDS ARND 3-3.5K WILL MOVE ACROSS MSP AIRPORT DURING THE AFTN...BUT WILL CONTINUE WITH VFR CIGS OF 4-5K AT THIS TIME. WNDS CURRENTLY FROM THE SW...BUT IT SHOULD CHG DURING THE AFTN AS MIXING DEVELOPS AND ALLOWS FOR SOME GUSTS UP TO 22 KTS FROM THE WNW. WNDS WILL DECREASE TOWARD SUNSET...THEN BECOME MORE WSW/SW BY MORNING...BUT REMAIN UNDER 8 KTS. OUTLOOK FOR SATURDAY STILL LOOKS FAVORABLE FOR MVFR/IFR CIGS/VSBYS AS A STORM SYSTEM MOVES FROM THE CENTRAL PLAINS/INTO THE UPPER MIDWEST. TIMING AND TRANSITION FROM RA TO SN WILL REMAIN PROBLEMATIC /MAINLY SOUTH OF RWF TO MSP AND RNH/...BUT CURRENT TRENDS INDICATE THAT THE WORSE CONDITIONS WILL BE FROM 18Z/19...TO 06Z/20. OR LATE SATURDAY AFTN...THRU THE EVENING. ..JLT.. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ JPR/JLT
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1126 AM CST WED NOV 16 2011 .DISCUSSION... A COLD WEST-NORTHWEST FLOW OF AIR WILL COVER THE REGION INTO THURSDAY. A SHORT WAVE OVER NORTH DAKOTA WILL PROGRESS TO THE WESTERN GREAT LAKES BY TONIGHT. SOME CLOUDINESS OVER CENTRAL MN AND WEST CENTRAL WI EARLY THIS MORNING WILL PART FOR A TIME BEFORE ANOTHER SURGE OF LOW CLOUDINESS ARRIVES FOR THE AFTERNOON AND EVENING HOURS. OUR LOCAL MODEL AND THE RUC PAINT SOME LIGHT ECHOES ACROSS CENTRAL MN AND WEST CENTRAL WI DURING THE AFTERNOON AND EVENING HOURS...SO KEPT THE MENTION OF FLURRIES TO THESE AREAS. THERE SHOULD BE A GOOD DEAL OF SUNSHINE ACROSS SOUTHERN MN TODAY. THE MIX-DOWN TD TOOL POINTS TO DEW POINT LOWERING TO AROUND 5 DEG C DURING THE AFTERNOON. WE ARE CURRENTLY SEEING SOME SINGLE DIGIT DEW POINTS NEAR THE SD/NE EARLY THIS MORNING. THE ARW/NMM WRFS ALSO INDICATE DINGLE DIGIT DEW POINT IN THE SOUTH THIS AFTERNOON. HENCE...BLENDED IN THE MIX DOWN DPS WITH CONSENSUS FOR THE AFTERNOON AND EVENING HOURS. TRENDED A FEW DEGREES HIGHER ON HIGH TEMPERATURES TODAY OVER THE SOUTHERN HALF OF THE CWA VERSUS MET/MAV MOS DUE TO MORE SUNSHINE AND WHAT THE MIX DOWN MAX T WAS SHOWING. FLURRIES/CLOUDS WILL DIMINISH TONIGHT OVER THE NORTHERN AND EASTERN CWA AS HIGH PRESSURE MOVES IN LATE IN THE NIGHT. THE RIDGE WILL MOVE ACROSS THE CWA ON THURSDAY WITH FLOW BECOMING MORE SOUTHERLY. IT WILL STILL BE A COOL DAY WITH HIGHS ONLY IN THE 30S. AS THE RIDGE MOVES EAST THURSDAY NIGHT...A WARM FRONT WILL DEVELOP AND MOVE NORTHEAST ACROSS THE CWA. ONLY SOME CLOUDS EXPECTED WITH THE WARM FRONT. THIS WILL LEAD TO A WARMER FRIDAY WITH HIGHS REACHING WELL INTO THE 40S IN MOST AREAS WITH SOME 50S IN THE SOUTH. THE LOW PRESSURE SYSTEM AND PRECIPITATION EVENT FOR SATURDAY AND SATURDAY NIGHT REMAINS ON TRACK. THE GEM AND ECMWF ARE IN STEP WITH THIS SYSTEM WHILE THE GFS LAGS BY ABOUT 6 HOURS. THE GFS ENSEMBLE IS EVEN SLOWER BY ABOUT ANOTHER 6 HOURS. STILL EXPECT A LOW TO TRACK FROM EASTERN NEBRASKA SATURDAY MORNING TO EASTERN WI BY SATURDAY NIGHT. ALL SOLUTIONS INDICATE THE LOW SLOWLY FILLING DURING THIS PERIOD WHICH IS NOTE GOOD FOR A HEAVY SNOW EVENT. WE ALSO CONTINUE TO SEE AN OPEN WAVE ALOFT WHICH SPEAKS FOR THE QUICKNESS WITH THIS SYSTEM. LOOKING AT SOME OF THE MID/UPPER LEVEL FEATURES SHOWS THE H5 HEIGHT FALL TRACK FROM YELLOW MEDICINE COUNTY TO BURNETT COUNTY. THE -15 DEG C OMEGA IS ON THE LEFT SIDE OF THIS TRACK WITH THE DEPTH OF THE DENDRITIC GROWTH ZONE BEING ABOUT 1100M. THE WARM POCKET AT H2 ALSO TRACKS ALONG THE AFOREMENTIONED AXIS WITH 10 DEG OF WARMING NOTED. THE 295K THETA SURFACE PLACES 700 MB ABOUT IN THIS GENERAL AREA AS WELL WITH PLENTY OF SATURATION AND ADIABATIC OMEGA NOTED TO THE NORTH AND WEST. THE MIX RATIO CONTINUES TO RUN BETWEEN 2 AND 3 G/KG AND IS ALIGNED WITH THE -FN VECTOR DIVERGENCE. THIS ALL POINTS TO A BAND OF 4 TO LOCALLY 6 INCHES FROM WEST CENTRAL MN ON NORTHEAST TO DULUTH AND HAYWARD. THE CARIBOU SNOW TOOL USING THE GFS AGREES PRETTY WELL WITH THIS SCENARIO. ALSO INTERESTING IS THE 16/00Z CIPS DATA...BASED ON THE TOP 15 ANALOGS...WHICH SHOWS MEAN SNOWFALL OF 4 TO 6 FROM WEST CENTRAL MN THROUGH THE ARROWHEAD AND FAR NORTHERN AREAS OF WI WITH 2 TO 3 INCHES FROM SOUTHWEST MN THROUGH THE METRO AND ACROSS MUCH OF WEST CENTRAL WI. IN THE WAKE OF THE LOW PRESSURE SYSTEM...A RATHER SUBSTANTIAL HIGH WILL BUILD OVER THE REGION FROM SUNDAY THROUGH TUESDAY WITH DRY WEATHER AND BELOW NORMAL TEMPERATURES OCCURRING. && .AVIATION.../18Z TAF ISSUANCE/ MVFR CIGS HAVE DEVELOPED ALONG THE LEADING EDGE OF DEEPER MOISTURE MOVING ACROSS WC MN...AND CENTRAL MN. MOST OF THE CLDS ARE ASSOCIATED WITH A DIURNAL TREND WHICH SHOULD ABATE AFT SUNSET. HOWEVER...THICKER CLD CVR ACROSS SC ND...AND INTO NE SD MAY ALLOW FOR THE CLDS TO LINGER INTO THE EVENING. THIS IS THE MAIN AVIATION CONCERN IN THE SHORT TERM...WITH THE COMMON DIURNAL TREND OF THE GUSTY W/NW WNDS THIS AFTN. BASED ON UPSTREAM OBS IN SD/ND AND ACROSS PORTIONS OF WC/C MN...WILL CONTINUE THE HIGH END MVFR CIGS FOR AXN...AND POSSIBLY STC IF CONDITIONS WARRANT. MOST OF THE OTHER MPX TAF SITES WILL REMAIN VFR OR AT LEAST HAVE CIGS ABV 3K. SOME -SN HAS DEVELOPED IN THE PORTIONS OF SC/SE ND WHERE DEEPER MOISTURE AND ASSOCIATED DENDRITIC ZONE HAS ALLOWED FOR -SN...BUT COVERAGE WILL REMAIN TOO LOW FOR ANY TYPE OF -SN IN THE AFTN TAF. WILL MONITOR IF CONDITIONS BECOME MORE SCATTERED/WIDESPREAD AS THE LATEST RUC IS HINTING ON THIS. WNDS WILL BECOME MORE W/SW OVERNIGHT...THEN SW/S BY THU MORNING. MSP...SCT/BKN CLDS ARND 3-3.5K WILL MOVE ACROSS MSP AIRPORT DURING THE AFTN...BUT WILL CONTINUE WITH VFR CIGS OF 4-5K AT THIS TIME. WNDS CURRENTLY FROM THE SW...BUT IT SHOULD CHG DURING THE AFTN AS MIXING DEVELOPS AND ALLOWS FOR SOME GUSTS UP TO 22 KTS FROM THE WNW. WNDS WILL DECREASE TOWARD SUNSET...THEN BECOME MORE WSW/SW BY MORNING...BUT REMAIN UNDER 8 KTS. OUTLOOK FOR SATURDAY STILL LOOKS FAVORABLE FOR MVFR/IFR CIGS/VSBYS AS A STORM SYSTEM MOVES FROM THE CENTRAL PLAINS/INTO THE UPPER MIDWEST. TIMING AND TRANSITION FROM RA TO SN WILL REMAIN PROBLEMATIC /MAINLY SOUTH OF RWF TO MSP AND RNH/...BUT CURRENT TRENDS INDICATE THAT THE WORSE CONDITIONS WILL BE FROM 18Z/19...TO 06Z/20. OR LATE SATURDAY AFTN...THRU THE EVENING. ..JLT.. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ RAH/JLT
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
