Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 12/24/13


AREA FORECAST DISCUSSION
NWS PUEBLO CO
341 AM MST SUN DEC 22 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 325 AM MST SUN DEC 22 2013 CURRENTLY... LIGHT SNOW SHOWERS WERE NOTED OVER THE S MTNS/GREATER I-25 CORRIDOR REGION EARLY THIS MORNING. ELSEWHERE...KALS WAS REPORTING DENSE FOG ALTHOUGH THE KALS AIRPORT WEB CAMS WERE NOT SHOWING MUCH IN THE WAY OF FOG AT 2 AM. OTHERWISE...SKIES OVER MOST OF THE REGION WERE MOSTLY CLOUDY...WITH MAINLY MID LVL CLOUDIENESS. TODAY... LIGHT SNOW OVER THE S MTNS/I-25 CORRIDOR REGION WILL DECREASE TOWARDS SUNRISE WITH CLOUDS GRADUALLY DECREASING LATER THIS MORNING. IT WILL BE A COOL DAY ACROSS THE REGION WITH HIGHS GENERALLY IN THE 30S ACROSS THE PLAINS...AND MAINLY TEENS AND 20S MOUNTAINS/VALLEYS. SNOW OVER THE C MTNS WILL DECREASE AND DO NOT EXPECT ANY SIGNIF ACCUMS THIS MORNING AND EARLY AFTERNOON. BY LATER TODAY...ANOTHER DISTURBANCE IN THE NW FLOW WILL MOVE TOWARDS THE C MTNS AND SNOW WILL ONCE AGAIN PICK UP...MAINLY ON THE NW SLOPES. TONIGHT... SNOW IS LIKELY OVER THE C MTNS...ESPECIALLY N OF COTTONWOOD PASS. HEAVIEST ACCUMS...A FEW INCHES..WILL BE LIKELY. WITH THE JET MOVING BACK OVER THE REGION...WINDS AT THE HIGHER ELEVATIONS WILL BE PICKING UP OVER THE MTNS...AND EXPECT WE WILL SEE SOME GUSTS INTO THE 40+ MPH RANGE...ESPECIALLY OVER THE C MTNS...PIKES PEAK AND S MTNS. TRAVEL ACROSS THE C MTN PASSES WILL BE A BIT TRICKY DUE TO THE BLOWING AND FALLING SNOW. TEMPS TONIGHT SHOULD BE A FEW DEGREEES COLDER THAN SUN MORNINGS LOWS AS CLEAR SKIES SHOULD ALLOW FOR BETTER RADIATIONAL COOLING. THE SAN LUIS VALLEY WILL BE QUITE COLD WITH LOWS AOA -10F. /HODANISH .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 325 AM MST SUN DEC 22 2013 ...A DRY WEEK AHEAD... OVERALL WX PATTERN CONTINUES TO LOOK PRETTY DRY FOR THE REMAINDER OF 2013. FIRST FEW DAYS OF THE COMING WEEK WE WILL BE UNDER NW FLOW ALOFT...AND A COUPLE WEAK SHORT WAVES WILL BRING THE CHANCE OF A FEW SHSN FOR THE MTS OF LAKE AND CHAFFEE COUNTY...BUT THE REMAINDER OF SERN CO LOOKS DRY. THE ECMWF IS STILL PROGGING SOME LIGHT QPF WITH THE SHORTWAVE ARRIVING ON TUE...BUT EVEN THE EC HAS BACKED OFF PREVIOUS FORECASTS...AND THE NAM AND GFS ARE COMPLETELY DRY SAVE FOR THE LIGHT SHOWERS OVER THE DVD. HAVE LOWERED POPS TO NEAR ZERO FOR THE REMAINDER OF OUR CWA...SO THERE WILL NOT BE A WHITE CHRISTMAS THIS YEAR. MAIN IMPACT FROM THIS SYSTEM WILL BE TO BRING SLIGHTLY COOLER WX TO OUR AREA FOR CHRISTMAS. A BROAD UPPER RIDGE WILL REBUILD THURSDAY INTO FRIDAY...AND TEMPS OVER THE PLAINS WILL REBOUND TO THE 50S FRI INTO THE EARLY PART OF NEXT WEEKEND...AS H7 TEMPS RISE ABOVE ZERO E OF THE MTS. COULD EVEN SEE SOME 60 DEGREE TEMPS IF THE RIDGE FLATTENS A BIT MORE. POPS REMAIN NR ZERO FOR THIS LATTER PART OF THE WEEK...EVEN OVER THE MTS. THE ECMWF AND GFS THEN DIVERGE FOR THE BALANCE OF NEXT WEEKEND INTO THE NEW YEARS. THE EC BRINGS A WEAK UPPER LOW OVER OUR AREA NEXT SUNDAY...FOLLOWED BY THE RETURN OF NW FLOW AND DRY CONDITIONS. THE GFS SPLITS THE FLOW...LEAVING US MOSTLY DRY SUNDAY...BUT THEN PHASES THE TWO STREAMS BY NEW YEARS...POSSIBLY BRINGING US SOME SNOW TO START OFF 2014. LOW POPS IN THE ENSEMBLE GRIDS LOOK ON TARGET FOR NOW. ROSE && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 325 AM MST SUN DEC 22 2013 KCOS...MAY SEE A SNOWFLAKE OR TWO THIS MORNING PRODUCING BRIEF MVFR...BUT OVERALL EXPECT VFR CONDITIONS NEXT 24H. HRRR WIND FIELDS SHOWING A DIURNAL REGIME SHOOULD SET UP BY LATER TODAY. KPUB...MAY SEE BRIEF MVFR CIGS THIS MORNING...OTHERWISE VFR NEXT 24H. KALS...PATCHY DENSE GROUND FOG LIKELY AT KCOS THIS MORNING. FOG/LOW CLOUDS SHOULD DISSIPATE BY LATE MORNING. NOTICEABLY DRIER AIR JUST OFF THE SURFACE IS EXPECTED TO MOVE INTO THE VALLEY LATE THIS AFTERNOON AND THIS SHOULD DECREASE THE CHANCE OF LOW CLOUDS FORMING LATER TONIGHT. HOWEVER...LOCALLY DENSE GROUND FOG WILL BE POSSIBLE. SNOW SHOWERS WILL BE POSSIBLE OVER HE C MTNS TODAY. SNOW AND WIND WILL PICK UP OVER THE C MTNS LATE THIS AFTERNOON INTO TONIGHT. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...HODANISH LONG TERM...ROSE AVIATION...HODANISH
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1046 PM MST SAT DEC 21 2013 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 250 PM MST SAT DEC 21 2013 UPPER LOW IS LIFTING OUT INTO WESTERN OK WHILE TRAILING ENERGY IS DROPPING ACROSS THE FORECAST AREA IN NW FLOW ALOFT. PRECIPITATION HAS BEEN SLOW TO GET GOING ACROSS THE FORECAST AREA...THOUGH WEB CAMS AND SURFACE OBS ALONG THE CONTDVD HAVE BEEN REPORTING SOME SNOW THROUGH THE DAY. INITIALLY HEAVIEST SNOW AND BEST LIFT WILL BE OUT ACROSS THE FAR SOUTHEAST CORNER OF THE FORECAST AREA WHERE WRAP AROUND PRECIPITATION CONTINUES ACROSS BACA COUNTY. STILL SOME VARIABILITY IN THE SHORT RANGE MODELS FOR SNOW AMOUNTS OUT THAT WAY...BUT AN INCH OR TWO WOULDN`T BE OUT OF THE QUESTION ACROSS SOUTHEAST PORTIONS OF BACA COUNTY. MEANWHILE...SHOULD START TO SEE LIGHT SNOW RAMP UP ACROSS THE EASTERN MOUNTAINS AND ADJACENT PLAINS BY 4 PM...WHICH WILL SPREAD SOUTH AND EAST THROUGH THE EVENING. NAM12 AND HRRR SEEM TO BE BACKING OFF ON SNOWFALL AMOUNTS WITH EACH RUN...WITH NAM12 NOW SHOWING AROUND 2-4 INCHES FOR THE SE MTS. HAVE KEPT SNOW AMOUNTS IN THE 2-6 INCH RANGE AS SUSPECT THERE WILL BE POCKETS OF HEAVIER AMOUNTS...HOWEVER WITHOUT A PERSISTENT DEEP NE UPSLOPE FLOW...THINK THESE HEAVIER AMOUNTS WILL BE MORE LOCALIZED. THUS ADVISORIES DO NOT SEEM WARRANTED AT THIS POINT. LIGHT SNOW WILL WIND DOWN TOWARDS TOMORROW MORNING WITH PARTIAL CLEARING ACROSS WESTERN AND NORTHERN PORTIONS OF THE AREA TOWARDS DAWN. THIS OPENS UP THE POSSIBILITY FOR ANOTHER ROUND OF GROUND FOG AT KALS EARLY SUNDAY MORNING...AND HAVE INTRODUCED THIS TO THE GRIDS. QUIET WEATHER FOR SUNDAY...THOUGH NORTHWEST FLOW MAY KEEP SOME SCATTERED OROGRAPHIC SNOW SHOWERS CONTINUING ACROSS THE CENTRAL MTS. TEMPERATURES TOMORROW MAY END UP SIMILAR TO THOSE OF TODAY...PERHAPS A LITTLE WARMER ACROSS PORTIONS OF THE PLAINS AND A TAD COOLER ACROSS THE MTS WHERE H7 TEMPS WILL BE A LITTLE COOLER BEHIND THIS EVENINGS SYSTEM. -KT .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 250 PM MST SAT DEC 21 2013 SUNDAY NIGHT-MONDAY...STRONG NORTH TO NORTHWEST FLOW ALOFT ACROSS THE REGION SUNDAY NIGHT SLOWLY MODERATES THROUGH THE DAY MONDAY...AS A BROAD UPPER TROUGH AND ASSOCIATED 120KT JET CORE ACROSS THE NORTHERN ROCKIES TRANSLATES OUT ACROSS THE NORTHERN AND CENTRAL HIGH PLAINS. NORTHWEST FLOW ALOFT BEHIND THE SYSTEM LOOKS TO KEEP GENERALLY LIGHT SNOWFALL IN PLACE ACROSS THE CENTRAL MTS THROUGH EARLY MONDAY MORNING...WITH ACCUMULATIONS OF A FEW INCHES POSSIBLE ESPECIALLY NORTH OF COTTONWOOD PASS. PASSING SYSTEM STAYS TOO FAR NORTH AND EAST TO BRING PRECIPITATION TO THE REST OF SOUTH CENTRAL AND SOUTHEAST COLORADO...THOUGH DOES SEND A WEAK COLD FRONT ACROSS THE FAR EASTERN PLAINS EARLY MONDAY MORNING...KEEPING THE COOLEST TEMPERATURES OUT NEAR THE KANSAS BORDER. MONDAY NIGHT-CHRISTMAS DAY...LATEST MODELS CONTINUE TO DOWNPLAY SNOWFALL ACROSS THE AREA FOR CHRISTMAS EVE AND EARLY CHRISTMAS DAY WITH MODERATE NORTHWEST FLOW ALOFT ACROSS THE STATE AS ANOTHER UPPER TROUGH TRANSLATES ACROSS THE NORTHERN ROCKIES. THE 12Z ECMWF IS STILL A TAD DEEPER WITH SAID SYSTEM AND CONTINUES TO PRINT OUT SOME QPF ACROSS THE EASTERN MTS TUESDAY NIGHT...THOUGH WITH ITS H7 FLOW PROGGED TO REMAIN NORTH TO NORTHWEST...ANY SNOW WOULD GENERALLY REMAIN SOUTH OF HIGHWAY 50 ACROSS THE SOUTHERN I-25 CORRIDOR. AT ANY RATE...MODEL CONSENSUS KEEPS SLIGHT POPS ACROSS THE HIGHER TERRAIN AS WELL AS ALONG THE PALMER DVD AND RATON MESA FOR LATE TUESDAY AFTERNOON THROUGH EARLY WEDNESDAY MORNING AND HAVE STAYED THE COURSE FOR NOW. AS FOR TEMPS...WESTERLY FLOW AHEAD OF SAID SYSTEM LOOKS TO KEEP BREEZY WINDS AND WARMING TEMPERATURES ACROSS THE STATE MONDAY NIGHT AND TUESDAY...WITH ANOTHER WEAK COLD FRONT MOVING ACROSS THE PLAINS CHRISTMAS EVE HELPING TO COOL HIGHS TO NEAR SEASONAL AVERAGES FOR CHRISTMAS DAY. WEDNESDAY NIGHT-SATURDAY...MODERATE NORTHWEST FLOW PROGGED ACROSS THE REGION THROUGH THE REST OF THE EXTENDED PERIOD WITH A FEW MINOR DISTURBANCES MOVING THROUGH THE FLOW ACROSS THE NORTHERN ROCKIES AND INTO THE NORTHERN HIGH PLAINS. THIS WILL KEEP THE AREA GENERALLY WARM AND DRY...SAVE A FEW OCCASIONAL FLURRIES ACROSS THE HIGHER TERRAIN OF THE CENTRAL MTS...AS TEMPERATURES WARM BACK TO ABOVE SEASONAL LEVELS THROUGH THE PERIOD. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1044 PM MST SAT DEC 21 2013 VFR CONDITIONS ARE EXPECTED AT KCOS AND KPUB TONIGHT AND SUNDAY. KALS WL PROBABLY SEE SOME STRATUS AND FOG DEVELOP LATER TONIGHT WITH IFR/LIFR CONDITIONS THRU ABOUT 16Z. OTHERWISE KALS WILL HAVE VFR CONDITIONS. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...KT LONG TERM...MW AVIATION...28
AREA FORECAST DISCUSSION
NWS NEW YORK NY
826 PM EST MON DEC 23 2013 .SYNOPSIS... A WEAK COLD FRONT WILL MOVE THROUGH THE REGION TONIGHT...WITH ANOTHER WEAK COLD FRONT MOVING ACROSS THE AREA TUESDAY. HIGH PRESSURE MOVES ACROSS WEDNESDAY AND OFFSHORE WEDNESDAY NIGHT. A WEAK COLD FRONT MOVES ACROSS THURSDAY FOLLOWED BY ANOTHER HIGH BUILDING IN FROM THE SOUTH AND WEST THROUGH MUCH OF THE REMAINDER OF THE PERIOD. A STRONGER COLD FRONT AFFECTS THE REGION LATE NEXT SUNDAY INTO MONDAY. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... FOLLOWED THE 23Z HRRR FOR PCPN TIMING THE REMAINDER OF THE EVE. NO OTHER CHANGES ATTM. UPPER TROUGH CONTINUES TO SHARPEN AND SLIDE THROUGH NEW ENGLAND AND TOWARDS THE NE TONIGHT...WHILE A SECONDARY COLD FRONT CROSSES THE REGION THIS EVENING IN THE WAKE OF A DEPARTING SURFACE WAVE. LIGHT TO MODERATE RAIN WILL GRADUALLY WORK EAST THROUGH THE EVENING...WITH GRADUAL CAA AND DRYING ON GUSTY NW FLOW TONIGHT. LOW LEVEL DRYING EXPECTED...BUT HIGH AND MID CLOUD LIKELY REMAIN OVER THE REGION AHEAD OF APPROACHING SHORTWAVE TROUGH. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... MODELS IN GOOD AGREEMENT WITH SHORTWAVE TROUGH...WITH STRONG VORT ENERGY AT THE BASE...APPROACHING THE REGION TUESDAY AND SWINGING THROUGH TUESDAY EVENING. AT THE SURFACE AN ARCTIC FRONT CROSSES THE REGION LATE TUESDAY/TUESDAY EVENING. MODELS HAVE BEEN FAIRLY CONSISTENT IN SIGNALING A WEAK CLIPPER WITH THE ARCTIC FRONT IN RESPONSE TO THE SHORTWAVE COMING THROUGH...PRODUCING A SWATH OF SNOW SHOWERS ACROSS SW PORTIONS OF THE REGION. CONFIDENCE IS INCREASING IN SEEING A SWATH OF SNOW SHOWERS DEVELOP...BUT THE EXACT AXIS IS STILL A BIT UNCERTAIN. BEST CHANCE FOR SOME SNOW SHOWER ACTIVITY APPEARS TO BE ACROSS SW 1/2 OF THE CWA. POTENTIAL EXISTS FOR A FEW HEAVY SNOW SHOWERS/OR SNOW SQUALLS WITH THIS FEATURE DUE TO COMBINATION OF VORT ENERGY LIFT...MARGINAL INSTABILITY...AND SUFFICIENT MOISTURE CONVERGENCE AHEAD OF THE ARCTIC FRONT. WILL ADDRESS POTENTIAL FOR LOCALLY HAZARDOUS DRIVING CONDITIONS IN HWO FOR LATE CHRISTMAS EVE DAY INTO EVENING...WITH COMBINATION OF LOCALIZED LIGHT SNOW ACCUM AND DROPPING TEMPS. GUSTY NW FLOW AND GLANCING BLOW OF ARCTIC AIR EXPECTED IN THE WAKE OF THIS FEATURE TUESDAY NIGHT. TEMPS ON CHRISTMAS EVE WITH CAA AND INCREASING CLOUD COVER WILL LIKELY ON TOP OUT AROUND FREEZING ACROSS THE INTERIOR AND UPPER 30S COAST. LOWS EARLY CHRISTMAS MORNING LIKELY DROP INTO THE TEENS INTERIOR AND LOWER 20S COAST...WITH WINDCHILLS IN THE SINGLE DIGITS. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... ON THE LARGE SCALE...THE JET STREAM WILL BE LOCATED SOUTH OF THE REGION WED THROUGH NEXT WEEKEND. A SHORTWAVE WILL MOVE ACROSS THU WITH OTHERS THAT MOVE TO THE NORTH FRI AND SAT WITH A LONGER WAVELENGTH TROUGH SETTING UP AND APPROACHING LATE NEXT WEEKEND. AT THE SURFACE...HIGH PRESSURE MOVES ACROSS WED AND OFFSHORE WED NIGHT. A WEAK COLD FRONT MOVES ACROSS THU FOLLOWED BY ANOTHER HIGH BUILDING IN FROM THE SOUTH AND WEST THROUGH MUCH OF THE REMAINDER OF THE PERIOD. A STRONGER COLD FRONT APPROACHES LATE NEXT SUNDAY. TEMPERATURES WILL BE VERY COLD AND APPROXIMATELY 10 DEGREES BELOW NORMAL FOR WEDNESDAY. THEREAFTER TEMPERATURES WILL RETURN TO NEAR NORMAL LEVELS FOR THIS TIME OF YEAR. THE ONLY CHANCES OF PRECIPITATION WILL BE ON THURSDAY AHEAD AND ALONG THE WEAK COLD FRONT. THE VERTICAL FORCING WILL COME FROM POSITIVE VORTICITY ADVECTION AHEAD OF THE DEEPENING SHORTWAVE AND CLOSE PROXIMITY TO THE RIGHT REAR QUAD OF A DEVELOPING SOUTHWEST TO NORTHEAST UPPER LEVEL JET. MODELS DEPICT MUCH OF THIS PRECIP TO BE OFFSHORE SO THE POPS ARE JUST AT SLIGHT CHANCE. THE MODE OF THIS PRECIP WILL BE INITIALLY LIGHT SNOW SHOWERS GRADUALLY CHANGING TO LIGHT RAIN SHOWERS GOING THROUGH THE DAY FROM SOUTH TO NORTH. OTHER SHORTWAVES MOVE ACROSS THEREAFTER WELL TO OUR NORTH WITH HIGH PRESSURE BEING THE GREATER INFLUENCE IN KEEPING CONDITIONS DRY. THE STRONGER COLD FRONT NEXT SUNDAY WILL ALLOW FOR MORE GUSTY WINDS AHEAD OF IT BUT MOISTURE IS MINIMAL WITH THE FRONT WITH ONLY LOW PROBABILITY OF PRECIP. && .AVIATION /02Z TUESDAY THROUGH SATURDAY/... LOW PRES S OF NOVA SCOTIA WILL CONTINUE TO TRACK NE TONIGHT AS WEAK HIGH PRES BUILDS IN FROM THE W. AN UPPER LEVEL DISTURBANCE WILL MOVE ACROSS THE AREA LATE TUE AFTN/EVE. RAIN HAS BEEN SLOW TO PUSH EASTWARD...BUT IT HAS BECOME MORE SCT IN NATURE AND WILL BE OFF AND ON FOR THE NEXT 3-6 HOURS BEFORE FINALLY ENDING. GUSTS ASSOCIATED WITH COLDER AIR/SECONDARY COLD FRONT HAVE STARTED TO MOVE INTO THE AREA AND TIMING OF 02Z AT NYC AIRPORTS LOOKS ON TRACK. DIRECTIONS WILL REMAIN RIGHT OF 310 MAG THROUGH TUE MORNING. THEN...SOME UNCERTAINTY IF WINDS AT KJFK/KLGA BACK TO THE LEFT OF 310 MAG AFT 18Z...HIGHER CONFIDENCE AT KEWR. LOCALIZED IFR/LIFR CONDS AT EASTERN TERMINALS SHOULD IMPROVE BETWEEN 01Z AND 04Z...WITH VFR CONDS ALL TERMINALS AT LEAST THROUGH 18Z TUE. ALL NYC METRO TERMINALS/KSWF/KISP HAVE A CHC TO SEE IFR CONDS IN -SHSN LATE TUE AFTN/EVE AS AN UPPER TROUGH MOVES THROUGH. ...NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KJFK FCSTER COMMENTS: SCT -SHRA ENDING 03-04Z. GUSTS MAY CEASE BEFORE 12Z. OCNL GUSTS IN TEENS POSSIBLE TUE AFTN. KLGA FCSTER COMMENTS: SCT -SHRA ENDING 03-04Z. GUSTS MAY CEASE BEFORE 12Z. OCNL GUSTS IN TEENS POSSIBLE TUE AFTN. KEWR FCSTER COMMENTS: SCT -SHRA ENDING 02-03Z. GUSTS MAY CEASE BEFORE 10Z. OCNL GUSTS IN TEENS POSSIBLE TUE AFTN. KTEB FCSTER COMMENTS: SCT -SHRA ENDING 02-03Z. OCNL GUSTS IN TEENS POSSIBLE TUE AFTN. KHPN FCSTER COMMENTS: SCT -SHRA ENDING 03-04Z. OCNL GUSTS IN TEENS POSSIBLE TUE AFTN. KISP FCSTER COMMENTS: SCT -SHRA ENDING 04-05Z. OCNL GUSTS IN TEENS POSSIBLE TUE AFTN. .OUTLOOK FOR 00Z WEDNESDAY THROUGH SATURDAY... .TUESDAY NIGHT...VFR RETURNS IN LATE EVE WITH NW WINDS 15-20G20-30KT DEVELOPING. .WEDNESDAY-SATURDAY...VFR. WEST-NORTHWEST WINDS AROUND 10 KT. && .MARINE... OCCASIONAL SCA GUSTS EXPECTED THIS EVENING IN WAKE OF COLD FRONTAL PASSAGE...WITH MARGINAL SCA SEAS INTO TUESDAY. A LULL OF A FEW HOURS OF WINDS AND SEAS POSSIBLE TUESDAY MORNING INTO EARLY AFTERNOON...BUT THEN SCA CONDS LIKELY ON OCEAN AND POSSIBLE ON ALL WATERS TUE NIGHT IN WAKE OF ARCTIC FRONTAL PASSAGE. OTHER THAN SOME BRIEF POSSIBLE SCA WIND GUSTS ON THE EASTERN WATERS EARLY WED...BELOW SCA CONDITIONS ARE FORECAST THROUGH WED NIGHT. ANOTHER POSSIBLE PERIOD OF SCA GUSTS FOR EASTERN WATERS THU-THU EVENING BEFORE AND AFTER COLD FRONTAL PASSAGE. ANOTHER CHANCE FOR SCA CONDS SUNDAY INTO MONDAY. && .HYDROLOGY... ADDITIONAL RAINFALL THROUGH THIS EVENING WILL RANGE FROM AROUND 1/10 INCH ACROSS NW AREAS TO 1/3 OF AN INCH FOR EASTERN AREAS. NO HYDROLOGIC PROBLEMS ARE EXPECTED. NO SIGNIFICANT WIDESPREAD PRECIP EXPECTED TUESDAY THROUGH THE END OF THE WEEK. && .EQUIPMENT... THE NEW YORK CITY NOAA ALL HAZARDS WEATHER RADIO STATION KWO35 IS OUT OF SERVICE. DUE TO INTERFERENCE ISSUES WITH THE U.S. COAST GUARD EMERGENCY BROADCAST CHANNEL...THE NEW YORK CITY NOAA ALL HAZARDS WEATHER RADIO STATION KWO35 IS OUT OF SERVICE. DURING THE TIME...THE TRANSMITTER MAY BE RETURNED TO SERVICE INTERMITTENTLY FOR USE OF THE NOAA ALL HAZARDS WEATHER RADIO DURING POTENTIALLY DANGEROUS WEATHER SITUATIONS...FOR ROUTINE WEEKLY TEST OF THE WARNING SYSTEM...AND TO DETERMINE IF THE INTERFERENCE ISSUE HAS BEEN RESOLVED. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST WEDNESDAY FOR ANZ350-353- 355. && $$ SYNOPSIS...SEARS/NV NEAR TERM...JMC/NV SHORT TERM...NV LONG TERM...SEARS/NV AVIATION... MARINE...SEARS/NV HYDROLOGY...SEARS/NV EQUIPMENT...
AREA FORECAST DISCUSSION
NWS ALBANY NY
1257 PM EST SUN DEC 22 2013 .SYNOPSIS... A NEARLY STATIONARY FRONT FROM CENTRAL NEW YORK TO THE MAINE COAST WILL SHIFT SLIGHTLY AS A STORM MOVES ALONG IT TODAY. NORTH OF IT IT WILL BE CHILLY WITH RAIN AND FREEZING RAIN...WITH RAIN AND VERY MILD WEATHER TO ITS SOUTH. THE STORM WILL DRAG A COLD FRONT THROUGH THE REGION TONIGHT AND THEN SLIDE SLOWLY OFFSHORE MONDAY. HIGH PRESSURE WILL BUILD FROM ONTARIO INTO NEW YORK TUESDAY INTO CHRISTMAS...WITH MUCH COLDER AIR FILTERING INTO THE REGION. THE WEEK WILL END WITH A SERIES OF FAST MOVING WEATHER SYSTEMS WITH BOUTS OF SNOW SHOWERS AND GENERALLY SEASONABLE TEMPERATURES. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 1100 AM...HIGHLY VARIABLE CONDITIONS PERSIST ACROSS THE FORECAST AREA. TEMPS ARE IN THE UPPER 20S TO LOWER 30S FROM THE LAKE GEORGE SARATOGA REGION INTO THE CAPITAL DISTRICT...IN THE UPPER 30S TO LOWER 40S IN THE MOHAWK VALLEY...THE ADIRONDACKS AND THE VALLEYS OF SOUTHERN VERMONT...AND IN THE 50S TO MID 60S ELSEWHERE. EVENTUALLY EXPECT THE WARM AIR TO ARRIVE IN ALL LOCATIONS...BUT FOR NOW HAVE ADJUSTED THE HOURLY TEMPS/DEWPOINTS TO REFLECT CURRENT CONDITIONS...AND ALSO LOWERED MAX TEMPS BY AROUND 10 DEGREES IN THOSE AREAS WERE THE LOW-LEVEL COLD AIR STILL PERSISTS. WITH TEMPS NOT MOVING MUCH WHERE THE LOW-LEVEL COLD AIR STILL LINGERS...HAVE EXTENED THE FREEZING RAIN ADVISORY IN THE LAKE GEORGE SARATOGA REGION THROUGH 200 PM. PCPN HAS BECOME INTERMITENT AND LIGHT SO ADDITIONAL ICE ACCUMULATIONS WILL GENERALLY BE UNDER A TENTH OF AN INCH. WITH THE NEXT UPDATE WILL CONSIDER DROPPING THE FLOOD WATCH SINCE IT APPEARS LIKELY THAT ADDITIONAL RAINFALL TODAY WILL BE FAIRLY LIGHT. .PREVIOUS DISCUSSION... AS OF 635 AM EST...WIDE VARIETY OF TEMPERATURES ACROSS THE REGION THIS MORNING WITH STALLED FRONTAL BOUNDARY SITUATED DIRECTLY ACROSS THE CENTRAL PORTION OF THE CWA. NORTH OF THE BOUNDARY...VERY COLD CANADIAN AIR IS BEING PULLED SOUTHWARD THANKS TO A LOW LEVEL NNE FLOW THROUGH THE CHAMPLAIN VALLEY AND INTO THE HUDSON VALLEY REGION. THIS HAS ALLOWED TEMPS TO DROP BELOW FREEZING FOR THE GLENS FALLS AND SARATOGA SPRINGS AREA. TEMPS HAVE FALLEN INTO THE LOW TO MID 30S IN THE CAPITAL REGION. AT THE SAME TIME...VERY WARM TEMPS ALOFT ARE IN PLACE THANKS TO A STRONG SOUTHERLY FLOW. AS A RESULT...SOME OF THE WARMER TEMPS AT THIS HOUR ARE ACROSS THE MOUNTAIN PEAKS OF THE CATSKILLS...SRN GREENS AND BERKSHIRES...WHERE TEMPS ARE WELL INTO THE 50S. ALSO...A SOUTHERLY LOW LEVEL WIND COMING UP THE MID HUDSON VALLEY HAS ALLOWED SOME WARMER AIR TO MOVE TOWARDS POUGHKEEPSIE AND HUDSON...WITH SFC TEMPS HAVING JUMPED UP INTO THE LOW 60S! THE JUST LAUNCHED 12Z KALY SOUNDING SHOWS THE COLD SFC LAYER IS ONLY ABOUT 200 METERS THICK...WITH A WARM NOSE OF ABOUT +16 C AT 850 HPA. WITH AN APPROACHING LOW PRESSURE AREA AND THE SFC BOUNDARY IN PLACE...OVERRUNNING PRECIP HAS MOVED TO THE NORTH OF THE REGION...FALLING AS FZRA/PL ACROSS THE BTV CWA. RIGHT NOW...MUCH OF OUR CWA IS IN A DRY SLOT...WITH JUST SOME SPOTTY FREEZING RAIN ACROSS THE SOUTHEASTERN ADIRONDACKS...AND SOME LIGHT RAIN SHOWERS ACROSS WESTERN NEW ENGLAND. THE LATEST 08Z 3KM HRRR SHOWS THIS DRY SLOT SHOULD START TO FILL IN TOWARDS THE MID MORNING AS THE LOW PRESSURE AREA MOVES NORTHEAST ACROSS THE OHIO VALLEY AND EVENTUALLY TOWARDS UPSTATE NY. RIGHT NOW...WE WILL HOLD CHC POPS FOR THE NEXT FEW HOURS ACROSS CENTRAL/SOUTHERN PARTS OF THE AREA...WITH LIKELY/CATEGORICAL POPS ACROSS THE FAR NORTH NEAR THE BTV CWA BORDER. BY THE LATE MORNING...WE WILL RISE POPS TO LIKELY/CATEGORICAL FOR WESTERN AND CENTRAL PARTS OF THE CWA AS WELL. FOR NOW...IT DOESN/T APPEAR THAT THE CAPITAL REGION WILL BE SEEING ANY MEASUREABLE FREEZING RAIN...AS THE APPROACHING STORM SHOULD ALLOW THE STALLED BOUNDARY TO START TO MOVE NORTHWARD AS A WARM FRONT...AND BRING THE ALBANY AREA INTO THE WARM SECTOR ONCE THE NEXT ROUND OF RAINFALL BEGINS. ALTHOUGH THERE MAY BE A SPOTTY SPRINKLE BEFORE THAT OCCURS...IT SHOULDN/T BE ABLE TO ACCRETE MUCH ICE AT ALL WITH MARGINAL TEMPS AND AN ALREADY WET GROUND. STILL...WE HAVE PASSED ALONG THE MESSAGE THROUGH OUR SOCIAL MEDIA CHANNELS THAT WITH TEMPS NEAR FREEZING...SOME WET SURFACES COULD POTENTIALLY BE SLICK...ALTHOUGH THIS WILL LIKELY BE RATHER SPOTTY. BASED ON WHATS HAPPENING AT KPOU/1B1...THIS WARMER AIR IS ON THE MOVE...AND SHOULD WIN OUT OVER THE COLD AIR IN THE CAPITAL REGION AS THE STRONG STORM SYSTEM MOVES TOWARDS OUR AREA FAIRLY SOON. HOWEVER...FURTHER NORTH ACROSS THE LAKE GEORGE AREA...IT MAY TAKE UNTIL THE MID TO LATE MORNING FOR THE WARM FRONT TO MOVE THROUGH AND TEMPS TO WARM UP. AS A RESULT...A PROLONGED PERIOD OF FREEZING RAIN CAN BE EXPECTED ACROSS THE LAKE GEORGE SARATOGA REGION. ICE ACCRETION AMOUNTS WILL RANGE FROM A TRACE TO A TENTH ACROSS THE SARATOGA SPRINGS AREA TO A FEW TENTHS FOR GLENS FALLS TO ABOUT FOUR TENTHS ACROSS THE NORTH END OF LAKE GEORGE. ASIDE FROM SOME HAZARDOUS DRIVING CONDITIONS...THIS MAY LEAD TO SOME ISOLATED POWER OUTAGES. AREAS IN THE WARM SECTOR SHOULD SEE SFC TEMPS WARM SIGNIFICANTLY...AS THOSE WARMER TEMPS ALOFT ARE MIXED IN THE BOUNDARY LAYER. MAX TEMPS LOOK TO REACH INTO THE 50S ACROSS MUCH OF THE CENTRAL AND SOUTHERN PARTS OF THE AREA...WITH SOME MID 60S FOR THE MID HUDSON VALLEY. WHILE IT WILL RAIN DURING THE MID TO LATE MORNING HOURS...MOST AREAS WILL BE DONE SEEING PRECIPITATION BY THE EARLY TO MID AFTN HOURS...AS THE STORM/S COLD FRONT PASSES THROUGH THE AREA. TOTAL RAINFALL FOR SUNDAY WILL RANGE FROM JUST A QUARTER OF AN INCH ACROSS LITCHFIELD COUNTY CT...TO AROUND THREE QUARTERS OF AN INCH IN THE CAPITAL REGION TO ABOUT AN INCH AND A HALF OVER THE ADIRONDACKS. SEE THE HYDRO SECTION ON HOW WE EXPECT THIS RAINFALL TO AFFECT AREA RIVERS AND STREAMS. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/... FOR THIS PERIOD THE MODEL SUITE (GEM/GFS/ECMWF) ARE IN FAIRLY GOOD AGREEMENT. DURING THE THIS EVENING THE SFC LOW AND ITS UPPER DYNAMICS WILL LIFT NE OUT OF FCA. A SERIES OF 500HPA SHORT WAVES WILL DIG A TROF OVER GRTLKS...MAINTAINING A STRONG SW 500HPA FLOW OVER THE EASTERN THIRD OF THE NATION. FOR A TIME THIS WILL ACT TO WEAKEN THE SFC LOW FURTHER OVER NEW ENG...BUT THE SFC LOW WILL DRAG A CDFNT THROUGH THE REGION TNGT. GIVEN THE UPPER FLOW COOLER AIR WILL BE SLOW TO FILTER IN OVERNIGHT....AND TEMPS WILL REMAIN ABV FREEZING IN MOST AREAS...WITH SNOW MELT CONTINUING. BY MONDAY THIS CDFNT WILL NEARLY STALL ALONG THE EASTERN SEABOARD...AND WITH DIGGING 500HPA TROF INTERACTING WITH THE COASTAL BAROCLINIC ZONE WILL TRIGGER A BOUT OF OVERRUNINNG RAIN...ALONG THE I-95 CORRIDOR THAT WILL BACK BUILD INTO SE PORTIONS OF FCA. QPF DURING MONDAY WITH THIS SHOULD BE 0.25 TO 0.50 IN THESE AREAS...AND GIVEN THESE AREAS WERE IN THE WARM SECTOR MUCH OF THE CURRENT EVENT...THEY MELTED MOST OF THEIR SNOW...BUT HAD LITTLE RAINFALL. ADD TO THAT THE 2-3 DAYS THIS OCCURRED...THE ADDITIONAL RAIN IN SOUTHEAST AREAS MONDAY SHOULD NOT RESULT IN ANYTHING OTHER THAN WITHIN BANK RISES. FURTHER WEST MONDAY AS HIGH PRESSURE BUILDS EAST WIND GRADIENT WILL INCR AND AS THE 500HPA TROF PUSHES EAST A MUCH STRONGER 2NDRY CDFNT WILL PUSH INTO THE REGION LATE MONDAY AND THROUGH MONDAY NIGHT. TEMPS MONDAY WILL HOLDS STEADY THEN FALL DURING THE AFTN. MONDAY NIGHT INTO TUES THE PASSAGE OF THE 500HPA TROF...CAA WILL RESULT IN SCT -SHSN ACTIVITY. HWVR LLVL FLOW WILL BE TOTALLY UNFAVORABLE FOR LK EFFECT OVER EASTERN NY. ONCE THE 500HPA TROF EXITS CHRISTMAS EVE BOTH A 500HPA RIDGE...AND SFC HIGH PRESSURE WILL SETTLE OVER NYS AND MID ATLC REGION. THIS WILL SET THE STAGE FOR A FRIGID NIGHT WITH IDEAL RADIATIONAL COOLING...ONE OF THE LONGEST NIGHTS OF THE YEAR...CLEAR SKIES AND DRY AIR MASS. LOWS WILL PLUNGE TO -20F IN PARTS OF THE ADIRONDACKS TO AROUND 10 IN THE SE. TEMPS WILL RECOVER CHRISTMAS DAY TO THE TEENS AND 20S AS SFC HIGH SLIDES OFFSHORE. SOME CLOUDS MAY ARRIVE IN THE AFTERNOON AS NEXT WEAK SYSTEM APPROACHES. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... THE EFP WILL FEATURE A SERIES OF FAST MOVING SYSTEMS IN W-NW FLOW. MOST WILL BE FAIRLY WK CDFNTS AND/OR 500HPA SHORT WVS...WHICH WILL INCR CLOUDS AND PRODUCE SCT -SHSN AND AT TIMES HAVE SOME INTERACTION WITH THE GRTLKS. TEMPS WILL RETURN TO NEAR NORMALS AFTER A FRIGID CHRISTMAS. TYPICAL WINTER IN UPSTATE NY. CHRISTMAS NIGHT AND THURS THE FIRST OF THESE SYSTEMS RACES ACROSS ONTARIO...WITH A FEW WEAK FRONTS AND A 500HPA SHORT WV. MAIN IMPACTS WILL INCR CLOUDS MAINLY N & W. THU NT IT WILL DRAG A CDFNT THROUGH WITH SOME -SHSN ACTIVITY MAINLY N & WEST. IN ITS WAKE FRI CAA AND A 2NDARY CDFNT AND NW FLOW WILL TRIGGER SCT -SHSN WITH SOME LK ASSISTANCE. WK SFC HIGH BUILDS OVER FCA FRI NT. SAT ANOTHER WK SHORT WV AND SFC SYSTEM MOVES THROUGH THE GRTLKS WITH A LITTLE WAA INCRG CLOUDS AND SCT -SHSN IN ECMWF...GETTING SOME ASSIST FM THE LKS. GFS HAS MORE CLOUDS AND A WIDESPREAD LT -SN OF MAYBE AN INCH. SAT NT INTO SUN FLOW BCMS ZONAL TO WSW AT 500HPA. WMFNT AND SFC LOW SETS UP N OF RGN. NOT MUCH DIFFERENCE BWTN GFS AND ECMWF. WILL POPULATE WITH HPC MID SHIFT AND TWEAK POPS A TAD. OTHERWISE A QUIET PERIOD FOR THE HOLIDAY WEEK. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... THIS AFTERNOON...FLIGHT CONDITIONS WILL CONTINUE TO DEPEND ON THE PLACEMENT OF A STALLED FRONTAL BOUNDARY...AND THE DIVIDING LINE BETWEEN COOLER AND MORE STABLE AIR AND WARMER AND MORE WELL-MIXED AIR. EXPECT KGFL/KALB TO REMAIN IN PREDOMINATELY IFR FLYING CONDITIONS...AS MOISTURE AND COOL AIR FUNNELING DOWN THE HUDSON RIVER VALLEY COMBINED WITH AN EXTREMELY STABLE BOUNDARY LAYER KEEP FOG AT THESE LOCATIONS. HAVE ADDRESSED A TEMPO GROUP FROM 18Z-20Z AT KGFL WHERE SUB-FREEZING TEMPERATURES AND PASSING SHOWERS MAY ALLOW FOR A BRIEF PERIOD OF PATCHY FREEZING DRIZZLE AS WELL. MEANWHILE...WARMER AND MORE MIXED AIR WILL ALLOW FOR PREDOMINATELY VFR FLYING CONDITIONS MINUS OCCASIONAL MVFR FROM PASSING SHOWERS AT KPOU/KPSF. HAVE ADDRESSED THESE WITH TEMPO GROUPS. THE SHOWERS WILL GRADUALLY END FROM WEST TO EAST BY THIS EVENING. WINDS WILL BE INITIALLY LIGHT AND VARIABLE AT KGFL/KALB BEFORE BECOMING SOUTHWEST AROUND 5-10 KNOTS BY THE EARLY EVENING HOURS. SOUTHWEST WINDS WILL BE AROUND 10 KNOTS AT KPOU AND KPSF...WITH GUSTS UP TO 20-25 KNOTS. HAVE INCLUDED LLWS AT KGFL AND KALB THROUGH THE AFTERNOON HOURS AS A STRONG LOW-LEVEL JET MOVES ACROSS THE REGION BEFORE LIFTING TO THE NORTHEAST THIS EVENING. TONIGHT INTO MONDAY...DESPITE THE EXPECTED FRONTAL PASSAGE TONIGHT AND ASSOCIATED MIXING ALONG WITH IT...ABUNDANT RESIDUAL LOW-LEVEL MOISTURE WILL REMAIN ENTRENCHED ACROSS THE REGION. THE BOUNDARY LAYER NIGHTTIME PROFILE WILL ALSO CONTINUE TO BE STABLE ALLOWING FOR PERSISTING IFR FOG AT KGFL/KALB...AND MVFR LOW STRATUS AT KPOU/KPSF. WINDS WILL BE LIGHT TONIGHT GENERALLY LESS THAN 5 KNOTS. ANOTHER STORM SYSTEM APPROACHING FROM THE MID-ATLANTIC WILL PROVIDE THE FOCUS FOR ADDITIONAL ROUNDS OF SHOWERS MAINLY FOR KPOU/KPSF LATE IN THE TAF PERIOD. WINDS WILL BECOME SOUTHWESTERLY MONDAY AROUND 5-10 KNOTS. OUTLOOK... MONDAY: LOW OPERATIONAL IMPACT. CHANCE OF -SHRAS. MONDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...SHSN. TUESDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. TUESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. CHRISTMAS DAY: NO OPERATIONAL IMPACT. NO SIG WX. WEDNESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. THURSDAY-FRIDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. && .HYDROLOGY... MILD TO UNSEASONABLY WARM TEMPERATURES WILL OCCUR THOUGH TONIGHT WITH INCREASING SNOW MELT. LOW PRESSURE WILL MOVE ALONG A NEARLY STATIONARY FRONT FROM THE NIAGARA FRONTIER TO NEW ENGLAND BY THIS EVENING. 1-2 INCHES OF ADDITIONAL RAINFALL IS EXPECTED IN THE ADIRONDACKS...WITH LESSER AMOUNTS SOUTH. TEMPERATURES TODAY WILL WARM INTO THE 50S AND 60S REMAIN ABOVE FREEZING TONIGHT. IN THE NORTH RAINFALL AMOUNTS WILL BE GREATEST...BUT SNOW MELT SLOWER...WHILE IN THE SOUTH RAINFALL WILL BE AROUND A HALF INCH...BUT ALMOST ALL THE SNOW WILL MELT. EVEN AS THE RAIN TAPERS OFF THIS EVENING...SNOW MELT AND RUNOFF WILL CONTINUE TONIGHT. IN THE SOUTH THE RAINFALL WILL BE SUFFICIENT FOR SIGNIFICANT WITHIN BANK RISES...BUT FLOODING IS NOT EXPECTED AT THIS TIME. THE GREATEST POTENTIAL FOR FLOODING WILL EXIST FROM THE MOHAWK VALLEY INTO THE ADIRONDACKS WHERE 1 TO 2 INCHES ADDITIONAL RAIN AND UP TO AN INCH OF LIQUID EQUIVALENT FROM SNOW MELT IS EXPECTED. FLOOD WATCHES REMAIN IN EFFECT THROUGH TONIGHT. 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...FREEZING RAIN ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR NYZ041>043-083-084. MA...NONE. VT...NONE. && $$ SYNOPSIS...SNYDER NEAR TERM...FRUGIS/GJM SHORT TERM...SNYDER LONG TERM...SNYDER AVIATION...IRL HYDROLOGY...SNYDER
AREA FORECAST DISCUSSION
NWS ALBANY NY