318 PM EST WED NOV 16 2011 .SYNOPSIS... A COLD FRONT OVER THE TENNESSEE VALLEY WILL SLIDE EASTWARD BRINGING SHOWERS AND A CHANCE OF THUNDERSTORMS...INCLUDING SEVERE WEATHER...TONIGHT THROUGH THURSDAY MORNING. MUCH COOLER AND DRIER AIR WILL FOLLOW LATE THURSDAY AND FRIDAY. HIGH PRESSURE WILL MOVE OVERHEAD WITH TEMPERATURES MODERATING DURING THE WEEKEND. A SECOND FRONT WILL DROP SOUTH THROUGH THE AREA TUESDAY. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... AS OF 300 PM WEDNESDAY...TROPICAL WARMTH AND HUMIDITY WILL COME TO A CRASHING HALT LATE TONIGHT AS A STRONG COLD FRONT ARRIVES FROM THE WEST. THE TRANSITION FROM A TROPICAL TO AN ARCTIC AIRMASS WILL NOT BE AN EASY ONE...AND SEVERE THUNDERSTORMS APPEAR POSSIBLE ACROSS THE EASTERN CAROLINAS TONIGHT. INSTABILITY PARAMETERS ARE IMPRESSIVE FOR A COOL-SEASON EVENT. ALTHOUGH SURFACE CAPE FALLS AWAY TO A FEW HUNDRED J/KG AFTER DARK WITH 75-100 J/KG OF INHIBITION TO OVERCOME...STARTING TO LIFT A PARCEL FROM AROUND 925 MB YIELDS 600-1500 J/KG OF UNINHIBITED CAPE AIDED BY REASONABLY STEEP MID AND UPPER LEVEL LAPSE RATES. UNLIKE OUR TYPICAL WINTERTIME "SEVERE SHOWER" SCENARIOS THERE COULD ACTUALLY BE DEEP (40+ KFT) CONVECTION TONIGHT. WIND SHEAR PARAMETERS ARE ALSO IMPRESSIVE: 50-60 KT OF 0-6 KM BULK SHEAR...200-300 M^2/S^2 0-3 KM HELICITY...AND 50 KT WIND SPEEDS WITHIN 2500 FEET OF THE GROUND ALL POINT TOWARD ORGANIZED STORMS...PERHAPS EVEN SUPERCELLS...WITH THE POTENTIAL FOR WIND DAMAGE AND TORNADOES. SYNOPTICALLY A 300 MB JET STREAK WILL MOVE EAST THROUGH THE MID-ATLANTIC STATES TONIGHT. THIS WILL PLACE THE EASTERN CAROLINAS WITHIN THE RIGHT-ENTRANCE REGION OF THE JET STREAK AIDING IN DEEP-LAYER LIFT. TIMING-WISE...THE LAST THREE RUNS (15-16-17Z) OF THE HRRR RAPID UPDATE MODEL ALL PLACE THE LEADING EDGE OF THE SQUALL LINE IN WESTERN DARLINGTON COUNTY AT 7 PM...MOVING INTO FLORENCE... DILLON AND LUMBERTON BY 8 PM...AND TO THE COAST BETWEEN 10 PM AND MIDNIGHT. OUR HIGHEST POPS (80-90%) EXTEND FROM FLORENCE...MARION AND MYRTLE BEACH NORTHWARD THROUGH SOUTHEASTERN NORTH CAROLINA. LOWER POPS (50-60%) ARE FORECAST SOUTH INTO THE GEORGETOWN AREA WHERE THIS FIRST BATCH OF CONVECTION MAY BE TOO FAR NORTH FOR IMPACTS. ADDITIONAL SHOWERS AND POSSIBLY THUNDERSTORMS MAY DEVELOP BEHIND THIS FIRST BATCH...ASSOCIATED WITH SUBTLE UPPER DISTURBANCES WORKING ON RESIDUAL ELEVATED INSTABILITY. THIS SECOND BATCH OF CONVECTIVE ACTIVITY COULD CONTINUE UP UNTIL THE TIME OF THE FRONTAL PASSAGE AROUND DAYBREAK THURSDAY. LOW TEMPERATURES TONIGHT WILL BE TRICKY WITH THE SURFACE COLD FRONT LIKELY ARRIVING AROUND 12Z. WE ARE FORECASTING MID 60S ON THE COAST AND 59-63 INLAND...HOWEVER THERE IS SIGNIFICANT BUST POTENTIAL IN EITHER DIRECTION IF THE FRONT IS ONLY A COUPLE HOURS FASTER OR SLOWER THAN IS CURRENTLY FORECAST. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/... AS OF 300 PM WEDNESDAY...CONCERN DURING THE PERIOD REVOLVES AROUND COLD FRONTAL PASSAGE AND ASSOCIATED CONVECTION EARLY THURSDAY...FOLLOWED BY A DRASTIC DROP IN TEMPERATURES WHICH WILL MAKE IT FEEL ONCE AGAIN LIKE EARLY WINTER. STRONG COLD FRONT WILL BE JUST INSIDE WESTERN EDGE OF THE CWA THURSDAY MORNING AND RAPIDLY MOVING EAST. THE UNCERTAINTY WITH STRENGTH OF CONVECTION REVOLVES AROUND THE FACT THAT FROPA IS OCCURRING AT A NON-IDEAL TIME WITH RESPECT TO INSTABILITY. HOWEVER...PARAMETERS DO SUGGEST THAT CONVECTION WILL BE ONGOING AT THE BEGINNING OF THE PERIOD...ESPECIALLY ACROSS THE EASTERN ZONES. RIDGE OF LOW LEVEL THETA-E AIR REMAINS IN PLACE THROUGH THURSDAY MORNING ALONG WITH STEEP MID LEVEL LAPSE RATES AND PWATS NEAR 1.5 INCHES. ADDITIONALLY...SOME PVA NEAR A VORT LOBE TRAILING THROUGH THE EASTERN CAROLINAS...LOCALLY ENHANCED DIFFLUENCE IN THE RIGHT ENTRANCE REGION OF AN EXITING UPPER JET...AND THE COLD FRONT ITSELF WILL HELP FORCE SOME LIFT AND KEEP CONVECTION GOING THROUGH LATE MORNING. 12 HOUR SREF PRECIP PROBS DO NOT DROP BELOW 50 PERCENT UNTIL AFTER 03Z FRIDAY...SO ALTHOUGH THE SEVERE THREAT AFTER SUNRISE THURSDAY APPEARS LIMITED WILL KEEP TSTM MENTION THROUGH LATE MORNING ALONG THE COAST...WITH SOME LIGHT RAIN POSSIBLE UNTIL EARLY AFTN. FROPA OCCURS ACROSS THE ENTIRE CWA BY THE AFTN BRINGING AN END TO PRECIP THROUGH THE REMAINDER OF THE SHORT TERM. DRYING WILL OCCUR BEHIND FRONT AS HIGH PRESSURE BUILDS INTO THE REGION...BUT POST FRONTAL CLOUD COVER/STRATUS WILL EXIST THROUGH MUCH OF THURSDAY BEFORE CLEARING ON FRIDAY. THE HIGHEST TEMPS OF THE PERIOD WILL OCCUR THURSDAY MORNING ALONG AND AHEAD OF THE FRONT...DROPPING RAPIDLY IN THE AFTN AS STRONG CAA DEVELOPS. LARGE BUST POTENTIAL ON MAX TEMPS THURSDAY DEPENDING ON EXACT TIMING OF FROPA...BUT EXPECT TEMPS AROUND 60 INLAND...MID 60S AT THE COAST AT DAYBREAK THURSDAY...THEN FALLING THROUGH THE DAY. MEX/MAV IN AGREEMENT WITH MAX TEMPS FRIDAY IN THE MID 50S...BUT GUIDANCE HAS A TENDENCY TO OVER FORECAST HIGHS THE DAY AFTER A STRONG FROPA. WILL TREND MAXES DOWN TO THE LOW/MID 50S...BUT NOTE THIS MAY STILL BE TOO WARM. MINS EACH NIGHT WILL BE IN THE MID 30S AT THE COAST...AROUND 30 IN THE COLDER SPOTS. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... AS OF 300 PM WEDNESDAY...WEAK RIDGING ALOFT WILL BECOME SUPPRESSED LATE IN THE PERIOD AS 5H FLOW BECOMES MORE ZONAL. MUCH OF THE PERIOD WILL BE DOMINATED BY ELONGATED SURFACE HIGH WITH A WEAK COASTAL TROF DEVELOPING SAT INTO SUN. COASTAL TROF LOOKS PRETTY WEAK SO DO NOT THINK PRECIP WILL NOT BE AN ISSUE. BACKDOOR COLD FRONT STALLED NORTH OF THE AREA MON WILL PUSH SOUTH ACROSS THE AREA TUE. NOT MUCH FORCING ALONG THE FRONT AS IT HEADS SOUTH. FROPA WILL BE MARKED BY AIR MASS CHANGE BUT VERY LITTLE IF ANY PRECIP. WEAK ISENTROPIC LIFT LATE IN THE PERIOD AS MID LEVEL RIDGE SHIFTS EAST WILL PROVIDE THE BEST CHANCE FOR PRECIP DURING THE PERIOD. HOWEVER...GIVEN THE UNCERTAINTY WITH RESPECT TO THE EVENT PLAN TO CARRY SILENT POP FOR NOW. TEMPERATURES WILL START OUT NEAR CLIMO SAT BUT END UP ABOVE CLIMO SAT NIGHT AND FOR THE REST OF THE PERIOD. HIGHS WILL RUN 5 TO 8 DEGREES ABOVE CLIMO WITH LOWS CLOSER TO 10 DEGREES ABOVE. && .AVIATION /20Z WEDNESDAY THROUGH MONDAY/... AS OF 17Z...A LARGE PORTION OF THE CWA HAS SCATTERED OUT...HOWEVER EXPECT AN MVFR CEILING TO RE-EMERGE AS CU SPREADS OUT INTO A CEILING DUE TO A PERSISTENT SUBSIDENCE INVERSION. GUSTY SOUTHWEST WINDS WILL CONTINUE THROUGH THE AFTERNOON HOURS. THIS EVENING...EXPECT IFR CEILINGS TO COME BACK...AS LOW LEVEL MOISTURE GETS TRAPPED. CONVECTION AHEAD OF A FRONTAL BOUNDARY WILL AFFECT THE WESTERN TERMINALS BEFORE MIDNIGHT...WITH THE PRE-FRONTAL TROUGH WITH MODERATE OMEGA REACHING THE COAST BY 07-08Z. LOOK FOR INTERMITTENT IFR VISIBILITIES IN THE HEAVY SHOWERS WITH SOME INCREASE IN WINDS. THE FIRST SET OF CONVECTION WILL MOVE OFFSHORE BEFORE DAYBREAK...MEANWHILE MORE CONVECTION ASSOCIATED WITH THE FRONT WILL MOVE THROUGH THE CWA DURING THE DAY...AGAIN WITH INTERMITTENT HEAVY RAIN WITH MODERATE FRONTAL LIFT. WINDS WILL SHIFT TO THE NORTH AND GUSTY BEHIND THE FRONT. MODELS INDICATE LOW CEILINGS WILL REMAIN BEHIND THE FRONT...BUT WOULD NOT BE SURPRISE TO SEE VFR CONDITIONS BY THE END OF THE FORECAST PERIOD. EXTENDED OUTLOOK...EXPECT VFR FRIDAY AND SATURDAY...WITH LOWERED CONFIDENCE FOR POTENTIAL IFR FOG/STRATUS SUNDAY AND MONDAY MORNINGS. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 300 PM WEDNESDAY...TROPICAL MOISTURE MOVING ACROSS CHILLY NEARSHORE OCEAN WATERS HAS RESULTED IN AREAS OF DENSE SEA FOG TODAY. THIS SHOULD CONTINUE INTO THE EVENING HOURS WITH VISIBILITIES LESS THAN ONE MILE AT TIMES. THE WORST VISIBILITIES ARE EXPECTED ACROSS THE WATERS WITHIN 5-8 MILES OF SHORE WHERE WATER TEMPERATURES AND AIR TEMPERATURES ARE COOLEST. OTHERWISE...SOUTHWEST WINDS WILL RAMP UP OVERNIGHT IN ADVANCE OF A STRONG COLD FRONT MOVING EAST TOWARD THE CAROLINAS. LATEST HIGH- RESOLUTION MODELS SUGGEST THE FIRST BATCH OF SHOWERS AND STRONG THUNDERSTORMS COULD REACH THE COASTLINE AROUND 10 PM THIS EVENING... WITH ADDITIONAL SHOWERS AND STORMS POSSIBLE OVERNIGHT UP UNTIL THE ACTUAL SURFACE COLD FRONT ARRIVES AFTER DAYBREAK THURSDAY MORNING. SEAS SHOULD GRADUALLY BUILD TONIGHT WITH THE STRONGER SOUTHWEST WINDS ARRIVING AHEAD OF THE FRONT...REACHING AS HIGH AS 6-8 FT NEAR CAPE FEAR LATE TONIGHT. THE STRONGEST WINDS SHOULD REMAIN OUT BEYOND 20 MILES FROM SHORE WHERE WARMER AIR AND WATER TEMPERATURES WILL SUPPORT DEEPER MIXING...BRINGING THESE WINDS DOWN TO THE OCEAN SURFACE. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 300 PM WEDNESDAY...PERIOD BEGINS WITH SOLID SCA CONDITIONS ACROSS THE COASTAL WATERS AS PINCHED GRADIENT EXISTS AHEAD OF A COLD FRONT. WINDS THURSDAY WILL QUICKLY VEER FROM SW IN THE MORNING TO NORTHERLY DURING THE AFTN BEHIND THE COLD FRONT. SPEEDS WILL INCREASE AS WELL...BECOMING SUSTAINED AT NEARLY 25 KTS UNTIL THURSDAY NIGHT...HELPING TO GENERATE SEAS OF 5-7 FT. CHALLENGE THEN BECOMES DETERMINING EXACTLY WHEN CONDITIONS WILL DROP BELOW SCA THRESHOLDS. ALTHOUGH GRADIENT WILL REMAIN PINCHED AS HIGH PRESSURE SLIDES TOWARDS THE AREA...EXPECT IT WILL SLACKEN ENOUGH TO DROP WINDS TO 15-20 KTS AND SEAS TO 4-5 FT BY FRIDAY MORNING...SO HAVE LEFT CURRENT SCA AS-IS. WINDS VEER TO THE NE FRIDAY NIGHT AND EASE FURTHER...REDUCING SEAS TO 2-4 FT BY THE END OF THE PERIOD. LONG TERM /SATURDAY THROUGH SUNDAY/... AS OF 300 PM WEDNESDAY...LIGHT NORTHEAST FLOW WILL BE QUICK TO VEER TO SOUTHEASTERLY AS WEAK COASTAL TROUGH DEVELOPS. REMAINS OF THE TROUGH PUSH INLAND SAT NIGHT INTO SUN AND HIGH PRESSURE RETURNS. WEAK GRADIENT WILL REMAIN IN PLACE THROUGH THE END OF THE PERIOD WITH SOUTH TO SOUTHWEST FLOW AROUND 10 KT. COLD FRONT MAY DROP IN FROM THE NORTH AT THE END OF THE PERIOD...THOUGH TIMING IS STILL IN QUESTION. SEAS WILL RUN 2 TO 4 FT SAT DROPPING TO 2 TO 3 FT SUN AND MON. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST THURSDAY NIGHT FOR AMZ250-252-254-256. && $$ SYNOPSIS...TRA/JDW NEAR TERM...TRA SHORT TERM...JDW LONG TERM...III AVIATION...DL MARINE...ALL
AREA FORECAST DISCUSSION...CORRECTED
NWS WILMINGTON NC
1149 AM EST WED NOV 16 2011 .SYNOPSIS... A COLD FRONT OVER THE TENNESSEE VALLEY WILL SLIDE EASTWARD BRINGING SHOWERS AND A CHANCE OF THUNDERSTORMS...INCLUDING SEVERE WEATHER...TONIGHT INTO THROUGH THURSDAY MORNING. MUCH COOLER AND DRIER AIR WILL FOLLOW LATE THURSDAY AND FRIDAY. HIGH PRESSURE WILL MOVE OVERHEAD WITH TEMPERATURES MODERATING DURING THE WEEKEND. ANOTHER FRONT WILL SHIFT TOWARD THE AREA EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1030 AM WEDNESDAY...WARM MOIST SOUTHWEST FLOW CONTINUES OVER THE CAROLINAS TODAY IN ADVANCE OF A STRONG COLD FRONT NOW LOCATED IN EASTERN TENNESSEE...NORTHERN ALABAMA...AND MISSISSIPPI. TODAY SHOULD BE THE WARMEST DAY OF THIS ENTIRE STRING OF MILD WEATHER DATING BACK TO SUNDAY...WITH THIS AFTERNOON`S HIGHS REACHING THE LOWER 80S INLAND AWAY FROM MARINE INFLUENCES. 850 MB TEMPS IN THE +15C TO +16C RANGE WOULD BE MORE AT HOME IN JUNE THAN IN NOVEMBER...AND WILL SUPPORT THESE VERY MILD READINGS. RECORD HIGHS FOR TODAY ARE IN THE MID TO UPPER 80S AND SHOULD REMAIN UNTOUCHED. DEWPOINTS IN THE UPPER 60S PLUS A LONG WIND FETCH ACROSS THE COLD NEARSHORE COASTAL WATERS IS PRODUCING AREAS OF FOG AND VERY LOW STRATUS CLOUDS OVER THE OCEAN AND SOME OF THE BEACHES. VISIBILITIES IN THE 0.25 TO 1 MILE RANGE ARE COMMON ON THE BEACHES AND OUT OVER THE COASTAL WATERS. AS LONG AS THE SUN IS SHINING TODAY THIS FOG SHOULD HAVE LITTLE SUCCESS MAKING IT MORE THAN 1 MILE INLAND OR SO...BUT ANY REMAINING FOG THIS EVENING COULD PUSH FARTHER INLAND. FIRST WE HAVE TRIMMED BACK POPS TODAY WITH ALL SHORT-TERM GUIDANCE SUGGESTING WE WILL SEE LITTLE IF ANY SHOWER ACTIVITY OVER OUR FORECAST AREA BEFORE DARK. WE DID LEAVE A SMALL 20 POP WEST OF I-95 LATE THIS AFTERNOON WHERE ONE OF THE PREVIOUS THREE HRRR RUNS SHOWS SOME SHOWERS POSSIBLE. THERE IS INSTABILITY (CAPE AROUND 1000 J/KG) FORECAST TO DEVELOP THIS AFTERNOON BUT TRIGGERS FOR CONVECTION ARE LARGELY ABSENT. THE BIG STORY IS THE POTENTIAL FOR SEVERE WEATHER AHEAD OF THE FRONT TONIGHT. ALTHOUGH SURFACE-BASED CAPE/INSTABILITY IS NOT IMPRESSIVE AFTER SUNSET THERE IS RATHER LARGE ELEVATED CAPE WHEN PARCELS AT 950/925 MB ARE CONSIDERED. RATHER STEEP LAPSE RATES THROUGH ALL THE MID AND UPPER LEVELS OF THE ATMOSPHERE WILL BE SUPPORTIVE OF DEEP CONVECTION. SYNOPTIC FACTORS SUPPORTIVE OF LIFT INCLUDE A FAVORABLY-POSITIONED JET STREAK MOVING THROUGH THE MID-ATLANTIC REGION TONIGHT PLACING THE CAROLINAS SQUARELY IN THE FAVORED RIGHT-ENTRANCE REGION...STRONG AND SLIGHTLY BACKED LOW LEVEL WINDS RELATIVE TO THE MID AND UPPER LEVEL FLOW PRODUCING 0-6 KM BULK SHEAR VALUES ON THE ORDER OF 50-70 KT...AND SEVERAL 500 MB VORTICITY CENTERS PASSING OVER OR JUST NORTH OF OUR FORECAST AREA. THE LATEST SPC CONVECTIVE OUTLOOK INCREASED SEVERE WEATHER PROBABILITIES FOR WIND AND TORNADOES...AND WE WOULD NOT BE AT ALL SURPRISED TO SEE TORNADO WATCHES FOR PORTIONS OF OUR FORECAST AREA THIS EVENING AND OVERNIGHT. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 3 AM WEDNESDAY...FORECAST MODELS HAVE SLOWED DOWN THE PROGRESSION OF THE COLD FRONT EVER SO SLIGHTLY AND HAVE THEREFORE EXTENDED POPS ACROSS THE BOARD INTO THE LATE MORNING HOURS...ESPECIALLY COASTAL AREAS. OTHERWISE INTERESTING TEMPERATURE FORECAST FOR THURSDAY HIGHS AS THE MAV NUMBERS SHOW NO WARMING IN WILMINGTON WITH LITTLE ELSEWHERE. WITH THE DOWNSLOPE FLOW AND COLD AIR ADVECTION NOT THAT IMPRESSIVE...DID ADD A DEGREE OR TWO TO THE MAV NUMBERS. FOR FRIDAY MORNING WINDS DECOUPLE INLAND WHILE REMAINING UP SLIGHTLY ALONG THE COAST AND ADJUSTED MOS NUMBERS ACCORDINGLY. COOL DAY FRIDAY WITH MOST AREAS REMAINING BELOW 60. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 3 AM WEDNESDAY...EXTENDED FORECAST IS RATHER UNEVENTFUL AS THE PATTERN QUICKLY EVOLVES FROM ZONAL TO RIDGING ACROSS THE SOUTHEAST...SIMILAR TO THE PATTERN WE HAVE EXPERIENCED THE PAST FEW DAYS. HPC IS FAVORING A BLEND OF THE GFS/ECMWF AND UKMET. REALLY THE ONLY FORECAST CHALLENGES INVOLVE LIGHT COASTAL TROUGH QPF SATURDAY AND A BACKDOOR FRONT TUESDAY. AS FOR THE FORMER...MAINTAINED A DRY FORECAST AS THE MODELS ARE USUALLY OVERDONE WITH THE QPF AND IN REALITY IT IS GENERALLY A STRATUS LAYER. REGARDING THE FRONT...THE LATEST GFS IS MORE BULLISH IN PUSHING THE FRONT SOUTH WITH THE EFFECTS ONLY BEING AN AIRMASS CHANGE. THE 0000 UTC ECMWF HAS BACKED OFF A FURTHER SOUTH SOLUTION. OTHERWISE...AS WE JUST EXPERIENCED...ABOVE NORMAL TO DOWN RIGHT BALMY CONDITIONS FOR LATE IN THE WEEKEND AND EARLY NEXT WEEK. && .AVIATION /17Z WEDNESDAY THROUGH MONDAY/... AS OF 17Z...A LARGE PORTION OF THE CWA HAS SCATTERED OUT...HOWEVER EXPECT AN MVFR CEILING TO RE-EMERGE AS CU SPREADS OUT INTO A CEILING DUE TO A PERSISTENT SUBSIDENCE INVERSION. GUSTY SOUTHWEST WINDS WILL CONTINUE THROUGH THE AFTERNOON HOURS. THIS EVENING...EXPECT IFR CEILINGS TO COME BACK...AS LOW LEVEL MOISTURE GETS TRAPPED. CONVECTION AHEAD OF A FRONTAL BOUNDARY WILL AFFECT THE WESTERN TERMINALS BEFORE MIDNIGHT...WITH THE PRE-FRONTAL TROUGH WITH MODERATE OMEGA REACHING THE COAST BY 07-08Z. LOOK FOR INTERMITTENT IFR VISIBILITIES IN THE HEAVY SHOWERS WITH SOME INCREASE IN WINDS. THE FIRST SET OF CONVECTION WILL MOVE OFFSHORE BEFORE DAYBREAK...MEANWHILE MORE CONVECTION ASSOCIATED WITH THE FRONT WILL MOVE THROUGH THE CWA DURING THE DAY...AGAIN WITH INTERMITTENT HEAVY RAIN WITH MODERATE FRONTAL LIFT. WINDS WILL SHIFT TO THE NORTH AND GUSTY BEHIND THE FRONT. MODELS INDICATE LOW CEILINGS WILL REMAIN BEHIND THE FRONT...BUT WOULD NOT BE SURPRISE TO SEE VFR CONDITIONS BY THE END OF THE FORECAST PERIOD. EXTENDED OUTLOOK...EXPECT VFR FRIDAY AND SATURDAY...WITH LOWERED CONFIDENCE FOR POTENTIAL IFR FOG/STRATUS SUNDAY AND MONDAY MORNINGS. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1030 AM WEDNESDAY...SATELLITE IMAGERY...SURF CAMS...AND OBSERVATIONS FROM NORTH MYRTLE BEACH AND SOUTHPORT CONTINUE TO INDICATE EXPANSIVE AREAS OF DENSE SEA FOG THIS MORNING. WE WILL LIKELY HAVE TO EXTEND THE TIME OF THE DENSE FOG ADVISORY LATER THIS MORNING AS THE MOIST SOUTHWESTERLY FLOW IS EXPECTED TO CONTINUE THROUGH TODAY AND INTO THIS EVENING. THERE IS QUITE A THERMAL GRADIENT ACROSS THE AREA WITH THE FRYING PAN SHOALS BUOY REPORTING AN AIR TEMP OF 75...WHILE 66-67 DEGREE TEMPS ARE BEING REPORTED ON THE BEACHES NEAR CAPE FEAR. SOUTHWESTERLY WINDS AROUND 15 KT WILL INCREASE FURTHER TONIGHT AS THE GRADIENT TIGHTENS AHEAD OF THE INCOMING STRONG COLD FRONT. SHOWERS AND THUNDERSTORMS WILL ALSO INCREASE IN COVERAGE TONIGHT. THE SMALL CRAFT ADVISORY REMAINS IN PLACE FOR THE ROUGHER CONDITIONS NEAR AND AHEAD OF THE FRONT. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 3 AM WEDNESDAY...MAIN FORECAST CHALLENGE WILL BE WHEN TO CONCLUDE THE SMALL CRAFT ADVISORY LATE THURSDAY EVENING. A PERIOD OF STRONG NORTHERLY WINDS WILL FOLLOW THE FRONT THURSDAY INTO THURSDAY EVENING. FOR NOW WITH THE TIMING STILL OUT FOUR PERIODS...WILL NOT TWEAK BUT ISSUE THE DISCLAIMER THE HEADLINE MAY HAVE TO BE EXTENDED A FEW HOURS. WINDS VEER TO NORTHEASTERLY FRIDAY AND DIMINISH SOMEWHAT TO A MANAGEABLE RANGE OF 15-20 KNOTS MAINLY TO THE LOWER END. HIGH SEAS EARLY GET CONFINED TO THE OUTER WATERS WITH THE WIND SHIFT AND REMAIN THERE FOR THE MOST PART. SOME FIVE TO SIX FOOTERS MAY LINGER ACROSS THE OUTER WATERS GIVING THE FRIDAY. LONG TERM /SATURDAY THROUGH SUNDAY/... AS OF 3 AM WEDNESDAY...NORTHEAST FLOW INITIALLY WILL QUICKLY VEER TO SOUTHEAST AS HIGH PRESSURE WEAKENS AND LEAVES THE WIND FIELD TO BE FORCED BY LOCAL EFFECTS IE...THE SEABREEZE. THIS WILL OCCUR LATE SATURDAY AND SUNDAY AS WINDS DROP TO BELOW 10 KNOTS. SEAS FOLLOW A SIMILAR TREND WITH 2-4 FEET INITIALLY DROPPING TO 2-3 FEET. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...DENSE FOG ADVISORY UNTIL 10 PM TONIGHT FOR AMZ250-252 DENSE FOG ADVISORY UNTIL 5 PM EST TODAY FOR AMZ254-256. SMALL CRAFT ADVISORY FROM NOON TODAY TO MIDNIGHT EST THURSDAY NIGHT FOR AMZ250-252-254-256. && $$ NEAR TERM...TRA SHORT TERM...SHK LONG TERM...SHK AVIATION...43
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1135 AM EST WED NOV 16 2011 .SYNOPSIS... A COLD FRONT OVER THE TENNESSEE VALLEY WILL SLIDE EASTWARD BRINGING SHOWERS AND A CHANCE OF THUNDERSTORMS...INCLUDING SEVERE WEATHER...TONIGHT INTO THROUGH THURSDAY MORNING. MUCH COOLER AND DRIER AIR WILL FOLLOW LATE THURSDAY AND FRIDAY. HIGH PRESSURE WILL MOVE OVERHEAD WITH TEMPERATURES MODERATING DURING THE WEEKEND. ANOTHER FRONT WILL SHIFT TOWARD THE AREA EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1030 AM WEDNESDAY...WARM MOIST SOUTHWEST FLOW CONTINUES OVER THE CAROLINAS TODAY IN ADVANCE OF A STRONG COLD FRONT NOW LOCATED IN EASTERN TENNESSEE...NORTHERN ALABAMA...AND MISSISSIPPI. TODAY SHOULD BE THE WARMEST DAY OF THIS ENTIRE STRING OF MILD WEATHER DATING BACK TO SUNDAY...WITH THIS AFTERNOON`S HIGHS REACHING THE LOWER 80S INLAND AWAY FROM MARINE INFLUENCES. 850 MB TEMPS IN THE +15C TO +16C RANGE WOULD BE MORE AT HOME IN JUNE THAN IN NOVEMBER...AND WILL SUPPORT THESE VERY MILD READINGS. RECORD HIGHS FOR TODAY ARE IN THE MID TO UPPER 80S ARE SHOULD REMAIN UNTOUCHED. DEWPOINTS IN THE UPPER 60S PLUS A LONG WIND FETCH ACROSS THE COLD NEARSHORE COASTAL WATERS IS PRODUCING AREAS OF FOG AND VERY LOW STRATUS CLOUDS OVER THE OCEAN AND SOME OF THE BEACHES. VISIBILITIES IN THE 0.25 TO 1 MILE RANGE ARE COMMON ON THE BEACHES AND OUT OVER THE COASTAL WATERS. AS LONG AS THE SUN IS SHINING TODAY THIS FOG SHOULD HAVE LITTLE SUCCESS MAKING IT MORE THAN 1 MILE INLAND OR SO...BUT ANY REMAINING FOG THIS EVENING COULD PUSH FARTHER INLAND. FIRST WE HAVE TRIMMED BACK POPS TODAY WITH ALL SHORT-TERM GUIDANCE SUGGESTING WE WILL SEE LITTLE IF ANY SHOWER ACTIVITY OVER OUR FORECAST AREA BEFORE DARK. WE DID LEAVE A SMALL 20 POP WEST OF I-95 LATE THIS AFTERNOON WHERE ONE OF THE PREVIOUS THREE HRRR RUNS SHOWS SOME SHOWERS POSSIBLE. THERE IS INSTABILITY (CAPE AROUND 1000 J/KG) FORECAST TO DEVELOP THIS AFTERNOON BUT TRIGGERS FOR CONVECTION ARE LARGELY ABSENT. THE BIG STORY IS THE POTENTIAL FOR SEVERE WEATHER AHEAD OF THE FRONT TONIGHT. ALTHOUGH SURFACE-BASED CAPE/INSTABILITY IS NOT IMPRESSIVE AFTER SUNSET THERE IS RATHER LARGE ELEVATED CAPE WHEN PARCELS AT 950/925 MB ARE CONSIDERED. RATHER STEEP LAPSE RATES THROUGH ALL THE MID AND UPPER LEVELS OF THE ATMOSPHERE WILL BE SUPPORTIVE OF DEEP CONVECTION. SYNOPTIC FACTORS SUPPORTIVE OF LIFT INCLUDE A FAVORABLY-POSITIONED JET STREAK MOVING THROUGH THE MID-ATLANTIC REGION TONIGHT PLACING THE CAROLINAS SQUARELY IN THE FAVORED RIGHT-ENTRANCE REGION...STRONG AND SLIGHTLY BACKED LOW LEVEL WINDS RELATIVE TO THE MID AND UPPER LEVEL FLOW PRODUCING 0-6 KM BULK SHEAR VALUES ON THE ORDER OF 50-70 KT...AND SEVERAL 500 MB VORTICITY CENTERS PASSING OVER OR JUST NORTH OF OUR FORECAST AREA. THE LATEST SPC CONVECTIVE OUTLOOK INCREASED SEVERE WEATHER PROBABILITIES FOR WIND AND TORNADOES...AND WE WOULD NOT BE AT ALL SURPRISED TO SEE TORNADO WATCHES FOR PORTIONS OF OUR FORECAST AREA THIS EVENING AND OVERNIGHT. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 3 AM WEDNESDAY...FORECAST MODELS HAVE SLOWED DOWN THE PROGRESSION OF THE COLD FRONT EVER SO SLIGHTLY AND HAVE THEREFORE EXTENDED POPS ACROSS THE BOARD INTO THE LATE MORNING HOURS...ESPECIALLY COASTAL AREAS. OTHERWISE INTERESTING TEMPERATURE FORECAST FOR THURSDAY HIGHS AS THE MAV NUMBERS SHOW NO WARMING IN WILMINGTON WITH LITTLE ELSEWHERE. WITH THE DOWNSLOPE FLOW AND COLD AIR ADVECTION NOT THAT IMPRESSIVE...DID ADD A DEGREE OR TWO TO THE MAV NUMBERS. FOR FRIDAY MORNING WINDS DECOUPLE INLAND WHILE REMAINING UP SLIGHTLY ALONG THE COAST AND ADJUSTED MOS NUMBERS ACCORDINGLY. COOL DAY FRIDAY WITH MOST AREAS REMAINING BELOW 60. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 3 AM WEDNESDAY...EXTENDED FORECAST IS RATHER UNEVENTFUL AS THE PATTERN QUICKLY EVOLVES FROM ZONAL TO RIDGING ACROSS THE SOUTHEAST...SIMILAR TO THE PATTERN WE HAVE EXPERIENCED THE PAST FEW DAYS. HPC IS FAVORING A BLEND OF THE GFS/ECMWF AND UKMET. REALLY THE ONLY FORECAST CHALLENGES INVOLVE LIGHT COASTAL TROUGH QPF SATURDAY AND A BACKDOOR FRONT TUESDAY. AS FOR THE FORMER...MAINTAINED A DRY FORECAST AS THE MODELS ARE USUALLY OVERDONE WITH THE QPF AND IN REALITY IT IS GENERALLY A STRATUS LAYER. REGARDING THE FRONT...THE LATEST GFS IS MORE BULLISH IN PUSHING THE FRONT SOUTH WITH THE EFFECTS ONLY BEING AN AIRMASS CHANGE. THE 0000 UTC ECMWF HAS BACKED OFF A FURTHER SOUTH SOLUTION. OTHERWISE...AS WE JUST EXPERIENCED...ABOVE NORMAL TO DOWN RIGHT BALMY CONDITIONS FOR LATE IN THE WEEKEND AND EARLY NEXT WEEK. && .AVIATION /17Z WEDNESDAY THROUGH MONDAY/... AS OF 17Z...A LARGE PORTION OF THE CWA HAS SCATTERED OUT...HOWEVER EXPECT AN MVFR CEILING TO RE-EMERGE AS CU SPREADS OUT INTO A CEILING DUE TO A PERSISTENT SUBSIDENCE INVERSION. GUSTY SOUTHWEST WINDS WILL CONTINUE THROUGH THE AFTERNOON HOURS. THIS EVENING...EXPECT IFR CEILINGS TO COME BACK...AS LOW LEVEL MOISTURE GETS TRAPPED. CONVECTION AHEAD OF A FRONTAL BOUNDARY WILL AFFECT THE WESTERN TERMINALS BEFORE MIDNIGHT...WITH THE PRE-FRONTAL TROUGH WITH MODERATE OMEGA REACHING THE COAST BY 07-08Z. LOOK FOR INTERMITTENT IFR VISIBILITIES IN THE HEAVY SHOWERS WITH SOME INCREASE IN WINDS. THE FIRST SET OF CONVECTION WILL MOVE OFFSHORE BEFORE DAYBREAK...MEANWHILE MORE CONVECTION ASSOCIATED WITH THE FRONT WILL MOVE THROUGH THE CWA DURING THE DAY...AGAIN WITH INTERMITTENT HEAVY RAIN WITH MODERATE FRONTAL LIFT. WINDS WILL SHIFT TO THE NORTH AND GUSTY BEHIND THE FRONT. MODELS INDICATE LOW CEILINGS WILL REMAIN BEHIND THE FRONT...BUT WOULD NOT BE SURPRISE TO SEE VFR CONDITIONS BY THE END OF THE FORECAST PERIOD. EXTENDED OUTLOOK...EXPECT VFR FRIDAY AND SATURDAY...WITH LOWERED CONFIDENCE FOR POTENTIAL IFR FOG/STRATUS SUNDAY AND MONDAY MORNINGS. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1030 AM WEDNESDAY...SATELLITE IMAGERY...SURF CAMS...AND OBSERVATIONS FROM NORTH MYRTLE BEACH AND SOUTHPORT CONTINUE TO INDICATE EXPANSIVE AREAS OF DENSE SEA FOG THIS MORNING. WE WILL LIKELY HAVE TO EXTEND THE TIME OF THE DENSE FOG ADVISORY LATER THIS MORNING AS THE MOIST SOUTHWESTERLY FLOW IS EXPECTED TO CONTINUE THROUGH TODAY AND INTO THIS EVENING. THERE IS QUITE A THERMAL GRADIENT ACROSS THE AREA WITH THE FRYING PAN SHOALS BUOY REPORTING AN AIR TEMP OF 75...WHILE 66-67 DEGREE TEMPS ARE BEING REPORTED ON THE BEACHES NEAR CAPE FEAR. SOUTHWESTERLY WINDS AROUND 15 KT WILL INCREASE FURTHER TONIGHT AS THE GRADIENT TIGHTENS AHEAD OF THE INCOMING STRONG COLD FRONT. SHOWERS AND THUNDERSTORMS WILL ALSO INCREASE IN COVERAGE TONIGHT. THE SMALL CRAFT ADVISORY REMAINS IN PLACE FOR THE ROUGHER CONDITIONS NEAR AND AHEAD OF THE FRONT. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 3 AM WEDNESDAY...MAIN FORECAST CHALLENGE WILL BE WHEN TO CONCLUDE THE SMALL CRAFT ADVISORY LATE THURSDAY EVENING. A PERIOD OF STRONG NORTHERLY WINDS WILL FOLLOW THE FRONT THURSDAY INTO THURSDAY EVENING. FOR NOW WITH THE TIMING STILL OUT FOUR PERIODS...WILL NOT TWEAK BUT ISSUE THE DISCLAIMER THE HEADLINE MAY HAVE TO BE EXTENDED A FEW HOURS. WINDS VEER TO NORTHEASTERLY FRIDAY AND DIMINISH SOMEWHAT TO A MANAGEABLE RANGE OF 15-20 KNOTS MAINLY TO THE LOWER END. HIGH SEAS EARLY GET CONFINED TO THE OUTER WATERS WITH THE WIND SHIFT AND REMAIN THERE FOR THE MOST PART. SOME FIVE TO SIX FOOTERS MAY LINGER ACROSS THE OUTER WATERS GIVING THE FRIDAY. LONG TERM /SATURDAY THROUGH SUNDAY/... AS OF 3 AM WEDNESDAY...NORTHEAST FLOW INITIALLY WILL QUICKLY VEER TO SOUTHEAST AS HIGH PRESSURE WEAKENS AND LEAVES THE WIND FIELD TO BE FORCED BY LOCAL EFFECTS IE...THE SEABREEZE. THIS WILL OCCUR LATE SATURDAY AND SUNDAY AS WINDS DROP TO BELOW 10 KNOTS. SEAS FOLLOW A SIMILAR TREND WITH 2-4 FEET INITIALLY DROPPING TO 2-3 FEET. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...DENSE FOG ADVISORY UNTIL NOON EST TODAY FOR AMZ250-252- 254-256. SMALL CRAFT ADVISORY FROM NOON TODAY TO MIDNIGHT EST THURSDAY NIGHT FOR AMZ250-252-254-256. && $$ NEAR TERM...TRA SHORT TERM...SHK LONG TERM...SHK AVIATION...43