1112 AM EST SUN DEC 22 2013 .SYNOPSIS... A NEARLY STATIONARY FRONT FROM CENTRAL NEW YORK TO THE MAINE COAST WILL SHIFT SLIGHTLY AS A STORM MOVES ALONG IT TODAY. NORTH OF IT IT WILL BE CHILLY WITH RAIN AND FREEZING RAIN...WITH RAIN AND VERY MILD WEATHER TO ITS SOUTH. THE STORM WILL DRAG A COLD FRONT THROUGH THE REGION TONIGHT AND THEN SLIDE SLOWLY OFFSHORE MONDAY. HIGH PRESSURE WILL BUILD FROM ONTARIO INTO NEW YORK TUESDAY INTO CHRISTMAS...WITH MUCH COLDER AIR FILTERING INTO THE REGION. THE WEEK WILL END WITH A SERIES OF FAST MOVING WEATHER SYSTEMS WITH BOUTS OF SNOW SHOWERS AND GENERALLY SEASONABLE TEMPERATURES. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 1100 AM...HIGHLY VARIABLE CONDITIONS PERSIST ACROSS THE FORECAST AREA. TEMPS ARE IN THE UPPER 20S TO LOWER 30S FROM THE LAKE GEORGE SARATOGA REGION INTO THE CAPITAL DISTRICT...IN THE UPPER 30S TO LOWER 40S IN THE MOHAWK VALLEY...THE ADIRONDACKS AND THE VALLEYS OF SOUTHERN VERMONT...AND IN THE 50S TO MID 60S ELSEWHERE. EVENTUALLY EXPECT THE WARM AIR TO ARRIVE IN ALL LOCATIONS...BUT FOR NOW HAVE ADJUSTED THE HOURLY TEMPS/DEWPOINTS TO REFLECT CURRENT CONDITIONS...AND ALSO LOWERED MAX TEMPS BY AROUND 10 DEGREES IN THOSE AREAS WERE THE LOW-LEVEL COLD AIR STILL PERSISTS. WITH TEMPS NOT MOVING MUCH WHERE THE LOW-LEVEL COLD AIR STILL LINGERS...HAVE EXTENED THE FREEZING RAIN ADVISORY IN THE LAKE GEORGE SARATOGA REGION THROUGH 200 PM. PCPN HAS BECOME INTERMITENT AND LIGHT SO ADDITIONAL ICE ACCUMULATIONS WILL GENERALLY BE UNDER A TENTH OF AN INCH. WITH THE NEXT UPDATE WILL CONSIDER DROPPING THE FLOOD WATCH SINCE IT APPEARS LIKELY THAT ADDITIONAL RAINFALL TODAY WILL BE FAIRLY LIGHT. .PREVIOUS DISCUSSION... AS OF 635 AM EST...WIDE VARIETY OF TEMPERATURES ACROSS THE REGION THIS MORNING WITH STALLED FRONTAL BOUNDARY SITUATED DIRECTLY ACROSS THE CENTRAL PORTION OF THE CWA. NORTH OF THE BOUNDARY...VERY COLD CANADIAN AIR IS BEING PULLED SOUTHWARD THANKS TO A LOW LEVEL NNE FLOW THROUGH THE CHAMPLAIN VALLEY AND INTO THE HUDSON VALLEY REGION. THIS HAS ALLOWED TEMPS TO DROP BELOW FREEZING FOR THE GLENS FALLS AND SARATOGA SPRINGS AREA. TEMPS HAVE FALLEN INTO THE LOW TO MID 30S IN THE CAPITAL REGION. AT THE SAME TIME...VERY WARM TEMPS ALOFT ARE IN PLACE THANKS TO A STRONG SOUTHERLY FLOW. AS A RESULT...SOME OF THE WARMER TEMPS AT THIS HOUR ARE ACROSS THE MOUNTAIN PEAKS OF THE CATSKILLS...SRN GREENS AND BERKSHIRES...WHERE TEMPS ARE WELL INTO THE 50S. ALSO...A SOUTHERLY LOW LEVEL WIND COMING UP THE MID HUDSON VALLEY HAS ALLOWED SOME WARMER AIR TO MOVE TOWARDS POUGHKEEPSIE AND HUDSON...WITH SFC TEMPS HAVING JUMPED UP INTO THE LOW 60S! THE JUST LAUNCHED 12Z KALY SOUNDING SHOWS THE COLD SFC LAYER IS ONLY ABOUT 200 METERS THICK...WITH A WARM NOSE OF ABOUT +16 C AT 850 HPA. WITH AN APPROACHING LOW PRESSURE AREA AND THE SFC BOUNDARY IN PLACE...OVERRUNNING PRECIP HAS MOVED TO THE NORTH OF THE REGION...FALLING AS FZRA/PL ACROSS THE BTV CWA. RIGHT NOW...MUCH OF OUR CWA IS IN A DRY SLOT...WITH JUST SOME SPOTTY FREEZING RAIN ACROSS THE SOUTHEASTERN ADIRONDACKS...AND SOME LIGHT RAIN SHOWERS ACROSS WESTERN NEW ENGLAND. THE LATEST 08Z 3KM HRRR SHOWS THIS DRY SLOT SHOULD START TO FILL IN TOWARDS THE MID MORNING AS THE LOW PRESSURE AREA MOVES NORTHEAST ACROSS THE OHIO VALLEY AND EVENTUALLY TOWARDS UPSTATE NY. RIGHT NOW...WE WILL HOLD CHC POPS FOR THE NEXT FEW HOURS ACROSS CENTRAL/SOUTHERN PARTS OF THE AREA...WITH LIKELY/CATEGORICAL POPS ACROSS THE FAR NORTH NEAR THE BTV CWA BORDER. BY THE LATE MORNING...WE WILL RISE POPS TO LIKELY/CATEGORICAL FOR WESTERN AND CENTRAL PARTS OF THE CWA AS WELL. FOR NOW...IT DOESN/T APPEAR THAT THE CAPITAL REGION WILL BE SEEING ANY MEASUREABLE FREEZING RAIN...AS THE APPROACHING STORM SHOULD ALLOW THE STALLED BOUNDARY TO START TO MOVE NORTHWARD AS A WARM FRONT...AND BRING THE ALBANY AREA INTO THE WARM SECTOR ONCE THE NEXT ROUND OF RAINFALL BEGINS. ALTHOUGH THERE MAY BE A SPOTTY SPRINKLE BEFORE THAT OCCURS...IT SHOULDN/T BE ABLE TO ACCRETE MUCH ICE AT ALL WITH MARGINAL TEMPS AND AN ALREADY WET GROUND. STILL...WE HAVE PASSED ALONG THE MESSAGE THROUGH OUR SOCIAL MEDIA CHANNELS THAT WITH TEMPS NEAR FREEZING...SOME WET SURFACES COULD POTENTIALLY BE SLICK...ALTHOUGH THIS WILL LIKELY BE RATHER SPOTTY. BASED ON WHATS HAPPENING AT KPOU/1B1...THIS WARMER AIR IS ON THE MOVE...AND SHOULD WIN OUT OVER THE COLD AIR IN THE CAPITAL REGION AS THE STRONG STORM SYSTEM MOVES TOWARDS OUR AREA FAIRLY SOON. HOWEVER...FURTHER NORTH ACROSS THE LAKE GEORGE AREA...IT MAY TAKE UNTIL THE MID TO LATE MORNING FOR THE WARM FRONT TO MOVE THROUGH AND TEMPS TO WARM UP. AS A RESULT...A PROLONGED PERIOD OF FREEZING RAIN CAN BE EXPECTED ACROSS THE LAKE GEORGE SARATOGA REGION. ICE ACCRETION AMOUNTS WILL RANGE FROM A TRACE TO A TENTH ACROSS THE SARATOGA SPRINGS AREA TO A FEW TENTHS FOR GLENS FALLS TO ABOUT FOUR TENTHS ACROSS THE NORTH END OF LAKE GEORGE. ASIDE FROM SOME HAZARDOUS DRIVING CONDITIONS...THIS MAY LEAD TO SOME ISOLATED POWER OUTAGES. AREAS IN THE WARM SECTOR SHOULD SEE SFC TEMPS WARM SIGNIFICANTLY...AS THOSE WARMER TEMPS ALOFT ARE MIXED IN THE BOUNDARY LAYER. MAX TEMPS LOOK TO REACH INTO THE 50S ACROSS MUCH OF THE CENTRAL AND SOUTHERN PARTS OF THE AREA...WITH SOME MID 60S FOR THE MID HUDSON VALLEY. WHILE IT WILL RAIN DURING THE MID TO LATE MORNING HOURS...MOST AREAS WILL BE DONE SEEING PRECIPITATION BY THE EARLY TO MID AFTN HOURS...AS THE STORM/S COLD FRONT PASSES THROUGH THE AREA. TOTAL RAINFALL FOR SUNDAY WILL RANGE FROM JUST A QUARTER OF AN INCH ACROSS LITCHFIELD COUNTY CT...TO AROUND THREE QUARTERS OF AN INCH IN THE CAPITAL REGION TO ABOUT AN INCH AND A HALF OVER THE ADIRONDACKS. SEE THE HYDRO SECTION ON HOW WE EXPECT THIS RAINFALL TO AFFECT AREA RIVERS AND STREAMS. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/... FOR THIS PERIOD THE MODEL SUITE (GEM/GFS/ECMWF) ARE IN FAIRLY GOOD AGREEMENT. DURING THE THIS EVENING THE SFC LOW AND ITS UPPER DYNAMICS WILL LIFT NE OUT OF FCA. A SERIES OF 500HPA SHORT WAVES WILL DIG A TROF OVER GRTLKS...MAINTAINING A STRONG SW 500HPA FLOW OVER THE EASTERN THIRD OF THE NATION. FOR A TIME THIS WILL ACT TO WEAKEN THE SFC LOW FURTHER OVER NEW ENG...BUT THE SFC LOW WILL DRAG A CDFNT THROUGH THE REGION TNGT. GIVEN THE UPPER FLOW COOLER AIR WILL BE SLOW TO FILTER IN OVERNIGHT....AND TEMPS WILL REMAIN ABV FREEZING IN MOST AREAS...WITH SNOW MELT CONTINUING. BY MONDAY THIS CDFNT WILL NEARLY STALL ALONG THE EASTERN SEABOARD...AND WITH DIGGING 500HPA TROF INTERACTING WITH THE COASTAL BAROCLINIC ZONE WILL TRIGGER A BOUT OF OVERRUNINNG RAIN...ALONG THE I-95 CORRIDOR THAT WILL BACK BUILD INTO SE PORTIONS OF FCA. QPF DURING MONDAY WITH THIS SHOULD BE 0.25 TO 0.50 IN THESE AREAS...AND GIVEN THESE AREAS WERE IN THE WARM SECTOR MUCH OF THE CURRENT EVENT...THEY MELTED MOST OF THEIR SNOW...BUT HAD LITTLE RAINFALL. ADD TO THAT THE 2-3 DAYS THIS OCCURRED...THE ADDITIONAL RAIN IN SOUTHEAST AREAS MONDAY SHOULD NOT RESULT IN ANYTHING OTHER THAN WITHIN BANK RISES. FURTHER WEST MONDAY AS HIGH PRESSURE BUILDS EAST WIND GRADIENT WILL INCR AND AS THE 500HPA TROF PUSHES EAST A MUCH STRONGER 2NDRY CDFNT WILL PUSH INTO THE REGION LATE MONDAY AND THROUGH MONDAY NIGHT. TEMPS MONDAY WILL HOLDS STEADY THEN FALL DURING THE AFTN. MONDAY NIGHT INTO TUES THE PASSAGE OF THE 500HPA TROF...CAA WILL RESULT IN SCT -SHSN ACTIVITY. HWVR LLVL FLOW WILL BE TOTALLY UNFAVORABLE FOR LK EFFECT OVER EASTERN NY. ONCE THE 500HPA TROF EXITS CHRISTMAS EVE BOTH A 500HPA RIDGE...AND SFC HIGH PRESSURE WILL SETTLE OVER NYS AND MID ATLC REGION. THIS WILL SET THE STAGE FOR A FRIGID NIGHT WITH IDEAL RADIATIONAL COOLING...ONE OF THE LONGEST NIGHTS OF THE YEAR...CLEAR SKIES AND DRY AIR MASS. LOWS WILL PLUNGE TO -20F IN PARTS OF THE ADIRONDACKS TO AROUND 10 IN THE SE. TEMPS WILL RECOVER CHRISTMAS DAY TO THE TEENS AND 20S AS SFC HIGH SLIDES OFFSHORE. SOME CLOUDS MAY ARRIVE IN THE AFTERNOON AS NEXT WEAK SYSTEM APPROACHES. && .LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/... THE EFP WILL FEATURE A SERIES OF FAST MOVING SYSTEMS IN W-NW FLOW. MOST WILL BE FAIRLY WK CDFNTS AND/OR 500HPA SHORT WVS...WHICH WILL INCR CLOUDS AND PRODUCE SCT -SHSN AND AT TIMES HAVE SOME INTERACTION WITH THE GRTLKS. TEMPS WILL RETURN TO NEAR NORMALS AFTER A FRIGID CHRISTMAS. TYPICAL WINTER IN UPSTATE NY. CHRISTMAS NIGHT AND THURS THE FIRST OF THESE SYSTEMS RACES ACROSS ONTARIO...WITH A FEW WEAK FRONTS AND A 500HPA SHORT WV. MAIN IMPACTS WILL INCR CLOUDS MAINLY N & W. THU NT IT WILL DRAG A CDFNT THROUGH WITH SOME -SHSN ACTIVITY MAINLY N & WEST. IN ITS WAKE FRI CAA AND A 2NDARY CDFNT AND NW FLOW WILL TRIGGER SCT -SHSN WITH SOME LK ASSISTANCE. WK SFC HIGH BUILDS OVER FCA FRI NT. SAT ANOTHER WK SHORT WV AND SFC SYSTEM MOVES THROUGH THE GRTLKS WITH A LITTLE WAA INCRG CLOUDS AND SCT -SHSN IN ECMWF...GETTING SOME ASSIST FM THE LKS. GFS HAS MORE CLOUDS AND A WIDESPREAD LT -SN OF MAYBE AN INCH. SAT NT INTO SUN FLOW BCMS ZONAL TO WSW AT 500HPA. WMFNT AND SFC LOW SETS UP N OF RGN. NOT MUCH DIFFERENCE BWTN GFS AND ECMWF. WILL POPULATE WITH HPC MID SHIFT AND TWEAK POPS A TAD. OTHERWISE A QUIET PERIOD FOR THE HOLIDAY WEEK. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/... A FRONTAL BOUNDARY WILL BE OVER UPSTATE NY AND NEW ENGLAND TODAY WITH AREAS OF LOW PRESSURE MOVING ALONG IT. THIS BOUNDARY WILL DIVIDE VERY COLD AIR FROM UNSEASONABLY MILD AIR OVER THE E-CNTRL NY CORRIDOR WITH SOME FREEZING RAIN CONTINUING FOR KGFL INTO THE LATE MORNING...AND SOME SCT SHOWERS FROM KALB-KPSF SOUTHWARD LATE THIS MORNING INTO THE AFTERNOON. THE BOUNDARY WILL CONTINUE TO LIFT NORTH...AS A WARM FRONT RAPIDLY THIS MORNING. FLIGHT CONDITIONS VARY FROM LIFR/IFR AT KGFL/KALB/KPSF TO VFR/MVFR AT KPOU THIS MORNING. CONDITIONS WILL IMPROVE TO VFR LEVELS AT KPOU WITH BETTER MIXING...AS THE FRONTAL BOUNDARY LIFTS NORTHWARD. SOME PATCHY MVFR MIST MAY BE AROUND IN THE LATE MORNING THERE. FURTHER NORTH...IFR/MVFR CONDITIONS WILL PERSIST INTO THE AFTERNOON WITH LIGHT FREEZING RAIN TRANSITIONING TO RAIN AT KGFL AT 16Z. MOST OF THE FLIGHT CONDITIONS THIS AFTERNOON MAY BE IN THE MVFR RANGE...AS THE FRONT LIFTS NORTH OF ALL THE TERMINALS. SOME DRIZZLE SHOULD LINGER INTO THIS EVENING...WHICH MAY ALLOW FOR MVFR OR BRIEF PERIODS OF IFR CIGS/VSBYS AT ALL THE TAF SITES...EXCEPT FOR KALB WHERE LOW VFR LOOKS POSSIBLE. THE CIGS MAY START TO RISE AROUND MIDNIGHT WITH SOME DRIER AIR STARTING TO FILTER IN FROM THE SOUTHWEST. LOW LEVEL WIND SHEAR WILL BE A PROBLEM THIS MORNING AT ALL THE TAF SITES WITH 2 KFT AGL WINDS FROM THE S/SW AT 45-60 KTS. THE LOW LEVEL WIND SHEAR LOOKS TO LAST INTO THE EARLY TO MID AFTERNOON AT THE TERMINALS. THE LOW LEVEL JET STARTS TO LIFT NORTH AND EAST AT THAT TIME. AT THE SFC...THE WINDS WILL VEER FROM THE EAST OR NORTHEAST AT KGFL/KALB TO THE SOUTH AT 8-15 KTS WITH SOME GUSTS CLOSE TO 25 KTS AT KALB AND KPOU. THE WINDS WILL DECREASE FROM THE S/SW AT LESS THAN 10 KTS AFTER 00Z/MON. OUTLOOK... MONDAY: LOW OPERATIONAL IMPACT. CHANCE OF -SHRAS. MONDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...SHSN. TUESDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. TUESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. CHRISTMAS DAY: NO OPERATIONAL IMPACT. NO SIG WX. WEDNESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. THURSDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. && .HYDROLOGY... MILD TO UNSEASONABLY WARM TEMPERATURES WILL OCCUR THOUGH TONIGHT WITH INCREASING SNOW MELT. LOW PRESSURE WILL MOVE ALONG A NEARLY STATIONARY FRONT FROM THE NIAGARA FRONTIER TO NEW ENGLAND BY THIS EVENING. 1-2 INCHES OF ADDITIONAL RAINFALL IS EXPECTED IN THE ADIRONDACKS...WITH LESSER AMOUNTS SOUTH. TEMPERATURES TODAY WILL WARM INTO THE 50S AND 60S REMAIN ABOVE FREEZING TONIGHT. IN THE NORTH RAINFALL AMOUNTS WILL BE GREATEST...BUT SNOW MELT SLOWER...WHILE IN THE SOUTH RAINFALL WILL BE AROUND A HALF INCH...BUT ALMOST ALL THE SNOW WILL MELT. EVEN AS THE RAIN TAPERS OFF THIS EVENING...SNOW MELT AND RUNOFF WILL CONTINUE TONIGHT. IN THE SOUTH THE RAINFALL WILL BE SUFFICIENT FOR SIGNIFICANT WITHIN BANK RISES...BUT FLOODING IS NOT EXPECTED AT THIS TIME. THE GREATEST POTENTIAL FOR FLOODING WILL EXIST FROM THE MOHAWK VALLEY INTO THE ADIRONDACKS WHERE 1 TO 2 INCHES ADDITIONAL RAIN AND UP TO AN INCH OF LIQUID EQUIVALENT FROM SNOW MELT IS EXPECTED. FLOOD WATCHES REMAIN IN EFFECT THROUGH TONIGHT. 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...FREEZING RAIN ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR NYZ041>043-083-084. FLOOD WATCH THROUGH MONDAY MORNING FOR NYZ032-033-038>040-042- 043-082. MA...NONE. VT...NONE. && $$ SYNOPSIS...SNYDER NEAR TERM...GJM/FRUGIS SHORT TERM...SNYDER LONG TERM...SNYDER AVIATION...WASULA HYDROLOGY...SNYDER
AREA FORECAST DISCUSSION
NWS ALBANY NY
956 AM EST SUN DEC 22 2013 .SYNOPSIS... A NEARLY STATIONARY FRONT FROM CENTRAL NEW YORK TO THE MAINE COAST WILL SHIFT SLIGHTLY AS A STORM MOVES ALONG IT TODAY. NORTH OF IT IT WILL BE CHILLY WITH RAIN AND FREEZING RAIN...WITH RAIN AND VERY MILD WEATHER TO ITS SOUTH. THE STORM WILL DRAG A COLD FRONT THROUGH THE REGION TONIGHT AND THEN SLIDE SLOWLY OFFSHORE MONDAY. HIGH PRESSURE WILL BUILD FROM ONTARIO INTO NEW YORK TUESDAY INTO CHRISTMAS...WITH MUCH COLDER AIR FILTERING INTO THE REGION. THE WEEK WILL END WITH A SERIES OF FAST MOVING WEATHER SYSTEMS WITH BOUTS OF SNOW SHOWERS AND GENERALLY SEASONABLE TEMPERATURES. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 930 AM...HIGHLY VARIABLE CONDITIONS PERSIST ACROSS THE FORECAST AREA. TEMPS ARE IN THE UPPER 20S TO LOWER 30S FROMT THE LAKE GEORGE SARATOGA REGION INTO THE CAPITAL DISTRICT...IN THE UPPER 30S TO LOWER 40S IN THE MOHAWK VALLEY AND THE VALLEYS OF SOUTHERN VERMONT...AND IN THE 50S TO MID 60S ELSEWHERE. EVENTUALLY EXPECT THE WARM AIR TO ARRIVE IN ALL LOCATIONS...BUT FOR NOW HAVE ADJUSTED THE HOURLY TEMPS/DEWPOINTS TO REFLECT CURRENT CONDITIONS. IF TEMPS DO NOT RISE IN THE LAKE GEORGE SARATOGA REGION SOON...MAY NEED TO EXTEND THE FREEZING RAIN ADVISORY A LITTLE LONGER. .PREVIOUS DISCUSSION... AS OF 635 AM EST...WIDE VARIETY OF TEMPERATURES ACROSS THE REGION THIS MORNING WITH STALLED FRONTAL BOUNDARY SITUATED DIRECTLY ACROSS THE CENTRAL PORTION OF THE CWA. NORTH OF THE BOUNDARY...VERY COLD CANADIAN AIR IS BEING PULLED SOUTHWARD THANKS TO A LOW LEVEL NNE FLOW THROUGH THE CHAMPLAIN VALLEY AND INTO THE HUDSON VALLEY REGION. THIS HAS ALLOWED TEMPS TO DROP BELOW FREEZING FOR THE GLENS FALLS AND SARATOGA SPRINGS AREA. TEMPS HAVE FALLEN INTO THE LOW TO MID 30S IN THE CAPITAL REGION. AT THE SAME TIME...VERY WARM TEMPS ALOFT ARE IN PLACE THANKS TO A STRONG SOUTHERLY FLOW. AS A RESULT...SOME OF THE WARMER TEMPS AT THIS HOUR ARE ACROSS THE MOUNTAIN PEAKS OF THE CATSKILLS...SRN GREENS AND BERKSHIRES...WHERE TEMPS ARE WELL INTO THE 50S. ALSO...A SOUTHERLY LOW LEVEL WIND COMING UP THE MID HUDSON VALLEY HAS ALLOWED SOME WARMER AIR TO MOVE TOWARDS POUGHKEEPSIE AND HUDSON...WITH SFC TEMPS HAVING JUMPED UP INTO THE LOW 60S! THE JUST LAUNCHED 12Z KALY SOUNDING SHOWS THE COLD SFC LAYER IS ONLY ABOUT 200 METERS THICK...WITH A WARM NOSE OF ABOUT +16 C AT 850 HPA. WITH AN APPROACHING LOW PRESSURE AREA AND THE SFC BOUNDARY IN PLACE...OVERRUNNING PRECIP HAS MOVED TO THE NORTH OF THE REGION...FALLING AS FZRA/PL ACROSS THE BTV CWA. RIGHT NOW...MUCH OF OUR CWA IS IN A DRY SLOT...WITH JUST SOME SPOTTY FREEZING RAIN ACROSS THE SOUTHEASTERN ADIRONDACKS...AND SOME LIGHT RAIN SHOWERS ACROSS WESTERN NEW ENGLAND. THE LATEST 08Z 3KM HRRR SHOWS THIS DRY SLOT SHOULD START TO FILL IN TOWARDS THE MID MORNING AS THE LOW PRESSURE AREA MOVES NORTHEAST ACROSS THE OHIO VALLEY AND EVENTUALLY TOWARDS UPSTATE NY. RIGHT NOW...WE WILL HOLD CHC POPS FOR THE NEXT FEW HOURS ACROSS CENTRAL/SOUTHERN PARTS OF THE AREA...WITH LIKELY/CATEGORICAL POPS ACROSS THE FAR NORTH NEAR THE BTV CWA BORDER. BY THE LATE MORNING...WE WILL RISE POPS TO LIKELY/CATEGORICAL FOR WESTERN AND CENTRAL PARTS OF THE CWA AS WELL. FOR NOW...IT DOESN/T APPEAR THAT THE CAPITAL REGION WILL BE SEEING ANY MEASUREABLE FREEZING RAIN...AS THE APPROACHING STORM SHOULD ALLOW THE STALLED BOUNDARY TO START TO MOVE NORTHWARD AS A WARM FRONT...AND BRING THE ALBANY AREA INTO THE WARM SECTOR ONCE THE NEXT ROUND OF RAINFALL BEGINS. ALTHOUGH THERE MAY BE A SPOTTY SPRINKLE BEFORE THAT OCCURS...IT SHOULDN/T BE ABLE TO ACCRETE MUCH ICE AT ALL WITH MARGINAL TEMPS AND AN ALREADY WET GROUND. STILL...WE HAVE PASSED ALONG THE MESSAGE THROUGH OUR SOCIAL MEDIA CHANNELS THAT WITH TEMPS NEAR FREEZING...SOME WET SURFACES COULD POTENTIALLY BE SLICK...ALTHOUGH THIS WILL LIKELY BE RATHER SPOTTY. BASED ON WHATS HAPPENING AT KPOU/1B1...THIS WARMER AIR IS ON THE MOVE...AND SHOULD WIN OUT OVER THE COLD AIR IN THE CAPITAL REGION AS THE STRONG STORM SYSTEM MOVES TOWARDS OUR AREA FAIRLY SOON. HOWEVER...FURTHER NORTH ACROSS THE LAKE GEORGE AREA...IT MAY TAKE UNTIL THE MID TO LATE MORNING FOR THE WARM FRONT TO MOVE THROUGH AND TEMPS TO WARM UP. AS A RESULT...A PROLONGED PERIOD OF FREEZING RAIN CAN BE EXPECTED ACROSS THE LAKE GEORGE SARATOGA REGION. ICE ACCRETION AMOUNTS WILL RANGE FROM A TRACE TO A TENTH ACROSS THE SARATOGA SPRINGS AREA TO A FEW TENTHS FOR GLENS FALLS TO ABOUT FOUR TENTHS ACROSS THE NORTH END OF LAKE GEORGE. ASIDE FROM SOME HAZARDOUS DRIVING CONDITIONS...THIS MAY LEAD TO SOME ISOLATED POWER OUTAGES. AREAS IN THE WARM SECTOR SHOULD SEE SFC TEMPS WARM SIGNIFICANTLY...AS THOSE WARMER TEMPS ALOFT ARE MIXED IN THE BOUNDARY LAYER. MAX TEMPS LOOK TO REACH INTO THE 50S ACROSS MUCH OF THE CENTRAL AND SOUTHERN PARTS OF THE AREA...WITH SOME MID 60S FOR THE MID HUDSON VALLEY. WHILE IT WILL RAIN DURING THE MID TO LATE MORNING HOURS...MOST AREAS WILL BE DONE SEEING PRECIPITATION BY THE EARLY TO MID AFTN HOURS...AS THE STORM/S COLD FRONT PASSES THROUGH THE AREA. TOTAL RAINFALL FOR SUNDAY WILL RANGE FROM JUST A QUARTER OF AN INCH ACROSS LITCHFIELD COUNTY CT...TO AROUND THREE QUARTERS OF AN INCH IN THE CAPITAL REGION TO ABOUT AN INCH AND A HALF OVER THE ADIRONDACKS. SEE THE HYDRO SECTION ON HOW WE EXPECT THIS RAINFALL TO AFFECT AREA RIVERS AND STREAMS. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/... FOR THIS PERIOD THE MODEL SUITE (GEM/GFS/ECMWF) ARE IN FAIRLY GOOD AGREEMENT. DURING THE THIS EVENING THE SFC LOW AND ITS UPPER DYNAMICS WILL LIFT NE OUT OF FCA. A SERIES OF 500HPA SHORT WAVES WILL DIG A TROF OVER GRTLKS...MAINTAINING A STRONG SW 500HPA FLOW OVER THE EASTERN THIRD OF THE NATION. FOR A TIME THIS WILL ACT TO WEAKEN THE SFC LOW FURTHER OVER NEW ENG...BUT THE SFC LOW WILL DRAG A CDFNT THROUGH THE REGION TNGT. GIVEN THE UPPER FLOW COOLER AIR WILL BE SLOW TO FILTER IN OVERNIGHT....AND TEMPS WILL REMAIN ABV FREEZING IN MOST AREAS...WITH SNOW MELT CONTINUING. BY MONDAY THIS CDFNT WILL NEARLY STALL ALONG THE EASTERN SEABOARD...AND WITH DIGGING 500HPA TROF INTERACTING WITH THE COASTAL BAROCLINIC ZONE WILL TRIGGER A BOUT OF OVERRUNINNG RAIN...ALONG THE I-95 CORRIDOR THAT WILL BACK BUILD INTO SE PORTIONS OF FCA. QPF DURING MONDAY WITH THIS SHOULD BE 0.25 TO 0.50 IN THESE AREAS...AND GIVEN THESE AREAS WERE IN THE WARM SECTOR MUCH OF THE CURRENT EVENT...THEY MELTED MOST OF THEIR SNOW...BUT HAD LITTLE RAINFALL. ADD TO THAT THE 2-3 DAYS THIS OCCURRED...THE ADDITIONAL RAIN IN SOUTHEAST AREAS MONDAY SHOULD NOT RESULT IN ANYTHING OTHER THAN WITHIN BANK RISES. FURTHER WEST MONDAY AS HIGH PRESSURE BUILDS EAST WIND GRADIENT WILL INCR AND AS THE 500HPA TROF PUSHES EAST A MUCH STRONGER 2NDRY CDFNT WILL PUSH INTO THE REGION LATE MONDAY AND THROUGH MONDAY NIGHT. TEMPS MONDAY WILL HOLDS STEADY THEN FALL DURING THE AFTN. MONDAY NIGHT INTO TUES THE PASSAGE OF THE 500HPA TROF...CAA WILL RESULT IN SCT -SHSN ACTIVITY. HWVR LLVL FLOW WILL BE TOTALLY UNFAVORABLE FOR LK EFFECT OVER EASTERN NY. ONCE THE 500HPA TROF EXITS CHRISTMAS EVE BOTH A 500HPA RIDGE...AND SFC HIGH PRESSURE WILL SETTLE OVER NYS AND MID ATLC REGION. THIS WILL SET THE STAGE FOR A FRIGID NIGHT WITH IDEAL RADIATIONAL COOLING...ONE OF THE LONGEST NIGHTS OF THE YEAR...CLEAR SKIES AND DRY AIR MASS. LOWS WILL PLUNGE TO -20F IN PARTS OF THE ADIRONDACKS TO AROUND 10 IN THE SE. TEMPS WILL RECOVER CHRISTMAS DAY TO THE TEENS AND 20S AS SFC HIGH SLIDES OFFSHORE. SOME CLOUDS MAY ARRIVE IN THE AFTERNOON AS NEXT WEAK SYSTEM APPROACHES. && .LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/... THE EFP WILL FEATURE A SERIES OF FAST MOVING SYSTEMS IN W-NW FLOW. MOST WILL BE FAIRLY WK CDFNTS AND/OR 500HPA SHORT WVS...WHICH WILL INCR CLOUDS AND PRODUCE SCT -SHSN AND AT TIMES HAVE SOME INTERACTION WITH THE GRTLKS. TEMPS WILL RETURN TO NEAR NORMALS AFTER A FRIGID CHRISTMAS. TYPICAL WINTER IN UPSTATE NY. CHRISTMAS NIGHT AND THURS THE FIRST OF THESE SYSTEMS RACES ACROSS ONTARIO...WITH A FEW WEAK FRONTS AND A 500HPA SHORT WV. MAIN IMPACTS WILL INCR CLOUDS MAINLY N & W. THU NT IT WILL DRAG A CDFNT THROUGH WITH SOME -SHSN ACTIVITY MAINLY N & WEST. IN ITS WAKE FRI CAA AND A 2NDARY CDFNT AND NW FLOW WILL TRIGGER SCT -SHSN WITH SOME LK ASSISTANCE. WK SFC HIGH BUILDS OVER FCA FRI NT. SAT ANOTHER WK SHORT WV AND SFC SYSTEM MOVES THROUGH THE GRTLKS WITH A LITTLE WAA INCRG CLOUDS AND SCT -SHSN IN ECMWF...GETTING SOME ASSIST FM THE LKS. GFS HAS MORE CLOUDS AND A WIDESPREAD LT -SN OF MAYBE AN INCH. SAT NT INTO SUN FLOW BCMS ZONAL TO WSW AT 500HPA. WMFNT AND SFC LOW SETS UP N OF RGN. NOT MUCH DIFFERENCE BWTN GFS AND ECMWF. WILL POPULATE WITH HPC MID SHIFT AND TWEAK POPS A TAD. OTHERWISE A QUIET PERIOD FOR THE HOLIDAY WEEK. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/... A FRONTAL BOUNDARY WILL BE OVER UPSTATE NY AND NEW ENGLAND TODAY WITH AREAS OF LOW PRESSURE MOVING ALONG IT. THIS BOUNDARY WILL DIVIDE VERY COLD AIR FROM UNSEASONABLY MILD AIR OVER THE E-CNTRL NY CORRIDOR WITH SOME FREEZING RAIN CONTINUING FOR KGFL INTO THE LATE MORNING...AND SOME SCT SHOWERS FROM KALB-KPSF SOUTHWARD LATE THIS MORNING INTO THE AFTERNOON. THE BOUNDARY WILL CONTINUE TO LIFT NORTH...AS A WARM FRONT RAPIDLY THIS MORNING. FLIGHT CONDITIONS VARY FROM LIFR/IFR AT KGFL/KALB/KPSF TO VFR/MVFR AT KPOU THIS MORNING. CONDITIONS WILL IMPROVE TO VFR LEVELS AT KPOU WITH BETTER MIXING...AS THE FRONTAL BOUNDARY LIFTS NORTHWARD. SOME PATCHY MVFR MIST MAY BE AROUND IN THE LATE MORNING THERE. FURTHER NORTH...IFR/MVFR CONDITIONS WILL PERSIST INTO THE AFTERNOON WITH LIGHT FREEZING RAIN TRANSITIONING TO RAIN AT KGFL AT 16Z. MOST OF THE FLIGHT CONDITIONS THIS AFTERNOON MAY BE IN THE MVFR RANGE...AS THE FRONT LIFTS NORTH OF ALL THE TERMINALS. SOME DRIZZLE SHOULD LINGER INTO THIS EVENING...WHICH MAY ALLOW FOR MVFR OR BRIEF PERIODS OF IFR CIGS/VSBYS AT ALL THE TAF SITES...EXCEPT FOR KALB WHERE LOW VFR LOOKS POSSIBLE. THE CIGS MAY START TO RISE AROUND MIDNIGHT WITH SOME DRIER AIR STARTING TO FILTER IN FROM THE SOUTHWEST. LOW LEVEL WIND SHEAR WILL BE A PROBLEM THIS MORNING AT ALL THE TAF SITES WITH 2 KFT AGL WINDS FROM THE S/SW AT 45-60 KTS. THE LOW LEVEL WIND SHEAR LOOKS TO LAST INTO THE EARLY TO MID AFTERNOON AT THE TERMINALS. THE LOW LEVEL JET STARTS TO LIFT NORTH AND EAST AT THAT TIME. AT THE SFC...THE WINDS WILL VEER FROM THE EAST OR NORTHEAST AT KGFL/KALB TO THE SOUTH AT 8-15 KTS WITH SOME GUSTS CLOSE TO 25 KTS AT KALB AND KPOU. THE WINDS WILL DECREASE FROM THE S/SW AT LESS THAN 10 KTS AFTER 00Z/MON. OUTLOOK... MONDAY: LOW OPERATIONAL IMPACT. CHANCE OF -SHRAS. MONDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...SHSN. TUESDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. TUESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. CHRISTMAS DAY: NO OPERATIONAL IMPACT. NO SIG WX. WEDNESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. THURSDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. && .HYDROLOGY... MILD TO UNSEASONABLY WARM TEMPERATURES WILL OCCUR THOUGH TONIGHT WITH INCREASING SNOW MELT. LOW PRESSURE WILL MOVE ALONG A NEARLY STATIONARY FRONT FROM THE NIAGARA FRONTIER TO NEW ENGLAND BY THIS EVENING. 1-2 INCHES OF ADDITIONAL RAINFALL IS EXPECTED IN THE ADIRONDACKS...WITH LESSER AMOUNTS SOUTH. TEMPERATURES TODAY WILL WARM INTO THE 50S AND 60S REMAIN ABOVE FREEZING TONIGHT. IN THE NORTH RAINFALL AMOUNTS WILL BE GREATEST...BUT SNOW MELT SLOWER...WHILE IN THE SOUTH RAINFALL WILL BE AROUND A HALF INCH...BUT ALMOST ALL THE SNOW WILL MELT. EVEN AS THE RAIN TAPERS OFF THIS EVENING...SNOW MELT AND RUNOFF WILL CONTINUE TONIGHT. IN THE SOUTH THE RAINFALL WILL BE SUFFICIENT FOR SIGNIFICANT WITHIN BANK RISES...BUT FLOODING IS NOT EXPECTED AT THIS TIME. THE GREATEST POTENTIAL FOR FLOODING WILL EXIST FROM THE MOHAWK VALLEY INTO THE ADIRONDACKS WHERE 1 TO 2 INCHES ADDITIONAL RAIN AND UP TO AN INCH OF LIQUID EQUIVALENT FROM SNOW MELT IS EXPECTED. FLOOD WATCHES REMAIN IN EFFECT THROUGH TONIGHT. 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...FREEZING RAIN ADVISORY UNTIL 11 AM EST THIS MORNING FOR NYZ041>043-083-084. FLOOD WATCH THROUGH MONDAY MORNING FOR NYZ032-033-038>040-042- 043-082. MA...NONE. VT...NONE. && $$ SYNOPSIS...SNYDER NEAR TERM...GJM/FRUGIS SHORT TERM...SNYDER LONG TERM...SNYDER AVIATION...WASULA HYDROLOGY...SNYDER
AREA FORECAST DISCUSSION
NWS ALBANY NY
652 AM EST SUN DEC 22 2013 .SYNOPSIS... A NEARLY STATIONARY FRONT FROM CENTRAL NEW YORK TO THE MAINE COAST WILL SHIFT SLIGHTLY AS A STORM MOVES ALONG IT TODAY. NORTH OF IT IT WILL BE CHILLY WITH RAIN AND FREEZING RAIN...WITH RAIN AND VERY MILD WEATHER TO ITS SOUTH. THE STORM WILL DRAG A COLD FRONT THROUGH THE REGION TONIGHT AND THEN SLIDE SLOWLY OFFSHORE MONDAY. HIGH PRESSURE WILL BUILD FROM ONTARIO INTO NEW YORK TUESDAY INTO CHRISTMAS...WITH MUCH COLD AIR FILTERING INTO THE REGION. THE WEEK WILL END WITH A SERIES OF FAST MOVING WEATHER SYSTEMS WITH BOUTS OF SNOW SHOWERS AND GENERALLY SEASONABLE TEMPERATURES. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 635 AM EST...WIDE VARIETY OF TEMPERATURES ACROSS THE REGION THIS MORNING WITH STALLED FRONTAL BOUNDARY SITUATED DIRECTLY ACROSS THE CENTRAL PORTION OF THE CWA. NORTH OF THE BOUNDARY...VERY COLD CANADIAN AIR IS BEING PULLED SOUTHWARD THANKS TO A LOW LEVEL NNE FLOW THROUGH THE CHAMPLAIN VALLEY AND INTO THE HUDSON VALLEY REGION. THIS HAS ALLOWED TEMPS TO DROP BELOW FREEZING FOR THE GLENS FALLS AND SARATOGA SPRINGS AREA. TEMPS HAVE FALLEN INTO THE LOW TO MID 30S IN THE CAPITAL REGION. AT THE SAME TIME...VERY WARM TEMPS ALOFT ARE IN PLACE THANKS TO A STRONG SOUTHERLY FLOW. AS A RESULT...SOME OF THE WARMER TEMPS AT THIS HOUR ARE ACROSS THE MOUNTAIN PEAKS OF THE CATSKILLS...SRN GREENS AND BERKSHIRES...WHERE TEMPS ARE WELL INTO THE 50S. ALSO...A SOUTHERLY LOW LEVEL WIND COMING UP THE MID HUDSON VALLEY HAS ALLOWED SOME WARMER AIR TO MOVE TOWARDS POUGHKEEPSIE AND HUDSON...WITH SFC TEMPS HAVING JUMPED UP INTO THE LOW 60S! THE JUST LAUNCHED 12Z KALY SOUNDING SHOWS THE COLD SFC LAYER IS ONLY ABOUT 200 METERS THICK...WITH A WARM NOSE OF ABOUT +16 C AT 850 HPA. WITH AN APPROACHING LOW PRESSURE AREA AND THE SFC BOUNDARY IN PLACE...OVERRUNNING PRECIP HAS MOVED TO THE NORTH OF THE REGION...FALLING AS FZRA/PL ACROSS THE BTV CWA. RIGHT NOW...MUCH OF OUR CWA IS IN A DRY SLOT...WITH JUST SOME SPOTTY FREEZING RAIN ACROSS THE SOUTHEASTERN ADIRONDACKS...AND SOME LIGHT RAIN SHOWERS ACROSS WESTERN NEW ENGLAND. THE LATEST 08Z 3KM HRRR SHOWS THIS DRY SLOT SHOULD START TO FILL IN TOWARDS THE MID MORNING AS THE LOW PRESSURE AREA MOVES NORTHEAST ACROSS THE OHIO VALLEY AND EVENTUALLY TOWARDS UPSTATE NY. RIGHT NOW...WE WILL HOLD CHC POPS FOR THE NEXT FEW HOURS ACROSS CENTRAL/SOUTHERN PARTS OF THE AREA...WITH LIKELY/CATEGORICAL POPS ACROSS THE FAR NORTH NEAR THE BTV CWA BORDER. BY THE LATE MORNING...WE WILL RISE POPS TO LIKELY/CATEGORICAL FOR WESTERN AND CENTRAL PARTS OF THE CWA AS WELL. FOR NOW...IT DOESN/T APPEAR THAT THE CAPITAL REGION WILL BE SEEING ANY MEASUREABLE FREEZING RAIN...AS THE APPROACHING STORM SHOULD ALLOW THE STALLED BOUNDARY TO START TO MOVE NORTHWARD AS A WARM FRONT...AND BRING THE ALBANY AREA INTO THE WARM SECTOR ONCE THE NEXT ROUND OF RAINFALL BEGINS. ALTHOUGH THERE MAY BE A SPOTTY SPRINKLE BEFORE THAT OCCURS...IT SHOULDN/T BE ABLE TO ACCRETE MUCH ICE AT ALL WITH MARGINAL TEMPS AND AN ALREADY WET GROUND. STILL...WE HAVE PASSED ALONG THE MESSAGE THROUGH OUR SOCIAL MEDIA CHANNELS THAT WITH TEMPS NEAR FREEZING...SOME WET SURFACES COULD POTENTIALLY BE SLICK...ALTHOUGH THIS WILL LIKELY BE RATHER SPOTTY. BASED ON WHATS HAPPENING AT KPOU/1B1...THIS WARMER AIR IS ON THE MOVE...AND SHOULD WIN OUT OVER THE COLD AIR IN THE CAPITAL REGION AS THE STRONG STORM SYSTEM MOVES TOWARDS OUR AREA FAIRLY SOON. HOWEVER...FURTHER NORTH ACROSS THE LAKE GEORGE AREA...IT MAY TAKE UNTIL THE MID TO LATE MORNING FOR THE WARM FRONT TO MOVE THROUGH AND TEMPS TO WARM UP. AS A RESULT...A PROLONGED PERIOD OF FREEZING RAIN CAN BE EXPECTED ACROSS THE LAKE GEORGE SARATOGA REGION. ICE ACCRETION AMOUNTS WILL RANGE FROM A TRACE TO A TENTH ACROSS THE SARATOGA SPRINGS AREA TO A FEW TENTHS FOR GLENS FALLS TO ABOUT FOUR TENTHS ACROSS THE NORTH END OF LAKE GEORGE. ASIDE FROM SOME HAZARDOUS DRIVING CONDITIONS...THIS MAY LEAD TO SOME ISOLATED POWER OUTAGES. AREAS IN THE WARM SECTOR SHOULD SEE SFC TEMPS WARM SIGNIFICANTLY...AS THOSE WARMER TEMPS ALOFT ARE MIXED IN THE BOUNDARY LAYER. MAX TEMPS LOOK TO REACH INTO THE 50S ACROSS MUCH OF THE CENTRAL AND SOUTHERN PARTS OF THE AREA...WITH SOME MID 60S FOR THE MID HUDSON VALLEY. WHILE IT WILL RAIN DURING THE MID TO LATE MORNING HOURS...MOST AREAS WILL BE DONE SEEING PRECIPITATION BY THE EARLY TO MID AFTN HOURS...AS THE STORM/S COLD FRONT PASSES THROUGH THE AREA. TOTAL RAINFALL FOR SUNDAY WILL RANGE FROM JUST A QUARTER OF AN INCH ACROSS LITCHFIELD COUNTY CT...TO AROUND THREE QUARTERS OF AN INCH IN THE CAPITAL REGION TO ABOUT AN INCH AND A HALF OVER THE ADIRONDACKS. SEE THE HYDRO SECTION ON HOW WE EXPECT THIS RAINFALL TO AFFECT AREA RIVERS AND STREAMS. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/... FOR THIS PERIOD THE MODEL SUITE (GEM/GFS/ECMWF) ARE IN FAIRLY GOOD AGREEMENT. DURING THE THIS EVENING THE SFC LOW AND ITS UPPER DYNAMICS WILL LIFT NE OUT OF FCA. A SERIES OF 500HPA SHORT WAVES WILL DIG A TROF OVER GRTLKS...MAINTAINING A STRONG SW 500HPA FLOW OVER THE EASTERN THIRD OF THE NATION. FOR A TIME THIS WILL ACT TO WEAKEN THE SFC LOW FURTHER OVER NEW ENG...BUT THE SFC LOW WILL DRAG A CDFNT THROUGH THE REGION TNGT. GIVEN THE UPPER FLOW COOLER AIR WILL BE SLOW TO FILTER IN OVERNIGHT....AND TEMPS WILL REMAIN ABV FREEZING IN MOST AREAS...WITH SNOW MELT CONTINUING. BY MONDAY THIS CDFNT WILL NEARLY STALL ALONG THE EASTERN SEABOARD...AND WITH DIGGING 500HPA TROF INTERACTING WITH THE COASTAL BAROCLINIC ZONE WILL TRIGGER A BOUT OF OVERRUNINNG RAIN...ALONG THE I-95 CORRIDOR THAT WILL BACK BUILD INTO SE PORTIONS OF FCA. QPF DURING MONDAY WITH THIS SHOULD BE 0.25 TO 0.50 IN THESE AREAS...AND GIVEN THESE AREAS WERE IN THE WARM SECTOR MUCH OF THE CURRENT EVENT...THEY MELTED MOST OF THEIR SNOW...BUT HAD LITTLE RAINFALL. ADD TO THAT THE 2-3 DAYS THIS OCCURRED...THE ADDITIONAL RAIN IN SOUTHEAST AREAS MONDAY SHOULD NOT RESULT IN ANYTHING OTHER THAN WITHIN BANK RISES. FURTHER WEST MONDAY AS HIGH PRESSURE BUILDS EAST WIND GRADIENT WILL INCR AND AS THE 500HPA TROF PUSHES EAST A MUCH STRONGER 2NDRY CDFNT WILL PUSH INTO THE REGION LATE MONDAY AND THROUGH MONDAY NIGHT. TEMPS MONDAY WILL HOLDS STEADY THEN FALL DURING THE AFTN. MONDAY NIGHT INTO TUES THE PASSAGE OF THE 500HPA TROF...CAA WILL RESULT IN SCT -SHSN ACTIVITY. HWVR LLVL FLOW WILL BE TOTALLY UNFAVORABLE FOR LK EFFECT OVER EASTERN NY. ONCE THE 500HPA TROF EXITS CHRISTMAS EVE BOTH A 500HPA RIDGE...AND SFC HIGH PRESSURE WILL SETTLE OVER NYS AND MID ATLC REGION. THIS WILL SET THE STAGE FOR A FRIGID NIGHT WITH IDEAL RADIATIONAL COOLING...ONE OF THE LONGEST NIGHTS OF THE YEAR...CLEAR SKIES AND DRY AIR MASS. LOWS WILL PLUNGE TO -20F IN PARTS OF THE ADIRONDACKS TO AROUND 10 IN THE SE. TEMPS WILL RECOVER CHRISTMAS DAY TO THE TEENS AND 20S AS SFC HIGH SLIDES OFFSHORE. SOME CLOUDS MAY ARRIVE IN THE AFTERNOON AS NEXT WEAK SYSTEM APPROACHES. && .LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/... THE EFP WILL FEATURE A SERIES OF FAST MOVING SYSTEMS IN W-NW FLOW. MOST WILL BE FAIRLY WK CDFNTS AND/OR 500HPA SHORT WVS...WHICH WILL INCR CLOUDS AND PRODUCE SCT -SHSN AND AT TIMES HAVE SOME INTERACTION WITH THE GRTLKS. TEMPS WILL RETURN TO NEAR NORMALS AFTER A FRIGID CHRISTMAS. TYPICAL WINTER IN UPSTATE NY. CHRISTMAS NIGHT AND THURS THE FIRST OF THESE SYSTEMS RACES ACROSS ONTARIO...WITH A FEW WEAK FRONTS AND A 500HPA SHORT WV. MAIN IMPACTS WILL INCR CLOUDS MAINLY N & W. THU NT IT WILL DRAG A CDFNT THROUGH WITH SOME -SHSN ACTIVITY MAINLY N & WEST. IN ITS WAKE FRI CAA AND A 2NDARY CDFNT AND NW FLOW WILL TRIGGER SCT -SHSN WITH SOME LK ASSISTANCE. WK SFC HIGH BUILDS OVER FCA FRI NT. SAT ANOTHER WK SHORT WV AND SFC SYSTEM MOVES THROUGH THE GRTLKS WITH A LITTLE WAA INCRG CLOUDS AND SCT -SHSN IN ECMWF...GETTING SOME ASSIST FM THE LKS. GFS HAS MORE CLOUDS AND A WIDESPREAD LT -SN OF MAYBE AN INCH. SAT NT INTO SUN FLOW BCMS ZONAL TO WSW AT 500HPA. WMFNT AND SFC LOW SETS UP N OF RGN. NOT MUCH DIFFERENCE BWTN GFS AND ECMWF. WILL POPULATE WITH HPC MID SHIFT AND TWEAK POPS A TAD. OTHERWISE A QUIET PERIOD FOR THE HOLIDAY WEEK. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/... A FRONTAL BOUNDARY WILL BE OVER UPSTATE NY AND NEW ENGLAND TODAY WITH AREAS OF LOW PRESSURE MOVING ALONG IT. THIS BOUNDARY WILL DIVIDE VERY COLD AIR FROM UNSEASONABLY MILD AIR OVER THE E-CNTRL NY CORRIDOR WITH SOME FREEZING RAIN CONTINUING FOR KGFL INTO THE LATE MORNING...AND SOME SCT SHOWERS FROM KALB-KPSF SOUTHWARD LATE THIS MORNING INTO THE AFTERNOON. THE BOUNDARY WILL CONTINUE TO LIFT NORTH...AS A WARM FRONT RAPIDLY THIS MORNING. FLIGHT CONDITIONS VARY FROM LIFR/IFR AT KGFL/KALB/KPSF TO VFR/MVFR AT KPOU THIS MORNING. CONDITIONS WILL IMPROVE TO VFR LEVELS AT KPOU WITH BETTER MIXING...AS THE FRONTAL BOUNDARY LIFTS NORTHWARD. SOME PATCHY MVFR MIST MAY BE AROUND IN THE LATE MORNING THERE. FURTHER NORTH...IFR/MVFR CONDITIONS WILL PERSIST INTO THE AFTERNOON WITH LIGHT FREEZING RAIN TRANSITIONING TO RAIN AT KGFL AT 16Z. MOST OF THE FLIGHT CONDITIONS THIS AFTERNOON MAY BE IN THE MVFR RANGE...AS THE FRONT LIFTS NORTH OF ALL THE TERMINALS. SOME DRIZZLE SHOULD LINGER INTO THIS EVENING...WHICH MAY ALLOW FOR MVFR OR BRIEF PERIODS OF IFR CIGS/VSBYS AT ALL THE TAF SITES...EXCEPT FOR KALB WHERE LOW VFR LOOKS POSSIBLE. THE CIGS MAY START TO RISE AROUND MIDNIGHT WITH SOME DRIER AIR STARTING TO FILTER IN FROM THE SOUTHWEST. LOW LEVEL WIND SHEAR WILL BE A PROBLEM THIS MORNING AT ALL THE TAF SITES WITH 2 KFT AGL WINDS FROM THE S/SW AT 45-60 KTS. THE LOW LEVEL WIND SHEAR LOOKS TO LAST INTO THE EARLY TO MID AFTERNOON AT THE TERMINALS. THE LOW LEVEL JET STARTS TO LIFT NORTH AND EAST AT THAT TIME. AT THE SFC...THE WINDS WILL VEER FROM THE EAST OR NORTHEAST AT KGFL/KALB TO THE SOUTH AT 8-15 KTS WITH SOME GUSTS CLOSE TO 25 KTS AT KALB AND KPOU. THE WINDS WILL DECREASE FROM THE S/SW AT LESS THAN 10 KTS AFTER 00Z/MON. OUTLOOK... MONDAY: LOW OPERATIONAL IMPACT. CHANCE OF -SHRAS. MONDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...SHSN. TUESDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. TUESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. CHRISTMAS DAY: NO OPERATIONAL IMPACT. NO SIG WX. WEDNESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. THURSDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. && .HYDROLOGY... MILD TO UNSEASONABLY WARM TEMPERATURES WILL OCCUR THOUGH TONIGHT WITH INCREASING SNOW MELT. LOW PRESSURE WILL MOVE ALONG A NEARLY STATIONARY FRONT FROM THE NIAGARA FRONTIER TO NEW ENGLAND BY THIS EVENING. 1-2 INCHES OF ADDITIONAL RAINFALL IS EXPECTED IN THE ADIRONDACKS...WITH LESSER AMOUNTS SOUTH. TEMPERATURES TODAY WILL WARM INTO THE 50S AND 60S REMAIN ABOVE FREEZING TONIGHT. IN THE NORTH RAINFALL AMOUNTS WILL BE GREATEST...BUT SNOW MELT SLOWER...WHILE IN THE SOUTH RAINFALL WILL BE AROUND A HALF INCH...BUT ALMOST ALL THE SNOW WILL MELT. EVEN AS THE RAIN TAPERS OFF THIS EVENING...SNOW MELT AND RUNOFF WILL CONTINUE TONIGHT. IN THE SOUTH THE RAINFALL WILL BE SUFFICIENT FOR SIGNIFICANT WITHIN BANK RISES...BUT FLOODING IS NOT EXPECTED AT THIS TIME. THE GREATEST POTENTIAL FOR FLOODING WILL EXIST FROM THE MOHAWK VALLEY INTO THE ADIRONDACKS WHERE 1 TO 2 INCHES ADDITIONAL RAIN AND UP TO AN INCH OF LIQUID EQUIVALENT FROM SNOW MELT IS EXPECTED. FLOOD WATCHES REMAIN IN EFFECT THROUGH TONIGHT. 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...FREEZING RAIN ADVISORY UNTIL 11 AM EST THIS MORNING FOR NYZ041>043-083-084. FLOOD WATCH THROUGH MONDAY MORNING FOR NYZ032-033-038>040-042- 043-082. MA...NONE. VT...NONE. && $$ SYNOPSIS...SNYDER NEAR TERM...FRUGIS SHORT TERM...SNYDER LONG TERM...SNYDER AVIATION...WASULA HYDROLOGY...SNYDER
AREA FORECAST DISCUSSION
NWS ALBANY NY
635 AM EST SUN DEC 22 2013 .SYNOPSIS... A NEARLY STATIONARY FRONT FROM CENTRAL NEW YORK TO THE MAINE COAST WILL SHIFT SLIGHTLY AS A STORM MOVES ALONG IT TODAY. NORTH OF IT IT WILL BE CHILLY WITH RAIN AND FREEZING RAIN...WITH RAIN AND VERY MILD WEATHER TO ITS SOUTH. THE STORM WILL DRAG A COLD FRONT THROUGH THE REGION TONIGHT AND THEN SLIDE SLOWLY OFFSHORE MONDAY. HIGH PRESSURE WILL BUILD FROM ONTARIO INTO NEW YORK TUESDAY INTO CHRISTMAS...WITH MUCH COLD AIR FILTERING INTO THE REGION. THE WEEK WILL END WITH A SERIES OF FAST MOVING WEATHER SYSTEMS WITH BOUTS OF SNOW SHOWERS AND GENERALLY SEASONABLE TEMPERATURES. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 635 AM EST...WIDE VARIETY OF TEMPERATURES ACROSS THE REGION THIS MORNING WITH STALLED FRONTAL BOUNDARY SITUATED DIRECTLY ACROSS THE CENTRAL PORTION OF THE CWA. NORTH OF THE BOUNDARY...VERY COLD CANADIAN AIR IS BEING PULLED SOUTHWARD THANKS TO A LOW LEVEL NNE FLOW THROUGH THE CHAMPLAIN VALLEY AND INTO THE HUDSON VALLEY REGION. THIS HAS ALLOWED TEMPS TO DROP BELOW FREEZING FOR THE GLENS FALLS AND SARATOGA SPRINGS AREA. TEMPS HAVE FALLEN INTO THE LOW TO MID 30S IN THE CAPITAL REGION. AT THE SAME TIME...VERY WARM TEMPS ALOFT ARE IN PLACE THANKS TO A STRONG SOUTHERLY FLOW. AS A RESULT...SOME OF THE WARMER TEMPS AT THIS HOUR ARE ACROSS THE MOUNTAIN PEAKS OF THE CATSKILLS...SRN GREENS AND BERKSHIRES...WHERE TEMPS ARE WELL INTO THE 50S. ALSO...A SOUTHERLY LOW LEVEL WIND COMING UP THE MID HUDSON VALLEY HAS ALLOWED SOME WARMER AIR TO MOVE TOWARDS POUGHKEEPSIE AND HUDSON...WITH SFC TEMPS HAVING JUMPED UP INTO THE LOW 60S! THE JUST LAUNCHED 12Z KALY SOUNDING SHOWS THE COLD SFC LAYER IS ONLY ABOUT 200 METERS THICK...WITH A WARM NOSE OF ABOUT +16 C AT 850 HPA. WITH AN APPROACHING LOW PRESSURE AREA AND THE SFC BOUNDARY IN PLACE...OVERRUNNING PRECIP HAS MOVED TO THE NORTH OF THE REGION...FALLING AS FZRA/PL ACROSS THE BTV CWA. RIGHT NOW...MUCH OF OUR CWA IS IN A DRY SLOT...WITH JUST SOME SPOTTY FREEZING RAIN ACROSS THE SOUTHEASTERN ADIRONDACKS...AND SOME LIGHT RAIN SHOWERS ACROSS WESTERN NEW ENGLAND. THE LATEST 08Z 3KM HRRR SHOWS THIS DRY SLOT SHOULD START TO FILL IN TOWARDS THE MID MORNING AS THE LOW PRESSURE AREA MOVES NORTHEAST ACROSS THE OHIO VALLEY AND EVENTUALLY TOWARDS UPSTATE NY. RIGHT NOW...WE WILL HOLD CHC POPS FOR THE NEXT FEW HOURS ACROSS CENTRAL/SOUTHERN PARTS OF THE AREA...WITH LIKELY/CATEGORICAL POPS ACROSS THE FAR NORTH NEAR THE BTV CWA BORDER. BY THE LATE MORNING...WE WILL RISE POPS TO LIKELY/CATEGORICAL FOR WESTERN AND CENTRAL PARTS OF THE CWA AS WELL. FOR NOW...IT DOESN/T APPEAR THAT THE CAPITAL REGION WILL BE SEEING ANY MEASUREABLE FREEZING RAIN...AS THE APPROACHING STORM SHOULD ALLOW THE STALLED BOUNDARY TO START TO MOVE NORTHWARD AS A WARM FRONT...AND BRING THE ALBANY AREA INTO THE WARM SECTOR ONCE THE NEXT ROUND OF RAINFALL BEGINS. ALTHOUGH THERE MAY BE A SPOTTY SPRINKLE BEFORE THAT OCCURS...IT SHOULDN/T BE ABLE TO ACCRETE MUCH ICE AT ALL WITH MARGINAL TEMPS AND AN ALREADY WET GROUND. STILL...WE HAVE PASSED ALONG THE MESSAGE THROUGH OUR SOCIAL MEDIA CHANNELS THAT WITH TEMPS NEAR FREEZING...SOME WET SURFACES COULD POTENTIALLY BE SLICK...ALTHOUGH THIS WILL LIKELY BE RATHER SPOTTY. BASED ON WHATS HAPPENING AT KPOU/1B1...THIS WARMER AIR IS ON THE MOVE...AND SHOULD WIN OUT OVER THE COLD AIR IN THE CAPITAL REGION AS THE STRONG STORM SYSTEM MOVES TOWARDS OUR AREA FAIRLY SOON. HOWEVER...FURTHER NORTH ACROSS THE LAKE GEORGE AREA...IT MAY TAKE UNTIL THE MID TO LATE MORNING FOR THE WARM FRONT TO MOVE THROUGH AND TEMPS TO WARM UP. AS A RESULT...A PROLONGED PERIOD OF FREEZING RAIN CAN BE EXPECTED ACROSS THE LAKE GEORGE SARATOGA REGION. ICE ACCRETION AMOUNTS WILL RANGE FROM A TRACE TO A TENTH ACROSS THE SARATOGA SPRINGS AREA TO A FEW TENTHS FOR GLENS FALLS TO ABOUT FOUR TENTHS ACROSS THE NORTH END OF LAKE GEORGE. ASIDE FROM SOME HAZARDOUS DRIVING CONDITIONS...THIS MAY LEAD TO SOME ISOLATED POWER OUTAGES. AREAS IN THE WARM SECTOR SHOULD SEE SFC TEMPS WARM SIGNIFICANTLY...AS THOSE WARMER TEMPS ALOFT ARE MIXED IN THE BOUNDARY LAYER. MAX TEMPS LOOK TO REACH INTO THE 50S ACROSS MUCH OF THE CENTRAL AND SOUTHERN PARTS OF THE AREA...WITH SOME MID 60S FOR THE MID HUDSON VALLEY. WHILE IT WILL RAIN DURING THE MID TO LATE MORNING HOURS...MOST AREAS WILL BE DONE SEEING PRECIPITATION BY THE EARLY TO MID AFTN HOURS...AS THE STORM/S COLD FRONT PASSES THROUGH THE AREA. TOTAL RAINFALL FOR SUNDAY WILL RANGE FROM JUST A QUARTER OF AN INCH ACROSS LITCHFIELD COUNTY CT...TO AROUND THREE QUARTERS OF AN INCH IN THE CAPITAL REGION TO ABOUT AN INCH AND A HALF OVER THE ADIRONDACKS. SEE THE HYDRO SECTION ON HOW WE EXPECT THIS RAINFALL TO AFFECT AREA RIVERS AND STREAMS. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/... FOR THIS PERIOD THE MODEL SUITE (GEM/GFS/ECMWF) ARE IN FAIRLY GOOD AGREEMENT. DURING THE THIS EVENING THE SFC LOW AND ITS UPPER DYNAMICS WILL LIFT NE OUT OF FCA. A SERIES OF 500HPA SHORT WAVES WILL DIG A TROF OVER GRTLKS...MAINTAINING A STRONG SW 500HPA FLOW OVER THE EASTERN THIRD OF THE NATION. FOR A TIME THIS WILL ACT TO WEAKEN THE SFC LOW FURTHER OVER NEW ENG...BUT THE SFC LOW WILL DRAG A CDFNT THROUGH THE REGION TNGT. GIVEN THE UPPER FLOW COOLER AIR WILL BE SLOW TO FILTER IN OVERNIGHT....AND TEMPS WILL REMAIN ABV FREEZING IN MOST AREAS...WITH SNOW MELT CONTINUING. BY MONDAY THIS CDFNT WILL NEARLY STALL ALONG THE EASTERN SEABOARD...AND WITH DIGGING 500HPA TROF INTERACTING WITH THE COASTAL BAROCLINIC ZONE WILL TRIGGER A BOUT OF OVERRUNINNG RAIN...ALONG THE I-95 CORRIDOR THAT WILL BACK BUILD INTO SE PORTIONS OF FCA. QPF DURING MONDAY WITH THIS SHOULD BE 0.25 TO 0.50 IN THESE AREAS...AND GIVEN THESE AREAS WERE IN THE WARM SECTOR MUCH OF THE CURRENT EVENT...THEY MELTED MOST OF THEIR SNOW...BUT HAD LITTLE RAINFALL. ADD TO THAT THE 2-3 DAYS THIS OCCURRED...THE ADDITIONAL RAIN IN SOUTHEAST AREAS MONDAY SHOULD NOT RESULT IN ANYTHING OTHER THAN WITHIN BANK RISES. FURTHER WEST MONDAY AS HIGH PRESSURE BUILDS EAST WIND GRADIENT WILL INCR AND AS THE 500HPA TROF PUSHES EAST A MUCH STRONGER 2NDRY CDFNT WILL PUSH INTO THE REGION LATE MONDAY AND THROUGH MONDAY NIGHT. TEMPS MONDAY WILL HOLDS STEADY THEN FALL DURING THE AFTN. MONDAY NIGHT INTO TUES THE PASSAGE OF THE 500HPA TROF...CAA WILL RESULT IN SCT -SHSN ACTIVITY. HWVR LLVL FLOW WILL BE TOTALLY UNFAVORABLE FOR LK EFFECT OVER EASTERN NY. ONCE THE 500HPA TROF EXITS CHRISTMAS EVE BOTH A 500HPA RIDGE...AND SFC HIGH PRESSURE WILL SETTLE OVER NYS AND MID ATLC REGION. THIS WILL SET THE STAGE FOR A FRIGID NIGHT WITH IDEAL RADIATIONAL COOLING...ONE OF THE LONGEST NIGHTS OF THE YEAR...CLEAR SKIES AND DRY AIR MASS. LOWS WILL PLUNGE TO -20F IN PARTS OF THE ADIRONDACKS TO AROUND 10 IN THE SE. TEMPS WILL RECOVER CHRISTMAS DAY TO THE TEENS AND 20S AS SFC HIGH SLIDES OFFSHORE. SOME CLOUDS MAY ARRIVE IN THE AFTERNOON AS NEXT WEAK SYSTEM APPROACHES. && .LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/... THE EFP WILL FEATURE A SERIES OF FAST MOVING SYSTEMS IN W-NW FLOW. MOST WILL BE FAIRLY WK CDFNTS AND/OR 500HPA SHORT WVS...WHICH WILL INCR CLOUDS AND PRODUCE SCT -SHSN AND AT TIMES HAVE SOME INTERACTION WITH THE GRTLKS. TEMPS WILL RETURN TO NEAR NORMALS AFTER A FRIGID CHRISTMAS. TYPICAL WINTER IN UPSTATE NY. CHRISTMAS NIGHT AND THURS THE FIRST OF THESE SYSTEMS RACES ACROSS ONTARIO...WITH A FEW WEAK FRONTS AND A 500HPA SHORT WV. MAIN IMPACTS WILL INCR CLOUDS MAINLY N & W. THU NT IT WILL DRAG A CDFNT THROUGH WITH SOME -SHSN ACTIVITY MAINLY N & WEST. IN ITS WAKE FRI CAA AND A 2NDARY CDFNT AND NW FLOW WILL TRIGGER SCT -SHSN WITH SOME LK ASSISTANCE. WK SFC HIGH BUILDS OVER FCA FRI NT. SAT ANOTHER WK SHORT WV AND SFC SYSTEM MOVES THROUGH THE GRTLKS WITH A LITTLE WAA INCRG CLOUDS AND SCT -SHSN IN ECMWF...GETTING SOME ASSIST FM THE LKS. GFS HAS MORE CLOUDS AND A WIDESPREAD LT -SN OF MAYBE AN INCH. SAT NT INTO SUN FLOW BCMS ZONAL TO WSW AT 500HPA. WMFNT AND SFC LOW SETS UP N OF RGN. NOT MUCH DIFFERENCE BWTN GFS AND ECMWF. WILL POPULATE WITH HPC MID SHIFT AND TWEAK POPS A TAD. OTHERWISE A QUIET PERIOD FOR THE HOLIDAY WEEK. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/... A FRONTAL BOUNDARY WILL BE OVER UPSTATE NY AND NEW ENGLAND TODAY WITH AREAS OF LOW PRESSURE MOVING ALONG IT. THIS BOUNDARY WILL DIVIDE VERY COLD AIR FROM MILD AIR OVER THE E-CNTRL NY CORRIDOR WITH SOME FREEZING RAIN CONTINUING FOR KGFL EARLY THIS MORNING...AND OCCASIONAL LIGHT RAIN FOR KALB-KPSF SOUTHWARD BEFORE A STEADIER RAINSHIELD MOVES IN TOWARDS 12Z. FLIGHT CONDITIONS VARY FROM LIFR/IFR AT KGFL/KALB TO VFR/MVFR AT KPOU AND KPSF THIS MORNING. THE TREND WILL BE FOR WIDESPREAD IFR/MVFR CONDITIONS TO IMPACT THE TERMINALS BTWN 09Z-12Z. THE MVFR CONDITIONS MAY CONTINUE AT KPOU UNTIL AFTER 12Z...BUT EXPECT IFR CIGS/VSBYS FOR KGFL...KALB...KPSF THROUGH MOST OF THE LATE MORNING INTO THE EARLY PM...AS LOW PRESSURE MOVES ACROSS CNTRL/NRN NY. EXPECT TEMPS TO MOVE BACK ABOVE FREEZING AT KGFL AROUND 10Z. THE RAINFALL SHOULD DIMINISH BTWN 18Z-21Z FOR THE E-CNTRL NY TERMINALS WITH SOME SCT SHOWERS AND DRIZZLE LINGERING INTO THE EARLY EVENING. SOME IFR/MVFR VISIBILITIES MAY PERSIST INTO THE EARLY EVENING WITH MVFR CIGS. THE CIGS MAY START TO RISE TOWARDS MIDNIGHT WITH SOME DRIER AIR STARTING TO FILTER IN FROM THE SOUTHWEST. THE SFC WINDS WILL BE FROM THE E TO NE AT KALB AND KGFL EARLY THIS MORNING AT 5-10 KTS...THEN VEER TO TO SOUTH AT AROUND 10 KTS BY 12Z WITH SOME GUSTS AT KALB IN THE 20-25 KT RANGE. KPOU AND KPSF WILL CONTINUE TO HAVE S/SW WINDS 5-10 KTS...THEN INCREASE TO 8-15 KTS WITH SOME GUSTS CLOSE TO 25 KTS AT KPSF...AS THE STRONGER LLJ MOVES IN ALOFT. THE WINDS WILL DECREASE FROM THE S/SW AT LESS THAN 10 KTS AFTER 00Z/MON. OUTLOOK... MONDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...SHSN. TUESDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. TUESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. CHRISTMAS DAY: NO OPERATIONAL IMPACT. NO SIG WX. WEDNESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. THURSDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. THURSDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX. && .HYDROLOGY... MILD TO UNSEASONABLY WARM TEMPERATURES WILL OCCUR THOUGH TONIGHT WITH INCREASING SNOW MELT. LOW PRESSURE WILL MOVE ALONG A NEARLY STATIONARY FRONT FROM THE NIAGARA FRONTIER TO NEW ENGLAND BY THIS EVENING. 1-2 INCHES OF ADDITIONAL RAINFALL IS EXPECTED IN THE ADIRONDACKS...WITH LESSER AMOUNTS SOUTH. TEMPERATURES TODAY WILL WARM INTO THE 50S AND 60S REMAIN ABOVE FREEZING TONIGHT. IN THE NORTH RAINFALL AMOUNTS WILL BE GREATEST...BUT SNOW MELT SLOWER...WHILE IN THE SOUTH RAINFALL WILL BE AROUND A HALF INCH...BUT ALMOST ALL THE SNOW WILL MELT. EVEN AS THE RAIN TAPERS OFF THIS EVENING...SNOW MELT AND RUNOFF WILL CONTINUE TONIGHT. IN THE SOUTH THE RAINFALL WILL BE SUFFICIENT FOR SIGNIFICANT WITHIN BANK RISES...BUT FLOODING IS NOT EXPECTED AT THIS TIME. THE GREATEST POTENTIAL FOR FLOODING WILL EXIST FROM THE MOHAWK VALLEY INTO THE ADIRONDACKS WHERE 1 TO 2 INCHES ADDITIONAL RAIN AND UP TO AN INCH OF LIQUID EQUIVALENT FROM SNOW MELT IS EXPECTED. FLOOD WATCHES REMAIN IN EFFECT THROUGH TONIGHT. 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...FREEZING RAIN ADVISORY UNTIL 11 AM EST THIS MORNING FOR NYZ041>043-083-084. FLOOD WATCH THROUGH MONDAY MORNING FOR NYZ032-033-038>040-042- 043-082. MA...NONE. VT...NONE. && $$ SYNOPSIS...SNYDER NEAR TERM...FRUGIS SHORT TERM...SNYDER LONG TERM...SNYDER AVIATION...WASULA HYDROLOGY...SNYDER
AREA FORECAST DISCUSSION
NWS TAUNTON MA
445 AM EST SUN DEC 22 2013 .SYNOPSIS... A FRONTAL BOUNDARY WILL GENERALLY BE TO THE NORTH OF THE REGION THROUGH MONDAY. PERIODS OF RAIN SHOWERS AND UNSEASONABLY MILD TEMPS ARE EXPECTED...ESPECIALLY TODAY INTO MONDAY FOR MUCH OF THE AREA. SOUTHERN NEW HAMPSHIRE MAY EXPERIENCE SOME LIGHT FREEZING RAIN LATE TODAY INTO TONIGHT. MAINLY DRY AND MUCH COLDER WEATHER ARRIVES TUE AND WED. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 445 AM UPDATE...KEEPING A CLOSE EYE ON TEMPERATURES THIS MORNING ACROSS SOUTHERN NH. 22/06Z NAM IS TOO WARM AT THE SURFACE AT 09Z...BUT IS NOT AS OVERLY WARM AS THE OTHER AVAILABEL GUIDANCE. THE 22/07Z RAP ALSO SEEMS TO HAVE A BETTER HANDLE ON SURFACE TEMPERATURES. BETWEEN THESE TWO SOURCES...EXPECTATIONS FOR SOME ICING IN HILLSBOROUGH COUNTY HAVE INCREASED. IT IS POSSIBLE THIS ICING COULD EXPAND WEST INTO CHESHIRE COUNTY...BUT IT IS SLIGHTLY MORE LIKELY FOR THE COLDER AIR TO SURGE SOUTH INTO MIDDLESEX AND ESSEX COUNTIES WHERE THE TERRAIN IS NOT AS MUCH OF AN IMPEDIMENT. POSTED A FREEZING RAIN ADVISORY FOR HILLSBOROUGH COUNTY WHERE CONFIDENCE IN SOME ICING IS HIGHEST. THE NEXT SHIFT MAY NEED TO EXPAND THIS ADVISORY BASED ON THE PROGRESS OF THE COLD AIR. LATEST NEAR-TERM GUIDANCE CONTINUES TO PRODUCE WIDESPREAD LOW CLOUDS AND FOG ACROSS SOUTHERN NEW ENGLAND. JUST STARTING TO SE SIGNS OF ITS DEVELOPMENT ACROSS THE CAPE AND ISLANDS...AS WELL AS ACROSS PORTIONS OF THE CT RIVER VALLEY IN SOUTHWEST NH. STARTING TO THINK THIS WILL BE A CASE WHERE THE STRATUS SORT OF DEVELOPS IN PLACE RATHER THAN BEING ENTIRELY ADVECTED INTO OUR REGION. STILL HAVING TROUBLE GETTING MEASURABLE RAINFALL WELL EAST OF THE BERKSHIRES. RADAR MOSAICS CONTINUE TO DEPICT ECHOES DIMINISHING AS THEY MOVE EAST. THIS IS LIKELY DUE TO DEEP...LINGERING DRY AIR ACROSS SOUTHERN NEW ENGLAND...AS EVIDENCED IN THE 22/00Z CHH AND OKX SOUNDINGS. DO NOT EXPECT THIS DRY AIR TO LAST ALL DAY...BUT DID SLOW THE ARRIVAL OF WIDESPREAD MEASURABLE RAINFALL SOUTH OF I-90. ONLY HAVE MODERATE CONFIDENCE IN THE TIMING...AND WILL CONTINUE TO TWEAK THE TIMING OVER THE NEXT COUPLE OF HOURS. LOCATION OF A FRONT WILL BE CRITICAL IN DETERMINING TODAY/S FORECAST. BESIDES DETERMINING PRECIPITATION TYPE ACROSS SOUTHERN NH...THIS FRONT WILL ALSO PROVIDE A FOCUS FOR MORE WIDESPREAD PRECIPITATION. MODEL CONSENSUS IS THIS FRONT SHOULD DROP INTO NORTHERN MA LATER TODAY. THIS MEANS THERE WILL BE A LARGE TEMPERATURE GRADIENT SOMEWHERE IN SOUTHERN NEW ENGLAND. COULD BE AS MUCH AS A 20 DEGREE DIFFERENCE IN FORECAST TEMPERATURES DEPENDING ON WHICH SIDE OF THIS FRONT AN AREA HAPPENS TO BE. MORE THOUGHT WILL NEED TO BE GIVEN TO TEMPERATURES LATER TODAY. IF TEMPERATURES DROP BELOW FREEZING...IT WILL NOT BE UNTIL LATE AFTERNOON...EVEN LOOKING AT THE COLDER NAM SOLUTION. WILL LIKELY NEED TO CONSIDER A FREEZING RAIN ADVISORY SOMEWHERE ACROSS NORTHERN MA INTO SOUTHERN NH LATE TODAY INTO TONIGHT. NEED TO FIGURE OUT THE PROGRESS OF THIS FRONT FIRST THOUGH. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/... RAIN AND/OR FREEZING RAIN WILL CONTINUE THROUGH TONIGHT. IN ADDITION...DENSE FOG WILL REMAIN A CONCERN...PARTICULARLY ON THE WARM SIDE OF THE FRONT. THE TIGHT TEMPERATURE GRADIENT WILL CONTINUE WITH THE COLDEST TEMPERATURES ACROSS SOUTHEASTERN NEW HAMPSHIRE AND NORTHEASTERN MASSACHUSETTS. A MILD NIGHT FOR THE REST OF THE AREA. EXPECTING ANOTHER LOW PRESSURE TO MOVE ALONG A FRONTAL BOUNDARY ACROSS SOUTHERN NEW ENGLAND MONDAY. MOISTURE IS RATHER HIGH FOR THIS TIME OF YEAR...WITH PRECIPITABLE WATER VALUES BETWEEN 1.00-1.75 INCHES. THUS...COULD SEE LOCALLY HEAVY RAINFALL TONIGHT INTO MONDAY. THE GREATEST RISK WOULD BE TOWARD THE SOUTH COAST. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... HIGHLIGHTS... *MAINLY DRY BUT MUCH COLDER CHRISTMAS EVE AND DAY * DRY HIGH PRESSURE FOR THE REMAINDER OF THE WEEK OVERVIEW AND MODEL PREFERENCES... 22/00Z MODEL GUIDANCE SUITE WITH THIS UPDATE IS SHOWING GENERALLY GOOD AGREEMENT THROUGH MUCH OF THE COMING WEEK. THE SOMEWHAT AMPLIFIED RIDGE-TROF-RIDGE SETUP ACROSS MUCH OF THE NORTHEASTERN CONUS ARE FAIRLY WELL AGREED UPON AT THE SYNOPTIC SCALE. GIVEN THIS...FEEL THAT A GENERAL CONSENUS OF DETERMINISTIC AND ENSEMBLE GUIDANCE ALONG WITH THE PREVIOUS FORECAST WILL WORK AS A GOOD BASELINE FOR THIS LONG-TERM FORECAST UPDATE. IN TERMS OF THE SYNOPTIC SETUP...THROUGH MID WEEK A LONGWAVE TROF WILL BE SETTLING OVER NEW ENGLAND AS STRONG RIDGING CONTINUES IN THE ATLANTIC BUT SLIDES A BIT FURTHER E. THIS TROF WILL CARRY WITH IT SOME COLDER TEMPERATURES FOR MID WEEK WHICH WILL WARM A SECONDARY AND WEAKER RIDGE /AND ASSOCIATED 1040 HIGH PRES/ MOVES OVER. THE DRY CONDITIONS LOOK TO PREVAIL WITH YET ANOTHER TROF BY LATE IN THE WEEK AS IT IS EXPECTED TO WEAKEN AND OPEN AS IT INTERACTS WITH THE STRONG RIDGING OFFSHORE. THERFORE...WITH THIS UDPATE...IT APPEARS MUCH OF THE LONG TERM PERIOD WILL BE DRY AS THE GENERAL FLOW PATTERN KEEPS SUBTROPICAL MOISTURE AT BAY. DETAILS... MON NIGHT... FRONTAL WAVE OF LOW PRES WILL BE MOVING FURTHER OFFSHORE DURING THE OVERNIGHT HOURS. PRECIP SHIELS ACROSS THE SOUTHEASTERN THIRD OF THE BOX CWA WILL ALSO GRADUALLY SHIFT OFFSHORE WITH TIME SUCH THAT IT WILL LIKELY BE CLEAR OF THE EVEN THE CAPE AND ISLANDS BY 12Z. AT THIS POINT...EXAMINING BUFKIT PROFILES SUGGESTS MUCH OF THE REMNANT PRECIP IS RAIN...BUT A BRIEF CHANGEOVER TO SNOW IS POSSIBLE DURING THE EARLY MORNING HOURS. AS COLD ADVECTION INCREASES AHEAD OF HIGH PRES AND A MUCH COLDER AIRMASS. ANY ACCUMS WOULD BE LIGHT TO NONE. TUE INTO WED... AS TROF SETTLES ACROSS THE REGION THE NOSE OF 1040 HPA HIGH PRES AND A MUCH COLDER AIRMASS WILL SETTLE ACROSS THE REGION. H85 TEMPS AVERAGE AROUND -12C DURING THE DAY TUE THEN SLIDE DOWN AS LOW AS -20C BY EARLY WED. CONDITIONS ARE EXPECTED TO BE MORE BLUSTERY ON TUE WITH DECENT PRES GRADIENT APPARENT...YIELDING 20+ MPH NW FLOW...BUT AMBIENT TEMPERATURES ARE COOLER ON WED. AVERAGE TEMPS ARE LIKELY TO BE 10-15 DEGREES /F/ BELOW NORMAL FOR LATE DEC. DRY WEATHER PREVAILS OTHERWISE UNDER STRONG SUBSIDENCE WITH 1040 HIGH PRES. THU AND FRI... SECONDARY SHORTWAVE WILL WEAKEN AND OPEN AS IT APPROAHCES THE NORTHEAST US/CANADA. ATTENDANT CLIPPER LOW PRES IS EXPECTED TO MOVE ACROSS NRN NEW ENGLAND AND SRN QUEBEC. THIS IS LIKELY TO KEEP SRN NEW ENGLAND ON THE CLIMATOLOGICALLY DRY SIDE OF THIS CLIPPER. NOT OUT OF THE QUESTION A FEW FLURRIES ARE SEEN WITH THE ACTUAL COLD FRONT LATE THU...BUT ITS LIKELY ONLY CLOUD COVER IS OBSERVED. THE ONLY CAVEAT WILL BE AN OFFSHORE WAVE WHICH MAY RIDE THE FRONT JUST AS IT MOVES OFFSHORE...WILL NEED TO KEEP AN EYE ON THIS BUT AT THIS POINT IT APPEARS THE WAVE PHASING IS FAR TOO LATE TO AFFECT SRN NEW ENGLAND. AFTER A SLIGHT MODERATE WITH TEMPERATURES CLOSER TO NORMAL ON THU...THE COLD FRONT ASSOCIATED CLIPPER WILL BRING ANOTHER ROUND OF BLUSTERY AND COOLER WX FOR THE DAY FRI. NEXT WEEKEND... STILL A LOT OF UNCERTAINTY /AS IS TYPICAL/ FROM DAY 6 ONWARD. EARLY INDICATION IS THAT HIGH PRES MAY ONCE AGAIN SETTLE ACROSS THE REGION BEHIND THE CLIPPER AND PHASING WAVES OFFSHORE...BUT THIS WOULD BE DEPENDENT ON THE FINAL FLOW PATTERN ONCE THE PHASING DOES/DOES NOT OCCUR. FOR NOW...WILL ERR ON THE SUGGESTED DRIER SOLUTION. && .AVIATION /09Z SUNDAY THROUGH THURSDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. NEAR TERM /THROUGH MONDAY/... 430 AM UPDATE... IFR BECOMING MORE WIDESPREAD ACROSS SOUTHERN NEW ENGLAND THIS MORNING. HAVE HIGH CONFIDENCE CONDITIONS WILL LOWER THROUGH TODAY...BUT LOW CONFIDENCE ON THE PRECISE TIMING. LLWS EXPECTED THROUGH THIS MORNING ACROSS SOUTHEAST MA WITH STRONG WSW JET JUST ABOVE THE SURFACE. MODERATE PROBABILITY OF FREEZING RAIN ACROSS PORTIONS OF SOUTHERN NH AND POSSIBLY NORTHEAST MA LATE TODAY. AIRPORT WEATHER WARNING HAS BEEN ISSUED FOR KMHT. TONIGHT...MODERATE CONFIDENCE. MVFR/IFR CONDITIONS CONTINUE IN FOG AND -SHRA. SOME IMPROVEMENT FROM NORTHWEST TO SOUTHEAST AS A FRONT MOVES THROUGH SOUTHERN NEW ENGLAND. MONDAY...MODERATE CONFIDENCE. PERIODS OF IFR POSSIBLE IN RAIN... POSSIBLY HEAVY AT TIMES. AREAS OF FOG. KBOS TAF...HIGH CONFIDENCE IN TRENDS. LOW CONFIDENCE IN TIMING. KBDL TAF...HIGH CONFIDENCE IN TRENDS. LOW CONFIDENCE IN TIMING. OUTLOOK...MONDAY NIGHT THROUGH THURSDAY... MON NIGHT...HIGH CONFIDENCE. IMPROVING TO MVFR/VFR AS PRECIP ENDS NW TO SE. TUE AND WED...HIGH CONFIDENCE. VFR. SOME NW WINDS 25-30 KT AT TIMES TUE. THURSDAY...HIGH CONFIDENCE. VFR. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. PERSISTENT SOUTHWEST WINDS AS A FRONTAL BOUNDARY REMAINS DRAPED ACROSS CENTRAL AND NORTHERN NEW ENGLAND WITH WAVES OF LOW PRESSURE TRACKING ALONG THIS FRONT. SOUTHWEST WINDS DIMINISH MONDAY AS A FRONT AND AREA OF LOW PRES MOVE SOUTH INTO THE REGION. PERIODS OF HEAVY RAIN WILL LIKELY REDUCE VISIBILITY MONDAY. MODERATE TO HIGH CONFIDENCE THRU MONDAY. OUTLOOK...MON NIGHT THROUGH THU... MON NIGHT INTO TUE NIGHT...HIGH CONFIDENCE. SEAS WILL CONTINUE TO DECLINE ACROSS THE REGION ESPECIALLY AS WINDS SHIFT TO THE NW LATE MON NIGHT. HOWEVER...WITH THIS NW WIND SHIFT...WIND GUSTS OF 25-30 MPH ARE EXPECTED ACROSS ALL WATERS. SMALL CRAFT ADVISORIES ARE LIKELY TO CONTINUE. WED AND WED NIGHT...HIGH CONFIDENCE. IT APPEARS SEAS WILL SLACKEN ENOUGH AS WINDS RECEDE EARLY WED THAT A PERIOD OF MAINLY QUIET BOATING WEATHER IS EXPECTED UNDER HIGH PRES. THU...MODERATE CONFIDENCE. WINDS AND SEAS MAY BEGIN TO BUILDS FROM THE S AHEAD OF A COLD FRONT DURING THE DAY THU. IT IS POSSIBLE THAT SMALL CRAFT ADVISORY CONDITIONS ARE REACHED...OVER THE SRN WATERS FIRST. && .CLIMATE... RECORD HIGHS FOR DECEMBER 22ND... HARTFORD /BDL/ 59 DEGREES...1990 WORCESTER /ORH/ 63 DEGREES...1923 BOSTON /BOS/ 62 DEGREES...1990 PROVIDENCE /PVD/ 61 DEGREES...1990 && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...FREEZING RAIN ADVISORY FROM NOON TODAY TO MIDNIGHT EST TONIGHT FOR NHZ012-015. RI...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST MONDAY FOR ANZ235-237-250. SMALL CRAFT ADVISORY UNTIL 6 AM EST TUESDAY FOR ANZ254>256. && $$ SYNOPSIS...BELK/DOODY NEAR TERM...BELK SHORT TERM...BELK LONG TERM...DOODY AVIATION...BELK/DOODY MARINE...BELK/DOODY CLIMATE...STAFF
AREA FORECAST DISCUSSION
NWS ALBANY NY
403 AM EST SUN DEC 22 2013 .SYNOPSIS... A NEARLY STATIONARY FRONT FROM CENTRAL NEW YORK TO THE MAINE COAST WILL SHIFT SLIGHTLY AS A STORM MOVES ALONG IT TODAY. NORTH OF IT IT WILL BE CHILLY WITH RAIN AND FREEZING RAIN...WITH RAIN AND VERY MILD WEATHER TO ITS SOUTH. THE STORM WILL DRAG A COLD FRONT THROUGH THE REGION TONIGHT AND THEN SLIDE SLOWLY OFFSHORE MONDAY. HIGH PRESSURE WILL BUILD FROM ONTARIO INTO NEW YORK TUESDAY INTO CHRISTMAS...WITH MUCH COLD AIR FILTERING INTO THE REGION. THE WEEK WILL END WITH A SERIES OF FAST MOVING WEATHER SYSTEMS WITH BOUTS OF SNOW SHOWERS AND GENERALLY SEASONABLE TEMPERATURES. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 321 AM EST...WIDE VARIETY OF TEMPERATURES ACROSS THE REGION EARLY THIS MORNING WITH STALLED FRONTAL BOUNDARY SITUATED DIRECTLY ACROSS THE CENTRAL PORTION OF THE CWA. NORTH OF THE BOUNDARY...VERY COLD CANADIAN AIR IS PULLED SOUTHWARD THANKS TO A LOW LEVEL NNE FLOW THROUGH THE CHAMPLAIN VALLEY AND INTO THE UPPER HUDSON VALLEY REGION. THIS HAS ALLOWED TEMPS TO DROP BELOW FREEZING FOR THE GLENS FALLS AND SARATOGA SPRINGS AREA. TEMPS HAVE FALLEN INTO THE MID 30S IN THE CAPITAL REGION. AT THE SAME TIME...VERY WARM TEMPS ALOFT ARE IN PLACE THANKS TO A STRONG SOUTHERLY FLOW ALOFT. 850 HPA TEMPS HAVE RISEN TO +7 TO +15 DEGREES C ACROSS OUR REGION. AS A RESULT...THE WARMER TEMPS AT THIS HOUR ARE ACROSS THE MOUNTAIN PEAKS OF THE CATSKILLS...SRN GREENS AND BERKSHIRES...WHERE TEMPS ARE WELL INTO THE 50S. WITH AN APPROACHING LOW PRESSURE AREA AND THE SFC BOUNDARY IN PLACE...OVERRUNNING PRECIP...MAINLY IN THE FORM OF RAIN...IS MOVING ACROSS THE WESTERN ADIRONDACKS. SOME LIGHTER RAIN AND FREEZING RAIN IS OCCURRING FURTHER EAST ACROSS THE LAKE GEORGE/SARATOGA REGION AND SOME LIGHT RAIN SHOWERS ARE OVER WESTERN NEW ENGLAND. THERE IS A BREAK IN THE PRECIP OVER THE REMAINDER OF THE AREA...AS A DRY SLOT IS ATTEMPTING TO MOVE INTO THE AREA WITH LITTLE PRECIP SHOWN ON UPSTREAM RADARS. THE LATEST 03Z 3KM HRRR SHOWS THIS DRY SLOT SHOULD START TO FILL IN TOWARDS DAYBREAK AS THE LOW PRESSURE AREA MOVES NORTHEAST ACROSS THE OHIO VALLEY AND EVENTUALLY TOWARDS UPSTATE NY...SO WE WILL CONTINUE RATHER HIGH POPS BY AROUND DAYBREAK DESPITE THE CURRENT LULL IN THE PRECIP AS SHOWN ON RADAR. FOR NOW...IT DOESN/T APPEAR THAT THE CAPITAL REGION WILL BE SEEING ANY FREEZING RAIN...AS THE APPROACHING STORM SHOULD ALLOW THE STALLED BOUNDARY TO START TO MOVE NORTHWARD AS A WARM FRONT...AND BRING THE ALBANY AREA INTO THE WARM SECTOR ONCE THE NEXT ROUND OF RAINFALL BEGINS. FURTHER NORTH...IT MAY TAKE UNTIL THE MID TO LATE MORNING FOR THE WARM FRONT TO MOVE THROUGH AND TEMPS TO WARM UP. AS A RESULT...A PROLONGED PERIOD OF FREEZING RAIN CAN BE EXPECTED ACROSS THE LAKE GEORGE SARATOGA REGION. ICE ACCRETION AMOUNTS WILL RANGE FROM A TRACE TO A TENTH ACROSS THE SARATOGA SPRINGS AREA TO A FEW TENTHS FOR GLENS FALLS TO ABOUT FOUR TENTHS ACROSS THE NORTH END OF LAKE GEORGE. ASIDE FROM SOME HAZARDOUS DRIVING CONDITIONS...THIS MAY LEAD TO SOME ISOLATED POWER OUTAGES. AREAS IN THE WARM SECTOR SHOULD SEE SFC TEMPS WARM SIGNIFICANTLY...AS THOSE WARMER TEMPS ALOFT ARE MIXED IN THE BOUNDARY LAYER. MAX TEMPS LOOK TO REACH INTO THE 50S ACROSS MUCH OF THE CENTRAL AND SOUTHERN PARTS OF THE AREA...WITH SOME LOW TO MID 60S FOR THE MID HUDSON VALLEY. WHILE IT WILL RAIN THROUGH THE MORNING HOURS...MOST AREAS WILL BE DONE SEEING PRECIPITATION BY THE EARLY TO MID AFTN HOURS...AS THE STORM/S COLD FRONT PASSES THROUGH THE AREA. TOTAL RAINFALL FOR SUNDAY WILL RANGE FROM JUST A QUARTER OF AN INCH ACROSS LITCHFIELD COUNTY CT...TO AROUND THREE QUARTERS OF AN INCH IN THE CAPITAL REGION TO ABOUT AN INCH AND A HALF OVER THE ADIRONDACKS. SEE THE HYDRO SECTION ON HOW WE EXPECT THIS RAINFALL TO AFFECT AREA RIVERS AND STREAMS. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/... FOR THIS PERIOD THE MODEL SUITE (GEM/GFS/ECMWF) ARE IN FAIRLY GOOD AGREEMENT. DURING THE THIS EVENING THE SFC LOW AND ITS UPPER DYNAMICS WILL LIFT NE OUT OF FCA. A SERIES OF 500HPA SHORT WAVES WILL DIG A TROF OVER GRTLKS...MAINTAINING A STRONG SW 500HPA FLOW OVER THE EASTERN THIRD OF THE NATION. FOR A TIME THIS WILL ACT TO WEAKEN THE SFC LOW FURTHER OVER NEW ENG...BUT THE SFC LOW WILL DRAG A CDFNT THROUGH THE REGION TNGT. GIVEN THE UPPER FLOW COOLER AIR WILL BE SLOW TO FILTER IN OVERNIGHT....AND TEMPS WILL REMAIN ABV FREEZING IN MOST AREAS...WITH SNOW MELT CONTINUING. BY MONDAY THIS CDFNT WILL NEARLY STALL ALONG THE EASTERN SEABOARD...AND WITH DIGGING 500HPA TROF INTERACTING WITH THE COASTAL BAROCLINIC ZONE WILL TRIGGER A BOUT OF OVERRUNINNG RAIN...ALONG THE I-95 CORRIDOR THAT WILL BACK BUILD INTO SE PORTIONS OF FCA. QPF DURING MONDAY WITH THIS SHOULD BE 0.25 TO 0.50 IN THESE AREAS...AND GIVEN THESE AREAS WERE IN THE WARM SECTOR MUCH OF THE CURRENT EVENT...THEY MELTED MOST OF THEIR SNOW...BUT HAD LITTLE RAINFALL. ADD TO THAT THE 2-3 DAYS THIS OCCURRED...THE ADDITIONAL RAIN IN SOUTHEAST AREAS MONDAY SHOULD NOT RESULT IN ANYTHING OTHER THAN WITHIN BANK RISES. FURTHER WEST MONDAY AS HIGH PRESSURE BUILDS EAST WIND GRADIENT WILL INCR AND AS THE 500HPA TROF PUSHES EAST A MUCH STRONGER 2NDRY CDFNT WILL PUSH INTO THE REGION LATE MONDAY AND THROUGH MONDAY NIGHT. TEMPS MONDAY WILL HOLDS STEADY THEN FALL DURING THE AFTN. MONDAY NIGHT INTO TUES THE PASSAGE OF THE 500HPA TROF...CAA WILL RESULT IN SCT -SHSN ACTIVITY. HWVR LLVL FLOW WILL BE TOTALLY UNFAVORABLE FOR LK EFFECT OVER EASTERN NY. ONCE THE 500HPA TROF EXITS CHRISTMAS EVE BOTH A 500HPA RIDGE...AND SFC HIGH PRESSURE WILL SETTLE OVER NYS AND MID ATLC REGION. THIS WILL SET THE STAGE FOR A FRIGID NIGHT WITH IDEAL RADIATIONAL COOLING...ONE OF THE LONGEST NIGHTS OF THE YEAR...CLEAR SKIES AND DRY AIR MASS. LOWS WILL PLUNGE TO -20F IN PARTS OF THE ADIRONDACKS TO AROUND 10 IN THE SE. TEMPS WILL RECOVER CHRISTMAS DAY TO THE TEENS AND 20S AS SFC HIGH SLIDES OFFSHORE. SOME CLOUDS MAY ARRIVE IN THE AFTERNOON AS NEXT WEAK SYSTEM APPROACHES. && .LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/... THE EFP WILL FEATURE A SERIES OF FAST MOVING SYSTEMS IN W-NW FLOW. MOST WILL BE FAIRLY WK CDFNTS AND/OR 500HPA SHORT WVS...WHICH WILL INCR CLOUDS AND PRODUCE SCT -SHSN AND AT TIMES HAVE SOME INTERACTION WITH THE GRTLKS. TEMPS WILL RETURN TO NEAR NORMALS AFTER A FRIGID CHRISTMAS. TYPICAL WINTER IN UPSTATE NY. CHRISTMAS NIGHT AND THURS THE FIRST OF THESE SYSTEMS RACES ACROSS ONTARIO...WITH A FEW WEAK FRONTS AND A 500HPA SHORT WV. MAIN IMPACTS WILL INCR CLOUDS MAINLY N & W. THU NT IT WILL DRAG A CDFNT THROUGH WITH SOME -SHSN ACTIVITY MAINLY N & WEST. IN ITS WAKE FRI CAA AND A 2NDARY CDFNT AND NW FLOW WILL TRIGGER SCT -SHSN WITH SOME LK ASSISTANCE. WK SFC HIGH BUILDS OVER FCA FRI NT. SAT ANOTHER WK SHORT WV AND SFC SYSTEM MOVES THROUGH THE GRTLKS WITH A LITTLE WAA INCRG CLOUDS AND SCT -SHSN IN ECMWF...GETTING SOME ASSIST FM THE LKS. GFS HAS MORE CLOUDS AND A WIDESPREAD LT -SN OF MAYBE AN INCH. SAT NT INTO SUN FLOW BCMS ZONAL TO WSW AT 500HPA. WMFNT AND SFC LOW SETS UP N OF RGN. NOT MUCH DIFFERENCE BWTN GFS AND ECMWF. WILL POPULATE WITH HPC MID SHIFT AND TWEAK POPS A TAD. OTHERWISE A QUIET PERIOD FOR THE HOLIDAY WEEK. && .AVIATION /09Z SUNDAY THROUGH THURSDAY/... A FRONTAL BOUNDARY WILL BE OVER UPSTATE NY AND NEW ENGLAND TODAY WITH AREAS OF LOW PRESSURE MOVING ALONG IT. THIS BOUNDARY WILL DIVIDE VERY COLD AIR FROM MILD AIR OVER THE E-CNTRL NY CORRIDOR WITH SOME FREEZING RAIN CONTINUING FOR KGFL EARLY THIS MORNING...AND OCCASIONAL LIGHT RAIN FOR KALB-KPSF SOUTHWARD BEFORE A STEADIER RAINSHIELD MOVES IN TOWARDS 12Z. FLIGHT CONDITIONS VARY FROM LIFR/IFR AT KGFL/KALB TO VFR/MVFR AT KPOU AND KPSF THIS MORNING. THE TREND WILL BE FOR WIDESPREAD IFR/MVFR CONDITIONS TO IMPACT THE TERMINALS BTWN 09Z-12Z. THE MVFR CONDITIONS MAY CONTINUE AT KPOU UNTIL AFTER 12Z...BUT EXPECT IFR CIGS/VSBYS FOR KGFL...KALB...KPSF THROUGH MOST OF THE LATE MORNING INTO THE EARLY PM...AS LOW PRESSURE MOVES ACROSS CNTRL/NRN NY. EXPECT TEMPS TO MOVE BACK ABOVE FREEZING AT KGFL AROUND 10Z. THE RAINFALL SHOULD DIMINISH BTWN 18Z-21Z FOR THE E-CNTRL NY TERMINALS WITH SOME SCT SHOWERS AND DRIZZLE LINGERING INTO THE EARLY EVENING. SOME IFR/MVFR VISIBILITIES MAY PERSIST INTO THE EARLY EVENING WITH MVFR CIGS. THE CIGS MAY START TO RISE TOWARDS MIDNIGHT WITH SOME DRIER AIR STARTING TO FILTER IN FROM THE SOUTHWEST. THE SFC WINDS WILL BE FROM THE E TO NE AT KALB AND KGFL EARLY THIS MORNING AT 5-10 KTS...THEN VEER TO TO SOUTH AT AROUND 10 KTS BY 12Z WITH SOME GUSTS AT KALB IN THE 20-25 KT RANGE. KPOU AND KPSF WILL CONTINUE TO HAVE S/SW WINDS 5-10 KTS...THEN INCREASE TO 8-15 KTS WITH SOME GUSTS CLOSE TO 25 KTS AT KPSF...AS THE STRONGER LLJ MOVES IN ALOFT. THE WINDS WILL DECREASE FROM THE S/SW AT LESS THAN 10 KTS AFTER 00Z/MON. OUTLOOK... MONDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...SHSN. TUESDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. TUESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. CHRISTMAS DAY: NO OPERATIONAL IMPACT. NO SIG WX. WEDNESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. THURSDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. THURSDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX. && .HYDROLOGY... MILD TO UNSEASONABLY WARM TEMPERATURES WILL OCCUR THOUGH TONIGHT WITH INCREASING SNOW MELT. LOW PRESSURE WILL MOVE ALONG A NEARLY STATIONARY FRONT FROM THE NIAGARA FRONTIER TO NEW ENGLAND BY THIS EVENING. 1-2 INCHES OF ADDITIONAL RAINFALL IS EXPECTED IN THE ADIRONDACKS...WITH LESSER AMOUNTS SOUTH. TEMPERATURES TODAY WILL WARM INTO THE 50S AND 60S REMAIN ABOVE FREEZING TONIGHT. IN THE NORTH RAINFALL AMOUNTS WILL BE GREATEST...BUT SNOW MELT SLOWER...WHILE IN THE SOUTH RAINFALL WILL BE AROUND A HALF INCH...BUT ALMOST ALL THE SNOW WILL MELT. EVEN AS THE RAIN TAPERS OFF THIS EVENING...SNOW MELT AND RUNOFF WILL CONTINUE TONIGHT. IN THE SOUTH THE RAINFALL WILL BE SUFFICIENT FOR SIGNIFICANT WITHIN BANK RISES...BUT FLOODING IS NOT EXPECTED AT THIS TIME. THE GREATEST POTENTIAL FOR FLOODING WILL EXIST FROM THE MOHAWK VALLEY INTO THE ADIRONDACKS WHERE 1 TO 2 INCHES ADDITIONAL RAIN AND UP TO AN INCH OF LIQUID EQUIVALENT FROM SNOW MELT IS EXPECTED. FLOOD WATCHES REMAIN IN EFFECT THROUGH TONIGHT. 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...FREEZING RAIN ADVISORY UNTIL 11 AM EST THIS MORNING FOR NYZ041>043-083-084. FLOOD WATCH THROUGH MONDAY MORNING FOR NYZ032-033-038>040-042- 043-082. MA...NONE. VT...NONE. && $$ SYNOPSIS...SNYDER NEAR TERM...FRUGIS SHORT TERM...SNYDER LONG TERM...SNYDER AVIATION...WASULA HYDROLOGY...SNYDER