AREA FORECAST DISCUSSION...CORRECTED
NWS WILMINGTON NC
1126 AM EST WED NOV 16 2011 .SYNOPSIS... A COLD FRONT OVER THE TENNESSEE VALLEY WILL SLIDE EASTWARD BRINGING SHOWERS AND A CHANCE OF THUNDERSTORMS...INCLUDING SEVERE WEATHER...TONIGHT INTO THROUGH THURSDAY MORNING. MUCH COOLER AND DRIER AIR WILL FOLLOW LATE THURSDAY AND FRIDAY. HIGH PRESSURE WILL MOVE OVERHEAD WITH TEMPERATURES MODERATING DURING THE WEEKEND. ANOTHER FRONT WILL SHIFT TOWARD THE AREA EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1030 AM WEDNESDAY...WARM MOIST SOUTHWEST FLOW CONTINUES OVER THE CAROLINAS TODAY IN ADVANCE OF A STRONG COLD FRONT NOW LOCATED IN EASTERN TENNESSEE...NORTHERN ALABAMA...AND MISSISSIPPI. TODAY SHOULD BE THE WARMEST DAY OF THIS ENTIRE STRING OF MILD WEATHER DATING BACK TO SUNDAY...WITH THIS AFTERNOON`S HIGHS REACHING THE LOWER 80S INLAND AWAY FROM MARINE INFLUENCES. 850 MB TEMPS IN THE +15C TO +16C RANGE WOULD BE MORE AT HOME IN JUNE THAN IN NOVEMBER...AND WILL SUPPORT THESE VERY MILD READINGS. RECORD HIGHS FOR TODAY ARE IN THE MID TO UPPER 80S AND SHOULD REMAIN UNTOUCHED. DEWPOINTS IN THE UPPER 60S PLUS A LONG WIND FETCH ACROSS THE COLD NEARSHORE COASTAL WATERS IS PRODUCING AREAS OF FOG AND VERY LOW STRATUS CLOUDS OVER THE OCEAN AND SOME OF THE BEACHES. VISIBILITIES IN THE 0.25 TO 1 MILE RANGE ARE COMMON ON THE BEACHES AND OUT OVER THE COASTAL WATERS. AS LONG AS THE SUN IS SHINING TODAY THIS FOG SHOULD HAVE LITTLE SUCCESS MAKING IT MORE THAN 1 MILE INLAND OR SO...BUT ANY REMAINING FOG THIS EVENING COULD PUSH FARTHER INLAND. FIRST WE HAVE TRIMMED BACK POPS TODAY WITH ALL SHORT-TERM GUIDANCE SUGGESTING WE WILL SEE LITTLE IF ANY SHOWER ACTIVITY OVER OUR FORECAST AREA BEFORE DARK. WE DID LEAVE A SMALL 20 POP WEST OF I-95 LATE THIS AFTERNOON WHERE ONE OF THE PREVIOUS THREE HRRR RUNS SHOWS SOME SHOWERS POSSIBLE. THERE IS INSTABILITY (CAPE AROUND 1000 J/KG) FORECAST TO DEVELOP THIS AFTERNOON BUT TRIGGERS FOR CONVECTION ARE LARGELY ABSENT. THE BIG STORY IS THE POTENTIAL FOR SEVERE WEATHER AHEAD OF THE FRONT TONIGHT. ALTHOUGH SURFACE-BASED CAPE/INSTABILITY IS NOT IMPRESSIVE AFTER SUNSET THERE IS RATHER LARGE ELEVATED CAPE WHEN PARCELS AT 950/925 MB ARE CONSIDERED. RATHER STEEP LAPSE RATES THROUGH ALL THE MID AND UPPER LEVELS OF THE ATMOSPHERE WILL BE SUPPORTIVE OF DEEP CONVECTION. SYNOPTIC FACTORS SUPPORTIVE OF LIFT INCLUDE A FAVORABLY-POSITIONED JET STREAK MOVING THROUGH THE MID-ATLANTIC REGION TONIGHT PLACING THE CAROLINAS SQUARELY IN THE FAVORED RIGHT-ENTRANCE REGION...STRONG AND SLIGHTLY BACKED LOW LEVEL WINDS RELATIVE TO THE MID AND UPPER LEVEL FLOW PRODUCING 0-6 KM BULK SHEAR VALUES ON THE ORDER OF 50-70 KT...AND SEVERAL 500 MB VORTICITY CENTERS PASSING OVER OR JUST NORTH OF OUR FORECAST AREA. THE LATEST SPC CONVECTIVE OUTLOOK INCREASED SEVERE WEATHER PROBABILITIES FOR WIND AND TORNADOES...AND WE WOULD NOT BE AT ALL SURPRISED TO SEE TORNADO WATCHES FOR PORTIONS OF OUR FORECAST AREA THIS EVENING AND OVERNIGHT. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 3 AM WEDNESDAY...FORECAST MODELS HAVE SLOWED DOWN THE PROGRESSION OF THE COLD FRONT EVER SO SLIGHTLY AND HAVE THEREFORE EXTENDED POPS ACROSS THE BOARD INTO THE LATE MORNING HOURS...ESPECIALLY COASTAL AREAS. OTHERWISE INTERESTING TEMPERATURE FORECAST FOR THURSDAY HIGHS AS THE MAV NUMBERS SHOW NO WARMING IN WILMINGTON WITH LITTLE ELSEWHERE. WITH THE DOWNSLOPE FLOW AND COLD AIR ADVECTION NOT THAT IMPRESSIVE...DID ADD A DEGREE OR TWO TO THE MAV NUMBERS. FOR FRIDAY MORNING WINDS DECOUPLE INLAND WHILE REMAINING UP SLIGHTLY ALONG THE COAST AND ADJUSTED MOS NUMBERS ACCORDINGLY. COOL DAY FRIDAY WITH MOST AREAS REMAINING BELOW 60. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 3 AM WEDNESDAY...EXTENDED FORECAST IS RATHER UNEVENTFUL AS THE PATTERN QUICKLY EVOLVES FROM ZONAL TO RIDGING ACROSS THE SOUTHEAST...SIMILAR TO THE PATTERN WE HAVE EXPERIENCED THE PAST FEW DAYS. HPC IS FAVORING A BLEND OF THE GFS/ECMWF AND UKMET. REALLY THE ONLY FORECAST CHALLENGES INVOLVE LIGHT COASTAL TROUGH QPF SATURDAY AND A BACKDOOR FRONT TUESDAY. AS FOR THE FORMER...MAINTAINED A DRY FORECAST AS THE MODELS ARE USUALLY OVERDONE WITH THE QPF AND IN REALITY IT IS GENERALLY A STRATUS LAYER. REGARDING THE FRONT...THE LATEST GFS IS MORE BULLISH IN PUSHING THE FRONT SOUTH WITH THE EFFECTS ONLY BEING AN AIRMASS CHANGE. THE 0000 UTC ECMWF HAS BACKED OFF A FURTHER SOUTH SOLUTION. OTHERWISE...AS WE JUST EXPERIENCED...ABOVE NORMAL TO DOWN RIGHT BALMY CONDITIONS FOR LATE IN THE WEEKEND AND EARLY NEXT WEEK. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... AS OF 12Z...SATELLITE AND OBSERVATIONS SHOW IFR/LIFR CONDITIONS ENTRENCHED OVER MUCH OF THE CWA...A MIXTURE OF STRATUS AND ADVECTION SEA FOG. EXPECT IFR CONDITIONS TO CONTINUE THROUGH THE MORNING HOURS...LIFTING OR SCATTERING AROUND 16Z...AS SOUTHWEST FLOW INCREASES AHEAD OF A COLD FRONT. EXPECT MVFR/NEAR VFR CONDITIONS FOR THE AFTERNOON HOURS...ONLY TO LOWER TO IFR SHORTLY AFTER 00Z. TONIGHT...DEEP MOISTURE ASSOCIATED WITH THE COLD FRONT WILL CROSS THE CWA...REACHING THE COAST BY 09Z. SHOWERS WILL BE SCATTERED TO NUMEROUS ALONG AND AHEAD OF THE FRONT. LOW PRESSURE ALONG THE COLD FRONT MAY ACTUALLY HAVE A DRY SLOT WITH IT...BUT CONFIDENCE IS LOW. EXTENDED OUTLOOK...SHOWERS LINGERING THURSDAY MORNING WILL LIFT OUT BY LATE MORNING WITH CONDITIONS IMPROVING TO VFR. EXPECT VFR FRIDAY AND SATURDAY...WITH LOWERED CONFIDENCE FOR POTENTIAL IFR FOG/STRATUS SUNDAY MORNING. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1030 AM WEDNESDAY...SATELLITE IMAGERY...SURF CAMS...AND OBSERVATIONS FROM NORTH MYRTLE BEACH AND SOUTHPORT CONTINUE TO INDICATE EXPANSIVE AREAS OF DENSE SEA FOG THIS MORNING. WE WILL LIKELY HAVE TO EXTEND THE TIME OF THE DENSE FOG ADVISORY LATER THIS MORNING AS THE MOIST SOUTHWESTERLY FLOW IS EXPECTED TO CONTINUE THROUGH TODAY AND INTO THIS EVENING. THERE IS QUITE A THERMAL GRADIENT ACROSS THE AREA WITH THE FRYING PAN SHOALS BUOY REPORTING AN AIR TEMP OF 75...WHILE 66-67 DEGREE TEMPS ARE BEING REPORTED ON THE BEACHES NEAR CAPE FEAR. SOUTHWESTERLY WINDS AROUND 15 KT WILL INCREASE FURTHER TONIGHT AS THE GRADIENT TIGHTENS AHEAD OF THE INCOMING STRONG COLD FRONT. SHOWERS AND THUNDERSTORMS WILL ALSO INCREASE IN COVERAGE TONIGHT. THE SMALL CRAFT ADVISORY REMAINS IN PLACE FOR THE ROUGHER CONDITIONS NEAR AND AHEAD OF THE FRONT. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 3 AM WEDNESDAY...MAIN FORECAST CHALLENGE WILL BE WHEN TO CONCLUDE THE SMALL CRAFT ADVISORY LATE THURSDAY EVENING. A PERIOD OF STRONG NORTHERLY WINDS WILL FOLLOW THE FRONT THURSDAY INTO THURSDAY EVENING. FOR NOW WITH THE TIMING STILL OUT FOUR PERIODS...WILL NOT TWEAK BUT ISSUE THE DISCLAIMER THE HEADLINE MAY HAVE TO BE EXTENDED A FEW HOURS. WINDS VEER TO NORTHEASTERLY FRIDAY AND DIMINISH SOMEWHAT TO A MANAGEABLE RANGE OF 15-20 KNOTS MAINLY TO THE LOWER END. HIGH SEAS EARLY GET CONFINED TO THE OUTER WATERS WITH THE WIND SHIFT AND REMAIN THERE FOR THE MOST PART. SOME FIVE TO SIX FOOTERS MAY LINGER ACROSS THE OUTER WATERS GIVING THE FRIDAY. LONG TERM /SATURDAY THROUGH SUNDAY/... AS OF 3 AM WEDNESDAY...NORTHEAST FLOW INITIALLY WILL QUICKLY VEER TO SOUTHEAST AS HIGH PRESSURE WEAKENS AND LEAVES THE WIND FIELD TO BE FORCED BY LOCAL EFFECTS IE...THE SEABREEZE. THIS WILL OCCUR LATE SATURDAY AND SUNDAY AS WINDS DROP TO BELOW 10 KNOTS. SEAS FOLLOW A SIMILAR TREND WITH 2-4 FEET INITIALLY DROPPING TO 2-3 FEET. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...DENSE FOG ADVISORY UNTIL NOON EST TODAY FOR AMZ250-252- 254-256. SMALL CRAFT ADVISORY FROM NOON TODAY TO MIDNIGHT EST THURSDAY NIGHT FOR AMZ250-252-254-256. && $$ NEAR TERM...TRA SHORT TERM...SHK LONG TERM...SHK AVIATION...43
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
412 PM EST WED NOV 16 2011 .SYNOPSIS... A COMPLICATED FRONTAL SYSTEM WILL FINALLY BE MOVING TO THE EAST TONIGHT AND COLD AIR WILL RETURN FOR A COUPLE OF DAYS. MINOR LAKE EFFECT SNOW IS EXPECTED IN THE SNOW BELT...THEN HIGH PRESSURE WILL SETTLE IN FOR THE WEEKEND. THE HIGH WILL SET UP ALONG THE EAST COAST BY EARLY NEXT WEEK. A WET BUT MILD PATTERN WILL THEN RETURN. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... DEW POINT IN KERI ALREADY INTO THE 30S...AND COLDER AIR ON THE WAY. WINDS NOW MAINLY NW OVER WRN PA. HRRR AND CURR RADAR TRENDS INDICATE THAT THERE IS A LIGHTER PATCH IN THE NEARLY CONSTANT RAIN SHIELD HEADING FOR THE LOWER SUSQ. THE DRIER AIR THAT HAS BEEN PULLED IN FROM THE SRN PLAINS AND THE CONSOLIDATION OF THE COLD FRONT AND WARMER/STATIONARY BOUNDARY TO OUR SOUTH IS STARTING TO WRAP THE SYSTEM UP A BIT AS IT PULLS NORTHEAST. PSEUDO DEFORMATION AREA RAIN OVER CENTRAL PA BACK TO ERN KY IS DIMINISHING AT THE SAME TIME...BUT CONTINUES TO SLIDE EASTWARD. WILL KEEP HIGH POPS IN FOR THE EVENING BUT TAPER THEM OFF RATHER QUICKLY AND BY 10 PM...ALL BUT THE FAR SE SHOULD BE DRY. TEMPS DROP BELOW FREEZING IN THE NW JUST AFTER MIDNIGHT. CLOUDS COULD HANG ON A LONG TIME IN THE WEST...THOUGH...AS WRLY UPSLOPE FLOW PRODUCES LIFT. AS IT GETS COLDER A FEW SHSN WILL PROBABLY DEVELOP OVER THE LAURELS/WRN HIGHLANDS. DO NOT EXPECT ANY MORE THAN A DUSTING TONIGHT WITH LITTLE MOISTURE AND SUBSIDENCE BATTLING THE LLVL UPSLOPE. MINS SHOULD HOLD IN THE 40S IN THE SE HALF OF THE AREA. THERE IS A TRICKY PART TO THE FORECAST THAT STARTS TONIGHT...BUT LASTS INTO THE NEXT PD. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/... THE FORECAST PROBLEM IS WHETHER A SECONDARY WAVE ON THE OLD FRONT DEVELOPS SOON ENOUGH AND CLOSE ENOUGH TO THE LOCAL AREA /BUT TO THE SOUTH/ TO PRODUCE LIGHT PCPN BACK INTO THE COOLING AIR OVER THE REGION...ESP THE SE. THE WAVE HAS BEEN HINTED AT FOR A FEW DAYS NOW...SO CONFIDENCE HAS INCREASED SLIGHTLY...BUT THE CUTOFF OF ANY PRECIP LOOKS RATHER SHARP. IT LOOKS LIKE MOST OF THE POSSIBLE PCPN WOULD STAY TO THE S/E OF THE AREA BUT MAKES A CLOSE PASS. BUFKIT SOUNDINGS FROM NAM DO LOOK PLENTY COLD FOR SNOW...BUT IT WOULD BE FALLING INTO UBER-FREEZING AIR AND DURING THE DAYLIGHT HOURS. WILL CALL IT A CHC OF RAIN/SNOW SHOWERS FOR NOW IN THE FAR LWR SUSQ AS IT IS WORTH A MENTION AT THIS POINT. TEMPS HARDLY MOVE ON THURS UNDER COLD ADVECTION. AN EASIER PART TO THE FCST IN THE SHORT TERM IS THAT WE WILL DOUBTLESSLY SEE LAKE EFFECT CLOUDS/FLURRIES IN THE WEST...AND ACCUMS IN THE SNOW BELT OF WARREN CO. POTTER AND MCKEAN COULD ALSO PICK UP AN INCH OR SO THURSDAY INTO THURS NIGHT. THE AXIS OF THE UPPER TROUGH CROSSES LAKE ERIE MID-DAY THURSDAY AND SHOULD DRIVE THE HEAVIEST SNOWS INLAND DURING THE LATE DAY AND INTO THE OVERNIGHT. DURATION OF THE BEST BANDS WOULD PROBABLY BE ONLY UNTIL FRIDAY MORNING...AS 8H THERMAL TROUGH OF -12C AIR PASSES BY 12Z FRI. LOCAL PROGRAM GIVES BAND OF AROUND 80 MI EVEN WITH THE FAVORABLE 280-290 FETCH AND DEEP 10KFT INVERSION. WIND SPEEDS ARE ONLY 30KTS...BUT ARE WELL-ALIGNED VERTICALLY. STORM TOTALS MIGHT GET INTO THE 3-4 INCH RANGE OVER 18-20 HRS. THIS IS NOT QUITE WORTH AN ADVY YET...ESP SINCE IT IS A LATE 2ND/3RD PD EVENT. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... UPPER TROF EXITING THE EASTERN U.S. AT THE START OF THE PERIOD WILL TRANSITION TO BROAD SOUTHWESTERLY FLOW WHICH IS THEN FORECAST TO DOMINATE MUCH OF THE LONG TERM PERIOD. FLOW IS FORECAST TO TURN MORE WESTERLY BY THE END OF THE PERIOD AS ENERGY OVER THE WESTERN U.S. WORKS ITS WAY EAST. AS THE UPPER TROUGH BUILDS OVER THE WESTERN US LATER THIS WEEK...THE SOUTHEASTERN RIDGE SHOULD PUSH WARMER AIR INTO OUR REGION SATURDAY. THE 850 HPA TEMPERATURES ARE PREDICTED TO BE 1SD ABOVE NORMAL LATE SATURDAY ACROSS THE NW PART OF THE STATE...AND AREA- WIDE ON SUNDAY. ANOTHER COLD FRONT APPROACHES WITH THE NEXT CHC FOR SHOWERS LATER SUNDAY INTO MONDAY. THIS FRONT IS FORECAST TO STALL OVER THE MID ATLANTIC REGION...WITH THE POTENTIAL FOR WAVES OF LOW PRESSURE TO BRING MORE PCPN INTO THE REGION NEXT MONDAY INTO TUE...BUT THE DETAILS AT THIS POINT ARE ANYTHING BUT CLEAR. && .AVIATION /21Z WEDNESDAY THROUGH MONDAY/... LOW CIGS STARTING TO LIFT AS THE COLDER AND DRIER AIR UNDERCUTS THE MOISTURE WHICH IS GETTING CUT OFF FROM THE GOMEX ALREADY. IMPROVEMENT MAY BE SLOW IN KJST WITH WINDS WNW IN A GOOD UPSLOPE ORIENTATION. SHSN MAY START IN KJST TONIGHT...BUT WILL KEEP FCST BETTER THAN VFR FOR NOW. RAIN SHIELD SHOULD GRADUALLY SHRINK AND SLIDE TO THE EAST PER TRENDS IN RADAR MOSAIC AND MESO MDLS. SLOW MOVEMENT TO THE SFC TROUGH TO THE SE WILL KEEP LIGHT RAIN GOING FOR MOST OF THE EVENING IN THE SE. LITTLE/NO PRECIP EXPECTED OVERNIGHT...BUT A SECONDARY WAVE MAY DEVELOP TONIGHT TO OUR SOUTH AND THROW SOME COLDER PRECIP BACK IN FROM THE SE. LOW POSS AT THIS POINT...AND AT THE OUTER REACHES OF THIS 18Z 24HR TAF PD...BUT SOMETHING TO WATCH FOR ON THURS. UPSLOPE IN THE WEST AND OFF LAKE ERIE WILL GENERATE LAKE EFFECT THURS AFTN INTO FRI AM VCTY KBFD. OUTLOOK... FRI-SAT...VFR. NO SIG WX. SUN...GENERALLY VFR. MVFR POSS LATE. MON...MVFR TS/SHRA/CIGS. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DANGELO/STEINBUGL NEAR TERM...DANGELO SHORT TERM...DANGELO LONG TERM...DEVOIR/GARTNER AVIATION...DANGELO