AREA FORECAST DISCUSSION
NWS NEW YORK NY
345 AM EST SUN DEC 22 2013 .SYNOPSIS... A WARM FRONT WILL REMAIN ANCHORED NORTH OF THE TRI-STATE REGION THROUGH SUNDAY. LOW PRESSURE RIDES ALONG A COLD FRONT MONDAY. THE FRONT MOVES SLOWLY EAST TUESDAY. HIGH PRESSURE THEN BUILDS TOWARD THE AREA WEDNESDAY. A COLD FRONT MOVES THROUGH LATE THURSDAY. HIGH PRESSURE BUILDS LATE IN THE WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... THE WATER VAPOR IMAGERY DEPICTS DIFFLUENT FLOW JUST WEST OF THE TENNESSEE VALLEY WITH A STRONG SHORTWAVE AND VORTICITY MAXIMUM MOVING ACROSS THE CENTRAL U.S. THE SURFACE LOW IS MOVING INTO THE OHIO VALLEY. THE LOW IS FORECAST TO MAINTAIN ITS STRENGTH FOR THE REMAINDER OF TONIGHT. THE LOCAL AREA WILL RECEIVE A CONTINUOUS FLOW OUT OF THE SOUTH TO SOUTHWEST...INCREASING THE WARM AND MOIST AIR ADVECTION. STRATUS HAS BEGUN TO MOVE IN ACROSS PORTIONS OF LONG ISLAND. FOG HAS STARTED TO DEVELOP BUT IS PATCHY IN COVERAGE WITHOUT TOO MUCH REDUCTION IN VISIBILITY. LOOKING AT LATEST BUFKIT SOUNDINGS...THE FOG LOOKS TO INCREASE BY 09Z AND LINGER INTO SUNDAY MORNING. KEEPING PATCHY COVERAGE OF FOG UNTIL 08Z AND THEN EXPAND TO AREAS. MOST MOS GUIDANCE IS NOT BRINGING MUCH LOWER VSBYS UNTIL AROUND 12-15Z WITH DENSE FOG POTENTIAL. THE POTENTIAL WILL BE THERE FOR DENSE FOG AND THIS WILL BE AN ADVECTION FOG. THE LIMITING FACTOR IS THE WINDS AND THIS CAN BE CONVEYED BY ONGOING CONDITIONS. RELATIVELY HIGHER WINDS ALONG THE COAST WITHOUT MUCH IF ANY VISIBILITY REDUCTION WITH A LITTLE MORE REDUCTION INLAND WHERE WINDS ARE LIGHTER. IF WINDS FURTHER DECOUPLE AND DECREASE...A MORE WIDESPREAD FOG WILL DEVELOP. REGARDING SHOWERS...TRENDED LOWER IN POPS WITH SCATTERED SHOWERS BEING RESTRICTED TO MAINLY INTERIOR PORTIONS. THIS IS CONSISTENT WITH HRRR FORECAST REFLECTIVITY FIELDS. STILL EXPECTING SOME DRIZZLE TO FORM TOWARDS MORNING WITH SATURATION OF THE BOUNDARY LAYER. LOW TEMPERATURES FOR THE MOST PART HAVE ALREADY BEEN REACHED WITH A STEADY TO SLIGHT INCREASE IN TEMPS EXPECTED TOWARDS MORNING. TEMPERATURES WILL BE MOSTLY FROM LOW AND MID 40S TO MID 50S. && .SHORT TERM /6 AM THIS MORNING THROUGH MONDAY NIGHT/... IF TEMPS WERE MIXED DOWN FROM H85...HIGHS WOULD BE IN THE LOW TO MID 80S ON SUN. DESPITE THESE EXTREMELY WARM TEMPS ALOFT HOWEVER...BOTH THE GFS AND NAM SUGGEST THE AREA WILL REMAIN SOCKED IN WITH STRATUS...FG AND DZ THRU THE DAY. THIS SHOULD LIMIT HIGHS SO WENT WITH THE COOLEST GUIDANCE...THE MET. MOST IF NOT ALL CLIMATE SITES HOWEVER SHOULD STILL BREAK THEIR RECORDS. IF THE CLOUDS DO BREAK UP IN THE EARLY AFTN...TEMPS WILL SHOOT UP INTO 70S GENERALLY FROM THE CITY N AND W. CONTINUED CHC FOR MEASUREABLE RAIN COVERED WITH -SHRA DURING THE DAY...BUT THE MAIN FORCING DOES NOT ARRIVE TIL SUN NGT PER THE NAM/GFS/ECMWF. FCST THEREFORE BRINGS POPS UP THRU THE NGT...AND TRANSITIONS PCPN TO MODERATE RAIN. THIS IS WHEN THE BEST WINDOW FOR ACCUMULATING PCPN WILL OCCUR. IT WILL REMAIN STEAMY WITH LOW TEMPS ABV MAX NORMALS. && .LONG TERM /TUESDAY THROUGH SATURDAY/... SOUTHEAST RIDGE GIVES WAY TO DEEP TROUGH MONDAY AND TUESDAY. THE TROUGH MOVES EAST WITH BRIEF RIDGING BY MID WEEK. AN UPSTREAM SHORTWAVE MOVES ACROSS THE NORTHEAST BY LATE IN THE WEEK. AT THE SFC...WAVE OF LOW PRESSURE RIDES ALONG THE STALLED OR SLOW MOVING FRONT MONDAY. THIS FRONT TRACKS TO THE EAST...WITH AN INVERTED TROUGH (ASSOCIATED WITH LARGE UPPER TROUGH) MOVING THROUGH SOMETIME TUESDAY. A TIGHT PRESSURE GRADIENT REMAINS IN PLACE MONDAY NIGHT THROUGH TUESDAY NIGHT. THEN HIGH PRESSURE BUILDS IN WEDNESDAY AND WEDNESDAY NIGHT. A COLD FRONT APPROACHES AND MOVES ACROSS THE AREA THURSDAY AND THURSDAY NIGHT...WITH HIGH PRESSURE BUILDING BEHIND THE FRONT LATE IN THE WEEK INTO NEXT WEEKEND. MODELS IN GENERAL AGREEMENT WITH REGARD TO THESE OVERALL FEATURES AND PATTERN THROUGH THE WEEK. RAIN...MODERATE TO PERHAPS HEAVY AT TIMES...MONDAY WILL TAPER OFF FROM WEST TO EAST LATE MONDAY AND MONDAY NIGHT. A FEW FLURRIES OR LIGHT SNOW SHOWERS ARE POSSIBLE LATE TUESDAY AND TUESDAY NIGHT...WITH WEAK INSTABILITY IN PLACE AS UPPER TROUGH MOVES THROUGH. MOISTURE THOUGH WILL BE LIMITED. DRY WEDNESDAY AND WEDNESDAY NIGHT...THEN A FEW MORE RAIN OR SNOW SHOWERS ARE POSSIBLE WITH THE COLD FRONT LATE THURSDAY AND THURSDAY NIGHT. DRY WEATHER RETURNS. AS FOR TEMPS...LITTLE CHANGE IN TEMPS FROM EARLY MORNING READINGS ARE EXPECTED MONDAY DUE TO THE CLOUDS AND RAIN. THEN A BRIEF SHOT OF COLDER AIR MOVES IN MONDAY NIGHT THROUGH WEDNESDAY. NEAR NORMAL TEMPS ARE EXPECTED THURSDAY IN WEAK WARM AIR ADVECTION BEHIND THE HIGH AND AHEAD OF THE FRONT. THE SEASONABLY CHILLY WEATHER CONTINUES LATE IN THE WEEK. FOLLOWED A MAV/MET BLEND MONDAY...AND WPC/ECE AND MEX NUMBERS FOLLOWED TUESDAY ONWARD. && .AVIATION /09Z SUNDAY THROUGH THURSDAY/... A FRONTAL BOUNDARY STRETCHING FROM JUST OFF THE TEXAS COAST THROUGH THE OHIO VALLEY AND INTO NORTHERN NEW ENGLAND WILL SLOWLY MOVE EAST THROUGH TODAY...THEN TRACK ACROSS THE TERMINALS LATE TONIGHT INTO MONDAY MORNING. TOUGH FORECAST CONTINUES AS THE STRATUS AND FOG HAS NOT YET DEVELOPED...WITH LOCAL MVFR CONDITIONS. TREND TO BETTER CONDITIONS CONTINUES. STILL HAVE LOW CONFIDENCE IN THE FORECAST. MODERATE CONFIDENCE IN WINDS. A 55-65KT LLJ BETWEEN 1500-2000 FT...WILL PEAK BETWEEN 10Z AND 16Z. THINK SOME OF THIS WILL MIX DOWN...WITH 20-30KT GUSTS BETWEEN 15Z AND 22Z. SCATTERED SHOWERS APPROACHING FROM THE SW. KSWF HAS THE HIGHEST CHC FOR ANY ACTIVITY TO IMPACT THE AIRFIELD. DIFFICULT TO PINPOINT WHERE SCT SHOWERS WILL BE BEYOND 12Z...BUT ORGANIZED FRONTAL SHOWERS NOT EXPECTED TO IMPACT OTHER TERMINALS UNTIL AFT 18Z. .OUTLOOK FOR 06Z MONDAY THROUGH THURSDAY... .SUN NIGHT...MVFR-IFR IN FG/BR AND -SHRA. .MON...MVFR-IFR IN -SHRA INTO THE AFTN...THEN CONDS IMPROVING W TO E. WIND SHIFT FROM SW-NW WITH COLD FROPA AFTER 18Z. .TUE...VFR. NW WIND 15-20G20-30KT. .WED-THU...VFR. && .MARINE... REDUCED VSBY AND MODERATE SSW FLOW WILL RESULT IN HAZARDOUS CONDITIONS THRU SUN NGT. A SCA FOR ALL WATERS EXCEPT THE HARBOR TNGT THRU SUN NGT. STRONGEST WINDS ON THE ERN WATERS DUE TO THE SW FETCH. IT IS UNCERTAIN IF THE WINDS WILL BE STRONG ENOUGH TO KEEP FOG DEVELOPMENT LIMITED. HAVE INCLUDED 1NM VSBY IN THE FCST...BUT POTENTIAL EXISTS FOR VSBY TO DROP BLW 1NM IF WINDS ARE WEAKER THAN FCST. THIS WOULD REQUIRE A DENSE FG ADVY. AS LOW PRESSURE PASSES ACROSS THE WATERS MONDAY...OCEAN SEAS REMAIN ELEVATED. THEN THE LOW AND COLD FRONT DEPART...WITH GUSTY WEST TO NORTHWEST WINDS ANTICIPATED MONDAY NIGHT THROUGH TUESDAY NIGHT. HIGH PRESSURE EVENTUALLY BUILDS IN WEDNESDAY AND THURSDAY. AS SUCH...WINDS WILL DIMINISH AND SEAS WILL SUBSIDE DURING THIS MID WEEK TIMEFRAME. && .HYDROLOGY... SPOTTY LIGHT PCPN CAN BE EXPECTED THRU SUN. THIS WILL RESULT IN MINOR ACCUMS. MOST OF THE MEASUREABLE RAIN IS FCST TO OCCUR SUN NGT INTO MON. AROUND AN INCH OF BASIN AVE RAINFALL IS EXPECTED ATTM. && .CLIMATE... THE FOLLOWING ARE RECORD HIGHS AND FORECAST HIGHS FOR SUNDAY DECEMBER 22 RECORD FORECAST EWR 65/1998 69 BDR 59/1998 59 NYC *63/1998 69 LGA 64/1998 67 JFK 62/1998 62 ISP 59/2011 62 * ALSO OCCURRED IN PREVIOUS YEARS NOTE: RECORD HIGH MINIMUMS ARE ALSO POSSIBLE AT JFK AND ISP ON SUNDAY DECEMBER 22. THE FORECAST LOW AT JFK IS 50 WITH A RECORD HIGH MINIMUM OF 50 IN 1990. THE FORECAST LOW AT ISP IS 53 WITH A RECORD HIGH MINIMUM OF 50 IN 1990. THE FOLLOWING ARE THE RECORD HIGH MINIMUMS FOR MONDAY DECEMBER 23 RECORD FORECAST EWR 58/1990 53 BDR 51/1990 49 NYC 57/1990 56 LGA 54/1990 56 JFK 50/1990 51 ISP 52/1990 54 && .EQUIPMENT... THE NEW YORK CITY NOAA ALL HAZARDS WEATHER RADIO STATION KWO35 IS OUT OF SERVICE. DUE TO INTERFERENCE ISSUES WITH THE U.S. COAST GUARD EMERGENCY BROADCAST CHANNEL...THE NEW YORK CITY NOAA ALL HAZARDS WEATHER RADIO STATION KWO35 IS OUT OF SERVICE. DURING THE TIME...THE TRANSMITTER MAY BE RETURNED TO SERVICE INTERMITTENTLY FOR USE OF THE NOAA ALL HAZARDS WEATHER RADIO DURING POTENTIALLY DANGEROUS WEATHER SITUATIONS...FOR ROUTINE WEEKLY TEST OF THE WARNING SYSTEM...AND TO DETERMINE IF THE INTERFERENCE ISSUE HAS BEEN RESOLVED. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST MONDAY FOR ANZ330-335-340- 345-350-353-355. && $$ AVIATION...MET
AREA FORECAST DISCUSSION
NWS ALBANY NY
321 AM EST SUN DEC 22 2013 .SYNOPSIS... A NEARLY STATIONARY FRONTAL BOUNDARY FROM CENTRAL NEW YORK TO THE MAINE COAST WILL SHIFT SLIGHTLY AS A STORM MOVES ALONG IT TODAY. NORTH OF IT IT WILL BE CHILLY WITH RAIN AND FREEZING RAIN...WITH RAIN AND VERY MILD WEATHER TO ITS SOUTH. THE STORM WILL DRAG A COLD FRONT THROUGH THE REGION TONIGHT AND THEN SLIDE SLOWLY OFFSHORE MONDAY. HIGH PRESSURE WILL BUILD FROM ONTARIO INTO NEW YORK TUES INTO CHRISTMAS...WITH SURGES OF MUCH COLD AIR FILTERING INTO THE REGION. THE WEEK WILL END WITH A SERIES OF FAST MOVING WEATHER SYSTEMS WITH BOUTS OF SNOW SHOWERS AND GENERALLY SEASONABLE TEMPERATURES. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 321 AM EST...WIDE VARIETY OF TEMPERATURES ACROSS THE REGION EARLY THIS MORNING WITH STALLED FRONTAL BOUNDARY SITUATED DIRECTLY ACROSS THE CENTRAL PORTION OF THE CWA. NORTH OF THE BOUNDARY...VERY COLD CANADIAN AIR IS PULLED SOUTHWARD THANKS TO A LOW LEVEL NNE FLOW THROUGH THE CHAMPLAIN VALLEY AND INTO THE UPPER HUDSON VALLEY REGION. THIS HAS ALLOWED TEMPS TO DROP BELOW FREEZING FOR THE GLENS FALLS AND SARATOGA SPRINGS AREA. TEMPS HAVE FALLEN INTO THE MID 30S IN THE CAPITAL REGION. AT THE SAME TIME...VERY WARM TEMPS ALOFT ARE IN PLACE THANKS TO A STRONG SOUTHERLY FLOW ALOFT. 850 HPA TEMPS HAVE RISEN TO +7 TO +15 DEGREES C ACROSS OUR REGION. AS A RESULT...THE WARMER TEMPS AT THIS HOUR ARE ACROSS THE MOUNTAIN PEAKS OF THE CATSKILLS...SRN GREENS AND BERKSHIRES...WHERE TEMPS ARE WELL INTO THE 50S. WITH AN APPROACHING LOW PRESSURE AREA AND THE SFC BOUNDARY IN PLACE...OVERRUNNING PRECIP...MAINLY IN THE FORM OF RAIN...IS MOVING ACROSS THE WESTERN ADIRONDACKS. SOME LIGHTER RAIN AND FREEZING RAIN IS OCCURRING FURTHER EAST ACROSS THE LAKE GEORGE/SARATOGA REGION AND SOME LIGHT RAIN SHOWERS ARE OVER WESTERN NEW ENGLAND. THERE IS A BREAK IN THE PRECIP OVER THE REMAINDER OF THE AREA...AS A DRY SLOT IS ATTEMPTING TO MOVE INTO THE AREA WITH LITTLE PRECIP SHOWN ON UPSTREAM RADARS. THE LATEST 03Z 3KM HRRR SHOWS THIS DRY SLOT SHOULD START TO FILL IN TOWARDS DAYBREAK AS THE LOW PRESSURE AREA MOVES NORTHEAST ACROSS THE OHIO VALLEY AND EVENTUALLY TOWARDS UPSTATE NY...SO WE WILL CONTINUE RATHER HIGH POPS BY AROUND DAYBREAK DESPITE THE CURRENT LULL IN THE PRECIP AS SHOWN ON RADAR. FOR NOW...IT DOESN/T APPEAR THAT THE CAPITAL REGION WILL BE SEEING ANY FREEZING RAIN...AS THE APPROACHING STORM SHOULD ALLOW THE STALLED BOUNDARY TO START TO MOVE NORTHWARD AS A WARM FRONT...AND BRING THE ALBANY AREA INTO THE WARM SECTOR ONCE THE NEXT ROUND OF RAINFALL BEGINS. FURTHER NORTH...IT MAY TAKE UNTIL THE MID TO LATE MORNING FOR THE WARM FRONT TO MOVE THROUGH AND TEMPS TO WARM UP. AS A RESULT...A PROLONGED PERIOD OF FREEZING RAIN CAN BE EXPECTED ACROSS THE LAKE GEORGE SARATOGA REGION. ICE ACCRETION AMOUNTS WILL RANGE FROM A TRACE TO A TENTH ACROSS THE SARATOGA SPRINGS AREA TO A FEW TENTHS FOR GLENS FALLS TO ABOUT FOUR TENTHS ACROSS THE NORTH END OF LAKE GEORGE. ASIDE FROM SOME HAZARDOUS DRIVING CONDITIONS...THIS MAY LEAD TO SOME ISOLATED POWER OUTAGES. AREAS IN THE WARM SECTOR SHOULD SEE SFC TEMPS WARM SIGNIFICANTLY...AS THOSE WARMER TEMPS ALOFT ARE MIXED IN THE BOUNDARY LAYER. MAX TEMPS LOOK TO REACH INTO THE 50S ACROSS MUCH OF THE CENTRAL AND SOUTHERN PARTS OF THE AREA...WITH SOME LOW TO MID 60S FOR THE MID HUDSON VALLEY. WHILE IT WILL RAIN THROUGH THE MORNING HOURS...MOST AREAS WILL BE DONE SEEING PRECIPITATION BY THE EARLY TO MID AFTN HOURS...AS THE STORM/S COLD FRONT PASSES THROUGH THE AREA. TOTAL RAINFALL FOR SUNDAY WILL RANGE FROM JUST A QUARTER OF AN INCH ACROSS LITCHFIELD COUNTY CT...TO AROUND THREE QUARTERS OF AN INCH IN THE CAPITAL REGION TO ABOUT AN INCH AND A HALF OVER THE ADIRONDACKS. SEE THE HYDRO SECTION ON HOW WE EXPECT THIS RAINFALL TO AFFECT AREA RIVERS AND STREAMS. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/... FOR THIS PERIOD THE MODEL SUITE (GEM/GFS/ECMWF) ARE IN FAIRLY GOOD AGREEMENT. DURING THE THIS EVENING THE SFC LOW AND ITS UPPER DYNAMICS WILL LIFT NE OUT OF FCA. A SERIES OF 500HPA SHORT WAVES WILL DIG A TROF OVER GRTLKS...MAINTAINING A STRONG SW 500HPA FLOW OVER THE EASTERN THIRD OF THE NATION. FOR A TIME THIS WILL ACT TO WEAKEN THE SFC LOW FURTHER OVER NEW ENG...BUT THE SFC LOW WILL DRAG A CDFNT THROUGH THE REGION TNGT. GIVEN THE UPPER FLOW COOLER AIR WILL BE SLOW TO FILTER IN OVERNIGHT....AND TEMPS WILL REMAIN ABV FREEZING IN MOST AREAS...WITH SNOW MELT CONTINUING. BY MONDAY THIS CDFNT WILL NEARLY STALL ALONG THE EASTERN SEABOARD...AND WITH DIGGING 500HPA TROF INTERACTING WITH THE COASTAL BAROCLINIC ZONE WILL TRIGGER A BOUT OF OVERRUNINNG RAIN...ALONG THE I-95 CORRIDOR THAT WILL BACK BUILD INTO SE PORTIONS OF FCA. QPF DURING MONDAY WITH THIS SHOULD BE 0.25 TO 0.50 IN THESE AREAS...AND GIVEN THESE AREAS WERE IN THE WARM SECTOR MUCH OF THE CURRENT EVENT...THEY MELTED MOST OF THEIR SNOW...BUT HAD LITTLE RAINFALL. ADD TO THAT THE 2-3 DAYS THIS OCCURRED...THE ADDITIONAL RAIN IN SOUTHEAST AREAS MONDAY SHOULD NOT RESULT IN ANYTHING OTHER THAN WITHIN BANK RISES. FURTHER WEST MONDAY AS HIGH PRESSURE BUILDS EAST WIND GRADIENT WILL INCR AND AS THE 500HPA TROF PUSHES EAST A MUCH STRONGER 2NDRY CDFNT WILL PUSH INTO THE REGION LATE MONDAY AND THROUGH MONDAY NIGHT. TEMPS MONDAY WILL HOLDS STEADY THEN FALL DURING THE AFTN. MONDAY NIGHT INTO TUES THE PASSAGE OF THE 500HPA TROF...CAA WILL RESULT IN SCT -SHSN ACTIVITY. HWVR LLVL FLOW WILL BE TOTALLY UNFAVORABLE FOR LK EFFECT OVER EASTERN NY. ONCE THE 500HPA TROF EXITS CHRISTMAS EVE BOTH A 500HPA RIDGE...AND SFC HIGH PRESSURE WILL SETTLE OVER NYS AND MID ATLC REGION. THIS WILL SET THE STAGE FOR A FRIGID NIGHT WITH IDEAL RADIATIONAL COOLING...ONE OF THE LONGEST NIGHTS OF THE YEAR...CLEAR SKIES AND DRY AIR MASS. LOWS WILL PLUNGE TO -20F IN PARTS OF THE ADIRONDACKS TO AROUND 10 IN THE SE. TEMPS WILL RECOVER CHRISTMAS DAY TO THE TEENS AND 20S AS SFC HIGH SLIDES OFFSHORE. SOME CLOUDS MAY ARRIVE IN THE AFTERNOON AS NEXT WEAK SYSTEM APPROACHES. && .LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/... THE EFP WILL FEATURE A SERIES OF FAST MOVING SYSTEMS IN W-NW FLOW. MOST WILL BE FAIRLY WK CDFNTS AND/OR 500HPA SHORT WVS...WHICH WILL INCR CLOUDS AND PRODUCE SCT -SHSN AND AT TIMES HAVE SOME INTERACTION WITH THE GRTLKS. TEMPS WILL RETURN TO NEAR NORMALS AFTER A FRIGID CHRISTMAS. TYPICAL WINTER IN UPSTATE NY. CHRISTMAS NIGHT AND THURS THE FIRST OF THESE SYSTEMS RACES ACROSS ONTARIO...WITH A FEW WEAK FRONTS AND A 500HPA SHORT WV. MAIN IMPACTS WILL INCR CLOUDS MAINLY N & W. THU NT IT WILL DRAG A CDFNT THROUGH WITH SOME -SHSN ACTIVITY MAINLY N & WEST. IN ITS WAKE FRI CAA AND A 2NDARY CDFNT AND NW FLOW WILL TRIGGER SCT -SHSN WITH SOME LK ASSISTANCE. WK SFC HIGH BUILDS OVER FCA FRI NT. SAT ANOTHER WK SHORT WV AND SFC SYSTEM MOVES THROUGH THE GRTLKS WITH A LITTLE WAA INCRG CLOUDS AND SCT -SHSN IN ECMWF...GETTING SOME ASSIST FM THE LKS. GFS HAS MORE CLOUDS AND A WIDESPREAD LT -SN OF MAYBE AN INCH. SAT NT INTO SUN FLOW BCMS ZONAL TO WSW AT 500HPA. WMFNT AND SFC LOW SETS UP N OF RGN. NOT MUCH DIFFERENCE BWTN GFS AND ECMWF. WILL POPULATE WITH HPC MID SHIFT AND TWEAK POPS A TAD. OTHERWISE A QUIET PERIOD FOR THE HOLIDAY WEEK. && .AVIATION /09Z SUNDAY THROUGH THURSDAY/... A FRONTAL BOUNDARY WILL BE OVER UPSTATE NY AND NEW ENGLAND TODAY WITH AREAS OF LOW PRESSURE MOVING ALONG IT. THIS BOUNDARY WILL DIVIDE VERY COLD AIR FROM MILD AIR OVER THE E-CNTRL NY CORRIDOR WITH SOME FREEZING RAIN CONTINUING FOR KGFL EARLY THIS MORNING...AND OCCASIONAL LIGHT RAIN FOR KALB-KPSF SOUTHWARD BEFORE A STEADIER RAINSHIELD MOVES IN TOWARDS 12Z. FLIGHT CONDITIONS VARY FROM LIFR/IFR AT KGFL/KALB TO VFR/MVFR AT KPOU AND KPSF THIS MORNING. THE TREND WILL BE FOR WIDESPREAD IFR/MVFR CONDITIONS TO IMPACT THE TERMINALS BTWN 09Z-12Z. THE MVFR CONDITIONS MAY CONTINUE AT KPOU UNTIL AFTER 12Z...BUT EXPECT IFR CIGS/VSBYS FOR KGFL...KALB...KPSF THROUGH MOST OF THE LATE MORNING INTO THE EARLY PM...AS LOW PRESSURE MOVES ACROSS CNTRL/NRN NY. EXPECT TEMPS TO MOVE BACK ABOVE FREEZING AT KGFL AROUND 10Z. THE RAINFALL SHOULD DIMINISH BTWN 18Z-21Z FOR THE E-CNTRL NY TERMINALS WITH SOME SCT SHOWERS AND DRIZZLE LINGERING INTO THE EARLY EVENING. SOME IFR/MVFR VISIBILITIES MAY PERSIST INTO THE EARLY EVENING WITH MVFR CIGS. THE CIGS MAY START TO RISE TOWARDS MIDNIGHT WITH SOME DRIER AIR STARTING TO FILTER IN FROM THE SOUTHWEST. THE SFC WINDS WILL BE FROM THE E TO NE AT KALB AND KGFL EARLY THIS MORNING AT 5-10 KTS...THEN VEER TO TO SOUTH AT AROUND 10 KTS BY 12Z WITH SOME GUSTS AT KALB IN THE 20-25 KT RANGE. KPOU AND KPSF WILL CONTINUE TO HAVE S/SW WINDS 5-10 KTS...THEN INCREASE TO 8-15 KTS WITH SOME GUSTS CLOSE TO 25 KTS AT KPSF...AS THE STRONGER LLJ MOVES IN ALOFT. THE WINDS WILL DECREASE FROM THE S/SW AT LESS THAN 10 KTS AFTER 00Z/MON. OUTLOOK... SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. BREEZY CHANCE OF SHRA. MONDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA. MONDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...SHSN. TUESDAY: LOW OPERATIONAL IMPACT. BREEZY. SLIGHT CHANCE OF SHSN. TUESDAY NIGHT: LOW OPERATIONAL IMPACT. BREEZY. NO SIG WX. CHRISTMAS DAY TO THURSDAY: NO OPERATIONAL IMPACT. NO SIG WX. && .HYDROLOGY... MILD TO UNSEASONABLY WARM TEMPERATURES WILL OCCUR THROUGH THE WEEKEND WITH INCREASING SNOW MELT. MEANWHILE A SERIES OF LOW PRESSURE SYSTEMS WILL BE PROPAGATING ALONG A NEARLY STATIONARY FRONT FROM THE NIAGARA FRONTIER TO VERMONT WITH 1-3 INCHES OF RAIN EXPECTED IN THE ADIRONDACKS...BUT LESSER AMOUNTS SOUTH. TEMPERATURES SUNDAY ARE EXPECTED TO WARM INTO THE 50S AND 60S. IN THE NORTH RAINFALL AMOUNTS WILL BE GREATEST...BUT SNOW MELT SLOWER...WHILE IN THE SOUTH RAINFALL WILL BE AROUND A HALF INCH...BUT ALMOST ALL THE SNOW WILL MELT. IN THE SOUTH THIS WILL BE SUFFICIENT FOR SIGNIFICANT WITHIN BANK RISES...BUT FLOODING IS NOT EXPECTED AT THIS TIME. THE GREATEST POTENTIAL FOR FLOODING WILL EXIST FROM THE MOHAWK VALLEY INTO THE ADIRONDACKS WHERE 1 TO 3 INCHES OF RAIN AND UP TO AN INCH OF LIQUID EQUIVALENT FROM SNOW MELT IS EXPECTED. FLOOD WATCHES HAVE BEEN ISSUED FOR TONIGHT THROUGH SUNDAY NIGHT. 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...FREEZING RAIN ADVISORY UNTIL 11 AM EST THIS MORNING FOR NYZ041>043-083-084. FLOOD WATCH THROUGH MONDAY MORNING FOR NYZ032-033-038>040-042- 043-082. MA...NONE. VT...NONE. && $$ SYNOPSIS...SNYDER NEAR TERM...FRUGIS SHORT TERM...SNYDER LONG TERM...SNYDER AVIATION...WASULA HYDROLOGY...GJM/SNYDER
AREA FORECAST DISCUSSION...CORRECTED
NWS NEW YORK NY
125 AM EST SUN DEC 22 2013 .SYNOPSIS... A WARM FRONT WILL REMAIN ANCHORED NORTH OF THE TRI-STATE REGION THROUGH SUNDAY. LOW PRESSURE RIDES ALONG A COLD FRONT MONDAY. THE FRONT MOVES SLOWLY EAST TUESDAY. HIGH PRESSURE THEN BUILDS TOWARD THE AREA WEDNESDAY. A COLD FRONT MOVES THROUGH LATE THURSDAY. HIGH PRESSURE BUILDS LATE IN THE WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... THE WATER VAPOR IMAGERY DEPICTS DIFFLUENT FLOW JUST WEST OF THE TENNESSEE VALLEY WITH A STRONG SHORTWAVE AND VORTICITY MAXIMUM MOVING ACROSS THE CENTRAL U.S. THE SURFACE LOW IS MOVING INTO THE OHIO VALLEY. THE LOW IS FORECAST TO MAINTAIN ITS STRENGTH FOR THE REMAINDER OF TONIGHT. THE LOCAL AREA WILL RECEIVE A CONTINUOUS FLOW OUT OF THE SOUTH TO SOUTHWEST...INCREASING THE WARM AND MOIST AIR ADVECTION. STRATUS HAS BEGUN TO MOVE IN ACROSS PORTIONS OF LONG ISLAND. FOG HAS STARTED TO DEVELOP BUT IS PATCHY IN COVERAGE WITHOUT TOO MUCH REDUCTION IN VISIBILITY. LOOKING AT LATEST BUFKIT SOUNDINGS...THE FOG LOOKS TO INCREASE BY 09Z AND LINGER INTO SUNDAY MORNING. KEEPING PATCHY COVERAGE OF FOG UNTIL 08Z AND THEN EXPAND TO AREAS. MOST MOS GUIDANCE IS NOT BRINGING MUCH LOWER VSBYS UNTIL AROUND 12-15Z WITH DENSE FOG POTENTIAL. THE POTENTIAL WILL BE THERE FOR DENSE FOG AND THIS WILL BE AN ADVECTION FOG. THE LIMITING FACTOR IS THE WINDS AND THIS CAN BE CONVEYED BY ONGOING CONDITIONS. RELATIVELY HIGHER WINDS ALONG THE COAST WITHOUT MUCH IF ANY VISIBILITY REDUCTION WITH A LITTLE MORE REDUCTION INLAND WHERE WINDS ARE LIGHTER. IF WINDS FURTHER DECOUPLE AND DECREASE...A MORE WIDESPREAD FOG WILL DEVELOP. REGARDING SHOWERS...TRENDED LOWER IN POPS WITH SCATTERED SHOWERS BEING RESTRICTED TO MAINLY INTERIOR PORTIONS. THIS IS CONSISTENT WITH HRRR FORECAST REFLECTIVITY FIELDS. STILL EXPECTING SOME DRIZZLE TO FORM TOWARDS MORNING WITH SATURATION OF THE BOUNDARY LAYER. LOW TEMPERATURES FOR THE MOST PART HAVE ALREADY BEEN REACHED WITH A STEADY TO SLIGHT INCREASE IN TEMPS EXPECTED TOWARDS MORNING. TEMPERATURES WILL BE MOSTLY FROM LOW AND MID 40S TO MID 50S. && .SHORT TERM /6 AM THIS MORNING THROUGH MONDAY NIGHT/... IF TEMPS WERE MIXED DOWN FROM H85...HIGHS WOULD BE IN THE LOW TO MID 80S ON SUN. DESPITE THESE EXTREMELY WARM TEMPS ALOFT HOWEVER...BOTH THE GFS AND NAM SUGGEST THE AREA WILL REMAIN SOCKED IN WITH STRATUS...FG AND DZ THRU THE DAY. THIS SHOULD LIMIT HIGHS SO WENT WITH THE COOLEST GUIDANCE...THE MET. MOST IF NOT ALL CLIMATE SITES HOWEVER SHOULD STILL BREAK THEIR RECORDS. IF THE CLOUDS DO BREAK UP IN THE EARLY AFTN...TEMPS WILL SHOOT UP INTO 70S GENERALLY FROM THE CITY N AND W. CONTINUED CHC FOR MEASUREABLE RAIN COVERED WITH -SHRA DURING THE DAY...BUT THE MAIN FORCING DOES NOT ARRIVE TIL SUN NGT PER THE NAM/GFS/ECMWF. FCST THEREFORE BRINGS POPS UP THRU THE NGT...AND TRANSITIONS PCPN TO MODERATE RAIN. THIS IS WHEN THE BEST WINDOW FOR ACCUMULATING PCPN WILL OCCUR. IT WILL REMAIN STEAMY WITH LOW TEMPS ABV MAX NORMALS. && .LONG TERM /TUESDAY THROUGH SATURDAY/... SOUTHEAST RIDGE GIVES WAY TO DEEP TROUGH MONDAY AND TUESDAY. THE TROUGH MOVES EAST WITH BRIEF RIDGING BY MID WEEK. AN UPSTREAM SHORTWAVE MOVES ACROSS THE NORTHEAST BY LATE IN THE WEEK. AT THE SFC...WAVE OF LOW PRESSURE RIDES ALONG THE STALLED OR SLOW MOVING FRONT MONDAY. THIS FRONT TRACKS TO THE EAST...WITH AN INVERTED TROUGH (ASSOCIATED WITH LARGE UPPER TROUGH) MOVING THROUGH SOMETIME TUESDAY. A TIGHT PRESSURE GRADIENT REMAINS IN PLACE MONDAY NIGHT THROUGH TUESDAY NIGHT. THEN HIGH PRESSURE BUILDS IN WEDNESDAY AND WEDNESDAY NIGHT. A COLD FRONT APPROACHES AND MOVES ACROSS THE AREA THURSDAY AND THURSDAY NIGHT...WITH HIGH PRESSURE BUILDING BEHIND THE FRONT LATE IN THE WEEK INTO NEXT WEEKEND. MODELS IN GENERAL AGREEMENT WITH REGARD TO THESE OVERALL FEATURES AND PATTERN THROUGH THE WEEK. RAIN...MODERATE TO PERHAPS HEAVY AT TIMES...MONDAY WILL TAPER OFF FROM WEST TO EAST LATE MONDAY AND MONDAY NIGHT. A FEW FLURRIES OR LIGHT SNOW SHOWERS ARE POSSIBLE LATE TUESDAY AND TUESDAY NIGHT...WITH WEAK INSTABILITY IN PLACE AS UPPER TROUGH MOVES THROUGH. MOISTURE THOUGH WILL BE LIMITED. DRY WEDNESDAY AND WEDNESDAY NIGHT...THEN A FEW MORE RAIN OR SNOW SHOWERS ARE POSSIBLE WITH THE COLD FRONT LATE THURSDAY AND THURSDAY NIGHT. DRY WEATHER RETURNS. AS FOR TEMPS...LITTLE CHANGE IN TEMPS FROM EARLY MORNING READINGS ARE EXPECTED MONDAY DUE TO THE CLOUDS AND RAIN. THEN A BRIEF SHOT OF COLDER AIR MOVES IN MONDAY NIGHT THROUGH WEDNESDAY. NEAR NORMAL TEMPS ARE EXPECTED THURSDAY IN WEAK WARM AIR ADVECTION BEHIND THE HIGH AND AHEAD OF THE FRONT. THE SEASONABLY CHILLY WEATHER CONTINUES LATE IN THE WEEK. FOLLOWED A MAV/MET BLEND MONDAY...AND WPC/ECE AND MEX NUMBERS FOLLOWED TUESDAY ONWARD. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... A FRONTAL BOUNDARY STRETCHING FROM JUST OFF THE TEXAS COAST THROUGH THE OHIO VALLEY AND INTO NORTHERN NEW ENGLAND WILL SLOWLY MOVE EAST THROUGH SUN THEN TRACK ACROSS THE TERMINALS LATE SUN NIGHT INTO MONDAY MORNING. DIFFICULT FORECAST THE NEXT 24 HOURS. THEREFORE...06Z TAFS ARE A LOW TO MODERATE CONFIDENCE FORECAST. STRATUS/FOG FINALLY DEVELOPING WITH IFR CONDS AT KGON/KISP. 00Z GUIDANCE SLIGHTLY MORE OPTIMISTIC LATE TONIGHT AND SUN AND SINCE CONDS AT W TERMINALS WILL TAKE A FEW MORE HOURS TO DROP...HAVE SIDED WITH THIS THINKING. EXCEPTIONS BEING KJFK/KHPN WHICH SHOULD DROP TO LIFR AROUND DAYBREAK. GUIDANCE CONTINUES TO VARY IN TIMING AND FLIGHT CAT AFT 12Z. MODERATE CONFIDENCE IN WINDS. A 55-65KT LLJ BETWEEN 1500-2000 FT...WILL PEAK BETWEEN 10Z AND 16Z. ALREADY SEEING 55KT AT 2K FT IN 435Z ACARS SOUNDING FROM KEWR. THINK SOME OF THIS WILL MIX DOWN...WITH 20-30KT GUSTS BETWEEN 15Z AND 22Z. SHOWERS APPROACHING FROM THE SW. LOOKS LIKE THEY MAY JUST MISS KEWR/KTEB/KHPN BUT WILL NEED TO MONITOR AS THEY GET CLOSER. KSWF HAS THE HIGHEST CHC FOR ANY ACTIVITY TO IMPACT THE AIRFIELD. DIFFICULT TO PINPOINT WHERE SCT SHOWERS WILL BE BEYOND 12Z...BUT ORGANIZED FRONTAL SHOWERS NOT EXPECTED TO IMPACT OTHER TERMINALS UNTIL AFT 18Z. .OUTLOOK FOR 06Z MONDAY THROUGH THURSDAY... .SUN NIGHT...MVFR-IFR IN FG/BR AND -SHRA. .MON...MVFR-IFR IN -SHRA INTO THE AFTN...THEN CONDS IMPROVING W TO E. WIND SHIFT FROM SW-NW WITH COLD FROPA AFTER 18Z. .TUE...VFR. NW WIND 15-20G20-30KT. .WED-THU...VFR. && .MARINE... REDUCED VSBY AND MODERATE SSW FLOW WILL RESULT IN HAZARDOUS CONDITIONS THRU SUN NGT. A SCA FOR ALL WATERS EXCEPT THE HARBOR TNGT THRU SUN NGT. STRONGEST WINDS ON THE ERN WATERS DUE TO THE SW FETCH. IT IS UNCERTAIN IF THE WINDS WILL BE STRONG ENOUGH TO KEEP FOG DEVELOPMENT LIMITED. HAVE INCLUDED 1NM VSBY IN THE FCST...BUT POTENTIAL EXISTS FOR VSBY TO DROP BLW 1NM IF WINDS ARE WEAKER THAN FCST. THIS WOULD REQUIRE A DENSE FG ADVY. AS LOW PRESSURE PASSES ACROSS THE WATERS MONDAY...OCEAN SEAS REMAIN ELEVATED. THEN THE LOW AND COLD FRONT DEPART...WITH GUSTY WEST TO NORTHWEST WINDS ANTICIPATED MONDAY NIGHT THROUGH TUESDAY NIGHT. HIGH PRESSURE EVENTUALLY BUILDS IN WEDNESDAY AND THURSDAY. AS SUCH...WINDS WILL DIMINISH AND SEAS WILL SUBSIDE DURING THIS MID WEEK TIMEFRAME. && .HYDROLOGY... SPOTTY LIGHT PCPN CAN BE EXPECTED THRU SUN. THIS WILL RESULT IN MINOR ACCUMS. MOST OF THE MEASUREABLE RAIN IS FCST TO OCCUR SUN NGT INTO MON. AROUND AN INCH OF BASIN AVE RAINFALL IS EXPECTED ATTM. && .CLIMATE... THE FOLLOWING ARE RECORD HIGHS AND FORECAST HIGHS FOR SUNDAY DECEMBER 22 RECORD FORECAST EWR 65/1998 69 BDR 59/1998 59 NYC *63/1998 69 LGA 64/1998 67 JFK 62/1998 62 ISP 59/2011 62 * ALSO OCCURRED IN PREVIOUS YEARS NOTE: RECORD HIGH MINIMUMS ARE ALSO POSSIBLE AT JFK AND ISP ON SUNDAY DECEMBER 22. THE FORECAST LOW AT JFK IS 50 WITH A RECORD HIGH MINIMUM OF 50 IN 1990. THE FORECAST LOW AT ISP IS 53 WITH A RECORD HIGH MINIMUM OF 50 IN 1990. THE FOLLOWING ARE THE RECORD HIGH MINIMUMS FOR MONDAY DECEMBER 23 RECORD FORECAST EWR 58/1990 53 BDR 51/1990 49 NYC 57/1990 56 LGA 54/1990 56 JFK 50/1990 51 ISP 52/1990 54 && .EQUIPMENT... THE NEW YORK CITY NOAA ALL HAZARDS WEATHER RADIO STATION KWO35 IS OUT OF SERVICE. DUE TO INTERFERENCE ISSUES WITH THE U.S. COAST GUARD EMERGENCY BROADCAST CHANNEL...THE NEW YORK CITY NOAA ALL HAZARDS WEATHER RADIO STATION KWO35 IS OUT OF SERVICE. DURING THE TIME...THE TRANSMITTER MAY BE RETURNED TO SERVICE INTERMITTENTLY FOR USE OF THE NOAA ALL HAZARDS WEATHER RADIO DURING POTENTIALLY DANGEROUS WEATHER SITUATIONS...FOR ROUTINE WEEKLY TEST OF THE WARNING SYSTEM...AND TO DETERMINE IF THE INTERFERENCE ISSUE HAS BEEN RESOLVED. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST MONDAY FOR ANZ330-335-340- 345-350-353-355. && $$ SYNOPSIS...JMC/PW NEAR TERM...JM SHORT TERM...JMC LONG TERM...PW AVIATION...24 MARINE...JMC/PW HYDROLOGY...JMC CLIMATE... EQUIPMENT...
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
240 PM EST SUN DEC 22 2013 .UPDATE... THE LONG TERM SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 249 AM EST SUN DEC 22 2013 A LOW PRESSURE SYSTEM OVER INDIANA WILL QUICKLY PULL NORTHEAST TODAY TO NEW ENGLAND AS HIGH PRESSURE OVER THE NORTHERN PLAINS BEGINS TO BUILD ACROSS THE OHIO VALLEY. COLD NORTH WINDS IN THE WAKE OF THE LOW WILL RESULT IN TEMPERATURES RETURNING TO BELOW NORMAL FOR THE NEXT FEW DAYS...HOWEVER THE DRY AIR MASS ASSOCIATED WITH THE HIGH WILL BRING SIGNIFICANT PRECIPITATION TO AN END. ANOTHER MUCH WEAKER CLIPPER TYPE SYSTEM WILL MOVE SOUTHEAST INTO THE GREAT LAKES MIDWEEK PRODUCING SOME LIGHT SNOW FOLLOWED BY REINFORCING COLD CANADIAN AIR TO END THE UPCOMING WEEK. && .NEAR TERM /TODAY/... ISSUED AT 1234 PM EST SUN DEC 22 2013 FORECAST REMAINS IN GOOD SHAPE...BUT FELT COMFORTABLE REMOVING POPS AND ONLY MENTIONING A CHANCE OF FLURRIES GIVEN UPSTREAM ECHOES OBSERVED THUS FAR AND HRRR PROGS. PREVIOUS DISCUSSION FOLLOWS. ISSUED AT 249 AM EST SUN DEC 22 2013 SURFACE ANALYSIS EARLY THIS MORNING SHOWS LOW PRESSURE OVER CENTRAL INDIANA. HIGH PRESSURE WAS FOUND OVER THE NORTHERN PLAINS. WATER VAPOR IMAGERY SHOWS A LARGE TROUGH OVER THE CENTRAL PART OF THE UNITED STATES...WITH A DRY SLOT PULLING NORTH INTO THE MISSISSIPPI RIVER VALLEY . THE TROPICAL PLUME OF MOISTURE WAS STILL STREAMING INTO ILLINOIS AND INDIANA...BUT WAS PULLING EAST QUICKLY. RADAR MOSAICS SHOW THE BACK EDGE OF PRECIPITATION HAS MOVED TO THE EAST OF TERRE HAUTE...VINCENNES AND LAFAYETTE. MAIN FORECAST CHALLENGE TODAY WILL BE POPS. NAM AND GFS ARE IN GOOD AGREEMENT THAT THE SURGE OF MOISTURE ASSOCIATED WITH THE TROPICAL PLUME WILL QUICKLY PULL EAST AND THE BULK OF PRECIPITATION ACROSS THE AREA WILL END BY 12Z...HOWEVER SEVERAL LINGERING THINGS STILL EXIST THAT COULD RESULT IN SOME VERY LIGHT ADDITIONAL PRECIPITATION TODAY. FIRST OFF...THE NAM AND THE GFS BOTH PUSH YET ANOTHER SHORT WAVE TOWARD CENTRAL INDIANA IN THE QUICK SW FLOW ALOFT AS THE DEEP TROUGH OVER THE CENTER OF THE COUNTRY BEGINS TO SLIDE EAST. LOWER LEVEL FLOW LOOKS TO REMAIN STRONGLY CYCLONIC TODAY AS THE SURFACE LOW DEPARTS TO THE EAST. FORECAST SOUNDINGS AND TIME HEIGHTS CONTINUE TO KEEP HIGH RH/S TRAPPED IN THE LOWER LEVELS. THUS WILL KEEP A SLIGHT CHANCE FOR SOME PRECIP TODAY...RAIN INITIALLY THIS MORNING...BUT AS STRONG COLD AIR ADVECTION CONTINUES THROUGH THE AFTERNOON...FORECAST SOUNDINGS FALL BELOW FREEZING THUS PRECIP TYPE WILL CHANGE TO SNOW BY LATE AFTERNOON. GIVEN THE STRONG COLD AIR ADVECTION THAT IS EXPECTED IN THE WAKE OF THE FRONT...TEMPS ARE NOT EXPECTED TO RISE TODAY AND A NON DIURNAL TEMP CURVE WILL BE USED. WILL TREND HIGHS TOWARD EXPECTED 12Z VALUES. && .SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/... ISSUED AT 249 AM EST SUN DEC 22 2013 MAIN FORECAST CHALLENGE DURING THIS PERIOD WILL BE TEMPS AND CLOUDS. MODELS ARE IN PRETTY GOOD AGREEMENT OVERALL AND WILL USE A BLEND. GFS AND NAM SUGGEST THE LARGE UPPER TROUGH WILL VERY SLOWLY PUSH EAST INTO THE OHIO VALLEY TONIGHT BEFORE FINALLY EXITING THE AREA ON TUESDAY NIGHT. MEANWHILE AT THE SURFACE STRONG COLD AIR ADVECTION WILL CONTINUE ACROSS INDIANA ON NORTHERLY WINDS AS 850MB TEMPS FALL TO -15C TO -18C DEPENDING UPON YOUR FAVORITE MODEL. FORECAST SOUNDINGS SHOW DEEP MOISTURE REMAINS UNAVAILABLE...YET THE LOWER LEVEL FLOW LOOKS TO REMAIN BROADLY CYCLONIC. FORECAST SOUNDINGS ARE ENTIRELY BELOW ZERO THROUGH TUESDAY NIGHT. FORECAST SOUNDINGS CONTINUE TO KEEP TRAPPED LOWER LEVEL MOISTURE ACROSS THE AREA...THROUGH MONDAY NIGHT AMID SUBSIDENCE ALOFT. THUS GIVEN ALL OF THIS WILL KEEP A SLIGHT CHANCE FOR SNOW SHOWERS OR FLURRIES THROUGH MONDAY NIGHT. GFS AND NAM PULL THE LARGE UPPER TROUGH WELL EAST OF INDIANA ON TUESDAY AS ANTICYCLONIC LOWER LEVEL FLOW BEGINS. THUS WILL TREND TOWARD A CLEAR SKY ON TUESDAY AND TUESDAY NIGHT WITH HIGH PRESSURE ACROSS THE AREA. AS FOR TEMPS GIVEN THE STRONG COLD AIR ADVECTION THROUGH THE PERIOD WILL TREND HIGHS AND LOWS COOLER THAN THE MAVMOS GUIDANCE THROUGH THE PERIOD. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... ISSUED AT 240 PM EST SUN DEC 22 2013 NO MAJOR WEATHER CONCERNS FOR THE EXTENDED WHICH SHOULD ALLOW RIVER FLOODING TO RUN ITS COURSE. THAT BEING SIAD...MODELS IN GENERAL AGREEMENT THAT TWO DIFFERENT SYSTEMS WILL BRING POTENTIAL FOR MINOR PRECIPITATION WEDNESDAY NIGHT AND THURSDAY AS WELL AS SUNDAY. SO...KEPT SMALL REGIONAL ALLBLEND POPS. IT SHOULD BE COLD ENOUGH FOR ONLY SNOW AS PRECIPITATION TYPE WEDNESDAY NIGHT AND THURSDAY...BUT SOUTHWEST FLOW AHEAD OF LATE WEEKEND FRONTAL SYSTEM SUGGESTS POSSIBILITY EXISTS OF A MIX OF RAIN AND SNOW IF NOT JUST RAIN. ALLBLEND TEMPERATURES LOOK REASONABLE WITH AFTERNOON TEMPERATURES STARTING OFF IN THE 20S AND 30S AND THEN WARMING TO THE 30S AND 40S BY SATURDAY. && .AVIATION /DISCUSSION FOR 221800Z TAF ISSUANCE/... ISSUED AT 1200 PM EST SUN DEC 22 2013 CONDITIONS EXPECTED TO IMPROVE TO MVFR ACROSS THE TAF SITES AT OR SHORTLY AFTER ISSUANCE TIME AND VFR AFTER 15Z MONDAY BASED ON BASED ON MODEL TIME SECTIONS. BASED ON CU DEVELOPMENT PROGS...HUF AND BMG SHOULD ONLY SEE SCATTERED CU TOMORROW WITH IND AND LAF EXPECTED TO SEE CEILINGS. CONFIDENCE IS GOOD REGARDING LIGHT CATEGORIES OVERALL. HOWEVER...WOULD NOT RULE OUT BRIEF IFR AT THE ONSET AND POSSIBLY BRIEF MID DAY MVFR CU MONDAY. WOULD NOT RULE OUT A BRIEF LIGHT RAIN SHOWER THIS AFTERNOON AND SNOW SHOWER TONIGHT AND MONDAY...BUT CHANCES TOO LOW TO MENTION. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...PUMA NEAR TERM...PUMA/NIELD SHORT TERM...PUMA LONG TERM....CP AVIATION...MK VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON TWITTER AND YOUTUBE AT: WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1234 PM EST SUN DEC 22 2013 .UPDATE... THE NEAR TERM SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 249 AM EST SUN DEC 22 2013 A LOW PRESSURE SYSTEM OVER INDIANA WILL QUICKLY PULL NORTHEAST TODAY TO NEW ENGLAND AS HIGH PRESSURE OVER THE NORTHERN PLAINS BEGINS TO BUILD ACROSS THE OHIO VALLEY. COLD NORTH WINDS IN THE WAKE OF THE LOW WILL RESULT IN TEMPERATURES RETURNING TO BELOW NORMAL FOR THE NEXT FEW DAYS...HOWEVER THE DRY AIR MASS ASSOCIATED WITH THE HIGH WILL BRING SIGNIFICANT PRECIPITATION TO AN END. ANOTHER MUCH WEAKER CLIPPER TYPE SYSTEM WILL MOVE SOUTHEAST INTO THE GREAT LAKES MIDWEEK PRODUCING SOME LIGHT SNOW FOLLOWED BY REINFORCING COLD CANADIAN AIR TO END THE UPCOMING WEEK. && .NEAR TERM /TODAY/... ISSUED AT 1234 PM EST SUN DEC 22 2013 FORECAST REMAINS IN GOOD SHAPE...BUT FELT COMFORTABLE REMOVING POPS AND ONLY MENTIONING A CHANCE OF FLURRIES GIVEN UPSTREAM ECHOES OBSERVED THUS FAR AND HRRR PROGS. PREVIOUS DISCUSSION FOLLOWS. ISSUED AT 249 AM EST SUN DEC 22 2013 SURFACE ANALYSIS EARLY THIS MORNING SHOWS LOW PRESSURE OVER CENTRAL INDIANA. HIGH PRESSURE WAS FOUND OVER THE NORTHERN PLAINS. WATER VAPOR IMAGERY SHOWS A LARGE TROUGH OVER THE CENTRAL PART OF THE UNITED STATES...WITH A DRY SLOT PULLING NORTH INTO THE MISSISSIPPI RIVER VALLEY . THE TROPICAL PLUME OF MOISTURE WAS STILL STREAMING INTO ILLINOIS AND INDIANA...BUT WAS PULLING EAST QUICKLY. RADAR MOSAICS SHOW THE BACK EDGE OF PRECIPITATION HAS MOVED TO THE EAST OF TERRE HAUTE...VINCENNES AND LAFAYETTE. MAIN FORECAST CHALLENGE TODAY WILL BE POPS. NAM AND GFS ARE IN GOOD AGREEMENT THAT THE SURGE OF MOISTURE ASSOCIATED WITH THE TROPICAL PLUME WILL QUICKLY PULL EAST AND THE BULK OF PRECIPITATION ACROSS THE AREA WILL END BY 12Z...HOWEVER SEVERAL LINGERING THINGS STILL EXIST THAT COULD RESULT IN SOME VERY LIGHT ADDITIONAL PRECIPITATION TODAY. FIRST OFF...THE NAM AND THE GFS BOTH PUSH YET ANOTHER SHORT WAVE TOWARD CENTRAL INDIANA IN THE QUICK SW FLOW ALOFT AS THE DEEP TROUGH OVER THE CENTER OF THE COUNTRY BEGINS TO SLIDE EAST. LOWER LEVEL FLOW LOOKS TO REMAIN STRONGLY CYCLONIC TODAY AS THE SURFACE LOW DEPARTS TO THE EAST. FORECAST SOUNDINGS AND TIME HEIGHTS CONTINUE TO KEEP HIGH RH/S TRAPPED IN THE LOWER LEVELS. THUS WILL KEEP A SLIGHT CHANCE FOR SOME PRECIP TODAY...RAIN INITIALLY THIS MORNING...BUT AS STRONG COLD AIR ADVECTION CONTINUES THROUGH THE AFTERNOON...FORECAST SOUNDINGS FALL BELOW FREEZING THUS PRECIP TYPE WILL CHANGE TO SNOW BY LATE AFTERNOON. GIVEN THE STRONG COLD AIR ADVECTION THAT IS EXPECTED IN THE WAKE OF THE FRONT...TEMPS ARE NOT EXPECTED TO RISE TODAY AND A NON DIURNAL TEMP CURVE WILL BE USED. WILL TREND HIGHS TOWARD EXPECTED 12Z VALUES. && .SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/... ISSUED AT 249 AM EST SUN DEC 22 2013 MAIN FORECAST CHALLENGE DURING THIS PERIOD WILL BE TEMPS AND CLOUDS. MODELS ARE IN PRETTY GOOD AGREEMENT OVERALL AND WILL USE A BLEND. GFS AND NAM SUGGEST THE LARGE UPPER TROUGH WILL VERY SLOWLY PUSH EAST INTO THE OHIO VALLEY TONIGHT BEFORE FINALLY EXITING THE AREA ON TUESDAY NIGHT. MEANWHILE AT THE SURFACE STRONG COLD AIR ADVECTION WILL CONTINUE ACROSS INDIANA ON NORTHERLY WINDS AS 850MB TEMPS FALL TO -15C TO -18C DEPENDING UPON YOUR FAVORITE MODEL. FORECAST SOUNDINGS SHOW DEEP MOISTURE REMAINS UNAVAILABLE...YET THE LOWER LEVEL FLOW LOOKS TO REMAIN BROADLY CYCLONIC. FORECAST SOUNDINGS ARE ENTIRELY BELOW ZERO THROUGH TUESDAY NIGHT. FORECAST SOUNDINGS CONTINUE TO KEEP TRAPPED LOWER LEVEL MOISTURE ACROSS THE AREA...THROUGH MONDAY NIGHT AMID SUBSIDENCE ALOFT. THUS GIVEN ALL OF THIS WILL KEEP A SLIGHT CHANCE FOR SNOW SHOWERS OR FLURRIES THROUGH MONDAY NIGHT. GFS AND NAM PULL THE LARGE UPPER TROUGH WELL EAST OF INDIANA ON TUESDAY AS ANTICYCLONIC LOWER LEVEL FLOW BEGINS. THUS WILL TREND TOWARD A CLEAR SKY ON TUESDAY AND TUESDAY NIGHT WITH HIGH PRESSURE ACROSS THE AREA. AS FOR TEMPS GIVEN THE STRONG COLD AIR ADVECTION THROUGH THE PERIOD WILL TREND HIGHS AND LOWS COOLER THAN THE MAVMOS GUIDANCE THROUGH THE PERIOD. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... ISSUED AT 325 AM EST SUN DEC 22 2013 A WEAK CLIPPER SYSTEM WILL MOVE THROUGH CENTRAL INDIANA EARLY IN THE LONG TERM. THERE WILL BE VERY LITTLE MOISTURE FOR THE SYSTEM TO WORK WITH AND LITTLE IN THE WAY OF SURFACE FORCING. STILL CAN/T RULE OUT ONE OR TWO TENTHS OF AN INCH OF SNOW GIVEN THE UPPER WAVE...SO WILL KEEP SLIGHT CHANCES FOR SNOW FROM WEDNESDAY THROUGH THURSDAY. BY THURSDAY NIGHT UPPER RIDGING MOVES IN AND SURFACE HIGH PRESSURE REESTABLISHES ITSELF AND DRY WEATHER WILL ENSUE. STILL SOME DISAGREEMENTS BETWEEN THE GFS AND ECMWF ON TIMING OF THE ARRIVAL OF COLD AIR SHOTS BUT SAW NO REASON TO DEVIATE FROM ALLBLEND WHICH REPRESENTS A GOOD COMPROMISE. && .AVIATION /DISCUSSION FOR 221800Z TAF ISSUANCE/... ISSUED AT 1200 PM EST SUN DEC 22 2013 CONDITIONS EXPECTED TO IMPROVE TO MVFR ACROSS THE TAF SITES AT OR SHORTLY AFTER ISSUANCE TIME AND VFR AFTER 15Z MONDAY BASED ON BASED ON MODEL TIME SECTIONS. BASED ON CU DEVELOPMENT PROGS...HUF AND BMG SHOULD ONLY SEE SCATTERED CU TOMORROW WITH IND AND LAF EXPECTED TO SEE CEILINGS. CONFIDENCE IS GOOD REGARDING LIGHT CATEGORIES OVERALL. HOWEVER...WOULD NOT RULE OUT BRIEF IFR AT THE ONSET AND POSSIBLY BRIEF MID DAY MVFR CU MONDAY. WOULD NOT RULE OUT A BRIEF LIGHT RAIN SHOWER THIS AFTERNOON AND SNOW SHOWER TONIGHT AND MONDAY...BUT CHANCES TOO LOW TO MENTION. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...PUMA NEAR TERM...PUMA/NIELD SHORT TERM...PUMA LONG TERM....CP AVIATION...MK VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON TWITTER AND YOUTUBE AT: WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1119 PM CST SAT DEC 21 2013 .UPDATE... UPDATE ISSUED AT 922 PM CST SAT DEC 21 2013 NO MAJOR CHANGES HAVE BEEN MADE THIS EVENING WITH REGARD TO THE IMPACTS OF THE WINTER STORM. HOWEVER...HERE IS AN UPDATE OF WHERE THINGS STAND. WE ARE IN THE BRIEF LULL IN STRONG FORCING BETWEEN THE EARLIER WAA PCPN OVER THE SOUTHEAST 1/3 AND THE UPCOMING STRONG DEFORMATION ZONE SPREADING NORTHEAST FROM MISSOURI. IN THE MEAN TIME...WIDESPREAD LIGHT FREEZING DRIZZLE/LIGHT SNOW/LIGHT SLEET CONTINUES OVER THE CWA. THE SNOW TO SLEET LINE SEEMS TO CURRENTLY BE FROM NEAR BURLINGTON TO JUST EAST OF MOLINE...TO DE KALB ILLINOIS. NORTHWEST OF THIS LINE...THE DOMINANT P-TYPE IS SNOW...AND IT WILL CONTINUE TO BE SO. THE RAP MODEL WHICH IS HANDLING THE 800MB WARM WEDGE NOTED ON THE 00Z DVN SOUNDING...SHOWS A TRANSITION TO SNOW OVER THE REMAINING CWA BETWEEN NOW AND 3 AM. HRRR AND RAP...ALONG WITH THE 00Z NAM INDICATE THE DEFORMATION ZONE SHOULD HIT HARD SOMETIME ABOUT 10 PM WEST...11 CENTRAL...TO MIDNIGHT NORTHEAST. IT SHOULD LAST THROUGH 15Z OR SO BEFORE RAPIDLY LIFTING NORTH OUT OF THE REGION. THUS...HEAVY SNOW RATES FOR ABOUT 5 HOURS SEEM LIKELY IN OUR WESTERN 1/2 TO 2/3RD...MATCHING AMOUNTS WELL ENOUGH NOT THE CHANGE THEM. ERVIN && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 318 PM CST SAT DEC 21 2013 VIGOROUS WINTER STORM NOW IMPINGING ON THE REGION. STORM IS LARGELY EVOLVING AS FORECAST. WARM WEDGE ALOFT RESULTING IN FREEZING RAIN OVER WEST CENTRAL AND CENTRAL ILLINOIS. SURFACE LOW NOW OVER ARKANSAS WILL TRACK UP THE OHIO VALLEY. EXPECT TO SEE PRECIP SHIELD SPREAD BACK TO THE NORTHWEST SLIGHTLY MORE INTO OUR AREA AS THE LOW PASSES TO OUR SOUTHEAST...RESULTING ANOTHER PERIOD OF MIXED PRECIP THIS EVENING FOR SOUTHEAST. FORECAST SOUNDINGS VIA AWIPS AND BUFKIT SHOW CONTINUED POTENTIAL FOR FREEZING RAIN UNTIL MIDNIGHT THEN FAIRLY RAPID TRANSITION TO SNOW AS THE MAIN WAVE APPROACHES. MAIN SNOWFALL EVENT WILL BE ASSOCIATED WITH THE DEFORMATION ZONE MOVING ACROSS THE AREA TONIGHT. ENERGY ASSOCIATED WITH PRECIP NOW OVER EASTERN OK AND KS WILL CONGEAL INTO INTENSE DEFORMATION ZONE ACROSS NORTHERN MO AND EASTERN IA THIS EVENING. IMPRESSIVE MOISTURE FOR THIS TIME OF YEAR WILL ONLY BE OFFSET BY RAPID MOVEMENT OF SYSTEM. STILL...WE ARE LOOKING AT A PERIOD OF INTENSE SNOWFALL RATES FROM LATE EVENING INTO EARLY MORNING. WINDS BEGIN TO INCREASE TOWARD MORNING...CREATING POTENTIAL FOR BLOWING SNOW ISSUES...ESPECIALLY IN RURAL AREAS SUNDAY. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 318 PM CST SAT DEC 21 2013 LIGHT SNOW FROM THE WINTER STORM WILL CONTINUE INTO SUNDAY EVENING AND SLOWLY END ALONG WITH DECREASING WINDS. CLOUD COVER WILL AID IN KEEPING TEMPERATURES UP BUT THE POSSIBILITY DOES EXIST THAT HEADLINES FOR WIND CHILL MIGHT BE NEEDED OVER PART OF THE WESTERN THIRD LATE SUNDAY NIGHT INTO MONDAY MORNING. WRAP AROUND MOISTURE AND COLD AIR MOVING INTO THE AREA IS EXPECTED TO KEEP FLURRIES OR VERY LIGHT SNOW GOING FOR A GOOD PART OF MONDAY OVER THE NORTHEAST HALF OF THE AREA. THE STRENGTH OF THE COLD AIR MOVING INTO THE AREA IS EXPECTED TO KEEP TEMPERATURES IN THE SINGLE DIGITS OVER MUCH OF THE AREA. ARCTIC HIGH PRESSURE MOVES ACROSS THE AREA MONDAY NIGHT INTO TUESDAY RESULTING IN DRY CONDITIONS BUT BITTER COLD TEMPERATURES. BASED ON PROJECTED LOWS AND WINDS...HEADLINES FOR WIND CHILL WOULD BE NEEDED MONDAY NIGHT INTO TUESDAY MORNING. SKIES SHOULD CLEAR MONDAY NIGHT AND WHEN COMBINED WITH FRESH SNOW AND DECREASING WINDS IS EXPECTED TO PUSH LOW TEMPERATURES WELL BELOW ZERO OVER MUCH OF THE AREA. LOWS MAY PUSH 20 BELOW IN THE FAVORED COLD AREAS WEST OF THE MISSISSIPPI. ON TUESDAY DRY CONDITIONS BUT VERY COLD TEMPERATURES WILL BE SEEN ACROSS THE AREA. THE NORTHERN THIRD TO 40 PERCENT OF THE AREA WILL STRUGGLE TO GET ABOVE 10 DEGREES. TUESDAY NIGHT ON... THE MODEL CONSENSUS HAS SLIGHT CHANCE/CHANCE POPS TUES NIGHT/WED AND SLIGHT CHANCE POPS WED NIGHT AS THE NEXT DISTURBANCE MOVES THROUGH THE AREA. MOISTURE WILL BE VERY LIMITED BUT SNOW/RAIN RATIOS WILL BE HIGH. SO WHAT MOISTURE IS AVAILABLE WILL GO INTO PRODUCING A VERY DRY SNOW. A REASONABLE GUESS ON AMOUNTS THIS FAR OUT WOULD BE AROUND AN INCH WITH PERHAPS A BIT MORE ACROSS THE NORTHERN THIRD OF THE AREA. THE NEXT ARCTIC HIGH BUILDS INTO THE MIDWEST THURSDAY INTO FRIDAY RESULTING IN DRY CONDITIONS BUT TEMPERATURES WELL BELOW NORMAL. THE MODEL CONSENSUS DEVELOPS WARMER RETURN FLOW FRIDAY NIGHT INTO SATURDAY WITH DRY CONDITIONS AND BUT TEMPERATURES WILL REMAIN BELOW NORMAL. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY EVENING) ISSUED AT 1116 PM CST SAT DEC 21 2013 IFR CONDITIONS TO LIFR CONDITIONS WILL PRECEDE A LARGE WINTER STORM OVERNIGHT AND SUNDAY IN EASTERN IOWA AND ILLINOIS. NORTHEAST WINDS WILL BECOME NORTHWEST BY LATE TONIGHT...AND CONTINUE TO BE 15 TO 20 KTS...GUSTING TO MID 20S AT TIMES. CIGS OF 100 FT TO 800 FT WILL BE COMMON THROUGH SUNDAY AFTERNOON MAINLY MODERATE TO HEAVY SNOW...VISIBILITIES DOWN TO 1/4 OR LESS AT TIMES...OVERNIGHT IN ALL LOCATIONS EXPECT POSSIBLY BRL. SNOW WILL END BY MID MORNING SUNDAY...BUT FOLLOWING THIS TIME...BLOWING AND DRIFTING SNOW CAN BE EXPECTED TO CONTINUE TO BRING IFR CONDITIONS TO ALL TERMINALS THROUGH SUNDAY AFTERNOON. THIS IS A VERY POOR FLYING FORECAST...WITH SHORT TERM ICING AT TERMINALS FOLLOWED BY HEAVY SNOW. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...WINTER STORM WARNING UNTIL 6 PM CST SUNDAY FOR BENTON-BUCHANAN- CEDAR-CLINTON-DELAWARE-DES MOINES-DUBUQUE-HENRY IA-IOWA- JACKSON-JEFFERSON-JOHNSON-JONES-KEOKUK-LEE-LINN-LOUISA- MUSCATINE-SCOTT-VAN BUREN-WASHINGTON. IL...WINTER STORM WARNING UNTIL 6 PM CST SUNDAY FOR BUREAU-CARROLL- HANCOCK-HENDERSON-HENRY IL-JO DAVIESS-MCDONOUGH-MERCER- PUTNAM-ROCK ISLAND-STEPHENSON-WARREN-WHITESIDE. MO...WINTER STORM WARNING UNTIL 6 PM CST SUNDAY FOR CLARK-SCOTLAND. && $$ UPDATE...ERVIN SHORT TERM...DMD LONG TERM...08 AVIATION...ERVIN
AREA FORECAST DISCUSSION
NWS CARIBOU ME
801 PM EST MON DEC 23 2013 .SYNOPSIS... WEAK LOW PRESSURE WILL MOVE EAST INTO THE MARITIMES OVERNIGHT. COLD HIGH PRESSURE WILL THEN MOVE IN TUESDAY AND WEDNESDAY. && .NEAR TERM /THROUGH TUESDAY/... 800 PM UPDATE...CALLS TO SPOTTERS FROM BROWNVILLE-LINCOLN- TOPSFIELD INDICATE THAT THE FREEZING RAIN HAS CHANGED TO SNOW. THE SNOW MAYBE MIXED WITH SOME SLEET AT TIMES FOR THE NEXT HOUR IN NORTHERN WASHINGTON COUNTY. HAVE ALLOWED ALL OF THE FREEZING RAIN ADVISORIES/WINTER WEATHER ADVISORIES IN THE ABOVE CORRIDOR TO EXPIRE AS OF 8 PM. MOISTURE CONTINUES TO STREAM ACROSS DOWNEAST AREAS WITH REPORTS OF MEASURABLE FREEZING RAIN UPSTREAM OF HANCOCK AND WASHINGTON COUNTIES. HAVE EXTENDED THE ICE STORM WARNINGS UNTIL 10 PM AND BEEFED UP THE POPS TO CATEGORICAL FOR A COUPLE OF MORE HOURS. THE FREEZING RAIN WILL LIKELY END AS A BRIEF PERIOD OF SNOW. PREVIOUS DISCUSSION... STILL SOME FZRA AFFECTING THE ICE STORM WRNG AND FZRA ADV AREAS AT THE TM OF THIS UPDATE. WE DID XTND THE END TM OF THESE HDLNS AND WHATS LEFT OF THE NRN WNTR WX ADV FOR A COUPLE OF MORE HRS...WHILE TRUNCATING ZONES 3...4 AND 10 FROM THE WNTR WX ADV DUE TO MIXED PRECIP ENDING THERE. OTHERWISE MODELS...INCLUDING THE HRRR IS SHOWING THE PRECIP WINDING DOWN FROM W TO E ACROSS THE FA BY LATE EVE...SO IT APPEARS UNLIKELY THAT WILL NEED TO XTND REMAINING WNTR WX HDLNS ANY FURTHER. OTHERWISE...COLDER AIR WITH CLRG TO PRTL CLRG SKIES ARE SLATED FOR THE FA LATE TNGT WITH INCREASING NW WINDS. A SIG NW BREEZE IS LIKELY TO CONT ON TUE...WITH POTENTIAL IMPLICATIONS FOR FURTHER DAMAGE IN THE MAX ICE ACCRETION ZONE DOWNEAST IN THE ABSENCE OF ANNY MELTING...WHICH DOES NOT APPEAR LIKELY N OF THE IMMEDIATE COAST. DUE TO MDTLY STRONG LLVL COLD ADVCN ON TUE...HI TEMPS TUE WILL ONLY RECOVER A FEW DEGREES AT BEST FROM OVRNGT LOWS UNDER MSLY CLR TO PTLY CLDY SKIES. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/... ARCTIC HIGH PRESSURE BUILDS INTO NEW ENGLAND FOR A BITTERLY COLD CHRISTMAS DAY. A WIND CHILL ADVISORY MAY BE NECESSARY LATE TUESDAY NIGHT INTO CHRISTMAS DAY MORNING. AFTER ANOTHER CHILLY NIGHT...TEMPERATURES WARM SIGNIFICANTLY ON THURSDAY AHEAD OF A CLIPPER SYSTEM. LIGHT SNOW SHOULD DEVELOP IN THE AFTERNOON AS THIS SYSTEM APPROACHES. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... A CLIPPER SYSTEM MOVES ACROSS THE GULF OF MAINE AND INTO THE MARITIMES THURSDAY NIGHT INTO EARLY FRIDAY. A COUPLE INCHES OF SNOWFALL WILL BE POSSIBLE WITH THE PASSAGE OF THIS SYSTEM...ESPECIALLY NEAR THE NEW BRUNSWICK BORDER. MORE ARCTIC AIR SPILLS INTO THE REGION BEHIND THIS SYSTEM. THE GFS AND ECMWF DIFFER ON YET ANOTHER LOW PRESSURE SYSTEM FORECAST TO APPROACH NORTHERN NEW ENGLAND ON SUNDAY. THE ECMWF IS FARTHER SOUTH WITH THE TRAJECTORY OF THIS SYSTEM WHICH RESULTS IN HIGHER QPF/SNOWFALL AMOUNTS. && .AVIATION /01Z TUESDAY THROUGH SATURDAY/... NEAR TERM: CURRENT IFR CONDITIONS IN SN AND/OR MIXED PRECIP SHOULD IMPROVE TO VFR BY DAYBREAK TUE ACROSS ALL TAF SITES...WITH VFR CONTG THRU THE DAY TUE. SHORT TERM:IFR CIGS AND VSBYS WILL BE POSSIBLE LATE THURSDAY THROUGH EARLY FRIDAY DUE TO SNOW AND FOG. OTHERWISE VFR CONDITIONS ARE EXPECTED. && .MARINE... NEAR TERM: WILL CONT WITH SCA FOR HAZ SEAS FOR OUTER MZS050-051 INTO TUE AFTN BASED ON BLENDED FCST WW3/SWAN NAM/SWAN GFS WV HTS WHICH ALSO HAD TO BE ADJUSTED UPWARDS BY 1 TO 2 FT THRU TNGT GIVEN THE LATEST LOW BIAS COMPARED TO BUOY OBS. SHORT TERM: AN SCA MAY BE NEEDED ON CHRISTMAS DAY FOR WIND GUSTS IN EXCESS OF 25 KNOTS AND FOR WAVE HEIGHTS 5-7 FEET THURSDAY AFTERNOON AND EVENING. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...ICE STORM WARNING UNTIL 10 PM EST THIS EVENING FOR MEZ015>017- 029-030. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM EST TUESDAY FOR ANZ050-051. && $$ NEAR TERM...CB/VJN SHORT TERM...OKULSKI LONG TERM...OKULSKI AVIATION...CB/VJN/OKULSKI MARINE...CB/VJN/OKULSKI
AREA FORECAST DISCUSSION
NWS CARIBOU ME
554 PM EST MON DEC 23 2013 .SYNOPSIS... WEAK LOW PRESSURE WILL MOVE EAST INTO THE MARITIMES OVERNIGHT. COLD HIGH PRESSURE WILL THEN MOVE IN TUESDAY AND WEDNESDAY. && .NEAR TERM /THROUGH TUESDAY/... 554 PM UPDATE...CALLS TO WEATHER SPOTTERS INDICATE A COUPLE OF REPORTS OF FREEZING RAIN IN SOUTHERN PISCATAQUIS COUNTY SHORTLY BEFORE 6 PM...SO WILL EXTEND THE WINTER WEATHER ADVISORY FOR TWO MORE HOURS. THE PRECIPITATION HAS CHANGED OVER TO ALL SNOW IN ZONES 5 AND 6...AND THE CORRELATION COEFFICIENT FROM THE KCBW 88-D IS DOING A GOOD JOB AT DIFFERENTIATING BETWEEN ALL SNOW AND FREEZING RAIN. UPDATES OUT SHORTLY. PREVIOUS DISCUSSION... STILL SOME FZRA AFFECTING THE ICE STORM WRNG AND FZRA ADV AREAS AT THE TM OF THIS UPDATE. WE DID XTND THE END TM OF THESE HDLNS AND WHATS LEFT OF THE NRN WNTR WX ADV FOR A COUPLE OF MORE HRS...WHILE TRUNCATING ZONES 3...4 AND 10 FROM THE WNTR WX ADV DUE TO MIXED PRECIP ENDING THERE. OTHERWISE MODELS...INCLUDING THE HRRR IS SHOWING THE PRECIP WINDING DOWN FROM W TO E ACROSS THE FA BY LATE EVE...SO IT APPEARS UNLIKELY THAT WILL NEED TO XTND REMAINING WNTR WX HDLNS ANY FURTHER. OTHERWISE...COLDER AIR WITH CLRG TO PRTL CLRG SKIES ARE SLATED FOR THE FA LATE TNGT WITH INCREASING NW WINDS. A SIG NW BREEZE IS LIKELY TO CONT ON TUE...WITH POTENTIAL IMPLICATIONS FOR FURTHER DAMAGE IN THE MAX ICE ACCRETION ZONE DOWNEAST IN THE ABSENCE OF ANNY MELTING...WHICH DOES NOT APPEAR LIKELY N OF THE IMMEDIATE COAST. DUE TO MDTLY STRONG LLVL COLD ADVCN ON TUE...HI TEMPS TUE WILL ONLY RECOVER A FEW DEGREES AT BEST FROM OVRNGT LOWS UNDER MSLY CLR TO PTLY CLDY SKIES. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/... ARCTIC HIGH PRESSURE BUILDS INTO NEW ENGLAND FOR A BITTERLY COLD CHRISTMAS DAY. A WIND CHILL ADVISORY MAY BE NECESSARY LATE TUESDAY NIGHT INTO CHRISTMAS DAY MORNING. AFTER ANOTHER CHILLY NIGHT...TEMPERATURES WARM SIGNIFICANTLY ON THURSDAY AHEAD OF A CLIPPER SYSTEM. LIGHT SNOW SHOULD DEVELOP IN THE AFTERNOON AS THIS SYSTEM APPROACHES. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... A CLIPPER SYSTEM MOVES ACROSS THE GULF OF MAINE AND INTO THE MARITIMES THURSDAY NIGHT INTO EARLY FRIDAY. A COUPLE INCHES OF SNOWFALL WILL BE POSSIBLE WITH THE PASSAGE OF THIS SYSTEM...ESPECIALLY NEAR THE NEW BRUNSWICK BORDER. MORE ARCTIC AIR SPILLS INTO THE REGION BEHIND THIS SYSTEM. THE GFS AND ECMWF DIFFER ON YET ANOTHER LOW PRESSURE SYSTEM FORECAST TO APPROACH NORTHERN NEW ENGLAND ON SUNDAY. THE ECMWF IS FARTHER SOUTH WITH THE TRAJECTORY OF THIS SYSTEM WHICH RESULTS IN HIGHER QPF/SNOWFALL AMOUNTS. && .AVIATION /22Z MONDAY THROUGH SATURDAY/... NEAR TERM: CURRENT IFR CONDITIONS IN SN AND/OR MIXED PRECIP SHOULD IMPROVE TO VFR BY DAYBREAK TUE ACROSS ALL TAF SITES...WITH VFR CONTG THRU THE DAY TUE. SHORT TERM:IFR CIGS AND VSBYS WILL BE POSSIBLE LATE THURSDAY THROUGH EARLY FRIDAY DUE TO SNOW AND FOG. OTHERWISE VFR CONDITIONS ARE EXPECTED. && .MARINE... NEAR TERM: WILL CONT WITH SCA FOR HAZ SEAS FOR OUTER MZS050-051 INTO TUE AFTN BASED ON BLENDED FCST WW3/SWAN NAM/SWAN GFS WV HTS WHICH ALSO HAD TO BE ADJUSTED UPWARDS BY 1 TO 2 FT THRU TNGT GIVEN THE LATEST LOW BIAS COMPARED TO BUOY OBS. SHORT TERM: AN SCA MAY BE NEEDED ON CHRISTMAS DAY FOR WIND GUSTS IN EXCESS OF 25 KNOTS AND FOR WAVE HEIGHTS 5-7 FEET THURSDAY AFTERNOON AND EVENING. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...FREEZING RAIN ADVISORY UNTIL 8 PM EST THIS EVENING FOR MEZ011- 032. ICE STORM WARNING UNTIL 8 PM EST THIS EVENING FOR MEZ015>017- 029-030. WINTER WEATHER ADVISORY UNTIL 8 PM EST THIS EVENING FOR MEZ031. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM EST TUESDAY FOR ANZ050-051. && $$ NEAR TERM...CB/VJN SHORT TERM...OKULSKI LONG TERM...OKULSKI AVIATION...CB/VJN/OKULSKI MARINE...CB/VJN/OKULSKI
AREA FORECAST DISCUSSION
NWS CARIBOU ME
335 PM EST MON DEC 23 2013 .SYNOPSIS... WEAK LOW PRESSURE WILL MOVE EAST INTO THE MARITIMES OVERNIGHT. COLD HIGH PRESSURE WILL THEN MOVE IN TUESDAY AND WEDNESDAY. && .NEAR TERM /THROUGH TUESDAY/... STILL SOME FZRA AFFECTING THE ICE STORM WRNG AND FZRA ADV AREAS AT THE TM OF THIS UPDATE. WE DID XTND THE END TM OF THESE HDLNS AND WHATS LEFT OF THE NRN WNTR WX ADV FOR A COUPLE OF MORE HRS...WHILE TRUNCATING ZONES 3...4 AND 10 FROM THE WNTR WX ADV DUE TO MIXED PRECIP ENDING THERE. OTHERWISE MODELS...INCLUDING THE HRRR IS SHOWING THE PRECIP WINDING DOWN FROM W TO E ACROSS THE FA BY LATE EVE...SO IT APPEARS UNLIKELY THAT WILL NEED TO XTND REMAINING WNTR WX HDLNS ANY FURTHER. OTHERWISE...COLDER AIR WITH CLRG TO PRTL CLRG SKIES ARE SLATED FOR THE FA LATE TNGT WITH INCREASING NW WINDS. A SIG NW BREEZE IS LIKELY TO CONT ON TUE...WITH POTENTIAL IMPLICATIONS FOR FURTHER DAMAGE IN THE MAX ICE ACCRETION ZONE DOWNEAST IN THE ABSENCE OF ANNY MELTING...WHICH DOES NOT APPEAR LIKELY N OF THE IMMEDIATE COAST. DUE TO MDTLY STRONG LLVL COLD ADVCN ON TUE...HI TEMPS TUE WILL ONLY RECOVER A FEW DEGREES AT BEST FROM OVRNGT LOWS UNDER MSLY CLR TO PTLY CLDY SKIES. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/... ARCTIC HIGH PRESSURE BUILDS INTO NEW ENGLAND FOR A BITTERLY COLD CHRISTMAS DAY. A WIND CHILL ADVISORY MAY BE NECESSARY LATE TUESDAY NIGHT INTO CHRISTMAS DAY MORNING. AFTER ANOTHER CHILLY NIGHT...TEMPERATURES WARM SIGNIFICANTLY ON THURSDAY AHEAD OF A CLIPPER SYSTEM. LIGHT SNOW SHOULD DEVELOP IN THE AFTERNOON AS THIS SYSTEM APPROACHES. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... A CLIPPER SYSTEM MOVES ACROSS THE GULF OF MAINE AND INTO THE MARITIMES THURSDAY NIGHT INTO EARLY FRIDAY. A COUPLE INCHES OF SNOWFALL WILL BE POSSIBLE WITH THE PASSAGE OF THIS SYSTEM...ESPECIALLY NEAR THE NEW BRUNSWICK BORDER. MORE ARCTIC AIR SPILLS INTO THE REGION BEHIND THIS SYSTEM. THE GFS AND ECMWF DIFFER ON YET ANOTHER LOW PRESSURE SYSTEM FORECAST TO APPROACH NORTHERN NEW ENGLAND ON SUNDAY. THE ECMWF IS FARTHER SOUTH WITH THE TRAJECTORY OF THIS SYSTEM WHICH RESULTS IN HIGHER QPF/SNOWFALL AMOUNTS. && .AVIATION /20Z MONDAY THROUGH SATURDAY/... NEAR TERM: CURRENT IFR CONDITIONS IN SN AND/OR MIXED PRECIP SHOULD IMPROVE TO VFR BY DAYBREAK TUE ACROSS ALL TAF SITES...WITH VFR CONTG THRU THE DAY TUE. SHORT TERM:IFR CIGS AND VSBYS WILL BE POSSIBLE LATE THURSDAY THROUGH EARLY FRIDAY DUE TO SNOW AND FOG. OTHERWISE VFR CONDITIONS ARE EXPECTED. && .MARINE... NEAR TERM: WILL CONT WITH SCA FOR HAZ SEAS FOR OUTER MZS050-051 INTO TUE AFTN BASED ON BLENDED FCST WW3/SWAN NAM/SWAN GFS WV HTS WHICH ALSO HAD TO BE ADJUSTED UPWARDS BY 1 TO 2 FT THRU TNGT GIVEN THE LATEST LOW BIAS COMPARED TO BUOY OBS. SHORT TERM: AN SCA MAY BE NEEDED ON CHRISTMAS DAY FOR WIND GUSTS IN EXCESS OF 25 KNOTS AND FOR WAVE HEIGHTS 5-7 FEET THURSDAY AFTERNOON AND EVENING. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...FREEZING RAIN ADVISORY UNTIL 8 PM EST THIS EVENING FOR MEZ011- 032. ICE STORM WARNING UNTIL 8 PM EST THIS EVENING FOR MEZ015>017- 029-030. WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR MEZ005- 006-031. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM EST TUESDAY FOR ANZ050-051. && $$ NEAR TERM...VJN SHORT TERM...OKULSKI LONG TERM...OKULSKI AVIATION...VJN/OKULSKI MARINE...VJN/OKULSKI
AREA FORECAST DISCUSSION
NWS GRAY ME
644 AM EST SUN DEC 22 2013 .SYNOPSIS... A COLD FRONT WILL SINK SLOWLY SOUTH TODAY AND FINALLY MOVE OFF THE COAST LATE MONDAY. HIGH PRESSURE WILL BUILD OVER THE AREA TUESDAY AND WEDNESDAY. HIGH PRESSURE WILL MOVE EAST OF THE REGION THURSDAY. A COLD FRONT WILL MOVE THROUGH NORTHERN NEW ENGLAND THURSDAY NIGHT. HIGH PRESSURE WILL BUILD OVER THE REGION THURSDAY AND FRIDAY. && .NEAR TERM /TODAY/... 645AM UPDATE... COLD AIR IS FINALLY MAKING PROGRESS TO THE SOUTHWEST... WITH PORTLAND NOW DOWN TO 32 DEGREES. HOWEVER... THE MAIN AREA OF PRECIPITATION HAS SHIFTED EAST. EXPECT ANOTHER FEW ROUNDS OF RAIN TO MOVE THROUGH... THOUGH THEY WILL BE LIGHTER THAN THE LAST ROUND. STILL MAINTAINING CURRENT HEADLINES THOUGH THERE IS SOME CONCERN THAT THERE COULD BE LESS TOTAL ICING ESPECIALLY IN SOUTHWESTERN ZONES...AND MORE OF A MIX IN NORTHEAST ZONES. THE MIDCOAST REGION AND INTERIOR AREAS LIKE AUGUSTA AND WATERVILLE WILL LIKELY BE HARDEST HIT BY THE ICE. MEANWHILE... THE FLIRTATIONS WITH SLEET AND SNOW CONTINUE. 12Z GYX SOUNDING HAS A +11C LAYER AT 850 MB (THOUGH -4C JUST ABOVE THE SURFACE)... WHICH IS VERY MUCH A FREEZING RAIN SOUNDING. HOWEVER... THE GRADIENT JUST NORTH OF HERE IS VERY STOUT. NAM MODEL IS SHOWING THIS WELL... BUT PROBABLY NOT EXTREME ENOUGH. SEVERAL REPORTS FROM AUGUSTA AREA OF SLEET AND OCCASIONALLY SNOW. THE SLEET IS LOGICAL FROM THE DEEP COLD LAYER BELOW THE WARM LAYER ALOFT... BUT THE SNOW IS NOT AS SIMPLE TO EXPLAIN. CURRENT THINKING IS THAT ANY SNOW IN THIS REGION IS BEING GENERATED BELOW THE ABOVE FREEZING LAYER... FULLY WITHIN THE LOW LEVEL COLD LAYER WHICH IS JUST COLD ENOUGH FOR SNOW FORMATION. AS A RESULT... SNOW WILL BE VERY LIGHT DUE TO THE SHALLOW DEPTH OF THE LAYER IN WHICH IT IS BEING GENERATED. EXPECT HEAVIER PRECIPITATION LATER IN THE DAY TO FALL AS FREEZING RAIN OR MAYBE SLEET. HAVE PUT A LOT OF EFFORT INTO THE HOURLY POP AND WEATHER GRIDS TO TRY TO SHOW THE PROGRESSION OF SEVERAL WAVES OF PRECIPITATION ACROSS THE AREA TODAY... BASED HEAVILY ON THE HRRR FORECAST. ORIGINAL DISCUSSION... FIRST ROUND OF HEAVIER PRECIPITATION IS MOVING EAST ACROSS WESTERN MAINE EARLY THIS MORNING. FREEZING LINE HAS NOT MOVED MUCH... WITH THE LINE EXISTING ROUGHLY FROM COLEBROOK TO NORTH OF BERLIN DOWN TO LEWISTON AND OFFSHORE NEAR WISCASSET AND HAS HELD STEADY FOR MUCH OF THE NIGHT. TO THE NORTH AND EAST OF THIS LINE... RAIN IS FREEZING AS IT REACHES THE SURFACE. FURTHER TO THE NORTH... A CHANGE TO SNOW HAS BEEN OBSERVED ROUGHLY FROM THE VT/QUEBEC BORDER ACROSS NORTHERN NEW HAMPSHIRE TO SOUTH OF EUSTIS AND SOUTH OF GREENVILLE AND OVER TO HOULTON. WITH FEW AUTOMATED OBSERVATIONS WHICH REPORT WEATHER IN THIS REGION... CONFIDENCE IN PRECIPITATION TYPE IS REGRETTABLY LOW. INTERPRETATION OF DUAL POL RADAR SEEMS TO PRODUCE A VERY SIMILAR SNOW LINE TO WHAT WAS JUST DESCRIBED... HOWEVER BECAUSE THE RADAR BEAM IS HIGH IN THIS AREA IT IS LESS USEFUL AS A DETERMINATOR. ONE OTHER INTERESTING FACT IS THAT BANGOR HAS BEEN REPORTING SLEET FOR SEVERAL HOURS... OCCASIONALLY MIXING WITH SNOW. THIS SUGGESTS THAT THE COLD AIR IN THIS AREA IS DEEP ENOUGH FOR AT LEAST SLEET... AND OCCASIONALLY SNOW. THIS COLD AIR IS EXPECTED TO CONTINUE TO DEEPEN AND PUSH SOUTHWARD ACROSS WESTERN MAINE TODAY AS THE CURRENT WAVE BRINGING THE PRECIPITATION MOVES EAST. THE FOOTHILLS AND INTERIOR MIDCOAST REGION HAS A CHANCE TO CHANGE TO SLEET OR SNOW FOR A BIT... BUT HAVE DECIDED TO KEEP CURRENT WARNING HEADLINES IN PLACE TO AVOID CONFUSION SINCE THE ICING HAZARD IS THE BIGGEST THREAT. BATCH OF HEAVIER PRECIPITATION AND A FEW EMBEDDED LIGHTNING STRIKES IS MOVING ACROSS UPSTATE NEW YORK. SOME MODELS ARE INDICATING THIS ELEVATED CONVECTION COULD MAINTAIN ITSELF A BIT INTO VERMONT AND NEW HAMPSHIRE AROUND 6-8 AM. HAVE INCLUDED A CHANCE OF THUNDER IN THE FORECAST... BUT DO NOT EXPECT HEAVY OR SEVERE THUNDERSTORMS. EXPECT A BREAK IN THE PRECIPITATION BY AROUND 15Z... WITH ANOTHER ROUND PROBABLY STARTING BY 18Z. BY THIS TIME... THE FREEZING LINE WILL LIKELY HAVE SHIFTED SOUTHWEST INTO NEW HAMPSHIRE... ALLOWING PRECIPITATION TO FALL AS FREEZING RAIN ACROSS A LARGER AREA. HAVE A LOWER THAN AVERAGE CONFIDENCE THAT THE FREEZING LINE WILL MOVE ALL THE WAY INTO ROCKINGHAM COUNTY OR CENTRAL MERRIMACK COUNTY... SO HAVE INCLUDED A CHANCE OF FREEZING RAIN THERE EVEN THOUGH HOURLY TEMPERATURES ARE ONLY FORECAST TO FALL TO 33-34 AS THERE IS A CHANCE TEMPERATURES FALL LOWER THAN FORECAST. WILL MAINTAIN THE STRUCTURE OF ADVISORY AND WARNING HEADLINES TODAY. AREAS THAT WILL LIKELY BE HARDEST HIT BY ICING TODAY ARE AREAS CURRENTLY BEING IMPACTED. THE AREA INCLUDING LEWISTON... AUGUSTA... AND BELFAST HAVE LIKELY ALREADY SEEN SIGNIFICANT ICING AND ARE THE MOST LIKELY AREAS TO REACH WARNING CRITERIA OF 0.5 INCHES. SOME REPORTS UP TO 1 INCH ARE POSSIBLE. AREAS FURTHER SOUTH HAVE AN INCREASINGLY LOWER CHANCE OF REACHING THE 0.5 INCH LEVEL AS TEMPERATURES HAVE REMAINED ABOVE FREEZING THROUGH THE FIRST HEAVY BATCH OF RAIN. && .SHORT TERM /TONIGHT AND MONDAY/... PRECIPITATION CHANCES DECREASE TONIGHT... AND ADVISORIES AND WARNINGS BEGIN TO EXPIRE AS THE MOST SIGNIFICANT PRECIPITATION MOVES EAST. IN FACT... AS THE LAST WAVE MOVES EAST... SOME WARMER AIR MAY MIX DOWN AND ALLOW MUCH OF THE NEW HAMPSHIRE TO RISE ABOVE FREEZING AND MUCH OF MAINE TO FOLLOW SUIT MONDAY MORNING. ON MONDAY... ANOTHER WAVE OF LOW PRESSURE TRACKS EAST ALONG THE OFFSHORE FRONT. MODELS ARE CONSISTENT IN BRINGING PRECIPITATION INTO COASTAL AREAS... BUT TEMPERATURES LOOK LIKELY TO BE ABOVE FREEZING BY LATE MONDAY MORNING. HAVE EXTENDED THE ICE STORM WARNING THROUGH NOON FOR THE COASTAL PLAIN OF MAINE AS TEMPERATURES HERE HAVE A BETTER CHANCE OF STAYING BELOW FREEZING AS PRECIPITATION STARTS UP AGAIN MONDAY MORNING. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... MODELS SHOWING THE COLD FRONT MOVING OFF THE COAST MONDAY NIGHT. AN AREA OF SLEET/FREEZING RAIN AND SNOW WILL END FROM NORTHWEST TO SOUTHEAST MONDAY EVENING AS THE FRONT PUSHES SOUTH. HIGH PRESSURE BUILDS IN FOR TUESDAY AND CHRISTMAS DAY. SHOULD BE A FEW SCATTERED SNOW SHOWERS IN THE MOUNTAINS TUESDAY AS THE UPPER LOW MOVES THROUGH. WEDNESDAY SHOULD BE THE COLDEST DAY OF THE WEEK BUT THIS COLD AIR LIFTS OUT QUICKLY. A COLD FRONT SHOULD MOVE THROUGH THURSDAY OR FRIDAY. THE ECMWF AND GFS ARE ABOUT 12 HOURS OFF ON THE TIMING OF THIS FRONT WITH THE ECMWF BEING SLOWER. && .AVIATION /08Z SUNDAY THROUGH THURSDAY/... SHORT TERM...FREEZING RAIN CONTINUES THROUGH TODAY WITH IFR CONDITIONS. MOST LIKELY AREAS TO SEE FREEZING RAIN ARE THE MAINE TERMINALS. PORTSMOUTH... CONCORD... WHITEFIELD... AND LEBANON MAY NOT SEE FREEZING RAIN. LONG TERM...EXPECT MVFR FOR PWM AND PSM MONDAY NIGHT BEFORE THE FRONT SLIDES OFF THE COAST. VFR TUESDAY THROUGH THE END OF THE WEEK. && .MARINE... SHORT TERM...NORTHEAST WINDS WILL PICK UP THIS MORNING TO THE NORTH OF THE OFFSHORE FRONT. COULD SEE SOME GUSTS TO 25 KT... SO THE SMALL CRAFT ADVISORY HAS BEEN CONVERTED TO A GENERIC ADVISORY TO COVER BOTH WINDS AND SEAS. LONG TERM...SMALL CRAFT ADVISORIES MAY BE NEEDED TUESDAY NIGHT AND WEDNESDAY. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...ICE STORM WARNING UNTIL NOON EST MONDAY FOR MEZ012>014-019>022- 024>028. FREEZING RAIN ADVISORY UNTIL 6 AM EST MONDAY FOR MEZ018-023. WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR MEZ007>009. NH...ICE STORM WARNING UNTIL 6 AM EST MONDAY FOR NHZ002-004. FREEZING RAIN ADVISORY UNTIL 6 AM EST MONDAY FOR NHZ003-005- 006-008>010-013. WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR NHZ001. MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST MONDAY FOR ANZ150-152-154. && $$ SHORT TERM...KIMBLE LONG TERM...HAWLEY
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
359 AM EST SUN DEC 22 2013 .SYNOPSIS... LOW PRESSURE OVER INDIANA WILL TRACK NORTHEAST TODAY...REACHING NEW ENGLAND MONDAY. THE ASSOCIATED COLD FRONT WILL MOVE INTO THE MID- ATLANTIC REGION TONIGHT...BECOMING STATIONARY ACROSS THE REGION MONDAY. HIGH PRESSURE WILL BUILD INTO THE AREA TUESDAY THROUGH THURSDAY. && .NEAR TERM /THROUGH TODAY/... SEVERE THUNDERSTORM WATCH 590 IN EFFECT UNTIL 15Z FOR THE ENTIRE CWA EXCEPT FOR LOWER SRN MD. AS OF 0830Z...AMPLIFIED WAVE PATTERN WITH DEEP TROUGH OVER THE HIGH PLAINS AND A BERMUDA HIGH. 988 MB SFC LOW OVER WRN OH AND TRACKING NE. QLCS QUICKLY APPROACHING THE ALLEGHENY FRONT FROM THE WEST. SYSTEM HAS A HISTORY OF 60 TO 65 MPH GUSTS. VERY DYNAMIC SYSTEM...HIGH SHEAR AND LOW CAPE. JUST BECAUSE THERE IS LITTLE IF ANY LIGHTNING DOES NOT MEAN THESE LINES ARE NOT STRONG. HOW WELL THE LINES SURVIVE CROSSING THE ROAD BUMPS OF THE APPALACHIAN RIDGES REMAINS TO BE SEEN. 05Z HRRR DOES BRING SOME SEMBLANCE OF A LINE ACROSS THE METRO AREAS THROUGH THE MID MORNING. A GOOD PROXY FOR BALT-WASH WILL BE KMRB AND KHGR WHICH SHOULD BE REACHED BETWEEN 10Z AND 11Z. BALT-WASH CORRIDOR IS PROGGED BE IMPACTED 11Z TO 13Z. WIND ADVISORY FOR 40 KT GUSTS ABOVE 2000 FT ON THE RIDGELINES. THIS IS ESSENTIALLY AHEAD OF THE LINE...I.E. UNTIL 8 AM OR SO. TODAY...THE SFC LOW SLOWLY FILLS AS IT MOVES NE TO NY STATE. THE TRAILING COLD FRONT REACHES WV BY SUNSET...BUT STALLS WELL INTO MONDAY. EXPECT A MORNING WAVE OF PRECIP...THEN A SECONDARY WAVE THIS AFTERNOON INTO THE EVENING. DYNAMICALLY DRIVEN TEMPERATURES TODAY...ALREADY AROUND 70F THIS MORNING. LOW TO MID 70S AHEAD OF MAIN PRECIP POSSIBLE...PARTICULARLY LATER THIS MORNING. && .SHORT TERM /TONIGHT THROUGH 6 PM MONDAY/... FLOODING THREAT FROM HEAVY RAIN ALONG STALLED COLD FRONT TONIGHT INTO MONDAY. WITH MESOSCALE FEATURES DOMINATING AT THIS TIME...NO FLOOD WATCH. WILL NEED TO MONITOR WHERE BOUNDARIES SET UP. THE 00Z GFS/ECMWF FAVOR AREAS SOUTHEAST OF DC FOR THE HEAVIEST RAINFALL. UPSLOPE SNOW ON BACK SIDE OF THE SYSTEM LOOKS LIGHT FOR LATE MONDAY...PERHAPS AN INCH OR SO ABOVE 3 KFT. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... THE NEXT 36 HRS WL FEATURE PLENTY OF WX...BEGINNING MON NGT THINGS BEGIN TO SETTLE DOWN. FNT IS XPCTD TO BE MOVG OFFSHORE...HIGH PRES BLDG INTO THE AREA. IT`S DFCLT TO ENVISION SNOW IN THE FCST WHEN THE CURRENT TEMPS ARE RANGING FM 65-70...BUT W/ COLDER AIR AND HIGH PRES STARTING TO BUILD BACK INTO THE RGN THE SUB-1300 850-1000 THCKNS LN LOOKS TO BE MOVG E OF THE BLU RDG AFTR MDNGT MON NGT. UPSLOPE SNOWS XPCTD TO BEGIN ON THE WRN SLOPES OF THE HIGHLANDS AFTR MDNGT AS WELL. IF ACCUMS OCCUR IT IS LOOKING TO BE LGT - UPR TROF WL MOVE E TO THE CST TUE AFTN...SFC HIGH PRES IS XPCTD TO BUILD IN QUICKLY. LOW ON NGT MOVG BACK TOWARDS LATE DEC NORMS...20S BLUE RDG AND W....30S E. TUE HIGHS IN THE 30S BLUE RDG AND W...L40S E. HIGH PRES SETTLES OVR THE AREA TUE NGT BRINGING CLR SKIES FOR CHRISTMAS EVE. LOWS IN THE 20S E OF THE MTNS...MU TEENS W OF BLUE RDG...L TEENS IN THE HIGHLANDS. CHRISTMAS DAY STILL LOOKING NICE UNDER HIGH PRES - SUNNY SKIES W/ HIGHS IN THE 30S. AN UPPER SHORT WV TROF LOOKS TO TRACK N OF THE AREA FRI. FOR NOW THE DAY WL BE LEFT DRY. HIGH PRES THEN XPCTD TO RETURN FOR NEXT WKND. && .AVIATION /07Z SUNDAY THROUGH THURSDAY/... MVFR CIGS IN STRONG SLY FLOW AHEAD OF A COLD FRONT THAT APPROACHES THIS EVENING. GUSTS TO AROUND 30 KT. LINES OF WINDY SHOWERS APPROACH THE TERMINALS THROUGH THE MID MORNING. WILL NEED TO MONITOR THEM AS THEY CROSS THE APPALACHIAN RIDGES. LOW CEILINGS THROUGH THE NIGHT AND INTO MONDAY AS THE COLD FRONT STALLS OVER THE AREA. SLOW BUT GRADUAL CLEARING BEHIND THE COLD FRONT MONDAY NIGHT WILL LEAD TO A RISE IN CEILINGS AND IMPROVING VISIBILITY...RESULTING IN VFR CONDITIONS. WINDS WILL SHIFT FROM SOUTH-SOUTHWEST TO NORTHWEST AT AROUND 10 KNOTS WITH OCCASIONAL GUSTS TO 20 KNOTS. VFR CONDS TUE THRU THU. && .MARINE... S-SWLY FLOW CONTINUES TO GUST UP TO 30 KT THROUGH AT LEAST THE MORNING...SLOWLY DECREASING THIS AFTERNOON. EXTENDED SCA FOR WATERS SOUTH OF SANDY PT AND MIDDLE/LOWER TIDAL POTOMAC FOR THIS EVENING. RAIN CONTINUES INTO MONDAY WITH STALLED COLD FRONT. GUSTS WITH THE RAIN COULD REQUIRE SPECIAL MARINE WARNINGS FOR GUSTS IN EXCESS OF 34 KT. HIGH PRES BLDG INTO THE AREA MON NGT AND TUE WL LKLY LEAD TO SCA`S FOR ALL OF THE WATERS. HIGH PRES BLDG OVR THE AREA TUE NGT THRU THU - NO PROBS ON THE WATERS. && .CLIMATE... RECORD HIGH TEMPS SET ON SAT AT IAD...DCA...BWI...MRB. RECORD HIGH MINS SET SAT AT IAD...DCA...AND BWI. THE BWI AND DCA MIN RECORDS WERE 118 YRS OLD! RECORDS HIGH TEMPS FOR TODAY AND MON: 12/22... MIN MAX BWI...48 (1931)......70 (1889) DCA...49 (1923)......72 (1889) IAD...49 (1990)......67 (1984) 12/23...(HI MIN ONLY) BWI...59 (1990)* DCA...57 (1990) IAD...61 (1990)* * = HIGHEST MIN TEMP IN DECEMBER. THE HIGHEST DECEMBER MIN TEMP FOR THE DCA PERIOD OF RECORD WAS 59 ON DEC 5 1973. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...WIND ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR VAZ025>027-029- 030-036>040-503-504. WV...WIND ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR WVZ055-501-502- 505-506. MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR ANZ532>534-536-537-540>543. SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ530- 531-535-538-539. && $$ PRODUCTS...BAJ/WOODY!