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
258 PM EST WED NOV 16 2011 .SYNOPSIS... A COMPLICATED FRONTAL SYSTEM WILL FINALLY BE MOVING TO THE EAST TONIGHT AND COLD AIR WILL RETURN FOR A COUPLE OF DAYS. MINOR LAKE EFFECT SNOW IS EXPECTED IN THE SNOW BELT...THEN HIGH PRESSURE WILL SETTLE IN FOR THE WEEKEND. THE HIGH WILL SET UP ALONG THE EAST COAST BY EARLY NEXT WEEK. A WET BUT MILD PATTERN WILL THEN RETURN. && .NEAR TERM /THROUGH TONIGHT/... DEW POINT IN KERI ALREADY INTO THE 30S...AND COLDER AIR ON THE WAY. WINDS NOW MAINLY NW OVER WRN PA. HRRR AND CURR RADAR TRENDS INDICATE THAT THERE IS A LIGHTER PATCH IN THE NEARLY CONSTANT RAIN SHIELD HEADING FOR THE LOWER SUSQ. THE DRIER AIR THAT HAS BEEN PULLED IN FROM THE SRN PLAINS AND THE CONSOLIDATION OF THE COLD FRONT AND WARMER/STATIONARY BOUNDARY TO OUR SOUTH IS STARTING TO WRAP THE SYSTEM UP A BIT AS IT PULLS NORTHEAST. PSEUDO DEFORMATION AREA RAIN OVER CENTRAL PA BACK TO ERN KY IS DIMINISHING AT THE SAME TIME...BUT CONTINUES TO SLIDE EASTWARD. WILL KEEP HIGH POPS IN FOR THE EVENING BUT TAPER THEM OFF RATHER QUICKLY AND BY 10 PM...ALL BUT THE FAR SE SHOULD BE DRY. TEMPS DROP BELOW FREEZING IN THE NW JUST AFTER MIDNIGHT. CLOUDS COULD HANG ON A LONG TIME IN THE WEST...THOUGH...AS WRLY UPSLOPE FLOW PRODUCES LIFT. AS IT GETS COLDER A FEW SHSN WILL PROBABLY DEVELOP OVER THE LAURELS/WRN HIGHLANDS. DO NOT EXPECT ANY MORE THAN A DUSTING TONIGHT WITH LITTLE MOISTURE AND SUBSIDENCE BATTLING THE LLVL UPSLOPE. MINS SHOULD HOLD IN THE 40S IN THE SE HALF OF THE AREA. THERE IS A TRICKY PART TO THE FORECAST THAT STARTS TONIGHT...BUT LASTS INTO THE NEXT PD. && .SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/... THE FORECAST PROBLEM IS WHETHER A SECONDARY WAVE ON THE OLD FRONT DEVELOPS SOON ENOUGH AND CLOSE ENOUGH TO THE LOCAL AREA /BUT TO THE SOUTH/ TO PRODUCE LIGHT PCPN BACK INTO THE COOLING AIR OVER THE REGION...ESP THE SE. THE WAVE HAS BEEN HINTED AT FOR A FEW DAYS NOW...SO CONFIDENCE HAS INCREASED SLIGHTLY...BUT THE CUTOFF OF ANY PRECIP LOOKS RATHER SHARP. IT LOOKS LIKE MOST OF THE POSSIBLE PCPN WOULD STAY TO THE S/E OF THE AREA BUT MAKES A CLOSE PASS. BUFKIT SOUNDINGS FROM NAM DO LOOK PLENTY COLD FOR SNOW...BUT IT WOULD BE FALLING INTO UBER-FREEZING AIR AND DURING THE DAYLIGHT HOURS. WILL CALL IT A CHC OF RAIN/SNOW SHOWERS FOR NOW IN THE FAR LWR SUSQ AS IT IS WORTH A MENTION AT THIS POINT. TEMPS HARDLY MOVE ON THURS UNDER COLD ADVECTION. AN EASIER PART TO THE FCST IN THE SHORT TERM IS THAT WE WILL DOUBTLESSLY SEE LAKE EFFECT CLOUDS/FLURRIES IN THE WEST...AND ACCUMS IN THE SNOW BELT OF WARREN CO. POTTER AND MCKEAN COULD ALSO PICK UP AN INCH OR SO THURSDAY INTO THURS NIGHT. THE AXIS OF THE UPPER TROUGH CROSSES LAKE ERIE MID-DAY THURSDAY AND SHOULD DRIVE THE HEAVIEST SNOWS INLAND DURING THE LATE DAY AND INTO THE OVERNIGHT. DURATION OF THE BEST BANDS WOULD PROBABLY BE ONLY UNTIL FRIDAY MORNING...AS 8H THERMAL TROUGH OF -12C AIR PASSES BY 12Z FRI. LOCAL PROGRAM GIVES BAND OF AROUND 80 MI EVEN WITH THE FAVORABLE 280-290 FETCH AND DEEP 10KFT INVERSION. WIND SPEEDS ARE ONLY 30KTS...BUT ARE WELL-ALIGNED VERTICALLY. STORM TOTALS MIGHT GET INTO THE 3-4 INCH RANGE OVER 18-20 HRS. THIS IS NOT QUITE WORTH AN ADVY YET...ESP SINCE IT IS A LATE 2ND/3RD PD EVENT. && .LONG TERM /FRIDAY THROUGH TUESDAY/... SOUTHWESTERLY FLOW ALOFT WILL DOMINATE MUCH OF THE LONG TERM PERIOD AS UPPER LOW SETS OVER CENTRAL CANADA AND UPPER RIDGING STRETCHES OVER THE WRN ATLANTIC AND EASTERN CARIBBEAN. ONE UPPER TROF MOVES THROUGH THE NORTHEAST THURSDAY INTO FRIDAY...THEN A SERIES OF WAVE MOVE THROUGH LATE IN THE PERIOD TURNING THE FLOW MORE ZONAL EARLY NEXT WEEK. TEMPERATURES MODERATE BACK TOWARD NORMAL FRIDAY. AS THE UPPER TROUGH BUILDS OVER THE WESTERN US LATER THIS WEEK...THE SOUTHEASTERN RIDGE SHOULD PUSH WARMER AIR INTO OUR REGION SATURDAY. THE 850 HPA TEMPERATURES ARE PREDICTED TO BE 1SD ABOVE NORMAL LATE SATURDAY ACROSS THE NW PART OF THE STATE...AND AREA- WIDE ON SUNDAY. ANOTHER COLD FRONT APPROACHES WITH THE NEXT CHC FOR SHOWERS LATER SUNDAY INTO MONDAY. THIS FRONT IS FORECAST TO STALL OVER THE MID ATLANTIC REGION...WITH THE POTENTIAL FOR WAVES OF LOW PRESSURE TO BRING MORE PCPN INTO THE REGION NEXT MONDAY INTO TUE...BUT THE DETAILS AT THIS POINT ARE ANYTHING BUT CLEAR. && .AVIATION /19Z WEDNESDAY THROUGH MONDAY/... LOW CIGS STRTING TO LIFT AS THE COLDER AND DRIER AIR UNDERCUTS THE MOISTURE WHICH IS GETTING CUT OFF FROM THE GOMEX ALREADY. IMPROVEMENT MAY BE SLOW IN KJST WITH WINDS WNW IN A GOOD UPSLOPE ORIENTATION. SHSN MAY START IN KJST TONIGHT...BUT WILL KEEP FCST BETTER THAN VFR FOR NOW. RAIN SHIELD SHOULD GRADUALLY SHRINK AND SLIDE TO THE EAST PER TRENDS IN RADAR MOSAIC AND MESO MDLS. SLOW MOVEMENT TO THE SFC TROUGH TO THE SE WILL KEEP LIGHT RAIN GOING FOR MOST OF THE EVENING IN THE SE. LITTLE/NO PRECIP EXPECTED OVERNIGHT...BUT A SECONDARY WAVE MAY DEVELOP TONIGHT TO OUR SOUTH AND THROW SOME COLDER PRECIP BACK IN FROM THE SE. LOW POSS AT THIS POINT...AND AT THE OUTER REACHES OF THIS 18Z 24HR TAF PD...BUT SOMETHING TO WATCH FOR ON THURS. UPSLOPE IN THE WEST AND OFF LAKE ERIE WILL GENERATE LAKE EFFECT THURS AFTN INTO FRI AM VCTY KBFD. OUTLOOK... FRI-SAT...VFR. NO SIG WX. SUN...GENERALLY VFR. MVFR POSS LATE. MON...MVFR TS/SHRA/CIGS. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DANGELO/STEINBUGL NEAR TERM...DANGELO SHORT TERM...DANGELO LONG TERM...DEVOIR/GARTNER AVIATION...DANGELO