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
730 PM EST MON DEC 23 2013 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 343 PM EST MON DEC 23 2013 LATEST WV SATELLITE IMAGERY AND RUC ANALYSIS SHOWS BROAD 5H TROUGH SLOWLY PUSHING E ACROSS THE WRN GREAT LAKES THIS AFTERNOON. WEAK 850-500MB Q-VECTOR CONVERGENCE ASSOC WITH THIS TROUGH OVER LAKE SUPERIOR WILL TRANSITION TO Q-VECTOR DIVERGENCE THIS EVENING. VIS IMAGERY SHOWS NE WIND PARALLEL LAKE EFFECT SNOW BANDS ACROSS LAKE SUPERIOR IMPACTING MAINLY FAR WESTERN AND NORTH CENTRAL UPPER MI. A FEW OF THE MORE INTENSE BANDS HAVE PRODUCED PERIODS OF MODERATE SNOW. LES HAS BEEN VERY FLUFFY WITH SNOW RATIOS 40-50/1. MAIN FORECAST CONCERN IS CONTINUING LES EVENT FOR FAR WESTERN AND NORTH CENTRAL COUNTIES INTO THIS EVENING AND THEN DIMINISHING LES OVERNIGHT INTO TUE MORNING. EXPECT ADDITIONAL SNOWFALL AMOUNTS OF 2 TO 5 INCHES THROUGH THIS EVENING. BEST LOW-LVL CONVERGENCE SUGGESTS MORE INTENSE LES BANDS AND THUS GREATEST SNOW AMOUNTS WILL BE OVER ERN HALF OF MQT COUNTY INTO PERHAPS WRN ALGER COUNTY. GIVEN EXPECTATION OF CONTINUING LES ACCUMULATION INTO AT LEAST THE EVENING HRS WILL CONTINUE ADVISORIES FOR GOGEBIC-ONTONAGON AND MQT-BARAGA INTO THE EARLY OVERNIGHT. LES SHOULD GENERALLY BE WINDING DOWN BY LATE EVENING INTO OVERNIGHT HRS WITH Q-VECT DIVERGENCE ACROSS THE AREA AND WEAKENING WIND FIELDS. LOW-LVL CONVERGENCE MAY STRENGTHEN DUE TO WEAKENING WINDS AND DEVELOPING LAND BREEZES TO ALLOW MORE LOCALLY INTENSE LES BANDS TO FORM AND PERHAPS EVEN A MESOLOW OR TWO OFF THE PORCUPINE MOUNTAINS AND OVER MQT BAY AS DEPICTED BY LOCAL AND REGIONAL MESOSCALE MODELS. HOWEVER...WINDS BACKING TO THE WEST/SOUTHWEST OVERNIGHT AHEAD OF ADVANCING SFC RDG AXIS SHOULD KEEP LES BANDS OR MESOLOW FEATURES MOVING ENOUGH EASTWARD TO EFFECTIVELY LIMIT ACCUMULATIONS FOR THE OVERNIGHT HRS. DECREASING CLOUD COVER OVERNIGHT AND LIGHT WINDS WILL ALLOW TEMPERATURES TO FALL OFF OUTSIDE OF THOSE AREAS WHERE THE LAKE EFFECT SNOWS LINGER. COLDEST TEMPERATURES ARE EXPECTED OVER THE FAR EAST AND INTERIOR WEST SECTIONS. THE WRN INTERIOR ALONG THE WI BDR WITH LIKELY SEE A FEW LOCATIONS PLUMMET TO 10 BELOW OR COLDER WHERE TYPICAL COLD SPOTS OVER LUCE COUNTY COULD ALSO DIP NEAR 10 BELOW ZERO. GENERALLY FOLLOWED A BLEND OF THE BETTER PERFORMING CANADIAN REGIONAL GEM AND ECMWF FOR MIN TEMPS. TUESDAY...DECENT MODEL AGREEMENT THAT LINGERING LAKE EFFECT OVER NCNTRL CWA WILL BE PUSHED OUT OVR SOUTH CENTRAL LK SUPERIOR THROUGH THE MORNING AS WINDS BECOME SSW AHEAD OF APPROACHING SHORTWAVE AND SFC TROUGH OVER THE NRN PLAINS. MAY BE ABLE TO SNEAK IN SOME SUNSHINE OVER MUCH OF THE CWA INTO EARLY AFTN BEFORE HIGH CLOUDS START INCREASING AHEAD OF SHORTWAVE TROUGH DROPPING ACROSS THE NORTHERN PLAINS. WARM ADVECTION SSW FLOW WILL ALLOW FOR MAX TEMPS TO REBOUND INTO THE TEENS ACROSS MUCH OF THE AREA. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 310 PM EST MON DEC 23 2013 UPPER AIR PATTERN WILL CONSIST OF A 500 MB RIDGE ON THE WEST COAST AND A TROUGH OVER THE NORTHERN PLAINS 00Z WED. NAM ALSO SHOWS A CLOSED 500 MB LOW OVER NORTHERN ALBERTA 00Z WED. BOTH THE LOW AND THE TROUGH MOVE TO THE EAST WITH THE REMAINS OF THE LOW HELPING TO DIG A DEEP UPPER TROUGH INTO THE UPPER GREAT LAKES ON WED. NAM SHOWS SOME 850-500 MB Q-VECTOR CONVERGENCE OVER THE CWA WITH DEEPER MOISTURE TUE NIGHT LASTING INTO WED BEFORE BOTH MOVE OUT WED NIGHT INTO THU. GFS AND ECMWF SHOW ABOUT THE SAME THING. DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST. CLIPPER TYPE SYSTEM COMES IN FOR TUE NIGHT INTO WED AND WILL HAVE SOME LAKE MICHIGAN LAKE ENHANCEMENT OVER THE ERN CWA WHICH WAS ALREADY COVERED IN THE PREVIOUS FORECAST. COULD SEE UP TO 8 INCHES IN ERN SCHOOLCRAFT AND LUCE COUNTIES FOR TUE NIGHT AND WED. DID LOWER TEMPERATURES A BIT THOUGH EACH DAY FOR LOWS AND HIGHS TUE NIGHT THROUGH THU AS THE TEMPERATURES SEEMED A BIT TOO WARM CONSIDERING THE PERSISTENT COLD PATTERN WE HAVE BEEN IN. IN THE EXTENDED...GFS AND ECMWF SHOW A 500 MB TROUGH OVER THE CENTRAL U.S. 12Z FRI WITH A RIDGE OVER THE WESTERN U.S. UPPER FLOW BECOMES MORE ZONAL OVER THE NORTHERN PLAINS AND UPPER GREAT LAKES 12Z SAT WHICH WILL MEAN A BRIEF WARMING TREND IS STARTING. A BROAD 500 MB TROUGH THEN MOVES INTO THE UPPER GREAT LAKES 12Z SUN AND INTO MONDAY WITH COLD AIR ONCE AGAIN OVER THE AREA WITH THE DEEP UPPER TROUGH. LAKE EFFECT SNOW WILL BE THE MAIN RULE FOR MOST OF THIS FORECAST PERIOD WITH TEMPERATURES GOING BACK BELOW NORMAL SUNDAY INTO MONDAY. CLIPPER SYSTEM MOVES THROUGH FOR SAT AND THIS WOULD BE THE WARMEST DAY OF THE WEEK. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING) ISSUED AT 729 PM EST MON DEC 23 2013 MAINLY MVFR CONDITIONS ARE EXPECTED TONIGHT WITH LINGERING LIGHT LAKE EFFECT SNOW SHOWERS MOVING THROUGH NORTHERN UPPER MICHIGAN ON LIGHT NRLY WINDS. EXPECT CIGS AND VSBYS TO IMPROVE TO VFR LATE TONIGHT AT IWD AND TUE MORNING AT CMX AND SAW AS LAKE EFFECT COMES TO AN ENDS WITH WINDS BACKING TO THE SOUTHWEST. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 343 PM EST MON DEC 23 2013 NORTHEAST WINDS WILL GRADUALLY DIMINISH THROUGH THE DAY. HEAVY FREEZING SPRAY WILL REMAIN A PROBLEM OVER THE WEST AND NORTH CENTRAL PORTIONS OF LAKE SUPERIOR UNTIL THE PRESSURE GRADIENT RELAXES A BIT MORE IN THE AFTERNOON. AFTER A BRIEF RESPITE...SOUTH WINDS PICK UP AGAIN AHEAD OF THE NEXT SYSTEM MOVING THROUGH TO THE NORTH OF LAKE SUPERIOR TUESDAY NIGHT WITH GALE FORCE WINDS TO 35 KNOTS EXPECTED THEN...MAINLY FOR THE EASTERN PORTION OF THE LAKE. WINDS DIMINISH WEDNESDAY AND REMAIN BELOW 20 KNOTS THROUGH FRIDAY. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... LAKE EFFECT SNOW ADVISORY UNTIL 3 AM EST TUESDAY FOR MIZ004-005. LAKE EFFECT SNOW ADVISORY UNTIL MIDNIGHT EST /11 PM CST/ TONIGHT FOR MIZ002-009. LAKE SUPERIOR... GALE WATCH FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY MORNING FOR LSZ266. LAKE MICHIGAN... NONE. && $$ SHORT TERM...VOSS LONG TERM...07 AVIATION...JLB MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
300 PM EST SUN DEC 22 2013 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 259 PM EST SUN DEC 22 2013 WATER VAPOR LOOP AND RUC ANALYSIS SHOWS SHORTWAVE AND ASSOC LOW PRESSURE SYSTEM LIFTING NE THROUGH THE LOWER GREAT LAKES. WEAKENING LIFT AS NOTED ON MID-LVL Q-VECT ANALYSIS AND EVENTUAL TRANSITION TO Q-VECT DIVERGENCE HAS QUICKLY DIMINISHED SYSTEM SNOW OVER THE EAST HALF OF UPPER MI THIS AFTERNOON. TOTAL SYSTEM SNOW ACCUMULATIONS ACROSS THE SCNTRL AND ERN COUNTIES IN THE WINTER WX ADVISORY AREA WILL LIKELY END UP IN THE 2 TO 3 INCH RANGE WITH A FEW SPOTS LOCALLY RECEIVING 4 INCHES. SNOW RATIOS APPEAR TO BE LOWER THAN EXPECTED IN PREV FCST LEADING TO DIMINISHED SNOW AMTS. SNOWFLAKES HERE AT NWS MQT ARE QUITE SMALL LEADING TO 6/1 SLR ON THE 18Z. DESPITE DIMINISHED SNOW AMTS...SMALL FLAKES ARE RESULTING IN REDUCED VSBYS. SOME ACCIDENTS ALSO REPORTED IN MENOMINEE COUNTY FROM SLIPPERY ROADS THIS AFTERNOON. WITH SYSTEM SNOW BASICALLY DONE THIS AFTERNOON...FOCUS WILL SHIFT TO LES WHICH IS EXPECTED TO IMPACT MAINLY WEST AND NCNTRL COUNTIES TONIGHT INTO MONDAY EVENING IN NE FLOW. GRADUALLY COLDER 8H TEMPS MOVING IN FM THE WEST BEHIND DEPARTED LOW SHOULD ALLOW SNOW RATIOS TO INCREASE THROUGH TONIGHT TO NEAR 20/1 WEST AND NCNTRL AS NOTED ON BUFKIT SNDG DATA. THE INCREASED INSTABILITY WITH COLDER OVER-WATER TEMPS ALONG WITH DEEPER MOISTURE AND ENHANCEMENT POTENTIAL FROM APPROACHING MID-LVL TROUGH FM THE NRN PLAINS SHOULD ALLOW FOR AN UPTICK IN LAKE EFFECT SNOW AMTS TONIGHT INTO MONDAY FOR FAR WEST AND NCNTRL COUNTIES. NO BIG CHANGES EXPECTED WITH FORECAST AS LES ADVISORIES STILL LOOK GOOD FOR GOGEBIC-ONTONAGON AND BARAGA-MARQUETTE COUNTIES HIGHLIGHTING STORM TOTAL SNOWFALL AMOUNTS POSSIBLY APPROACHING A FOOT OVER THE HIGHER TERRAIN AREAS FROM NORTH OF KIWD TO THE PORCUPINE MOUNTAINS AND FROM HERMAN THROUGH HURON MOUNTAINS TO NEGAUNEE. BIGGEST CONCERN OVER THE WRN COUNTIES IS THAT LES AMOUNTS MAY BE LESS THAN ORIGINALLY EXPECTED IN IWD AREA AS MODELS APPEAR TO BE HANGING ON TO THE NE FLOW A BIT LONGER THROUGH TONIGHT WHICH MAY PUSH THE BEST LOW-LVL CONVERGENCE AND THUS DOMINANT LES BANDS WEST OF KIWD. LES SHOULD EVENTUALLY PICK UP OVER THE FAR WEST BY MONDAY AFTERNOON AS WINDS BACK FM NE TO NNE BUT INITIAL LACK OF MODERATE SNOW COULD LIMIT STORM AMOUNTS IN THE KIWD AREA TO CLOSER TO 8 INCHES. PORCUPINE MOUNTAINS COULD STILL SEE TOTALS APPROACHING A FOOT THROUGH THE EVENT. AS MID-LVL TROUGH AXIS MOVES OVERHEAD LATE MON AFTERNOON...MODELS SHOW Q-VECT CONV DIMINISHING WHICH SHOULD LIMIT ENHANCEMENT POTENTIAL AT THAT TIME AND ALLOW FOR LES TO SLOWLY DIMINISH FROM WEST TO EAST INTO MON EVENING. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 259 PM EST SUN DEC 22 2013 THE UPPER TROUGH AXIS WILL BE OVER CENTRAL UPPER MI AT 00Z TUE...EXITING E BY 06Z TUE AS AN UPPER RIDGE MOVES TOWARD THE CWA FROM THE NW. THE RIDGE AXIS MOVES TO THE CENTRAL CWA BY 00Z WED. THE 12Z/22 NAM IS NOT AS STRONG OR AS FAST WITH THE RIDGE THAN THE GFS/ECMWF/GLOBAL GEM...AND ALSO HAS THE SFC TROUGH BEING STRONGER WITH A MESO LOW OVER SCENTRAL LAKE SUPERIOR EVEN AFTER THE RIDGE MOVES OVER. THINK THE SFC TROUGH WILL BE STRONGER THAN THE LARGER SCALE MODELS SHOW IT...BUT NOT AS STRONG AS THE NAM. EXPECT ONGOING LES AT THE START OF THE PERIOD TO TAPER OFF THROUGH MON NIGHT INTO TUE MORNING. GENERALLY...2-4 INCHES OF SNOW CAN BE EXPECTED MON NIGHT OVER THE HIGHER TERRAIN OF NCENTRAL UPPER MI...WITH OTHER AREAS NEAR LAKE SUPERIOR SEEING 1-2 INCHES. MODELS ARE IN GOOD AGREEMENT THAT A SHORTWAVE WILL BRING A QUICK /6 HOUR OR LESS DURATION/ COUPLE OF INCHES OF SNOW TO WEST AND CENTRAL UPPER MI TUE NIGHT. AS THE SHORTWAVE MOVES ACROSS THE ERN U.P. CHRISTMAS MORNING...SSE LOW LEVEL WINDS AND 850MB TEMPS AROUND -14C WILL ALLOW FOR LAKE ENHANCEMENT OFF LAKE MICHIGAN. COULD SEE ADVISORY LEVEL SNOW AMOUNTS IN EXCESS OF 6 INCHES IN AROUND 12 HOURS. COLDER AIR COMES IN WITH NW LOW LEVEL WINDS LATER CHRISTMAS DAY...LEADING TO NW WIND LES THAT WILL PERSIST UNTIL A RIDGE PASSES THU NIGHT INTO FRI. THE CWA MAY SEE ADDITIONAL LIGHT AREA WIDE SNOW FROM A SHORTWAVE THAT SOME MODELS SHOW MOVING THROUGH...BUT IF...WHEN AND WHERE ARE QUESTIONS THAT MAKE THIS VERY UNCERTAIN. ALTHOUGH CONFIDENCE DECREASES FARTHER OUT IN THE FORECAST PERIOD...MODELS DO GENERALLY AGREE ON MODERATING TEMPERATURES ON SAT AS A SHORTWAVE MOVES THROUGH THE REGION...WITH TEMPERATURES TURNING COLDER FOR NEXT SUN. RAN WITH A GENERAL CONSENSUS OF MODEL GUIDANCE FOR THIS PART OF THE FORECAST. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1252 PM EST SUN DEC 22 2013 WITH NE WINDS AND PLENTY OF LOW LEVEL MOISTURE AVAILABLE...MVFR CIGS SHOULD PREVAIL AT ALL THREE TAF SITES THROUGH MUCH OF THE FCST PD. VISIBILITIES HAVE DECREASED TO IFR TODAY AT KCMX AND KSAW WITH THE FINE-FLAKED SYSTEM SNOW SPREADING INTO THE REGION. AS SYSTEM SNOW EXITS EAST THIS EVENING EXPECT A TRANSITION TO LAKE EFFECT SNOW ACROSS THE AREA. PREVAILING VSBYS SHOULD REMAIN IN THE IFR RANGE ESPECIALLY AS FLOW BACKS FROM NE TO NNE ON MONDAY MORNING. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 259 PM EST SUN DEC 22 2013 NORTHEAST WINDS UP TO 30 KNOTS OVER WEST AND NORTH CENTRAL LAKE SUPERIOR WILL GRADUALLY DIMINISH THROUGH THE AFTERNOON/EARLY EVENING ...BUT GUSTS TO AROUND 25 KNOTS WILL CONTINUE INTO MONDAY. THESE WINDS ALONG WITH FALLING TEMPS THIS AFTERNOON/EVENING WILL PRODUCE HEAVY FREEZING SPRAY TODAY THROUGH MONDAY WHEN THE WINDS FINALLY SLACKEN. WINDS BEGIN TO INCREASE ONCE AGAIN TUESDAY NIGHT INTO WEDNESDAY AS THE NEXT SYSTEM PASSES TO THE NORTH OF LAKE SUPERIOR. GALE FORCE GUSTS OVER 35 KNOTS ARE POSSIBLE OVER EASTERN LAKE SUPERIOR TUESDAY NIGHT AND EARLY WEDNESDAY MORNING. WINDS GRADUALLY DIMINISH ONCE AGAIN WEDNESDAY NIGHT INTO FRIDAY AS HIGH PRESSURE STARTS TO BUILD INTO THE REGION. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... WINTER WEATHER ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR MIZ007- 013-014-085. LAKE EFFECT SNOW ADVISORY UNTIL MIDNIGHT EST /11 PM CST/ MONDAY NIGHT FOR MIZ002-009. WINTER WEATHER ADVISORY UNTIL 2 PM CST THIS AFTERNOON FOR MIZ012. LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST TUESDAY FOR MIZ004-005. LAKE SUPERIOR... HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST /NOON CST/ MONDAY FOR LSZ162-263-264. LAKE MICHIGAN... NONE. && $$ SHORT TERM...VOSS LONG TERM...TITUS AVIATION...VOSS MARINE...VOSS
AREA FORECAST DISCUSSION
NWS GAYLORD MI
202 AM EST SUN DEC 22 2013 .SYNOPSIS... ISSUED AT 411 PM EST SAT DEC 21 2013 AN AREA OF LOW PRESSURE WILL LIFT THROUGH THE OHIO VALLEY AND INTO SOUTHERN ONTARIO TONIGHT THROUGH SUNDAY. THIS WILL GENERATE PERIODS OF SNOW ACROSS NORTHERN MICHIGAN...WITH SOME MIXED PRECIPITATION IN MID AND SOUTHERN MICHIGAN THROUGH SUNDAY. COLD AIR WILL FILTER BACK INTO THE GREAT LAKES MONDAY AND TUESDAY AS THIS SYSTEM EXITS EAST...GENERATING SOME LAKE EFFECT SNOW ACROSS PARTS OF NORTHERN MICHIGAN. CHANCES FOR SNOW CONTINUES CHRISTMAS DAY THROUGH THE END OF THE WORK WEEK...AS A SERIES OF WEAK CLIPPERS PUSH ACROSS THE GREAT LAKES. && .UPDATE... ISSUED AT 158 AM EST SUN DEC 22 2013 WEATHER EVENT STARTING TO UNFOLD. INITIAL NRN EDGE OF OF PRECIPITATION SHIELD FROM SFC LOW MOVING THROUGH NORTH OF THE OHIO VALLEY...HAS WORKED INTO THE SE HALF OF THE CWA. THIS SNOW WAS ALREADY LIGHT...AND WILL LIGHTEN MORE AND MAYBE EVEN STOP FOR JUST A BIT OVER THE NEXT HOUR OR SO. THEN...NEXT ROUND OF DEVELOPING PRECIPITATION FROM SW LOWER AND SRN LAKE MICHIGAN RACE IN 09-12Z. THE LIGHT NATURE OF THE SNOW IS DUE IN PART TO JUST WEAK DEEP LAYER FORCING ATTM...AND POSSIBLY LESS LOW LEVEL WARM/MOIST ADVECTION...STOLEN TO SOME DEGREE FROM EARLIER CONVECTIVE LINE NOW MOVING INTO THE APPALACHIANS. THE MAIN SHOW IS STILL SET FOR LATER TONIGHT INTO TOMORROW MORNING. STRONGEST FORCING FROM SHORTWAVE LIFTING INTO THE KANSAS CITY AREA...NOW STARTING TO LIFT INTO NW IL/SRN WI...AND SNOW WAS DEVELOPING/EXPANDING. WHILE LATEST HI RES HRRR IS CURIOUSLY SUGGESTING A LULL 11-15Z...THAT IS WHEN THE STRONGEST SHORTWAVE FORCING/DEFORMATION WILL START TO MOVE IN. THIS IS WHEN IT SHOULD BE DEVELOPING THE MAIN SNOW OVERHEAD. HARDEST FALLING SNOW WILL BE 13Z-18Z IN NRN LOWER...AND 16-20Z ACROSS EASTERN UPPER. FCST SOUNDINGS STILL DO SUGGEST A MIX WITH SLEET MAYBE NEAR THE SAG BAY THROUGH 13Z...BUT THEN THINGS SHOULD BE ALL SNOW EVERYWHERE FOR TODAY. FORECAST IN GOOD SHAPE...SNOW AMOUNTS AND QPF LOOK GOOD. NO REAL SIGNIFICANT UPDATES. WILL BE SENDING OUT SPSAPX OVERNIGHT WHEN HEAVIER SNOWS START TO MOVE IN. UPDATE ISSUED AT 1011 PM EST SAT DEC 21 2013 SNOW HAS BACKED UP INTO ARENAC AND PARTS OF GLADWIN AND IOSCO COUNTIES. THE NEXT NORTHWARD PUSH IS STARTING TO TAKE SHAPE OVER THE SOUTH HALF OF LAKE MI. THAT SAID...MOST GRID FINE-TUNING TO THIS POINT INVOLVES SLOWING THE NORTHWARD PROGRESS OF SNOW INTO NORTHERN MI. ONSET HAS BEEN SLOWED BY A COUPLE OF HOURS IN MUCH OF NORTHERN MI...WITH PRECIP HELD BACK BY DRY LOW/MID-LEVEL AIR FEEDING INTO THE REGION FROM THE NE (NOTING THAT EASTERN UPPER MI IS CLEAR BELOW CIRRUS LEVEL). TO COUNTER THAT...SNOW INTENSITY MAY BE MORE IMPRESSIVE LATE TONIGHT (AFTER 08Z) THAN EARLIER PROGGED. STORM-RELATIVE EASTERLY FLOW IN THE COLD CONVEYOR BELT REALLY TAKES OFF AFTER 06Z...THANKS TO TIGHTENING PRESSURE/HEIGHT GRADIENTS OVER LAKE HURON AND SOUTHERN ONTARIO...AND A SLIGHT ACCELERATION IN STORM MOTION TO THE NE. DESPITE THE SLOWER ONSET...AM CONCERNED THAT QPF/SNOW AMOUNTS MAY BE A BIT LOW IN PARTS OF N CENTRAL/NE LOWER...ESPECIALLY FROM GRAYLING TO APN. COULD STAND TO ADD ANOTHER INCH OF ACCUMS TO THESE AREAS FOR THE OVERNIGHT (THOUGH ELIMINATING THE SAME FROM THE DAYTIME SUNDAY FORECAST...NOT CHANGING OVERALL SNOW AMOUNTS MUCH). NO CHANGES TO OUR PRESENT HEADLINES. NEW WSW WILL LIKELY BE ISSUED BETWEEN 11 PM AND MIDNIGHT TO FRESHEN TIMING. UPDATE ISSUED AT 717 PM EST SAT DEC 21 2013 998MB LOW PRESSURE IN THE MID MS VALLEY THIS EVENING. A WARM FRONT AHEAD OF THE LOW HAS LIFTED PAST LOUISVILLE...CINCY AND COLUMBUS. WARM CONVEYOR BELT ARCS FROM SW INDIANA TOWARD LAKES ERIE AND ONTARIO. THE COLD CONVEYOR BELT POKES SW-WARD FROM SOUTHERN LOWER MI TO NORTHERN MIZZOU...AND IT IS THIS PART OF THE STORM THAT WILL LIFT NORTHWARD INTO NORTHERN MI AS THE SURFACE LOW MOVES NE. SNOW WILL DEVELOP IN FAR SE SECTIONS LATE THIS EVENING...AND EXPAND NORTHWARD OVERNIGHT. SMALL ADJUSTMENTS TO PRECIP TIMING...NO MAJOR CHANGES NEEDED. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 411 PM EST SAT DEC 21 2013 INVERTED SFC TROUGH STRETCHES FROM THE WESTERN GULF UP THROUGH NEW ENGLAND WITH WIDESPREAD PRECIP UNDERWAY ALONG THE CONVERGENCE AXIS. STRONG SHORT WAVE MOVING ACROSS NRN TEXAS AND ABOUT TO SWING UP THROUGH THE CENTRAL PLAINS AND INTO THE MIDWEST TONIGHT...THEN UP THROUGH LOWER MICHIGAN DURING THE DAY SUNDAY. SFC LOW ON TRACK TO SPIN UP ALONG THE EXISTING BAROCLINIC ZONE AND ADVANCE UP THROUGH NRN OHIO/FAR SE LOWER MICHIGAN EARLY SUNDAY MORNING BEFORE KICKING INTO THE EASTERN GREAT LAKES THROUGH THE DAY. ONGOING WARM CONVEYOR PRECIP TO OUR SOUTH WILL INITIALLY PUSH UP INTO PARTS OF NRN LOWER MICHIGAN LATER TONIGHT BEFORE GETTING PINCHED OFF AND KICKED INTO THE EASTERN LAKES SUNDAY. HOWEVER...HEAVIER WRAP AROUND/DEFORMATION SNOW ON THE BACKSIDE OF THE DEPARTING LOW IS OUR BIGGEST CONCERN THROUGH THE DAY SUNDAY. PERIOD OF HEAVIEST SNOW LOOKING TO OCCUR BETWEEN 15Z AND 21Z AS THE MID LEVEL SHORT WAVE SWINGS UP THROUGH LOWER MICHIGAN. VERY LITTLE HAS CHANGED WITH THE ABOVE SCENARIO AMONGST GUIDANCE SOLUTIONS OVER THE LAST DAY...AND EVEN THE NAM SOLUTION (WHICH HAS HAD THE FURTHEST NORTHERN TRACK) HAS ADJUSTED BACK SOUTH WITH ITS 18Z RUN. SO ALL GUIDANCE SOURCES CONTINUE TO GIVE NRN LOWER MICHIGAN A MAINLY SNOW...WITH ONLY AN OUTSIDE CHANCE OF SOME SLEET OVER THE FAR SE COUNTIES TOWARD SAGINAW BAY LATER TONIGHT. CONSENSUS QPF FORECAST DRAGS HEAVIEST QPF BULLSEYE RIGHT UP ACROSS NRN LOWER MICHIGAN LATE TONIGHT AND THROUGH THE DAY SUNDAY...POSSIBLY SKIMMING FAR EASTERN UPPER MICHIGAN WITH SOME HEAVIER SNOW ON SUNDAY. AS FAR AS SNOW AMOUNTS GO...BASICALLY HAVE A 2 PERIOD (TONIGHT AND TOMORROW) COMBINED TOTAL OF 0.4 TO 0.6 INCHES LIQUID OVER NRN LOWER MICHIGAN...0.2 TO 0.4 INCHES IN EASTERN UPPER MICHIGAN. SNOW ACCUMULATIONS WILL OF COURSE BE DEPENDENT ON JUST WHAT SNOW:WATER RATIOS ARE REALIZED. HAVE <10:1 RATIOS OVER THE S/SE COUNTIES AND 10-15:1 FOR NRN HALF OF THE CWA...YIELDING A NICE 4 TO 7 INCHES SWEET SPOT CENTERED UP THROUGH NRN LOWER MICHIGAN. NOT MUCH DIFFERENT WITH WHAT WE HAVE BEEN FORECASTING FOR THE LAST DAY OR TWO. PLAN NO CHANGES TO THE CURRENT WINTER WEATHER ADVISORIES. HAVE ALREADY ADDED EASTERN UPPER MICHIGAN INTO AN ADVISORY FOR SOME BEEFIER SNOWFALL OVER THE EASTERN PART OF THOSE COUNTIES. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 411 PM EST SAT DEC 21 2013 LET THE COLD AND SNOW CONTINUE! REALLY NO BIG SIGNS OF ANY BREAK FROM THE ONGOING STRETCH OF COLD/SNOWY WEATHER THE NEXT 7 DAYS... WITH PERSISTENT GULF OF ALASKA RIDGING FAVORING DOWNSTREAM TROUGH RENEWAL THROUGH THE CENTRAL AND EASTERN PARTS OF THE COUNTRY. THAT WILL KEEP THE COLD AIR FLOWING OUT OF CANADA...WITH A COUPLE REINFORCING SHOTS OF CHILLY WEATHER EXPECTED AS STRONGER UPPER WAVES/CLIPPER SYSTEMS TRAVERSE THE NORTHERN LAKES. GUIDANCE TRENDS THE PAST FEW DAYS HAVE INCREASED CONFIDENCE ON THE TIMING OF SUCH FEATURES...WITH ONE EXPECTED TO ARRIVE ON CHRISTMAS DAY ITSELF...AND ANOTHER ONE THE DAY AFTER...SANDWICHED IN BETWEEN MORE TYPICAL LAKE EFFECT CONDITIONS BOTH EARLY AND LATE IN THE HOLIDAY WEEK. ALL THE WHILE...TEMPERATURES THROUGH MUCH OF THE WEEK LOOK TO REMAIN WELL BELOW NORMAL...PARTICULARLY MONDAY INTO TUESDAY. STARTING THIS WHOLE THING OFF...THE LAST VESTIGES OF HEAVIER SNOW SHOULD BE EXITING THE REGION BEFORE 00Z...AS THE STRONGER SOUTHERN STREAM WAVE SHEARS OUT INTO ONTARIO AND DYNAMIC FORCING GOES TO ZERO. THAT WILL LEAVE NORTHERN MICHIGAN IN A RATHER NEBULOUS REGIME SUNDAY NIGHT INTO PARTS OF MONDAY...AS THE PRESSURE GRADIENT WEAKENS CONSIDERABLY WHILE A STRONGER NORTHERN STREAM WAVE CARVES OUT OVER THE WESTERN LAKES. MEAN NORTHERLY FLOW IN THE WAKE OF THE INITIAL DEPARTING SYSTEM SHOULD DRAW IN SOME QUITE CHILLY BUT SHALLOW ARCTIC AIR RIGHT ON THROUGH THE DAY ON MONDAY...INTERACTING WITH THE BAGGY PRESSURE GRADIENT TO PERHAPS PRODUCE A COUPLE OF MESOSCALE LAKE VORTICES...NONE OF WHICH ARE HIGH CONFIDENCE AT THIS POINT. HOWEVER...THERE HAVE BEEN PERSISTENT HINTS OF A STRONGER CONVERGENCE BAND TAKING SHAPE DOWNSTATE WHERE THE LOW LEVEL CYCLONIC FLOW LOOKS TO REMAIN SHARPEST...ALL WHILE DRIER SUB-850MB AIR ADVECTS SOUTHWARD THROUGH NORTHERN MICHIGAN. HONESTLY...JUST A VERY LOW CONFIDENCE FORECAST FOR HOW THINGS WILL ULTIMATELY PLAY OUT...BUT DOES LOOK LIKE THERE COULD BE SOME PESKY LINGERING LIGHT SNOWS RIGHT ON THROUGH SUNDAY NIGHT AS THE COLUMN REMAINS NEARLY SATURATED...WITH PERHAPS EVEN A LITTLE FLUFF TO THE SNOW WITH AN EVER-DEEPENING DGZ. A STRONGER SOUTHERN MID-LAKE MICHIGAN CONVERGENCE BAND SHOULD GET TURNED ASHORE INTO MONDAY AFTERNOON/EVENING WITH THE APPROACH OF THE STRONGER SHORTWAVE ALOFT...BUT THE SETUP FOR NORTHERN MICHIGAN LOOKS MUCH LESS IMPRESSIVE...WITH MEAN LOW LEVEL NORTHERLY FLOW FAVORING SNOW SHOWER COVERAGE ONLY NEAR THE LAKESHORES...AS THE LOW LEVELS DRY EVEN FURTHER. IN FACT...THAT SETUP MAY EVEN LEAD TO SOME CLEARING LATER MONDAY NIGHT INTO TUESDAY FOR INLAND AREAS...WITH TUESDAY/CHRISTMAS EVE LOOKING DOWNRIGHT COLD AS SHALLOW ARCTIC AIR RESIDES OVERHEAD. SHOULD SEE HIGHS NO BETTER THAN THE MID TEENS FOR MOST AREAS...WITH SOME SPOTS (HIGHER TERRAIN/EASTERN UPPER) MORE THAN LIKELY STRUGGLING THROUGH THE UPPER SINGLE DIGITS. CHRISTMAS DAY LOOKING A LITTLE MORE SNOWY FOR MOST AREAS...WITH CONTINUED HINTS THAT ANOTHER DECENT NORTHERN STREAM WAVE WILL DROP INTO THE AREA. AT THE MOMENT...GUIDANCE IS PEGGING A MODERATE SHOT OF LOW/MID LEVEL WARM ADVECTION ASCENT...SUFFICIENT TO BRING A ROUND OF SYNOPTIC SNOW TO MOST OF NORTHERN MICHIGAN. A VERY PRELIMINARY ACCUMULATION GUESS WOULD BE A QUICK INCH OR TWO BASED ON THE FAST-HITTING NATURE OF THE SYSTEM...BUT OF COURSE LOTS CAN CHANGE. THE EXCEPTION SHOULD BE SOUTHWEST FLOW AREAS WITH A QUITE COLD PRE-SYSTEM AIRMASS IN PLACE...AND RATHER STRONG SUB-800MB SOUTHWEST FLOW PROGGED. DURATION OF THAT FLOW IS ALSO MODELED AROUND 18 HOURS...SO NOT IMPOSSIBLE SOME SPOTS COULD SEE SOME HEAVY TOTALS. CONFIDENCE A LITTLE LOWER WITH ANOTHER SYSTEM EXPECTED ON THURSDAY... AS A STRONGER NORTHERN STREAM WAVE DROPS INTO GREAT LAKES. ECMWF HAS FOR SEVERAL DAYS BEEN THE STRONGEST OUTLIER...WHICH WOULD SUPPORT A MODEST LAKE ENHANCEMENT EVENT ACROSS PARTS OF THE AREA. GFS HAS BEEN TRENDING THIS WAY SLOWLY...WITH WHAT LOOKS (ON PAPER AT LEAST) LIKE A FAIRLY GOOD SETUP FOR LAKE SNOWS AS STRONG HIGH PRESSURE FOLDS AROUND THE GREAT LAKES...WHILE AMBIENT THERMAL TROUGHING HANGS FIRM OVER THE WATERS...FAVORING A TIGHT CYCLONIC CURVATURE TO THE LOW LEVEL WIND FIELDS. AIRMASS ON ALL GUIDANCE IS PLENTY COLD...WITH H8 TEMPS AVERAGING -17C...SO SOMETHING TO WATCH CLOSELY AS THERE IS SOME SNEAKY POTENTIAL WITH THIS ONE. OTHERWISE...LOOKS LIKE THINGS MAY GET A LITTLE MORE QUIET AND PERHAPS SLIGHTLY WARMER TOWARD NEXT WEEKEND AS A LARGE EXPANSE OF HIGH PRESSURE PROGGED BY MOST GUIDANCE TO BUILD OVER MUCH OF THE EASTERN HALF OF THE CONUS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1152 PM EST SAT DEC 21 2013 SNOW ARRIVES OVERNIGHT...WITH IFR CONDITIONS LASTING THRU EARLY SUNDAY AFTERNOON. LOW PRESSURE BETWEEN INDY AND LOUISVILLE WILL MOVE NE...REACHING TOLEDO BY SUNDAY MORNING...AND NE NY STATE BY EVENING. SNOW ALONG THE N AND NW FLANK OF THE LOW WILL ARRIVE JUST AFTER 06Z TONIGHT. VSBYS/CIGS WILL QUICKLY LOWER TO IFR...AND WILL PROBABLY BE LIFR AT TIMES UP UNTIL SNOW DIMINISHES TOWARD 18Z. LIGHTER SHSN WILL LINGER INTO SUNDAY EVENING. NE-ERLY WINDS THRU MOST OF THE FORECAST...BACKING A BIT MORE NORTHERLY SUNDAY AFTERNOON. GUSTY AT APN...WITH SOME BLSN ISSUES. WIND BECOMING LIGHT SUNDAY NIGHT. && .MARINE... ISSUED AT 411 PM EST SAT DEC 21 2013 EASTERLY WINDS WILL INCREASE ACROSS NORTHERN MICHIGAN TONIGHT AND PERSIST THROUGH SUNDAY AS A WINTER STORM SYSTEM TRACKS THROUGH THE LOWER GREAT LAKES. GUSTS OF 20 TO 30 KNOTS WILL BE MOST COMMON ALTHOUGH FEW GUSTS REACHING GALE FORCE ON LAKE HURON ARE NOT OUT OF THE QUESTION. WINDS BACK NORTHERLY AND DIMINISH LATER SUNDAY AND SUNDAY NIGHT AS THE LOW TRACKS INTO THE EASTERN GREAT LAKES. && .APX WATCHES/WARNINGS/ADVISORIES... MI...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ016>036-041-042. WINTER WEATHER ADVISORY FROM 7 AM THIS MORNING TO 7 PM EST THIS EVENING FOR MIZ008-015. LH...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR LHZ345>347. GALE WARNING UNTIL 4 PM EST THIS AFTERNOON FOR LHZ348-349. LM...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR LMZ323-341- 342-344>346. LS...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR LSZ321-322. && $$ UPDATE...SD SYNOPSIS...KB SHORT TERM...BA LONG TERM...DL AVIATION...JZ MARINE...BA
AREA FORECAST DISCUSSION
NWS DULUTH MN
1142 PM CST SAT DEC 21 2013 .UPDATE... ISSUED AT 904 PM CST SAT DEC 21 2013 LIGHT SNOW OR FLURRIES CONTINUED TO FALL OVER MUCH OF NORTHEAST MINNESOTA THIS EVENING...WITH A STRONGER LAKE SNOW BAND NOW EVIDENT JUST EAST OF THE TWIN PORTS MOVING WEST. WE DON`T PLAN ON MAKING ANY CHANGES TO THE LAKE SNOW ADVISORY ALONG THE SOUTH SHORE AT THIS TIME. CONSIDERABLE SHEAR EXISTS IN THE SURFACE TO 850MB LAYER...WITH SURFACE/925MB WINDS NORTH TO NORTHEAST...AND THE 850MB FLOW EASTERLY. THIS IS NOT OUR TYPICAL SET UP FOR LES AND AT THIS POINT...THE PLUMES ARE DOMINATED BY THE 850MB FLOW. SIGNIFICANT SNOWFALL STILL LOOKS ON TRACK FOR THE SOUTH SHORE...AND LATER SHIFTS MAY NEED TO UPGRADE PORTIONS OF THE ADVISORY TO A WARNING. WE ARE ALSO SEEING THE AFFECTS OF THE NORTHERN STREAM WAVE WITH THE INVERTED TROUGH SHARPENING AND PRESSURE RISE MINIMUM OR SOME WEAK FALLS OCCURRING ALONG THE INVERTED TROUGH. WEAK RETURNS ARE ALSO EVIDENT ON AREA RADARS IN LINE WITH THE NAM. AS THIS LARGER SCALE LIFT INCREASES OVERNIGHT...WE EXPECT LIGHT SNOW TO INCREASE IN COVERAGE ACROSS THE REGION...AND FOR THE LAKE SNOW BANDS TO INCREASE AS WELL. WE WILL CONTINUE TO MONITOR THE LATEST DATA AND MAY HAVE TO CONSIDER AN ADVISORY FOR THE TWIN PORTS/COASTAL LAKE/CARLTON COUNTY AREAS INTO AT LEAST SUNDAY OR SUNDAY EVENING AS WE WILL BE UNDER THE INVERTED TROUGH AND THE EASTERLY 850MB FLOW. SNOWFALL AMOUNTS SO FAR HAVE BEEN LIGHT...WITH LUTSEN/SILVER BAY REPORTING AN INCH AS OF LATE AFTERNOON...AND DULUTH ONLY A TENTH OR TWO AS OF MID EVENING. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 330 PM CST SAT DEC 21 2013 AT 330 PM...IT WAS FAIRLY QUIET ACROSS THE NORTHLAND. THERE CONTINUED TO BE FLURRIES AND ISOLATED SNOW SHOWERS FOR MOST AREAS. THE EXCEPTION WAS ALONG THE NORTH SHORE OF LAKE SUPERIOR...WHERE AN INCH OF SNOW FELL THIS AFTERNOON IN COASTAL LAKE AND COOK COUNTIES. TEMPERATURES RANGED FROM THE SINGLE DIGITS AT INTERNATIONAL FALLS TO THE 20S IN NORTHWESTERN WISCONSIN. THE HIGH RESOLUTION MODEL DATA INDICATES THAT THERE WILL BE PERIODS OF LAKE EFFECT SNOW CONTINUING ACROSS WESTERN LAKE SUPERIOR TONIGHT. THE HRRR AND WRF INDICATE A CONVERGENT BAND OF SNOW ACROSS THE WESTERN PORTION OF THE LAKE...WITH SEVERAL WAVES IN THE LINE. THIS WILL RESULT IN LOCAL SWIRLS AND CONSIDERABLE VARIABILITY TO THE LAKE EFFECT OVERNIGHT. STRONG NORTHEAST WINDS AT ROCK OF AGES CONTINUED ON ONE SIDE OF THIS BAND...WITH GUSTY SOUTHERLY WINDS AT DEVILS ISLAND ON THE OTHER SIDE. WINDS WILL OVERWHELMINGLY BECOME NORTHEAST TO NORTH OVERNIGHT AND ON SUNDAY...WHILE THE OTHER SYSTEM MOVES IN FROM THE WEST. THE RESULT WILL BE A PHASING OF THE MOISTURE ACROSS THE WESTERN GREAT LAKES. OVERALL LOOKING FOR AN INCH OR TWO FOR MUCH OF THE AREA TONIGHT...AND ANOTHER INCH OR TWO ON SUNDAY. THE EXCEPTION WILL BE ACROSS THE SOUTH SHORE OF LAKE SUPERIOR. WE COULD HAVE HANDLED THIS EVENT IN A COUPLE WAYS REGARDING HEADLINES BUT AFTER EXTENSIVE DISCUSSION...WE DECIDED TO ISSUE A LAKE EFFECT SNOW ADVISORY FOR THE PERIOD TONIGHT THROUGH MONDAY...RATHER THAN HAVING A LARGE LAKE EFFECT SNOW WARNING OUT FOR 5 PERIODS...WITH GENERALLY ADVISORY TYPE SNOW FOR MOST OF THE PERIODS. THINK THERE IS A FAIR CHANCE WE MAY NEED TO UPGRADE TO A WARNING FOR MONDAY. BUT FOR TONIGHT AND SUNDAY...WE ARE LOOKING AT TRANSITIONAL LAKE EFFECT SNOWFALL BANDS...SWIRLS AND CONVERGENCE BANDS...AND THE RESULT SHOULD BE WIDESPREAD ADVISORY TYPE SNOW. WE ALSO COULD HAVE ISSUED THE ADVISORY FOR TONIGHT THROUGH SUNDAY NIGHT...AND MAINTAINED THE WATCH FOR MONDAY...BUT FOR SIMPLICITY SAKE...DECIDED TO HOLD OFF ON THAT FOR NOW. THE MAIN FOCUS FOR A POTENTIAL WARNING ON MONDAY WOULD BE THE GOGEBIC RANGE. WE DO AGREE THAT ADDED UP OVER 4-5 PERIODS...THE AMOUNTS COULD BE IMPRESSIVE...SOME ON THE ORDER OF A FOOT OR MORE IN THE GOGEBIC RANGE. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 345 PM CST SAT DEC 21 2013 FIRST CONCERN IN EXTENDED IS ON LONG DURATION LAKE EFFECT SNOW THAT WILL PERSIST THROUGH MONDAY EVENING. THE 12Z RUNS OF THE GFS/ECM/NAM ARE IN AGREEMENT THAT THE H85-H50 TROUGH AXIS PASSES OVER WRN LAKE SUPERIOR DURING THE DAY MONDAY...BRINGING A STRONG PUSH OF CAA WITH H85 TEMPS FALLING INTO THE NEGATIVE 20S AND BOUNDARY LAYER WINDS BACKING OUT OF THE NORTH THEN NORTHWEST. ALTHOUGH CONDITIONS REMAIN FAVORABLE FOR A FEW INCHES OF LIGHT SNOW ALONG THE SOUTH SHORE OF LAKE SUPERIOR SUN NIGHT...LAPSE RATES/INVERSION HTS SIGNIFICANTLY INCREASE MONDAY DUE TO THE ARRIVAL OF THE COLD AIR. HAVE INCREASED QPF/SN AMOUNTS MONDAY TO ACCOUNT FOR THE HIGHER INSTABILITY. FOCUS TURNS TO ELONGATED VORT MAX THAT DROPS OUT OF CANADA AND ACROSS THE NRN PLAINS TUESDAY/WEDNESDAY. LATEST ECM/GFS BOTH SUGGEST THE DIGGING WAVE...WITH SFC REFLECTION COLD FRONT...SWEEPS ACROSS THE NORTHLAND DURING THE CHRISTMAS HOLIDAY. CURRENT TIMING WOULD FAVOR A FEW INCHES OF SNOW OVER MUCH OF THE REGION TUESDAY NIGHT. HOWEVER...IF TIMING SLOWS...ITS POSSIBLE THE COLD FRONT/LIGHT SNOW HOLD OFF UNTIL CHRISTMAS DAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1141 PM CST SAT DEC 21 2013 WIDESPREAD MVFR CEILINGS...WITH SOME LOCALIZED IFR...COVERED MUCH OF THE REGION LATE THIS EVENING. SNOW CONTINUED AROUND LAKE SUPERIOR...WITH SOME FLURRIES ELSEWHERE. A NORTHERN STREAM SHORTWAVE WILL CAUSE AN INVERTED TROUGH TO STRENGTHEN ACROSS THE REGION AND CAUSE LIGHT SNOW TO EXPAND ACROSS INLAND AREAS OF THE NORTHLAND...WITH THE LAKE EFFECT SNOW CONTINUING AROUND THE LAKE. MVFR AND SOME IFR VSBYS WILL BECOME MORE WIDESPREAD AS THE NIGHT PROGRESSES...LASTING THROUGH MOST OF SUNDAY INTO THE EARLY EVENING HOURS. && .PRELIMINARY POINT TEMPS/POPS... DLH 8 13 -8 1 / 90 90 70 20 INL -9 2 -20 -5 / 40 50 20 10 BRD 4 11 -13 -2 / 70 90 50 10 HYR 11 21 1 6 / 60 90 80 70 ASX 11 21 9 9 / 80 90 90 80 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...LAKE EFFECT SNOW ADVISORY UNTIL 6 PM CST MONDAY FOR WIZ001>004. LS...SMALL CRAFT ADVISORY UNTIL 4 AM CST MONDAY FOR LSZ121-140>148. && $$ UPDATE...MELDE SHORT TERM...DAP LONG TERM...GRANING AVIATION...MELDE
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
842 PM MST MON DEC 23 2013 .UPDATE... WE HAVE ISSUED A FREEZING RAIN ADVISORY FOR SOUTHEASTERN MT UNTIL 13 UTC. RADAR IMAGERY SHOWS PRECIPITATION INCREASING OVER CENTRAL MT AS OF 0330 UTC...AND NEARLY ALL GUIDANCE SUGGESTS THE BATCH OF MOISTURE WILL CROSS SOUTHEASTERN MT BETWEEN 06 AND 12 UTC. A WARM LAYER ALOFT IS SHOWN ON FORECAST SOUNDINGS AND LOOKS TO BE ENOUGH TO MELT HYDROMETEORS...AND THEN ALLOW REFREEZE AT THE GROUND. THE NEAR-SURFACE AIR TEMPERATURES WILL BE AT OR EVEN HIGHER THAN 32 F IN SOME AREAS OVERNIGHT...BUT THE ROAD AND SIDEWALK SURFACES LOOK TO STAY BELOW FREEZING...SO EVEN IF LIQUID REACHES THE SURFACE IT WILL END UP FREEZING ON CONTACT. THE SREF OUTPUT FROM BOTH 15 AND 21 UTC LENDS CREDENCE TO THIS SCENARIO WITH 50-70 PERCENT CHANCES OF FREEZING RAIN /OR RAIN...WHICH IMPLIES FREEZING RAIN GIVEN THE STATE OF THE ROAD TEMPERATURES/. THE PRECIPITATION-TYPE ALGORITHM FROM NUMEROUS RECENT HRRR RUNS ALSO STRONGLY SUPPORTS THIS IDEA. THE ONLY PLACE WHERE THE MAGNITUDE OF WARM AIR ALOFT IS UNCERTAIN IS OVER FALLON COUNTY...WHERE SLEET OR A MIX TYPES IS POSSIBLE IF YOU TAKE GUIDANCE AT FACE VALUE. STILL...THERE WAS ENOUGH RISK TO INCLUDE THEM IN THE ADVISORY...THOUGH PROBABILITIES FOR FREEZING RAIN ARE RELATIVELY LOWER THAN FOR AREAS WEST AND SOUTH OF BAKER. FINALLY...WE DID MAKE SOME FORECAST ADJUSTMENTS FOR SOUTH CENTRAL MT TOO...NAMELY TO DECREASE POPS IN MANY PLACES IN RESPECT TO THE LOW-LEVEL DOWNSLOPE FLOW. PRECIPITABLE WATER VALUES ARE NEAR 0.40 INCHES THOUGH...DESERVING OF SOME CHANCE-STYLE POPS OVERNIGHT FOR PLACES LIKE BILLINGS. WE LEFT THE WIND ADVISORY UP FOR LIVINGSTON AND NYE AS WELL AS BIG TIMBER SINCE MID-EVENING OBSERVATIONS HAVE WINDS STILL NEAR CRITERIA AT THE LIVINGSTON AIRPORT. SCHULTZ && .SHORT TERM...VALID FOR TUE AND WED... WARMER AIR PUSHING EAST GRADUALLY AS BILLINGS HAS WARMED UP TO 30 DEGREES LATE THIS AFTERNOON. LIVINGSTON HAS RISEN TO 40 DEGREES. THE EAST WAS STILL STUCK IN THE ARCTIC HOWEVER WITH MILES CITY AT ZERO AND BAKER WITH 5 DEGREES. MODELS ADVANCE THE WARMER AIR EAST THROUGH THE EVENING...SO EXPECT RISING TEMPERATURES TONIGHT. LOW FORECAST VERY TRICKY AS LOWS WILL BE EARLY THIS EVENING. BLOWING SNOW HAS BECOME LESS OF AN ISSUE AS TEMPERATURES HAVE WARMED. APPEARS TO BE MORE DRIFTING THAN BLOWING AS TEMPERATURES CONTINUE TO WARM...THE THREAT WILL SUBSIDE. WILL CANCEL THE BLOWING SNOW ADVISORY. WINDS HAVE BEEN VERY STRONG AT LIVINGSTON WITH GUSTS TO 65 MPH EARLIER THIS AFTERNOON. THE SURFACE PRESSURE GRADIENT WAS TIGHTENING...SO EXPECT WINDS TO STAY UP TONIGHT. A PACIFIC COLD FRONT WILL DRIVE ACROSS THE AREA TONIGHT AND THIS WILL DECREASE WINDS AT LIVINGSTON. WINDS HAVE NOT HIT ADVISORY CRITERIA AT BIG TIMBER YET...BUT HAVE GOTTEN CLOSE. GRADIENT WILL ACTUALLY FAVOR BIG TIMBER ONCE THE PACIFIC COLD FRONT MOVES THROUGH TONIGHT SO WILL KEEP THE ADVISORY UP. MAY BE ABLE TO CANCEL THE LIVINGSTON ADVISORY EARLY TONIGHT AS WINDS TYPICALLY DECREASE BEHIND A FRONTAL PASSAGE...BUT WILL LET THE EVENING AND MIDNIGHT SHIFT MONITOR THAT. WILL LEAVE WIND HIGHLIGHTS IN PLACE. A STRONG WAVE WAS EVIDENT ON WATER VAPOR MOVING INTO EASTERN OREGON. VERY STRONG FORCING ASSOCIATED WITH THIS WAVE. MODELS LIMIT QPF OVER CENTRAL ZONES DUE TO STRONG DOWNSLOPE FLOW BUT FEEL FORCING WILL OVERPOWER THE DOWNSLOPE AT SOME POINT TONIGHT. RAISED POPS FOR MOST OF THE AREA. AREA OF GREATEST CONCERN WILL BE EAST OF BILLINGS. VERY COLD TEMPERATURES AT THE SURFACE MAY POSE A PROBLEM AS WARM AIR ADVECTION ON THE FRONT SIDE OF THE WAVE COULD PRODUCE PERIODS OF FREEZING RAIN OVER THE EAST TONIGHT AS THE WAVE MOVES ACROSS. WILL HAVE TO WATCH THIS AREA CLOSELY. RAISED POPS AND SNOW AMOUNTS AND WENT WITH A COUPLE OF INCHES THERE. THE WAVE SHIFTS OUT EARLY TUESDAY AND LEAVES BEHIND NORTHWEST FLOW WITH A DRYING TREND. SHORTWAVE ENERGY GETS DEFLECTED EASTWARD AND WILL LEAVE THE AREA DRY. GRADIENTS REMAIN TIGHT OVER THE WEST AND WILL KEEP WINDS UP FROM LIVINGSTON TO BIG TIMBER TO HARLOWTON. TWH .LONG TERM...VALID FOR THU...FRI...SAT...SUN...MON... MODELS REMAIN IN FAIRLY GOOD AGREEMENT THROUGH THE EXTENDED PERIOD. IN GENERAL...A FAST NORTHWEST FLOW ALOFT WILL BE OVER THE FORECAST AREA THROUGH THE PERIOD AS A HIGH PRESSURE RIDGE AXIS WILL REMAIN OVER THE PACIFIC NORTHWEST. THURSDAY INTO FRIDAY...HIGH PRESSURE RIDGING AND RISING HEIGHTS WILL BE OVER THE FORECAST AREA RESULTING IN DRY CONDITIONS AND ABOVE NORMAL TEMPERATURES. SURFACE LOW PRESSURE ACROSS SOUTHERN CANADA COMBINED WITH HIGH PRESSURE ACROSS IDAHO WILL SET UP LEE-SIDE TROUGHING ACROSS OUR AREA RESULTING IN CONTINUED WINDY CONDITIONS FOR THE BEARTOOTH/ABSAROKA FOOTHILLS LOCATIONS. ANOTHER FAST MOVING DISTURBANCE WILL DROP SOUTHEAST OUT OF CANADA SATURDAY INTO SUNDAY BRINGING ANOTHER ARCTIC FRONT AND A GOOD CHANCE FOR SNOW ACROSS THE AREA ESPECIALLY DURING THE DAY SATURDAY. DYNAMICS ARE DECENT WITH THIS SYSTEM AND MODELS SHOW A GOOD FRONTOGENESIS BAND ACROSS THE AREA ESPECIALLY THE BEARTOOTH/ABSAROKA FOOTHILLS AREA. 850MB TEMPERATURES DROP TO AROUND -12C TO -20C SATURDAY NIGHT. HAVE LOWERED SATURDAY HIGHS SEVERAL DEGREES ALONG WITH SUNDAY MORNING LOWS AND THESE MAY NEED TO GO LOWER IN THE FUTURE. LEE-SIDE TROUGHING RETURNS FOR MONDAY AND TUESDAY RESULTING IN A RETURN TO WINDY CONDITIONS AND WARMING TEMPERATURES. HOOLEY && .AVIATION... A DISTURBANCE WILL MOVE ACROSS THE FORECAST AREA BRINGING A CHANCE FOR RAIN AND SNOW SHOWERS. THERE IS ALSO A CHANCE OF FREEZING RAIN OR SLEET OVER PORTIONS OF SOUTHEAST MONTANA WHICH MAY AFFECT KMLS BETWEEN 05Z AND 10Z. VFR CONDITIONS WILL PREVAIL BUT MVFR TO IFR CONDITIONS WILL BE COMMON IN THE RAIN/SNOW SHOWER ACTIVITY. BT && .PRELIMINARY POINT TEMP/POPS... TUE WED THU FRI SAT SUN MON ----------------------------------------------------------- BIL 034/038 017/029 017/040 027/045 026/036 019/024 014/032 51/N 01/B 10/N 00/N 03/J 32/J 11/B LVM 032/034 021/032 017/041 025/045 023/035 016/025 015/029 42/S 01/N 10/N 00/N 13/J 33/J 11/B HDN 024/037 013/028 014/038 023/044 022/034 014/022 007/030 62/S 01/B 10/N 00/U 03/J 32/J 11/B MLS 015/035 012/024 008/031 020/039 021/031 011/015 901/027 93/S 01/B 10/B 00/B 13/J 32/J 11/B 4BQ 025/036 012/026 009/034 020/043 021/033 012/019 001/027 95/S 11/B 10/B 00/U 03/J 32/J 11/B BHK 015/032 011/022 001/029 019/038 020/029 007/011 903/025 95/S 11/B 10/B 00/B 13/J 21/E 11/B SHR 022/036 012/029 012/038 021/045 021/036 015/022 008/031 62/S 01/B 10/B 00/U 03/J 42/J 11/B && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...FREEZING RAIN ADVISORY IN EFFECT UNTIL 6 AM MST TUESDAY FOR ZONES 30>33-36-37. WIND ADVISORY IN EFFECT UNTIL 9 AM MST TUESDAY FOR ZONES 41-65-66. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS ELKO NV
1223 PM PST SUN DEC 22 2013 .SYNOPSIS...DRY QUIET WEATHER WILL PREVAIL ACROSS MOST OF NEVADA FOR MOST OF THIS WEEK. && .UPDATE...UPDATED TEMPERATURE GRIDS FOR THIS AFTERNOON, RAISING MAX TEMPS CLOSE TO CURRENT READINGS IN THE UPPER 30S AND LOWER 40S. BAT && .PREV DISCUSSION... /ISSUED AT 329 AM / SYNOPSIS...LINGERING PACIFIC MOISTURE WILL IMPACT PORTIONS OF ELKO COUNTY TODAY POTENTIALLY RESULTING IN FLURRIES. BIG PICTURE WISE...WIDESPREAD NORTHERLY FLOW WILL BE REPLACED BY RIDGING. EXPECTING INVERSIONS TO DEVELOP OVER THE VALLEYS WHICH WILL BRING THE SINGLE DIGIT TEMPERATURES BACK. OTHER THAN THE COLD SNAP OVER NORTHERN NEVADA...GENERALLY EXPECTING MILD CONDITIONS FOR CHRISTMAS AND THROUGH FRIDAY. SHORT TERM...TODAY THROUGH TUESDAY. THE PROGGED SOUNDING FOR ELKO CONTINUES TO DEPICT SATURATION OR NEAR SATURATION...WHICH IS CONSISTENT WITH THE RECENT SNOW MELT AND MOISTURE ADVECTION FROM THE PACIFIC SYSTEM. THE GFS PINGS INTO NEAR 90 PERCENT RH FROM 700 MB TO 500 MB OVER THE NORTHERN ZONES OF LKN THROUGH 18Z TODAY. MEANWHILE...THE NAM AND RUC TAKE IT ONE STEP FURTHER BRINGING SNOW INTO THE NORTHERN HALF OF ELKO COUNTY. FLURRIES WILL BE POSSIBLE IN THE JARBIDGE WILDERNESS AREA AND JACKPOT...BUT MOST OF THE REGION WILL BE UNEVENTFUL. IN THE WAKE OF THE EXTENSIVE MELTING THAT OCCURRED SATURDAY AFTERNOON...THERE HAS BEEN MUCH DISCOURSE OVER THE POTENTIAL FOR THE DEVELOPMENT OF FREEZING FOG THIS MORNING. KEPT PATCHY FREEZING FOG IN THE GRIDS. LONG TERM...CHRISTMAS EVE THROUGH NEXT SATURDAY. QUIET WEATHER CAN BE EXPECTED ACROSS THE WESTERN GREAT BASIN THROUGH CHRISTMAS WEEK. THE HOLIDAY WEEK BEGINS WITH A WEAK NORTHWEST FLOW IN PLACE ACROSS THE GREAT BASIN. AS THE WEEK CONTINUES A WEAK TROUGH SLIDES SOUTHEAST WITHIN THE NORTHWEST FLOW ALOFT ACROSS THE GREAT BASIN ON CHRISTMAS DAY. SINCE THIS TROUGH IS MOISTURE STAVED AND POSITIVELY TILTED...NOTHING MORE THAN A FEW CLOUDS CAN BE EXPECTED MAINLY OVER NORTHERN AREAS. FOLLOWING THIS TROUGH...A STRONG RIDGE OVER THE EASTERN PACIFIC WILL BUILD INTO THE WESTERN STATES CONTINUING DRY AND COLD CONDITIONS. MODEL SOUNDINGS BENEATH THIS RIDGE INDICATE A STRONG INVERSION WILL BE IN PLACE MAINLY ESPECIALLY OVER NORTHERN AREAS. STRONG RADIATIONAL COOLING ESPECIALLY IN SNOW COVER AREAS WILL DROP TEMPERATURES INTO THE SINGLE DIGITS AT NIGHT. RECOVERY DURING THE DAY WILL BE LIMITED WITH THE STRONG INVERSION IN PLACE...SO EXPECT MAXIMUM TEMPERATURES TO REBOUND INTO THE UPPER 20S/LOWER 30S IN MANY VALLEY AREAS. THE HIGHER ELEVATIONS ABOVE THE INVERSION WITH SEE TEMPERATURES IN THE 30S AND 40S. THE RIDGE GRADUALLY WILL BREAKDOWN DURING FRIDAY ALLOWING A TROUGH TO APPROACH FROM THE NORTHWEST WITH SOME MOISTURE FOR MAINLY NORTHERN AREAS ON SATURDAY. AVIATION...WITH ABUNDANT LOW LEVEL MOISTURE IN PLACE FROM RAPID SNOWMELT SATURDAY...FOG AND LOW CIGS BECOMES THE CONCERN FOR MAINLY THE NORTHERN AND EASTERN TAF LOCATIONS. WITH THE NEW AVIATION PACKAGE PLAN TO MENTION VCFG AT KWMC/KEKO/KELY THIS MORNING AND A COMBINATION OF MVFR/VFR CIGS THROUGH THE DAY. KTPH SHOULD BE IN BETTER SHAPE WITH SKC CONDITIONS. && .LKN WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 99/99
AREA FORECAST DISCUSSION
NWS ELKO NV
329 AM PST SUN DEC 22 2013 .SYNOPSIS...LINGERING PACIFIC MOISTURE WILL IMPACT PORTIONS OF ELKO COUNTY TODAY POTENTIALLY RESULTING IN FLURRIES. BIG PICTURE WISE...WIDESPREAD NORTHERLY FLOW WILL BE REPLACED BY RIDGING. EXPECTING INVERSIONS TO DEVELOP OVER THE VALLEYS WHICH WILL BRING THE SINGLE DIGIT TEMPERATURES BACK. OTHER THAN THE COLD SNAP OVER NORTHERN NEVADA...GENERALLY EXPECTING MILD CONDITIONS FOR CHRISTMAS AND THROUGH FRIDAY. && .SHORT TERM...TODAY THROUGH TUESDAY. THE PROGGED SOUNDING FOR ELKO CONTINUES TO DEPICT SATURATION OR NEAR SATURATION...WHICH IS CONSISTENT WITH THE RECENT SNOW MELT AND MOISTURE ADVECTION FROM THE PACIFIC SYSTEM. THE GFS PINGS INTO NEAR 90 PERCENT RH FROM 700 MB TO 500 MB OVER THE NORTHERN ZONES OF LKN THROUGH 18Z TODAY. MEANWHILE...THE NAM AND RUC TAKE IT ONE STEP FURTHER BRINGING SNOW INTO THE NORTHERN HALF OF ELKO COUNTY. FLURRIES WILL BE POSSIBLE IN THE JARBIDGE WILDERNESS AREA AND JACKPOT...BUT MOST OF THE REGION WILL BE UNEVENTFUL. IN THE WAKE OF THE EXTENSIVE MELTING THAT OCCURRED SATURDAY AFTERNOON...THERE HAS BEEN MUCH DISCOURSE OVER THE POTENTIAL FOR THE DEVELOPMENT OF FREEZING FOG THIS MORNING. KEPT PATCHY FREEZING FOG IN THE GRIDS. .LONG TERM...CHRISTMAS EVE THROUGH NEXT SATURDAY. QUIET WEATHER CAN BE EXPECTED ACROSS THE WESTERN GREAT BASIN THROUGH CHRISTMAS WEEK. THE HOLIDAY WEEK BEGINS WITH A WEAK NORTHWEST FLOW IN PLACE ACROSS THE GREAT BASIN. AS THE WEEK CONTINUES A WEAK TROUGH SLIDES SOUTHEAST WITHIN THE NORTHWEST FLOW ALOFT ACROSS THE GREAT BASIN ON CHRISTMAS DAY. SINCE THIS TROUGH IS MOISTURE STAVED AND POSITIVELY TILTED...NOTHING MORE THAN A FEW CLOUDS CAN BE EXPECTED MAINLY OVER NORTHERN AREAS. FOLLOWING THIS TROUGH...A STRONG RIDGE OVER THE EASTERN PACIFIC WILL BUILD INTO THE WESTERN STATES CONTINUING DRY AND COLD CONDITIONS. MODEL SOUNDINGS BENEATH THIS RIDGE INDICATE A STRONG INVERSION WILL BE IN PLACE MAINLY ESPECIALLY OVER NORTHERN AREAS. STRONG RADIATIONAL COOLING ESPECIALLY IN SNOW COVER AREAS WILL DROP TEMPERATURES INTO THE SINGLE DIGITS AT NIGHT. RECOVERY DURING THE DAY WILL BE LIMITED WITH THE STRONG INVERSION IN PLACE...SO EXPECT MAXIMUM TEMPERATURES TO REBOUND INTO THE UPPER 20S/LOWER 30S IN MANY VALLEY AREAS. THE HIGHER ELEVATIONS ABOVE THE INVERSION WITH SEE TEMPERATURES IN THE 30S AND 40S. THE RIDGE GRADUALLY WILL BREAKDOWN DURING FRIDAY ALLOWING A TROUGH TO APPROACH FROM THE NORTHWEST WITH SOME MOISTURE FOR MAINLY NORTHERN AREAS ON SATURDAY. && .AVIATION...WITH ABUNDANT LOW LEVEL MOISTURE IN PLACE FROM RAPID SNOWMELT SATURDAY...FOG AND LOW CIGS BECOMES THE CONCERN FOR MAINLY THE NORTHERN AND EASTERN TAF LOCATIONS. WITH THE NEW AVIATION PACKAGE PLAN TO MENTION VCFG AT KWMC/KEKO/KELY THIS MORNING AND A COMBINATION OF MVFR/VFR CIGS THROUGH THE DAY. KTPH SHOULD BE IN BETTER SHAPE WITH SKC CONDITIONS. && .LKN WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 97/89/89
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
132 AM EST SUN DEC 22 2013 .SYNOPSIS... A STORM SYSTEM WILL MOVE FROM THE MISSISSIPPI RIVER VALLEY TO THE LOWER GREAT LAKES TONIGHT AND BRING RAIN TO THE REGION. A COLD FRONT WILL SWING THRU THE AREA BRING DRIER AND SOMEWHAT COOLER AIR TO THE AREA SUNDAY NIGHT AND MONDAY. && .NEAR TERM /THROUGH TODAY/... 1245 AM SUN UPDATE... WE`VE ISSUED A FRZG RAIN ADVSY FOR OUR FAR NRN ZNS TIL 12Z. SFC/MESO-NET OBS HAVE SHOWN A STEADY DOWNWARD TEMP/DEW PT TREND THE LAST FEW HRS...AS LOW-LVL COLD AIR CONTS TO BLEED SWD ATTM. READINGS ARE DOWN TO 31-32F N/W OF A KPEO-KSYR- KRME LN...AND WE SUSPECT THEY`LL STAY ABT WHERE THEY ARE THE NEXT 3-6 HRS. GIVEN RADAR COVERAGE UPSTREAM...WE FELT AN ADVSY WAS OUR BEST BET. TWDS DAYBREAK (10-12Z)...AS THE MAIN SFC WV APPROACHES FROM THE SW...BLYR WAA SHOULD INCREASE...CAUSING THE LOW-LVL BAROCLINIC ZN TO LIKELY BEGIN LIFTING NWD AGN. AS THIS OCCURS...WE SHOULD SEE THE SHALLOW COLD AMS GET ERODED FROM S TO N...WITH -FZRA GETTING LESS WIDESPREAD. OUTSIDE OF MODIFICATIONS TO THE TEMP/DEW PT/WX GRIDS...WE JUST MADE OTHER SLIGHT TWEAKS ATTM. PREV DISC... 740 PM UPDATE... CHALLENGING NEAR TERM FORECAST AS FRONT WAVERS NORTH AND SOUTH IN ADVANCE OF NORTHEAST MOVING CYCLONE. AREAS NORTHWEST OF THE FRONT ARE FLIRTING WITH TEMPERATURES IN THE LOWER 30S, WITH FREEZING RAIN BECOMING A FACTOR. LATEST NAM12 925MB TEMPERATURE PATTERN SEEMS TO BE VERIFYING REASONABLY WELL, AND WE USED THIS AS OUR BASIS FOR MOVING THE FRONT OVER THE NEXT SEVERAL HOURS. BASED ON THIS ANALYSIS, BELIEVE THERE IS A CHANCE FOR THE COLD AIR TO POUR INTO THE NORTHWESTERN CORNER OF STEUBEN COUNTY, UP THROUGH WESTERN SENECA COUNTY, BETWEEN 3Z AND 8Z. THERE IS NOW A SLIGHT CHANCE FOR FREEZING RAIN FOR A SHORT WINDOW IN THIS AREA. THEREAFTER THE WARM AIR COMES THROUGH ON A TRUCK...DRIVEN BY STRONG SOUTHWESTERLY FLOW, AND PUSHING SURFACE TEMPS THROUGH THE 40S AND 50S ACROSS THE REGION FOR EARLY SUNDAY MORNING. THE OTHER PROBLEM OF THE EVENING IS OBVIOUSLY QPF. HAVE REWORKED THE 0Z-6Z QPF GRIDS BASED ON LATEST GUIDANCE, AND STAYED PRETTY MUCH IN LINE WITH HPC FOR 6Z-12Z. THE GFS HAS BEEN ALL OVER THE MAP THE LAST 24 HOURS, AT ONE TIME BEING AN OUTLIER ON THE HIGH SIDE OF QPF, AND NOW BEING ON THE LOW SIDE. ITS INCONSISTENCY GIVES ME LITTLE CONFIDENCE, SO I WEIGHTED IT LOW COMPARED TO THE NEW NAM12, HRRR, AND RAP PROJECTIONS. IN TOTAL, THE NET EFFECT WAS A DECREASE IN STORM TOTAL QPF OF ABOUT 0.15 TO 0.30 INCHES. THIS LOOKS PRETTY GOOD COMPARED WITH UPSTREAM RADAR DEPICTION. WILL CONTINUE TO ASSESS THE EARLY SUNDAY MORNING QPF SCENARIO. EARLIER DISC... 3 PM UPDATE... COMPLEX SCENARIO FOR THE FCST AS VERY WRM AIR STREAMS NEWRD TNGT LOADED WITH MOISTURE. MEANWHILE...CONFLUENT UPR FLOW TRIES TO BLD THE LL COLD OVER NRN NY WITH SFC RDGG. SOME OF THAT COLDER AIR ALREADY HAS AFFECTED THE FAR NRN ZONES AND SYR DROPPED 7F IN THE PAST HR. LOOKS LIKE A CLOSE CALL BUT THAT THE BLO FRZG AIR WILL REMAIN JUST NORTH OF THE FINGER LAKES ZONES THRU TNGT...BEFORE BEING PUSHED NWRD. OTR ISSUE IS THE HEAVY RAIN AND SNOW MELT. MODELS CONT TO KEEP THE AXIS OF HEAVY RAIN GNRLY NORTH OF THE SUSQ BASIN...AND JUST TOUCHING THE FINGER LAKES. 12 HR QPF LOOS TO BE UNDER 2 INCHES BUT WITH SNOW MELT...SOME FCST PTS WILL HIT A MINOR FLOOD STAGE BEGINNING SUNDAY. HAVE XTNDD THE CVRG OF THE WATCH TO INCLUDE ALL NY COUNTIES XCPT SULLIVAN...AND TWO NRN PA COUNTIES. SEE HYDRO DISC FOR DETAILS ON THE FLOOD PTNL. && .SHORT TERM /TONIGHT THROUGH TUESDAY/... NO REAL BRK IN THE SHRT TERM AS A GOOD SLUG OF PCPN PASSES WITH A SFC TROF/COLD FNT ON SUNDAY. GOOD NEWS IS THAT THE PCPN WILL BE PROGRESSIVE SO THERE WILL HOPEFULLY LTL XTRA EFFECT ON THE RVRS. FNT STALLS AGAIN...THIS TIME EAST OF THE FCST AREA. HWVR...THERE IS NO COLD AIR TO SPEAK OF AND AS A WV MVES UP THE MON...MSTLY RAIN WILL FALL OVER THE ERN ZONES WITH PERHAPS SOME SNOW LATE AS THE COLD AIR FNLY BEGINS TO ARRIVE. WLD NOT BE SURPRISED TO SEE AND INCH OR TWO OF SNOW ON THE BACK SIDE LATE MON. WILL WORRY ABT THAT LTR. UPR TROF SETTLES IN WITH SOME SYNOPTIC MOISTURE AND LE SNOWS AS H8 TEMPS APRCH -20C LATE IN THE DAY. FLOW IS RATHER SHEARED EARLY ON...BUT MAY ALIGN LATE IN THE PD INCRSG ACTIVITY. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... 1 PM EST UPDATE... FOLLOWED WPC GUIDANCE. GFS AND EURO ARE SIMILAR. COLDER AND DRIER THAN NORMAL. COLD ENOUGH FOR ALL SNOW BUT AMOUNTS WILL BE MINOR. MOSTLY IN A BROAD UPPER LEVEL TROF. LINGERING LAKE EFFECT SNOW IN CENTRAL NY TUES NGT GETS SHUT OFF AS A LARGE SFC HIGH PRESSURE SITS OVER THE EAST COAST WED AND WED NGT. A DIGGING SHORT WAVE SINKS SE INTO THE AREA LATE THU AND THU NGT WITH A SFC COLD FRONT. LAKE EFFECT BEHIND IT FRIDAY BUT LOW LEVEL FLOW SHIFTS TO THE WEST AND HIGH PRESSURE BUILDS IN SATURDAY. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... 06Z UPDATE... A COMPLEX WEATHER FORECAST IS EXPECTED FOR THE TAF PERIOD. A WARM FRONT IS LOCATED OVER CENTRAL NEW YORK THIS MORNING. THIS FRONT IS EXPECTED TO REMAIN STATIONARY FOR THE NEXT COUPLE OF HOURS.AROUND 10Z...THIS FRONT WILL SLOWLY LIFT NORTH. WITH THAT BEING SAID TAF SITES SOUTH OF THE FRONT ARE LOOKING AT VFR CONDITIONS. TAFS SITES NORTH OF THIS FRONT ARE LOOKING AT MVFR AND IFR CIGS AND VISBYS. CONFIDENCE IS NOT HIGH ON THE EXACT TIMING OF WHEN THE FRONT WILL LIFT NORTH. CONFIDENCE IS LOW THAT KELM AND KBGM WILL REMAIN AT FUEL ALTERNATE CIGS. THE CIGS AT THESE SITES MAY FALL TO AROUND 500 FT BUT CONFIDENCE IS LOW AND LEFT OUT OF TAF AS THEY WILL BE ON THE OUTER EDGE OF THE WARM FRONT. CIGS AT SITES KRME... KSYR... AND KITH WILL REMAIN LOW THROUGH MID MORNING AS THE FRONT REMAINS WELL TO SOUTH. LIGHT FREEZING RAIN IS A POSSIBILITY AT KRME AND KSYR AS COLD AIR WILL SLOWLY FUNNEL INTO THE REGION. THE CHANCE FOR FREEZING RAIN IS EXPECTED TO END AFTER SUNRISE AS TEMPS ARE EXPECTED TO WARM QUICKLY OVER THE REGION. CONDITIONS MAY IMPROVE BRIEFLY LATE SUNDAY NIGHT INTO MONDAY MORNING. OUTLOOK... SUN NGT-MON...RESTRICTIONS POSSIBLE FROM -SHRA/-SHSN. TUE AND WED...VFR...WITH ISOLATED MVFR IN -SHSN EARLY. THU...VFR. && .HYDROLOGY... 9 PM UPDATE... SEVERAL POINTS ARE FORECAST TO GET INTO MINOR FLOOD STAGE SUNDAY OR SUNDAY NIGHT...AND LAKELAND OF NINE MILE CREEK EVEN ECLIPSING MODERATE STAGE. MODEL CONSENSUS IS MORE DECIDEDLY NORTHWEST OF MOST OF THE AREA FOR THE HIGHEST RAINFALL AMOUNTS...YET DEGREE OF SNOWMELT IN LAST 12-24 HOURS HAS ALSO BEEN FASTER THAN EXPECTED. SNOWMELT AND THE ADDITIONAL THREE-QUARTERS OF AN INCH TO INCH- AND-A-QUARTER OF RAINFALL TONIGHT THROUGH SUNDAY FOR MOST OF THE FLOOD WATCH AREA /MOST OF CENTRAL NEW YORK AND INTO NORTHERN TIER PA/ WILL RESULT IN SIGNIFICANT RISES FOR RIVERS. RIVER FORECAST CENTERS ARE CRUNCHING UPDATED FORECASTS BASED ON OBSERVED AND EXPECTED RAINFALL ALONG WITH SNOWMELT AND CURRENT STAGES. WE ANTICIPATE MAKING SOME WARNING DECISIONS LATER THIS EVENING FOR SEVERAL OF OUR RIVER POINTS...JOINING LAKELAND WITH RIVER FLOOD WARNING. STILL EXPECTING ACTION STAGE TO SOMEWHERE INTO MINOR FLOOD STAGE FOR VAST MAJORITY OF AFFECTED RIVER POINTS. MODERATE STAGES SHOULD BE LIMITED TO ONLY ONE OR TWO SITES. SMALL STREAM AND STORM DRAIN TROUBLES STILL APPEAR LIKELY ACROSS THE CENTRAL NY COUNTIES TONIGHT THROUGH SUNDAY. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...FLOOD WATCH THROUGH MONDAY MORNING FOR PAZ038-039. NY...FLOOD WATCH THROUGH MONDAY MORNING FOR NYZ009-015>018-022>025- 036-037-044>046-055>057. FREEZING RAIN ADVISORY UNTIL 7 AM EST THIS MORNING FOR NYZ009- 015>018. && $$ SYNOPSIS...DGM NEAR TERM...DGM/DJP/MLJ SHORT TERM...DGM LONG TERM...TAC AVIATION...KAH HYDROLOGY...
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1253 AM EST SUN DEC 22 2013 .SYNOPSIS... A STORM SYSTEM WILL MOVE FROM THE MISSISSIPPI RIVER VALLEY TO THE LOWER GREAT LAKES TONIGHT AND BRING RAIN TO THE REGION. A COLD FRONT WILL SWING THRU THE AREA BRING DRIER AND SOMEWHAT COOLER AIR TO THE AREA SUNDAY NIGHT AND MONDAY. && .NEAR TERM /THROUGH TODAY/... 1245 AM SUN UPDATE... WE`VE ISSUED A FRZG RAIN ADVSY FOR OUR FAR NRN ZNS TIL 12Z. SFC/MESO-NET OBS HAVE SHOWN A STEADY DOWNWARD TEMP/DEW PT TREND THE LAST FEW HRS...AS LOW-LVL COLD AIR CONTS TO BLEED SWD ATTM. READINGS ARE DOWN TO 31-32F N/W OF A KPEO-KSYR- KRME LN...AND WE SUSPECT THEY`LL STAY ABT WHERE THEY ARE THE NEXT 3-6 HRS. GIVEN RADAR COVERAGE UPSTREAM...WE FELT AN ADVSY WAS OUR BEST BET. TWDS DAYBREAK (10-12Z)...AS THE MAIN SFC WV APPROACHES FROM THE SW...BLYR WAA SHOULD INCREASE...CAUSING THE LOW-LVL BAROCLINIC ZN TO LIKELY BEGIN LIFTING NWD AGN. AS THIS OCCURS...WE SHOULD SEE THE SHALLOW COLD AMS GET ERODED FROM S TO N...WITH -FZRA GETTING LESS WIDESPREAD. OUTSIDE OF MODIFICATIONS TO THE TEMP/DEW PT/WX GRIDS...WE JUST MADE OTHER SLIGHT TWEAKS ATTM. PREV DISC... 740 PM UPDATE... CHALLENGING NEAR TERM FORECAST AS FRONT WAVERS NORTH AND SOUTH IN ADVANCE OF NORTHEAST MOVING CYCLONE. AREAS NORTHWEST OF THE FRONT ARE FLIRTING WITH TEMPERATURES IN THE LOWER 30S, WITH FREEZING RAIN BECOMING A FACTOR. LATEST NAM12 925MB TEMPERATURE PATTERN SEEMS TO BE VERIFYING REASONABLY WELL, AND WE USED THIS AS OUR BASIS FOR MOVING THE FRONT OVER THE NEXT SEVERAL HOURS. BASED ON THIS ANALYSIS, BELIEVE THERE IS A CHANCE FOR THE COLD AIR TO POUR INTO THE NORTHWESTERN CORNER OF STEUBEN COUNTY, UP THROUGH WESTERN SENECA COUNTY, BETWEEN 3Z AND 8Z. THERE IS NOW A SLIGHT CHANCE FOR FREEZING RAIN FOR A SHORT WINDOW IN THIS AREA. THEREAFTER THE WARM AIR COMES THROUGH ON A TRUCK...DRIVEN BY STRONG SOUTHWESTERLY FLOW, AND PUSHING SURFACE TEMPS THROUGH THE 40S AND 50S ACROSS THE REGION FOR EARLY SUNDAY MORNING. THE OTHER PROBLEM OF THE EVENING IS OBVIOUSLY QPF. HAVE REWORKED THE 0Z-6Z QPF GRIDS BASED ON LATEST GUIDANCE, AND STAYED PRETTY MUCH IN LINE WITH HPC FOR 6Z-12Z. THE GFS HAS BEEN ALL OVER THE MAP THE LAST 24 HOURS, AT ONE TIME BEING AN OUTLIER ON THE HIGH SIDE OF QPF, AND NOW BEING ON THE LOW SIDE. ITS INCONSISTENCY GIVES ME LITTLE CONFIDENCE, SO I WEIGHTED IT LOW COMPARED TO THE NEW NAM12, HRRR, AND RAP PROJECTIONS. IN TOTAL, THE NET EFFECT WAS A DECREASE IN STORM TOTAL QPF OF ABOUT 0.15 TO 0.30 INCHES. THIS LOOKS PRETTY GOOD COMPARED WITH UPSTREAM RADAR DEPICTION. WILL CONTINUE TO ASSESS THE EARLY SUNDAY MORNING QPF SCENARIO. EARLIER DISC... 3 PM UPDATE... COMPLEX SCENARIO FOR THE FCST AS VERY WRM AIR STREAMS NEWRD TNGT LOADED WITH MOISTURE. MEANWHILE...CONFLUENT UPR FLOW TRIES TO BLD THE LL COLD OVER NRN NY WITH SFC RDGG. SOME OF THAT COLDER AIR ALREADY HAS AFFECTED THE FAR NRN ZONES AND SYR DROPPED 7F IN THE PAST HR. LOOKS LIKE A CLOSE CALL BUT THAT THE BLO FRZG AIR WILL REMAIN JUST NORTH OF THE FINGER LAKES ZONES THRU TNGT...BEFORE BEING PUSHED NWRD. OTR ISSUE IS THE HEAVY RAIN AND SNOW MELT. MODELS CONT TO KEEP THE AXIS OF HEAVY RAIN GNRLY NORTH OF THE SUSQ BASIN...AND JUST TOUCHING THE FINGER LAKES. 12 HR QPF LOOS TO BE UNDER 2 INCHES BUT WITH SNOW MELT...SOME FCST PTS WILL HIT A MINOR FLOOD STAGE BEGINNING SUNDAY. HAVE XTNDD THE CVRG OF THE WATCH TO INCLUDE ALL NY COUNTIES XCPT SULLIVAN...AND TWO NRN PA COUNTIES. SEE HYDRO DISC FOR DETAILS ON THE FLOOD PTNL. && .SHORT TERM /TONIGHT THROUGH TUESDAY/... NO REAL BRK IN THE SHRT TERM AS A GOOD SLUG OF PCPN PASSES WITH A SFC TROF/COLD FNT ON SUNDAY. GOOD NEWS IS THAT THE PCPN WILL BE PROGRESSIVE SO THERE WILL HOPEFULLY LTL XTRA EFFECT ON THE RVRS. FNT STALLS AGAIN...THIS TIME EAST OF THE FCST AREA. HWVR...THERE IS NO COLD AIR TO SPEAK OF AND AS A WV MVES UP THE MON...MSTLY RAIN WILL FALL OVER THE ERN ZONES WITH PERHAPS SOME SNOW LATE AS THE COLD AIR FNLY BEGINS TO ARRIVE. WLD NOT BE SURPRISED TO SEE AND INCH OR TWO OF SNOW ON THE BACK SIDE LATE MON. WILL WORRY ABT THAT LTR. UPR TROF SETTLES IN WITH SOME SYNOPTIC MOISTURE AND LE SNOWS AS H8 TEMPS APRCH -20C LATE IN THE DAY. FLOW IS RATHER SHEARED EARLY ON...BUT MAY ALIGN LATE IN THE PD INCRSG ACTIVITY. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... 1 PM EST UPDATE... FOLLOWED WPC GUIDANCE. GFS AND EURO ARE SIMILAR. COLDER AND DRIER THAN NORMAL. COLD ENOUGH FOR ALL SNOW BUT AMOUNTS WILL BE MINOR. MOSTLY IN A BROAD UPPER LEVEL TROF. LINGERING LAKE EFFECT SNOW IN CENTRAL NY TUES NGT GETS SHUT OFF AS A LARGE SFC HIGH PRESSURE SITS OVER THE EAST COAST WED AND WED NGT. A DIGGING SHORT WAVE SINKS SE INTO THE AREA LATE THU AND THU NGT WITH A SFC COLD FRONT. LAKE EFFECT BEHIND IT FRIDAY BUT LOW LEVEL FLOW SHIFTS TO THE WEST AND HIGH PRESSURE BUILDS IN SATURDAY. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... 00Z UPDATE... POOR AVIATION CONDITIONS FOR MOST LOCATIONS TONIGHT...WITH SHALLOW SURFACE BOUNDARY SLIPPING SOUTH TO ABOUT KELM-KBGM AND THUS LOW CIGS ALONG AND NORTH OF THERE. WAVES OF RAIN ALSO PASSING ALONG AND NORTH OF THE FRONT. IFR OR WORSE CONDITIONS FOR ALL TERMINALS. MEANWHILE...SOUTH OF THE FRONT...MOIST SSW WIND AT KAVP ALSO FAVORABLE FOR DEVELOPMENT OF IFR LATER TONIGHT THROUGH MOST OF SUNDAY. ANOTHER CONCERN IS FOR LLWS DURING EARLY MORNING HOURS AS A 50-60 KT JET PASSES AT ABOUT 2 KFT AGL. THE JET DECREASING MID MORNING ONWARD...BUT RESTRICTIONS FROM IFR CIGS AT LEAST OCCASIONAL MVFR OR WORSE VIS AS WAVES OF RAIN CONTINUE. SOME IMPROVEMENT TOWARDS THE END OF THE PERIOD AS FRONT BEGINS TO PASS THROUGH THE AREA AND WAVE ALOFT REMOVES DEEPER MOISTURE. OUTLOOK... SUN NGT-MON...RESTRICTIONS POSSIBLE FROM -SHRA/-SHSN. TUE AND WED...VFR...WITH ISOLATED MVFR IN -SHSN EARLY. THU...VFR. && .HYDROLOGY... 9 PM UPDATE... SEVERAL POINTS ARE FORECAST TO GET INTO MINOR FLOOD STAGE SUNDAY OR SUNDAY NIGHT...AND LAKELAND OF NINE MILE CREEK EVEN ECLIPSING MODERATE STAGE. MODEL CONSENSUS IS MORE DECIDEDLY NORTHWEST OF MOST OF THE AREA FOR THE HIGHEST RAINFALL AMOUNTS...YET DEGREE OF SNOWMELT IN LAST 12-24 HOURS HAS ALSO BEEN FASTER THAN EXPECTED. SNOWMELT AND THE ADDITIONAL THREE-QUARTERS OF AN INCH TO INCH- AND-A-QUARTER OF RAINFALL TONIGHT THROUGH SUNDAY FOR MOST OF THE FLOOD WATCH AREA /MOST OF CENTRAL NEW YORK AND INTO NORTHERN TIER PA/ WILL RESULT IN SIGNIFICANT RISES FOR RIVERS. RIVER FORECAST CENTERS ARE CRUNCHING UPDATED FORECASTS BASED ON OBSERVED AND EXPECTED RAINFALL ALONG WITH SNOWMELT AND CURRENT STAGES. WE ANTICIPATE MAKING SOME WARNING DECISIONS LATER THIS EVENING FOR SEVERAL OF OUR RIVER POINTS...JOINING LAKELAND WITH RIVER FLOOD WARNING. STILL EXPECTING ACTION STAGE TO SOMEWHERE INTO MINOR FLOOD STAGE FOR VAST MAJORITY OF AFFECTED RIVER POINTS. MODERATE STAGES SHOULD BE LIMITED TO ONLY ONE OR TWO SITES. SMALL STREAM AND STORM DRAIN TROUBLES STILL APPEAR LIKELY ACROSS THE CENTRAL NY COUNTIES TONIGHT THROUGH SUNDAY. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...FLOOD WATCH THROUGH MONDAY MORNING FOR PAZ038-039. NY...FLOOD WATCH THROUGH MONDAY MORNING FOR NYZ009-015>018-022>025- 036-037-044>046-055>057. FREEZING RAIN ADVISORY UNTIL 7 AM EST THIS MORNING FOR NYZ009- 015>018. && $$ SYNOPSIS...DGM NEAR TERM...DGM/DJP/MLJ SHORT TERM...DGM LONG TERM...TAC AVIATION...MDP HYDROLOGY...
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1027 PM EST MON DEC 23 2013 .SYNOPSIS... A SLOW MOVING COLD FRONT APPROACHING FROM THE WEST WILL MOVE OFF THE COAST TONIGHT. DRIER AND COOLER AIR WILL SPREAD ACROSS THE REGION IN THE WAKE OF THE COLD FRONT. A MOSTLY DRY COLD FRONT WILL PASS ACROSS THE AREA FRIDAY...MAINTAINING SEASONABLE TEMPERATURES INTO THE WEEKEND. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... AS OF 1015 PM MONDAY...THE SFC COLD FRONT HAS BEEN MAKING PROGRESS TO THE SOUTHEAST THIS EVENING...AND NOW EXTENDS ACROSS THE EASTERN CAROLINAS...HAVING PUSHED EAST OF THE I-95 CORRIDOR. THE COLD FRONT WILL PUSH ACROSS THE REMAINING PORTIONS OF THE FA LATE THIS EVENING OR EARLY ON DURING THE PRE-DAWN TUE HOURS. THE POST COLD FRONTAL SENSIBLE WX CONDITIONS ACROSS THE FA WILL EXPERIENCE A WIND DIRECTION CHANGE VEERING TO THE NW-N AT 5 TO 15 MPH...COLD AIR ADVECTION ACCOMPANIED BY LOWER DEWPOINTS. LATEST PROGS CONTINUE WITH POST-FRONTAL LIGHT RAIN AND SHOWERS PERSISTING OVERNIGHT INTO DAYLIGHT TUESDAY B4 FINALLY BEING PUSHED OFF THE COAST AND OFFSHORE FROM A PROGRESSIVE UPPER S/W TROF. OVERNITE LOWS HAVE BEEN TWEAKED...WITH MINS OCCURRING AROUND SUNRISE TUESDAY. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/... AS OF 240 PM MONDAY...A DRIER COLUMN WILL BUILD ACROSS THE AREA EARLY ON IN THE SHORT TERM PERIOD AS THE SUBTROPICAL MOISTURE PLUME SHIFTS AWAY FROM THE COAST. LINGERING LOW CLOUDS IN THE MORNING...BUT RAINFALL WILL COME TO AN END WITH THE DEPARTURE OF THE AFOREMENTIONED PLUME AND AS STRONG SUBSIDENCE DEVELOPS IN THE H85-H5 LAYER. THUS THE TREND FOR TUESDAY IS CLEARING SKIES AND MUCH COOLER TEMPERATURES COMPARED TO THE RECENT WARM SPELL. COLDER AIR ARRIVES TUESDAY NIGHT INTO WEDNESDAY MORNING (LOWS IN THE MID TO UPPER 20S) WITH COLD AIR ADVECTION LEADING TO HIGHS ONLY IN THE 40S FOR CHRISTMAS DAY. INCREASING CLOUDS WEDNESDAY NIGHT WILL RESULT IN SLIGHTLY WARMER MINS...BUT THEY WILL STILL BE AT OR JUST BELOW FREEZING ACROSS THE FORECAST AREA. && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 240 PM MONDAY...THE EXTENDED FORECAST CONTINUES TO LOOK RATHER UNEVENTFUL WITH THE OVERALL MID LEVEL PATTERN DEPICTING A MODEST TROUGH OVER THE EASTERN THIRD OF THE U.S. AND MODEST RIDGING ACROSS THE SOUTHWEST. AT THE SURFACE THERE WILL BE TWO FRONTS THAT MOVE ACROSS THE AREA THAT WILL ONLY SERVE TO RESET ANY TEMPERATURE MODIFICATION. TEMPERATURES THURSDAY AND FRIDAY WILL BE SLIGHTLY BELOW CLIMATOLOGY AS THE COLD AIR MASS THAT FOLLOWS THE SYSTEM MOVING THROUGH TODAY AND TONIGHT LINGERS. THERE IS A SLIGHT MODIFICATION OF TEMPERATURES SATURDAY AND SUNDAY VIA AIRMASS MODIFICATION. THIS BRIEF WARMUP IS SHORT LIVED AS ANOTHER DRY FRONT MOVES ACROSS MONDAY. THE TRENDS ARE RATHER CONSISTENT AND THE CONSOLATION IS THAT THE WILD TEMPERATURE SWINGS WE HAVE EXPERIENCED THE PAST FEW WEEKS ARE AT LEAST TEMPORARILY A THING OF THE PAST. FINALLY THE ONLY POPS IN THE FORECAST ARE THURSDAY INTO EARLY FRIDAY FROM WHAT APPEARS TO BE MORE OF A WEAK WAVE MOVING IN FROM THE SOUTHWEST FLOW ALOFT THAT SKIRTS THE AREA. THE SURFACE COASTAL TROUGH PATTERN SEEMS TO HAVE DISAPPEARED. REGARDLESS OF THE FORCING MECHANISMS...POPS REMAIN LOW AND MOSTLY CONFINED TO THE COASTAL AREAS. && .AVIATION /03Z TUESDAY THROUGH SATURDAY/... AS OF 00Z...AN INITIAL COLD FRONT/TROUGH IS APPROACHING THE COASTAL TERMINALS. A STRONGER COLD FRONT IS MOVING IN FROM THE NW. LIFR CONDITIONS IN SEA FOG WILL IMPROVE AND/OR SHIFT OFFSHORE OF KCRE/KMYR WITHIN THE NEXT HOUR OR TWO. STILL THROUGH THE NEXT SEVERAL HOURS THERE IS HIGH CONFIDENCE OF IFR CONDITIONS AT THE COASTAL TERMINALS ASSOCIATED WITH A BAND OF CONVECTIVE SHOWERS MOVING EAST ALONG AND AHEAD OF THE FRONT. NO LIGHTNING IS BEING DETECTED THUS THE THUNDERSTORM POTENTIAL REMAINS LOW. BRIEF GUSTY W WINDS TO 20 KNOTS ARE POSSIBLE WITH THE SHOWERS. WITH A WEAK RIDGE OF HIGH PRESSURE AND MOIST LOW LEVELS BEHIND THE INITIAL FRONT THERE IS LOW CONFIDENCE FOR IFR TO RE-DEVELOP AT KFLO/KLBT THIS EVENING. WITH THE ARRIVAL OF THE SECOND FRONT CIGS AT KFLO/KMYR SHOULD BE PREDOMINATELY MVFR THE REMAINDER OF THE NIGHT...ALTHOUGH CIGS COULD FLIRT WITH IFR AT TIMES AROUND 06Z. THERE SEEMS TO BE A HIGHER POTENTIAL OF POST FRONTAL IFR OR LOWER FLIGHT CONDITIONS TO DEVELOP AT THE COASTAL TERMINALS...AND IT MAY TAKE UNTIL SUNRISE FOR THESE CIGS TO RISE TO MVFR. MORNING MVFR CIGS SHOULD RISE TO VFR MID-LATE MORNING WITH VFR FOR THE REMAINDER OF TUESDAY. WINDS WILL BE NW-N. EXTENDED OUTLOOK...VFR THROUGH THE PERIOD. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1030 PM MONDAY...SCA WILL CONTINUE FOR THE ILM NC WATERS THROUGH 7 AM TUESDAY. SCEC HAS REPLACED THE SCA FOR THE ILM SC WATERS...AND WILL REMAIN IN EFFECT THRU 7 AM TUESDAY. SW-WSW AROUND 15 KT LATE THIS EVENING...WILL VEER TO THE NW AROUND 15 KT IMMEDIATELY AFTER THE COLD FRONTAL PASSAGE...AND FURTHER VEER TO THE NORTH AT 10-20 KT DURING THE PRE-DAWN TUE HOURS. THE LATEST NAM AND HRRR WIND PROGS ILLUSTRATE THIS NICELY. SIGNIFICANT SEAS WILL BE GOVERNED BY A 7 TO 8 SECOND PERIOD SSE BORDERLINE SWELL...AND A 10 SECOND PERIOD SE GROUND SWELL. COMBINED WITH LOCALLY PRODUCED WIND DRIVEN WAVES...SIGNIFICANT SEAS WILL RANGE BETWEEN 3 AND 5 FT FOR THE ILM SC WATERS...AND 4 TO 7 FT ACROSS THE ILM NC WATERS. THE 7 FOOTERS WILL OCCUR ACROSS THE OUTER WATERS OFF CAPE FEAR. AREAL COVERAGE OF SEA FOG HAS DECREASED...AND WILL FURTHER DECREASE OVERNIGHT ESPECIALLY ONCE THE POST FRONTAL LOWER DEWPOINTS ADVECT ACROSS THE LOCAL WATERS. SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 240 PM MONDAY...N TO NW FLOW WILL PREVAIL IN THE WAKE OF THE COLD FRONT TUESDAY AND TUESDAY NIGHT...THEN THE WIND WILL VEER TO THE NE DURING WEDNESDAY. WINDS WILL DIMINISH TO AROUND 10 KT OR LESS BY WEDNESDAY NIGHT AS WEAKENING RIDGE OF HIGH PRESSURE BUILD INTO THE VICINITY. THE OFFSHORE TRAJECTORY WILL RESULT IN A RANGE OF SEAS THAT WILL BE FETCH LIMITED NEAR THE COAST. FOR THE MOST PART SEAS WILL APPROACH 5 FT CLOSER TO 20 NM OFFSHORE THROUGH MOST OF THE PERIOD WITH 1-2 FT SEAS NEAR THE COAST. LONG TERM /THURSDAY THROUGH SATURDAY/... AS OF 240 PM MONDAY...ONCE AGAIN THE CENTRAL THEME FOR THE EXTENDED COASTAL WATERS FORECAST IS A NORTHERLY COMPONENT TO THE WINDS. FOR THURSDAY THE FLOW WILL BE 10-15 KNOTS WITH A COUPLE OF ROGUE GUSTS OVER 15 POSSIBLE. AS A DRY FRONT MOVES ACROSS FRIDAY SPEEDS WILL INCREASE TO 15-20 KNOTS. SATURDAY WINDS DROP BACK DOWN TO 10-15 KNOTS...AGAIN FROM THE NORTH. SEAS WILL FOLLOW THE WIND SPEED TRENDS WITH 2-4 FEET THURSDAY AND SATURDAY WITH 3-5 FEET FOR FRIDAY. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST TUESDAY FOR AMZ250-252. && $$ SYNOPSIS...SRP NEAR TERM...DCH SHORT TERM...SRP LONG TERM...SHK AVIATION...MRR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
810 PM EST MON DEC 23 2013 .SYNOPSIS... A SLOW MOVING COLD FRONT APPROACHING FROM THE WEST WILL MOVE OFF THE COAST TONIGHT. DRIER AND COOLER AIR WILL SPREAD ACROSS THE REGION IN THE WAKE OF THE COLD FRONT. A MOSTLY DRY COLD FRONT WILL PASS ACROSS THE AREA FRIDAY...MAINTAINING SEASONABLE TEMPERATURES INTO THE WEEKEND. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... AS OF 715 PM MONDAY...ROUGHLY...THE SFC COLD FRONT EXTENDS FROM NORFOLK VA SOUTHWESTWARD ACROSS LUMBERTON NC TO COLUMBIA SC. THE COLD FRONT WILL PUSH ACROSS THE FA LATE THIS EVENING AND INTO THE PRE-DAWN TUE HOURS. THE POST COLD FRONTAL WX CONDITIONS ACROSS THE FA WILL EXPERIENCE...WIND CHANGE TO THE NW-N...COLD AIR ADVECTION ACCOMPANIED BY LOWER DEWPOINTS. POST FRONTAL LIGHT RAIN AND SHOWERS WILL PERSIST OVERNIGHT INTO DAYLIGHT TUESDAY B4 FINALLY BEING PUSHED OFF THE COAST AND OFFSHORE FROM A PROGRESSIVE UPPER S/W TROF. WILL CONTINUE THE THREAT FOR AN ISOLATED THUNDERSTORM THIS EVENING DUE TO VERY WEAK SFC BASED INSTABILITY. OTHERWISE...WITH THE DAYS INSOLATION OVER-WITH THE THREAT FOR THUNDER WILL ONLY CONTINUE THRU MIDNIGHT. ONLY MASSAGED THE OVERNITE LOWS...WHICH WILL OCCUR AROUND SUNRISE TUESDAY. PREVIOUS DISCUSSION................................................ AS OF 240 PM MONDAY...THE COLD FRONT CONTINUES TO PRESS EASTWARD AS IT IS APPROACHES RALEIGH BUT IS IT STILL LAGS A BIT TO THE SOUTH. A POSSIBLE PRE-FRONTAL TROUGH IS RUNNING AHEAD OF THE FRONT TO THE SOUTH. THE 18Z UTC RUC IS SHOWING THE 850 LOW LEVEL JET MAX CENTERED OVER SOUTH CAROLINA AND THIS FEATURE WILL SHIFT NORTH OUT OF THE AREA BY 22 UTC. THIS APPEARS TO BE THE WHAT IS ENHANCING THE LOW TOP CONVECTION IN INLAND AREAS OF SOUTHEAST NORTH CAROLINA. SEA FOG IS NOW BREAKING UP ALONG THE GEORGETOWN COAST AND WILL LINGER FOR THE NEXT HALF HOUR BEFORE BECOMING A NONE FACTOR. MODELS STILL CONTINUE TO BRING A FRONT TO THE COAST BY 7 PM BUT THE MODELS MAINTAIN A GOOD CHANCE OF SHOWERS EARLY THEN SLOWLY TAPER THE RAIN OFF OVERNIGHT. QPF VALUES APPEAR TO BE LESS THAN A HALF OF AN INCH. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/... AS OF 240 PM MONDAY...A DRIER COLUMN WILL BUILD ACROSS THE AREA EARLY ON IN THE SHORT TERM PERIOD AS THE SUBTROPICAL MOISTURE PLUME SHIFTS AWAY FROM THE COAST. LINGERING LOW CLOUDS IN THE MORNING...BUT RAINFALL WILL COME TO AN END WITH THE DEPARTURE OF THE AFOREMENTIONED PLUME AND AS STRONG SUBSIDENCE DEVELOPS IN THE H85-H5 LAYER. THUS THE TREND FOR TUESDAY IS CLEARING SKIES AND MUCH COOLER TEMPERATURES COMPARED TO THE RECENT WARM SPELL. COLDER AIR ARRIVES TUESDAY NIGHT INTO WEDNESDAY MORNING (LOWS IN THE MID TO UPPER 20S) WITH COLD AIR ADVECTION LEADING TO HIGHS ONLY IN THE 40S FOR CHRISTMAS DAY. INCREASING CLOUDS WEDNESDAY NIGHT WILL RESULT IN SLIGHTLY WARMER MINS...BUT THEY WILL STILL BE AT OR JUST BELOW FREEZING ACROSS THE FORECAST AREA. && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 240 PM MONDAY...THE EXTENDED FORECAST CONTINUES TO LOOK RATHER UNEVENTFUL WITH THE OVERALL MID LEVEL PATTERN DEPICTING A MODEST TROUGH OVER THE EASTERN THIRD OF THE U.S. AND MODEST RIDGING ACROSS THE SOUTHWEST. AT THE SURFACE THERE WILL BE TWO FRONTS THAT MOVE ACROSS THE AREA THAT WILL ONLY SERVE TO RESET ANY TEMPERATURE MODIFICATION. TEMPERATURES THURSDAY AND FRIDAY WILL BE SLIGHTLY BELOW CLIMATOLOGY AS THE COLD AIR MASS THAT FOLLOWS THE SYSTEM MOVING THROUGH TODAY AND TONIGHT LINGERS. THERE IS A SLIGHT MODIFICATION OF TEMPERATURES SATURDAY AND SUNDAY VIA AIRMASS MODIFICATION. THIS BRIEF WARMUP IS SHORT LIVED AS ANOTHER DRY FRONT MOVES ACROSS MONDAY. THE TRENDS ARE RATHER CONSISTENT AND THE CONSOLATION IS THAT THE WILD TEMPERATURE SWINGS WE HAVE EXPERIENCED THE PAST FEW WEEKS ARE AT LEAST TEMPORARILY A THING OF THE PAST. FINALLY THE ONLY POPS IN THE FORECAST ARE THURSDAY INTO EARLY FRIDAY FROM WHAT APPEARS TO BE MORE OF A WEAK WAVE MOVING IN FROM THE SOUTHWEST FLOW ALOFT THAT SKIRTS THE AREA. THE SURFACE COASTAL TROUGH PATTERN SEEMS TO HAVE DISAPPEARED. REGARDLESS OF THE FORCING MECHANISMS...POPS REMAIN LOW AND MOSTLY CONFINED TO THE COASTAL AREAS. && .AVIATION /01Z TUESDAY THROUGH SATURDAY/... AS OF 00Z...AN INITIAL COLD FRONT/TROUGH IS APPROACHING THE COASTAL TERMINALS. A STRONGER COLD FRONT IS MOVING IN FROM THE NW. LIFR CONDITIONS IN SEA FOG WILL IMPROVE AND/OR SHIFT OFFSHORE OF KCRE/KMYR WITHIN THE NEXT HOUR OR TWO. STILL THROUGH THE NEXT SEVERAL HOURS THERE IS HIGH CONFIDENCE OF IFR CONDITIONS AT THE COASTAL TERMINALS ASSOCIATED WITH A BAND OF CONVECTIVE SHOWERS MOVING EAST ALONG AND AHEAD OF THE FRONT. NO LIGHTNING IS BEING DETECTED THUS THE THUNDERSTORM POTENTIAL REMAINS LOW. BRIEF GUSTY W WINDS TO 20 KNOTS ARE POSSIBLE WITH THE SHOWERS. WITH A WEAK RIDGE OF HIGH PRESSURE AND MOIST LOW LEVELS BEHIND THE INITIAL FRONT THERE IS LOW CONFIDENCE FOR IFR TO RE-DEVELOP AT KFLO/KLBT THIS EVENING. WITH THE ARRIVAL OF THE SECOND FRONT CIGS AT KFLO/KMYR SHOULD BE PREDOMINATELY MVFR THE REMAINDER OF THE NIGHT...ALTHOUGH CIGS COULD FLIRT WITH IFR AT TIMES AROUND 06Z. THERE SEEMS TO BE A HIGHER POTENTIAL OF POST FRONTAL IFR OR LOWER FLIGHT CONDITIONS TO DEVELOP AT THE COASTAL TERMINALS...AND IT MAY TAKE UNTIL SUNRISE FOR THESE CIGS TO RISE TO MVFR. MORNING MVFR CIGS SHOULD RISE TO VFR MID-LATE MORNING WITH VFR FOR THE REMAINDER OF TUESDAY. WINDS WILL BE NW-N. EXTENDED OUTLOOK...VFR THROUGH THE PERIOD. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 730 PM MONDAY...SCA WILL CONTINUE FOR THE ILM NC WATERS THROUGH 7 AM TUESDAY. SCEC HAS REPLACED THE SCA FOR THE ILM SC WATERS...AND IS ALSO IN EFFECT THRU 7 AM TUESDAY. SW AROUND 15 KT THIS EVENING...WILL VEER TO THE NW AROUND 15 KT IMMEDIATELY AFTER THE COLD FRONTAL PASSAGE...AND FURTHER VEER TO THE NORTH AT 10-20 KT BY DAYBREAK TUE. THE LATEST NAM AND HRRR WIND PROGS ILLUSTRATE THIS NICELY. SIGNIFICANT SEAS WILL BE GOVERNED BY A 7 TO 8 SECOND PERIOD SSE BORDERLINE SWELL...AND A 10 SECOND PERIOD SE GROUND SWELL. COMBINED WITH LOCALLY PRODUCED WIND DRIVEN WAVES...SIGNIFICANT SEAS WILL RANGE BETWEEN 3 AND 5 FT FOR THE ILM SC WATERS...AND 4 TO 7 FT ACROSS THE ILM NC WATERS. THE 7 FOOTERS WILL OCCUR ACROSS THE OUTER WATERS OFF CAPE FEAR. AREAL COVERAGE OF SEA FOG HAS DECREASED...AND WILL FURTHER DECREASE OVERNIGHT ESPECIALLY ONCE THE POST FRONTAL LOWER DEWPOINTS ADVECT ACROSS THE LOCAL WATERS. PREVIOUS DISCUSSION............................................. AS OF 240 PM MONDAY...THE DENSE FOG ADVISORY WILL BE ALLOWED TO EXPIRE AT 3 PM AS IT CONTINUE TO SLOWLY DISSIPATE AND ADVECT TO THE NORTH NORTHEAST AHEAD OF A SLOW MOVING FRONT FOR THE WATERS MAINLY SOUTH OF LITTLE RIVER INLET. THE FRONTAL PASSAGE ACROSS THE WATERS IS EXPECTED AFTER 7 PM AND WITH THIS FRONT A GOOD PUSH OF OFFSHORE FLOW IS EXPECTED AND THE SEAS WILL FALL BELOW SMALL CRAFT CONDITIONS AT 8 PM SOUTH OF LITTLE RIVER INLET AND 2 AM FOR THE WATERS TO THE NORTH. SEAS SHOULD RELAX LATE AND WILL BEGIN AT 4 TO 6 FEET BUT WILL SETTLE OUT TO A RANGE OF 2 FEET NEAR SHORE AND 5 FEET AT 20 MILES OFF THE COAST. SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 240 PM MONDAY...N TO NW FLOW WILL PREVAIL IN THE WAKE OF THE COLD FRONT TUESDAY AND TUESDAY NIGHT...THEN THE WIND WILL VEER TO THE NE DURING WEDNESDAY. WINDS WILL DIMINISH TO AROUND 10 KT OR LESS BY WEDNESDAY NIGHT AS WEAKENING RIDGE OF HIGH PRESSURE BUILD INTO THE VICINITY. THE OFFSHORE TRAJECTORY WILL RESULT IN A RANGE OF SEAS THAT WILL BE FETCH LIMITED NEAR THE COAST. FOR THE MOST PART SEAS WILL APPROACH 5 FT CLOSER TO 20 NM OFFSHORE THROUGH MOST OF THE PERIOD WITH 1-2 FT SEAS NEAR THE COAST. LONG TERM /THURSDAY THROUGH SATURDAY/... AS OF 240 PM MONDAY...ONCE AGAIN THE CENTRAL THEME FOR THE EXTENDED COASTAL WATERS FORECAST IS A NORTHERLY COMPONENT TO THE WINDS. FOR THURSDAY THE FLOW WILL BE 10-15 KNOTS WITH A COUPLE OF ROGUE GUSTS OVER 15 POSSIBLE. AS A DRY FRONT MOVES ACROSS FRIDAY SPEEDS WILL INCREASE TO 15-20 KNOTS. SATURDAY WINDS DROP BACK DOWN TO 10-15 KNOTS...AGAIN FROM THE NORTH. SEAS WILL FOLLOW THE WIND SPEED TRENDS WITH 2-4 FEET THURSDAY AND SATURDAY WITH 3-5 FEET FOR FRIDAY. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST TUESDAY FOR AMZ250-252. && $$ SYNOPSIS...SRP NEAR TERM...DCH/DRH SHORT TERM...SRP LONG TERM...SHK AVIATION...MRR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
636 PM EST MON DEC 23 2013 .SYNOPSIS... A SLOW MOVING COLD FRONT APPROACHING FROM THE WEST WILL MOVE OFF THE COAST TONIGHT. DRIER AND COOLER AIR WILL SPREAD ACROSS THE REGION IN THE WAKE OF THE COLD FRONT. A MOSTLY DRY COLD FRONT WILL PASS ACROSS THE AREA FRIDAY...MAINTAINING SEASONABLE TEMPERATURES INTO THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 240 PM MONDAY...THE COLD FRONT CONTINUES TO PRESS EASTWARD AS IT IS APPROACHES RALEIGH BUT IS IT STILL LAGS A BIT TO THE SOUTH. A POSSIBLE PREFRONTAL TROUGH IS RUNNING AHEAD OF THE FRONT TO THE SOUTH. THE 18Z UTC RUC IS SHOWING THE 850 LOW LEVEL JET MAX CENTERED OVER SOUTH CAROLINA AND THIS FEATURE WILL SHIFT NORTH OUT OF THE AREA BY 22 UTC. THIS APPEARS TO BE THE WHAT IS ENHANCING THE LOW TOP CONVECTION IN INLAND AREAS OF SOUTHEAST NORTH CAROLINA. SEA FOG IS NOW BREAKING UP ALONG THE GEORGETOWN COAST AND WILL LINGER FOR THE NEXT HALF HOUR BEFORE BECOMING A NONE FACTOR. MODELS STILL CONTINUE TO BRING A FRONT TO THE COAST BY 7 PM BUT THE MODELS MAINTAIN A GOOD CHANCE OF SHOWERS EARLY THEN SLOWLY TAPER THE RAIN OFF OVERNIGHT. QPF VALUES APPEAR TO BE LESS THAN A HALF OF AN INCH. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 240 PM MONDAY...A DRIER COLUMN WILL BUILD ACROSS THE AREA EARLY ON IN THE SHORT TERM PERIOD AS THE SUBTROPICAL MOISTURE PLUME SHIFTS AWAY FROM THE COAST. LINGERING LOW CLOUDS IN THE MORNING...BUT RAINFALL WILL COME TO AN END WITH THE DEPARTURE OF THE AFOREMENTIONED PLUME AND AS STRONG SUBSIDENCE DEVELOPS IN THE H85-H5 LAYER. THUS THE TREND FOR TUESDAY IS CLEARING SKIES AND MUCH COOLER TEMPERATURES COMPARED TO THE RECENT WARM SPELL. COLDER AIR ARRIVES TUESDAY NIGHT INTO WEDNESDAY MORNING (LOWS IN THE MID TO UPPER 20S) WITH COLD AIR ADVECTION LEADING TO HIGHS ONLY IN THE 40S FOR CHRISTMAS DAY. INCREASING CLOUDS WEDNESDAY NIGHT WILL RESULT IN SLIGHTLY WARMER MINS...BUT THEY WILL STILL BE AT OR JUST BELOW FREEZING ACROSS THE FORECAST AREA. && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 240 PM MONDAY...THE EXTENDED FORECAST CONTINUES TO LOOK RATHER UNEVENTFUL WITH THE OVERALL MID LEVEL PATTERN DEPICTING A MODEST TROUGH OVER THE EASTERN THIRD OF THE U.S. AND MODEST RIDGING ACROSS THE SOUTHWEST. AT THE SURFACE THERE WILL BE TWO FRONTS THAT MOVE ACROSS THE AREA THAT WILL ONLY SERVE TO RESET ANY TEMPERATURE MODIFICATION. TEMPERATURES THURSDAY AND FRIDAY WILL BE SLIGHTLY BELOW CLIMATOLOGY AS THE COLD AIR MASS THAT FOLLOWS THE SYSTEM MOVING THROUGH TODAY AND TONIGHT LINGERS. THERE IS A SLIGHT MODIFICATION OF TEMPERATURES SATURDAY AND SUNDAY VIA AIRMASS MODIFICATION. THIS BRIEF WARMUP IS SHORT LIVED AS ANOTHER DRY FRONT MOVES ACROSS MONDAY. THE TRENDS ARE RATHER CONSISTENT AND THE CONSOLATION IS THAT THE WILD TEMPERATURE SWINGS WE HAVE EXPERIENCED THE PAST FEW WEEKS ARE AT LEAST TEMPORARILY A THING OF THE PAST. FINALLY THE ONLY POPS IN THE FORECAST ARE THURSDAY INTO EARLY FRIDAY FROM WHAT APPEARS TO BE MORE OF A WEAK WAVE MOVING IN FROM THE SOUTHWEST FLOW ALOFT THAT SKIRTS THE AREA. THE SURFACE COASTAL TROUGH PATTERN SEEMS TO HAVE DISAPPEARED. REGARDLESS OF THE FORCING MECHANISMS...POPS REMAIN LOW AND MOSTLY CONFINED TO THE COASTAL AREAS. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... AS OF 00Z...AN INITIAL COLD FRONT/TROUGH IS APPROACHING THE COASTAL TERMINALS. A STRONGER COLD FRONT IS MOVING IN FROM THE NW. LIFR CONDITIONS IN SEA FOG WILL IMPROVE AND/OR SHIFT OFFSHORE OF KCRE/KMYR WITHIN THE NEXT HOUR OR TWO. STILL THROUGH THE NEXT SEVERAL HOURS THERE IS HIGH CONFIDENCE OF IFR CONDITIONS AT THE COASTAL TERMINALS ASSOCIATED WITH A BAND OF CONVECTIVE SHOWERS MOVING EAST ALONG AND AHEAD OF THE FRONT. NO LIGHTNING IS BEING DETECTED THUS THE THUNDERSTORM POTENTIAL REMAINS LOW. BRIEF GUSTY W WINDS TO 20 KNOTS ARE POSSIBLE WITH THE SHOWERS. WITH A WEAK RIDGE OF HIGH PRESSURE AND MOIST LOW LEVELS BEHIND THE INITIAL FRONT THERE IS LOW CONFIDENCE FOR IFR TO RE-DEVELOP AT KFLO/KLBT THIS EVENING. WITH THE ARRIVAL OF THE SECOND FRONT CIGS AT KFLO/KMYR SHOULD BE PREDOMINATELY MVFR THE REMAINDER OF THE NIGHT...ALTHOUGH CIGS COULD FLIRT WITH IFR AT TIMES AROUND 06Z. THERE SEEMS TO BE A HIGHER POTENTIAL OF POST FRONTAL IFR OR LOWER FLIGHT CONDITIONS TO DEVELOP AT THE COASTAL TERMINALS...AND IT MAY TAKE UNTIL SUNRISE FOR THESE CIGS TO RISE TO MVFR. MORNING MVFR CIGS SHOULD RISE TO VFR MID-LATE MORNING WITH VFR FOR THE REMAINDER OF TUESDAY. WINDS WILL BE NW-N. EXTENDED OUTLOOK...VFR THROUGH THE PERIOD. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 240 PM MONDAY...THE DENSE FOG ADVISORY WILL BE ALLOWED TO EXPIRE AT 3 PM AS IT CONTINUE TO SLOWLY DISSIPATE AND ADVECT TO THE NORTH NORTHEAST AHEAD OF A SLOW MOVING FRONT FOR THE WATERS MAINLY SOUTH OF LITTLE RIVER INLET. THE FRONTAL PASSAGE ACROSS THE WATERS IS EXPECTED AFTER 7 PM AND WITH THIS FRONT A GOOD PUSH OF OFFSHORE FLOW IS EXPECTED AND THE SEAS WILL FALL BELOW SMALL CRAFT CONDITIONS AT 8 PM SOUTH OF LITTLE RIVER INLET AND 2 AM FOR THE WATERS TO THE NORTH. SEAS SHOULD RELAX LATE AND WILL BEGIN AT 4 TO 6 FEET BUT WILL SETTLE OUT TO A RANGE OF 2 FEET NEAR SHORE AND 5 FEET AT 20 MILES OFF THE COAST. SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 240 PM MONDAY...N TO NW FLOW WILL PREVAIL IN THE WAKE OF THE COLD FRONT TUESDAY AND TUESDAY NIGHT...THEN THE WIND WILL VEER TO THE NE DURING WEDNESDAY. WINDS WILL DIMINISH TO AROUND 10 KT OR LESS BY WEDNESDAY NIGHT AS WEAKENING RIDGE OF HIGH PRESSURE BUILD INTO THE VICINITY. THE OFFSHORE TRAJECTORY WILL RESULT IN A RANGE OF SEAS THAT WILL BE FETCH LIMITED NEAR THE COAST. FOR THE MOST PART SEAS WILL APPROACH 5 FT CLOSER TO 20 NM OFFSHORE THROUGH MOST OF THE PERIOD WITH 1-2 FT SEAS NEAR THE COAST. LONG TERM /THURSDAY THROUGH SATURDAY/... AS OF 240 PM MONDAY...ONCE AGAIN THE CENTRAL THEME FOR THE EXTENDED COASTAL WATERS FORECAST IS A NORTHERLY COMPONENT TO THE WINDS. FOR THURSDAY THE FLOW WILL BE 10-15 KNOTS WITH A COUPLE OF ROGUE GUSTS OVER 15 POSSIBLE. AS A DRY FRONT MOVES ACROSS FRIDAY SPEEDS WILL INCREASE TO 15-20 KNOTS. SATURDAY WINDS DROP BACK DOWN TO 10-15 KNOTS...AGAIN FROM THE NORTH. SEAS WILL FOLLOW THE WIND SPEED TRENDS WITH 2-4 FEET THURSDAY AND SATURDAY WITH 3-5 FEET FOR FRIDAY. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EST THIS EVENING FOR AMZ254- 256. SMALL CRAFT ADVISORY UNTIL 2 AM EST TUESDAY FOR AMZ250-252. && $$ NEAR TERM...DRH SHORT TERM...SRP LONG TERM...SHK AVIATION...MRR
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
923 PM EST MON DEC 23 2013 .SYNOPSIS... WEAK DISTURBANCES WILL BRING LIGHT SNOW SHOWERS TO THE PORTIONS OF THE REGION TONIGHT...WEDNESDAY...AND ON THURSDAY. A COLD FRONT WILL MOVE THROUGH THE AREA ON SUNDAY. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... WE ARE STARTING TO SEE SOME LIGHT SNOW SHOWER ACTIVITY BACK TO OUR WEST THIS EVENING. THIS IS ASSOCIATED WITH SHORT WAVE ENERGY ROTATING THROUGH THE BASE OF THE MID/UPPER LEVEL TROUGH. AS IT PIVOTS ACROSS OUR AREA OVERNIGHT...EXPECT ISOLATED TO SCATTERED SNOW SHOWERS ACROSS THE AREA. ANY ACCUMULATION SHOULD BE LIGHT...GENERALLY JUST A TENTH OR TWO OF AN INCH AT MOST. GOOD CAA WILL DEVELOP THROUGH THE NIGHT...ALLOWING FOR TEMPERATURES TO FALL INTO THE TEENS ACROSS MUCH OF THE AREA. WINDS WILL STAY UP ENOUGH TO PRODUCE SOME SUB ZERO WIND CHILLS ACROSS OUR NORTHWEST LATE TONIGHT INTO EARLY TUESDAY. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/... HIGH PRESSURE WILL WORK INTO THE FA FOR TUESDAY AND TUESDAY NIGHT. TEMPERATURES WILL STRUGGLE TO RISE ON TUESDAY WITH COOL NW FLOW. LIMITED HIGH TEMPERATURES ON TUESDAY TO THE 20S. TEMPERATURES WILL DROP OFF PRETTY QUICKLY TUESDAY EVENING WITH MOSTLY CLEAR SKIES HOWEVER DO NOT EXPECT THAT SHARP OF A DROP OFF LATER IN THE NIGHT AS CLOUD COVER INCREASES ACROSS THE FA. THE INCREASING CLOUD COVER WILL HELP KEEP TEMPERATURES FROM FALLING INTO THE SINGLE DIGITS TUESDAY NIGHT. A COUPLE MORE WEAK DISTURBANCES WILL MOVE THROUGH ON WEDNESDAY AND THEN AGAIN LATE WEDNESDAY NIGHT. LIMITED ANY SNOW SHOWER MENTION TO NORTHERN PORTIONS OF THE FA. && .LONG TERM /THURSDAY THROUGH MONDAY/... THIS PERIOD BEGINS WITH RATHER STRONG LONGWAVE RIDGING ACROSS THE WRN CONUS WHICH TELECONNECTS TO ERN CONUS TROUGHING AND BELOW NORMAL HEIGHTS/TEMPS IN THE GREAT LAKES. A POTENT SHORTWAVE TROUGH CRESTING THE RIDGE ALLOWS TEMPORARY HEIGHT RISE AHEAD OF IT WHICH PUSH INTO THE OHIO VALLEY TOWARD THE END OF WEEK/EARLY WEEKEND WITH MODIFYING TEMPERATURES BACK TO NEAR OR SLIGHTLY ABOVE NORMAL. THIS SHORTWAVE WILL HAVE A POTENT ARCTIC FRONT ASSOCIATED WITH IT...AND AS THE WAVE MOVES THROUGH THE MEAN LONGWAVE TROUGH IN THE EAST...WILL ALLOW FOR ITS REORGANIZATION AND REDEVELOPMENT BACK TO THE WEST A BIT...WHICH PROMISES A SIGNIFICANT COOLDOWN LATE IN THE WEEKEND AND ESPECIALLY EARLY NEXT WEEK. IN THE DETAILS...THURS WILL FEATURE THE DEPARTURE OF A WEAK WAVE/COLD FRONT WITH A SMALL THREAT OF SNOW SHOWERS EARLY ON THURS. HIGH PRESSURE BUILDING SOUTH OF THE AREA BRINGS WEAK SOUTHERLY FLOW MEANING LAKE-INDUCED FLOW AND SNOW SHOWERS SHOULD NOT BE IN PLAY THUS DRY CONDITIONS THU AFTN THROUGH SAT. A LEADING WEAK SHORTWAVE AHEAD OF THE MORE POTENT WAVE ON FRIDAY NIGHT/SAT LOOKS TO REMAIN NORTH OF THE AREA WITH ITS DYNAMICS/MOISTURE...BUT SUNDAY/S WAVE WILL BRING A SHARP FRONTAL PASSAGE WITH AN AIRMASS OF ARCTIC ORIGIN IN ITS WAKE. THUS...EXPECT THE THREAT FOR SOME LIGHT RAIN/SNOW ON SUNDAY TO TRANSITION TO MORE OF A SNOW SHOWER/SQUALL THREAT ON STRONG COLD ADVECTION SUNDAY NIGHT INTO MONDAY WITH NWLY FLOW OFF LAKE MICHIGAN. BEYOND MONDAY...HINTS OF ANOTHER WEAK WAVE THAT MAY BRING LIGHT SNOWS AND REINFORCING COLD AIR FOR THE MIDDLE OF NEXT WEEK. EITHER WAY...THE ENTIRE PERIOD LOOKS TO BE DRIER THAN NORMAL...AND AVERAGING OUT COLDER THAN NORMAL...ESPECIALLY ON THUR/FRI AND AGAIN MON. && .AVIATION /02Z TUESDAY THROUGH SATURDAY/... A FAIRLY SOLID MVFR DECK IS IN PLACE ACROSS THE REGION EARLY THIS EVENING. SOME BREAKS ARE SHOWING UP ACROSS WESTERN INDIANA...BUT AS THE 500 MB TROUGH AXIS PIVOTS EAST ACROSS OUR AREA OVERNIGHT...NOT SURE HOW FAST THESE BREAKS WILL MAKE IT INTO OUR AREA. IN FACT...MANY OF THE HI RES MODELS...INCLUDING THE RAP AND ARW- WRF...ARE INDICATING SOME SNOW SHOWERS DEVELOPMENT LATER TONIGHT. WILL THEREFORE ALLOW FOR A VCSH AT ALL THE TAF SITES LATER TONIGHT AND SOME TEMPO VSBY RESTRICTIONS AT THE NORTHERN TAF SITES. HIGH PRESSURE WILL BEGIN TO BUILD IN FROM THE WEST THROUGH THE DAY ON TUESDAY...ALLOWING FOR A GRADUAL CLEARING TREND THROUGH THE LATER PART OF THE TAF PERIOD. OUTLOOK...NO SIGNIFICANT WEATHER IS EXPECTED. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...NOVAK NEAR TERM...JGL SHORT TERM...NOVAK LONG TERM...BINAU AVIATION...JGL
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
716 PM EST MON DEC 23 2013 .SYNOPSIS... WEAK DISTURBANCES WILL BRING LIGHT SNOW SHOWERS TO THE PORTIONS OF THE REGION TONIGHT...WEDNESDAY...AND ON THURSDAY. A COLD FRONT WILL MOVE THROUGH THE AREA ON SUNDAY. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... SOME OF THE CLOUDS ARE CLEARING OUT ACROSS SE PORTIONS OF THE FA HOWEVER EXPECT THIS TO BE SHORT LIVED. ADDITIONAL CLOUD COVER WILL MOVE INTO THE FA OVERNIGHT AS A WEAK DISTURBANCE MOVES THROUGH THE REGION. SNOW SHOWERS ARE EXPECTED TO BE LIGHT WITH THIS FEATURE AS IT MOVES ACROSS THE FA. LIMITED SNOWFALL ACCUMULATIONS TO A TENTH OF AN INCH OR TWO. WENT CLOSE TO GUIDANCE FOR LOW TEMPERATURES OVERNIGHT. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/... HIGH PRESSURE WILL WORK INTO THE FA FOR TUESDAY AND TUESDAY NIGHT. TEMPERATURES WILL STRUGGLE TO RISE ON TUESDAY WITH COOL NW FLOW. LIMITED HIGH TEMPERATURES ON TUESDAY TO THE 20S. TEMPERATURES WILL DROP OFF PRETTY QUICKLY TUESDAY EVENING WITH MOSTLY CLEAR SKIES HOWEVER DO NOT EXPECT THAT SHARP OF A DROP OFF LATER IN THE NIGHT AS CLOUD COVER INCREASES ACROSS THE FA. THE INCREASING CLOUD COVER WILL HELP KEEP TEMPERATURES FROM FALLING INTO THE SINGLE DIGITS TUESDAY NIGHT. A COUPLE MORE WEAK DISTURBANCES WILL MOVE THROUGH ON WEDNESDAY AND THEN AGAIN LATE WEDNESDAY NIGHT. LIMITED ANY SNOW SHOWER MENTION TO NORTHERN PORTIONS OF THE FA. && .LONG TERM /THURSDAY THROUGH MONDAY/... THIS PERIOD BEGINS WITH RATHER STRONG LONGWAVE RIDGING ACROSS THE WRN CONUS WHICH TELECONNECTS TO ERN CONUS TROUGHING AND BELOW NORMAL HEIGHTS/TEMPS IN THE GREAT LAKES. A POTENT SHORTWAVE TROUGH CRESTING THE RIDGE ALLOWS TEMPORARY HEIGHT RISE AHEAD OF IT WHICH PUSH INTO THE OHIO VALLEY TOWARD THE END OF WEEK/EARLY WEEKEND WITH MODIFYING TEMPERATURES BACK TO NEAR OR SLIGHTLY ABOVE NORMAL. THIS SHORTWAVE WILL HAVE A POTENT ARCTIC FRONT ASSOCIATED WITH IT...AND AS THE WAVE MOVES THROUGH THE MEAN LONGWAVE TROUGH IN THE EAST...WILL ALLOW FOR ITS REORGANIZATION AND REDEVELOPMENT BACK TO THE WEST A BIT...WHICH PROMISES A SIGNIFICANT COOLDOWN LATE IN THE WEEKEND AND ESPECIALLY EARLY NEXT WEEK. IN THE DETAILS...THURS WILL FEATURE THE DEPARTURE OF A WEAK WAVE/COLD FRONT WITH A SMALL THREAT OF SNOW SHOWERS EARLY ON THURS. HIGH PRESSURE BUILDING SOUTH OF THE AREA BRINGS WEAK SOUTHERLY FLOW MEANING LAKE-INDUCED FLOW AND SNOW SHOWERS SHOULD NOT BE IN PLAY THUS DRY CONDITIONS THU AFTN THROUGH SAT. A LEADING WEAK SHORTWAVE AHEAD OF THE MORE POTENT WAVE ON FRIDAY NIGHT/SAT LOOKS TO REMAIN NORTH OF THE AREA WITH ITS DYNAMICS/MOISTURE...BUT SUNDAY/S WAVE WILL BRING A SHARP FRONTAL PASSAGE WITH AN AIRMASS OF ARCTIC ORIGIN IN ITS WAKE. THUS...EXPECT THE THREAT FOR SOME LIGHT RAIN/SNOW ON SUNDAY TO TRANSITION TO MORE OF A SNOW SHOWER/SQUALL THREAT ON STRONG COLD ADVECTION SUNDAY NIGHT INTO MONDAY WITH NWLY FLOW OFF LAKE MICHIGAN. BEYOND MONDAY...HINTS OF ANOTHER WEAK WAVE THAT MAY BRING LIGHT SNOWS AND REINFORCING COLD AIR FOR THE MIDDLE OF NEXT WEEK. EITHER WAY...THE ENTIRE PERIOD LOOKS TO BE DRIER THAN NORMAL...AND AVERAGING OUT COLDER THAN NORMAL...ESPECIALLY ON THUR/FRI AND AGAIN MON. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... A FAIRLY SOLID MVFR DECK IS IN PLACE ACROSS THE REGION EARLY THIS EVENING. SOME BREAKS ARE SHOWING UP ACROSS WESTERN INDIANA...BUT AS THE 500 MB TROUGH AXIS PIVOTS EAST ACROSS OUR AREA OVERNIGHT...NOT SURE HOW FAST THESE BREAKS WILL MAKE IT INTO OUR AREA. IN FACT...MANY OF THE HI RES MODELS...INCLUDING THE RAP AND ARW- WRF...ARE INDICATING SOME SNOW SHOWERS DEVELOPMENT LATER TONIGHT. WILL THEREFORE ALLOW FOR A VCSH AT ALL THE TAF SITES LATER TONIGHT AND SOME TEMPO VSBY RESTRICTIONS AT THE NORTHERN TAF SITES. HIGH PRESSURE WILL BEGIN TO BUILD IN FROM THE WEST THROUGH THE DAY ON TUESDAY...ALLOWING FOR A GRADUAL CLEARING TREND THROUGH THE LATER PART OF THE TAF PERIOD. OUTLOOK...NO SIGNIFICANT WEATHER IS EXPECTED. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...NOVAK NEAR TERM...NOVAK SHORT TERM...NOVAK LONG TERM...BINAU AVIATION...JGL
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
702 AM EST SUN DEC 22 2013 .SYNOPSIS... LOW PRESSURE OVER NORTHERN OHIO WILL CONTINUE NORTHEAST TODAY GIVING A KICK TO A FRONT STALLED ACROSS THE AREA. THE FRONT WILL MOVE EAST OF THE AREA BY THE AFTERNOON ALLOWING DRIER BUT NOTABLY COLDER AIR TO MOVE INTO THE AREA FOR MUCH OF THE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... UPDATE...NO SIGNIFICANT CHANGES FOR THE UPDATE. ORIGINAL...MODERATE TO LOCALLY HEAVY RAIN STILL OCCURRING ACROSS THE CENTRAL AND EASTERN COUNTIES EARLY TODAY HOWEVER MODELS SHOW DRIER AIR WRAPPING AROUND THE SYSTEM WILL MOVE IN FROM THE SOUTHWEST TODAY. FOLLOWED SREF POP GUIDANCE STARTING WITH CATEGORICAL POPS EARLY...DROPPING TO SLIGHT CHANCE WEST OF A KCLE TO KMFD LINE BY 15Z. BY 18Z WILL DROP FAR EASTERN COUNTIES TO CHANCE AND MUCH OF THE REST OF THE AREA TO SLIGHT CHANCE OR LOWER. HIGHS WILL BE VERY TRICKY TODAY AND HAVE USED THE HRRR WHICH IS ABLE TO BEST GRAPHICALLY HANDLE MOVING THE TIGHT GRADIENT ACROSS THE AREA. IN SHORT...EXPECT TEMPS IN THE EAST AND CENTRAL COUNTIES TO RECOVER WITH THE MILD AIR LIFTING TO THE LAKESHORE AGAIN EARLY WHILE THE WEST WILL REMAIN COOL. DURING THE AFTERNOON THE COOLER AIR WILL SWEEP SOUTHEAST. WILL CONTINUE WITH THE FLOOD WATCH AS IS. MEDIA REMIND YOUR VIEWERS AND LISTENERS NOT TO DRIVE THROUGH FLOODED AREAS. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... SHOULD GET A BIT OF A BREAK TONIGHT AS THE DRY SLOT CONTINUE THROUGH THE AREA ALTHOUGH BY MORNING MONDAY 850MB TEMPS WILL BE DOWN TO -7 TO -9 ON THE LAKE. WHILE THIS WILL NOT BE ENOUGH FOR LAKE EFFECT TEMPS CONTINUE TO FALL TO -12C OR SO THROUGH THE AFTERNOON SO WOULD EXPECT CHANCES FOR SNOW WILL INCREASE AS THE DAY WEARS ON. WILL HAVE CHANCE POPS ACROSS THE SNOW BELT IN THE MORNING INCREASING TO LIKELY IN THE AFTERNOON. TEMPS CONTINUE TO DROP TO -14C BY 12Z TUESDAY WHILE THE CORE OF THE COLD AIR (-20C) THANKFULLY DROPS ACROSS SOUTHERN AND CENTRAL OHIO. STILL HOWEVER...-14C WILL BE LOW ENOUGH FOR LAKE EFFECT TO CONTINUE AND IN FACT WILL HAVE CATEGORICAL POPS FOR THE OVERNIGHT MONDAY NIGHT...DROPPING BACK TO LIKELY TUESDAY. TUESDAY NIGHT HIGH PRESSURE AND DRIER AIR WILL MOVE QUICKLY ACROSS THE AREA COUNTERING THE -16C TEMPS ON THE LAKE. WILL DROP POPS THROUGH LIKELY TO CHANCE THROUGH THE NIGHT. WEDNESDAY A WARM FRONT WILL MOVE THROUGH THE WESTERN LAKE WITH OVERRUNNING MOISTURE BRUSHING THE AREA. AM CONCERNED THAT A LIGHT SNOW DEVELOPS SO WILL HAVE LOW CHANCE POPS IN PLACE FOR THE DAY. WEDNESDAY NIGHT HEIGHTS DROP AS AN UPPER LOW/TROF MOVES BACK INTO THE GREAT LAKES REGION SO WILL CONTINUE WITH LOW CHANCE POPS. && .LONG TERM /THURSDAY THROUGH SATURDAY/... THURSDAY COLD FRONT MOVES THROUGH THE AREA HOWEVER THERE ARE DIFFERENCES BETWEEN THE GFS AND ECMWF TIMING WITH THE ECMWF SLOWER OF THE TWO. WILL FOLLOW WPC/ECMWF GUIDANCE THROUGH THE LONG TERM PERIOD GENERALLY BRINGING BACK A SHOT AT LAKE EFFECT SNOW THURSDAY THROUGH FRIDAY...DRYING IT OUT FOR SATURDAY AS HIGH PRESSURE BUILDS IN. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/... LOW PRESSURE NEAR TIFFIN OHIO IS MOVING QUICKLY TOWARD LAKE ERIE WITH ITS WARM FRONT SWEEPING QUICKLY TO THE NORTH INTO LAKE ERIE. GUSTY SOUTHERLY WINDS OF 25 TO 35 KNOTS PREVAIL EAST OF THE LOW. LOW CLOUDS HAVE CLEARED OUT OF THE WARM SECTOR AND HAVE LEFT ONLY MID CLOUDS WITH VFR CONDITIONS BUT STILL SOME LIGHT RAIN MAINLY EAST OF I-71. OVER WESTERN OHIO BEHIND THE COLD FRONT... SOUTHWESTERLY WINDS ARE ADVECTING LOW CLOUDS EAST WHICH WILL OVERSPREAD THE REGION TODAY. EXPECT MVFR TO IFR CIGS TO OVERSPREAD THE REGION. ONCE COOLER AIR SPREADS INTO THE REGION FROM THE WEST TOWARD NOON...WIND GUSTS SHOULD SUBSIDE TO 20 TO 25 KNOTS AND FURTHER WEAKEN AFTER 21Z. TOWARD SUNSET EXPECT IFR CIGS TO DEVELOP AND PERSIST OVERNIGHT AS COLDER AIR MOVES INTO THE REGION. SOME LIGHT SNOW WILL MOVE INTO THE AREA AND MAINLY AFFECT THE MFD CAK CLE YNG AND ERI TAF SITES IN NORTH CENTRAL AND NORTHEAST OHIO AND NW PA. .OUTLOOK...SPOTTY NON VFR LINGERS INTO MONDAY...IMPROVING BY TUESDAY NIGHT. BY WEDNESDAY MOSTLY VFR CONDITIONS. && .MARINE... UPDATED...WINDS IN THE WARM SECTOR GUSTING AROUND 30 KNOTS WHILE WINDS IN THE COOLER AIR ARE NOT AS STRONG. WHILE THE STRONGER WINDS WILL NOT REACH TOO FAR ONTO THE LAKE GIVEN THAT THE WATER IS MUCH COOLER THAN THE AIR...FELT STILL THAT A SMALL CRAFT WOULD BE WARRANTED AS WINDS CLOSE TO SHORE WOULD BE STRONG. PREVIOUS...EXPECTING A VARIABLE WIND EARLY TODAY AS LOW PRESSURE TRACKS ACROSS THE REGION. WINDS WILL TURN SOUTHWEST 15 TO 25 KNOTS BEHIND THE LOW HOWEVER FOR MUCH OF TODAY. HIGH PRESSURE WILL BUILD IN FOR LATE MONDAY AND TUESDAY TURNING WINDS NORTHWEST AT 10 TO 20 KNOTS OR SO. MID WEEK THE HIGH MOVES EAST AND WINDS TURN SOUTH TO SOUTHWEST AT 15 TO 25 KNOTS REACHING NEAR 30 KNOTS THURSDAY. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...FLOOD WATCH UNTIL 6 PM EST THIS EVENING FOR OHZ003-006>014- 017>023-027>033-036>038-047-089. PA...FLOOD WATCH UNTIL 6 PM EST THIS EVENING FOR PAZ001>003. MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR LEZ145>149. && $$ SYNOPSIS...TK NEAR TERM...TK SHORT TERM...TK LONG TERM...TK AVIATION...LAPLANTE MARINE...TK
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
637 AM EST SUN DEC 22 2013 .SYNOPSIS... LOW PRESSURE OVER NORTHERN OHIO WILL CONTINUE NORTHEAST TODAY GIVING A KICK TO A FRONT STALLED ACROSS THE AREA. THE FRONT WILL MOVE EAST OF THE AREA BY THE AFTERNOON ALLOWING DRIER BUT NOTABLY COLDER AIR TO MOVE INTO THE AREA FOR MUCH OF THE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... UPDATE...NO SIGNIFICANT CHANGES FOR THE UPDATE. ORIGINAL...MODERATE TO LOCALLY HEAVY RAIN STILL OCCURRING ACROSS THE CENTRAL AND EASTERN COUNTIES EARLY TODAY HOWEVER MODELS SHOW DRIER AIR WRAPPING AROUND THE SYSTEM WILL MOVE IN FROM THE SOUTHWEST TODAY. FOLLOWED SREF POP GUIDANCE STARTING WITH CATEGORICAL POPS EARLY...DROPPING TO SLIGHT CHANCE WEST OF A KCLE TO KMFD LINE BY 15Z. BY 18Z WILL DROP FAR EASTERN COUNTIES TO CHANCE AND MUCH OF THE REST OF THE AREA TO SLIGHT CHANCE OR LOWER. HIGHS WILL BE VERY TRICKY TODAY AND HAVE USED THE HRRR WHICH IS ABLE TO BEST GRAPHICALLY HANDLE MOVING THE TIGHT GRADIENT ACROSS THE AREA. IN SHORT...EXPECT TEMPS IN THE EAST AND CENTRAL COUNTIES TO RECOVER WITH THE MILD AIR LIFTING TO THE LAKESHORE AGAIN EARLY WHILE THE WEST WILL REMAIN COOL. DURING THE AFTERNOON THE COOLER AIR WILL SWEEP SOUTHEAST. WILL CONTINUE WITH THE FLOOD WATCH AS IS. MEDIA REMIND YOUR VIEWERS AND LISTENERS NOT TO DRIVE THROUGH FLOODED AREAS. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... SHOULD GET A BIT OF A BREAK TONIGHT AS THE DRY SLOT CONTINUE THROUGH THE AREA ALTHOUGH BY MORNING MONDAY 850MB TEMPS WILL BE DOWN TO -7 TO -9 ON THE LAKE. WHILE THIS WILL NOT BE ENOUGH FOR LAKE EFFECT TEMPS CONTINUE TO FALL TO -12C OR SO THROUGH THE AFTERNOON SO WOULD EXPECT CHANCES FOR SNOW WILL INCREASE AS THE DAY WEARS ON. WILL HAVE CHANCE POPS ACROSS THE SNOW BELT IN THE MORNING INCREASING TO LIKELY IN THE AFTERNOON. TEMPS CONTINUE TO DROP TO -14C BY 12Z TUESDAY WHILE THE CORE OF THE COLD AIR (-20C) THANKFULLY DROPS ACROSS SOUTHERN AND CENTRAL OHIO. STILL HOWEVER...-14C WILL BE LOW ENOUGH FOR LAKE EFFECT TO CONTINUE AND IN FACT WILL HAVE CATEGORICAL POPS FOR THE OVERNIGHT MONDAY NIGHT...DROPPING BACK TO LIKELY TUESDAY. TUESDAY NIGHT HIGH PRESSURE AND DRIER AIR WILL MOVE QUICKLY ACROSS THE AREA COUNTERING THE -16C TEMPS ON THE LAKE. WILL DROP POPS THROUGH LIKELY TO CHANCE THROUGH THE NIGHT. WEDNESDAY A WARM FRONT WILL MOVE THROUGH THE WESTERN LAKE WITH OVERRUNNING MOISTURE BRUSHING THE AREA. AM CONCERNED THAT A LIGHT SNOW DEVELOPS SO WILL HAVE LOW CHANCE POPS IN PLACE FOR THE DAY. WEDNESDAY NIGHT HEIGHTS DROP AS AN UPPER LOW/TROF MOVES BACK INTO THE GREAT LAKES REGION SO WILL CONTINUE WITH LOW CHANCE POPS. && .LONG TERM /THURSDAY THROUGH SATURDAY/... THURSDAY COLD FRONT MOVES THROUGH THE AREA HOWEVER THERE ARE DIFFERENCES BETWEEN THE GFS AND ECMWF TIMING WITH THE ECMWF SLOWER OF THE TWO. WILL FOLLOW WPC/ECMWF GUIDANCE THROUGH THE LONG TERM PERIOD GENERALLY BRINGING BACK A SHOT AT LAKE EFFECT SNOW THURSDAY THROUGH FRIDAY...DRYING IT OUT FOR SATURDAY AS HIGH PRESSURE BUILDS IN. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/... LOW PRESSURE IS NOW IN SOUTHWEST OHIO WITH A WARM FRONT EXTENDING NORTHEAST THROUGH MANSFIELD TO MEADVILLE. THE LOW WILL CONTINUE TO MOVE NORTHEAST ALONG THE FRONT AND KEEP THE RAIN GOING THROUGH MUCH OF THE NIGHT. A LINE OF SHOWERS AND MINIMAL THUNDERSTORMS WILL MOVE THROUGH MANSFIELD AND AKRON CANTON AREA AND WILL PRODUCE GUSTY WINDS AS IT MOVES THROUGH THE AREA. WE WILL CONTINUE TO SEE SOME VERY LOW CEILINGS THROUGH THE NIGHT DUE TO THE PROXIMITY OF THE FRONTAL BOUNDARY AND LOW PRESSURE SYSTEM. POCKETS OF HEAVY RAIN COULD DROP VISIBILITIES CONSIDERABLY FOR BRIEF PERIODS. EXPECTING RAIN TO FINALLY END FROM WEST TO EAST BEGINNING AROUND 12Z AS RAIN PULLS OUT OF THE REGION. WINDS WILL BE VARIABLE THROUGH THE FORECAST PERIOD DUE TO THE LOW PRESSURE SYSTEM TRACKING ACROSS THE AREA. .OUTLOOK...SPOTTY NON VFR LINGERS INTO MONDAY...IMPROVING BY TUESDAY NIGHT. BY WEDNESDAY MOSTLY VFR CONDITIONS. && .MARINE... UPDATED...WINDS IN THE WARM SECTOR GUSTING AROUND 30 KNOTS WHILE WINDS IN THE COOLER AIR ARE NOT AS STRONG. WHILE THE STRONGER WINDS WILL NOT REACH TOO FAR ONTO THE LAKE GIVEN THAT THE WATER IS MUCH COOLER THAN THE AIR...FELT STILL THAT A SMALL CRAFT WOULD BE WARRANTED AS WINDS CLOSE TO SHORE WOULD BE STRONG. PREVIOUS...EXPECTING A VARIABLE WIND EARLY TODAY AS LOW PRESSURE TRACKS ACROSS THE REGION. WINDS WILL TURN SOUTHWEST 15 TO 25 KNOTS BEHIND THE LOW HOWEVER FOR MUCH OF TODAY. HIGH PRESSURE WILL BUILD IN FOR LATE MONDAY AND TUESDAY TURNING WINDS NORTHWEST AT 10 TO 20 KNOTS OR SO. MID WEEK THE HIGH MOVES EAST AND WINDS TURN SOUTH TO SOUTHWEST AT 15 TO 25 KNOTS REACHING NEAR 30 KNOTS THURSDAY. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...FLOOD WATCH UNTIL 6 PM EST THIS EVENING FOR OHZ003-006>014- 017>023-027>033-036>038-047-089. PA...FLOOD WATCH UNTIL 6 PM EST THIS EVENING FOR PAZ001>003. MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR LEZ145>149. && $$ SYNOPSIS...TK NEAR TERM...TK SHORT TERM...TK LONG TERM...TK AVIATION...LOMBARDY MARINE...TK
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
417 AM EST SUN DEC 22 2013 .SYNOPSIS... LOW PRESSURE OVER NORTHERN OHIO WILL CONTINUE NORTHEAST TODAY GIVING A KICK TO A FRONT STALLED ACROSS THE AREA. THE FRONT WILL MOVE EAST OF THE AREA BY THE AFTERNOON ALLOWING DRIER BUT NOTABLY COLDER AIR TO MOVE INTO THE AREA FOR MUCH OF THE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... MODERATE TO LOCALLY HEAVY RAIN STILL OCCURRING ACROSS THE CENTRAL AND EASTERN COUNTIES EARLY TODAY HOWEVER MODELS SHOW DRIER AIR WRAPPING AROUND THE SYSTEM WILL MOVE IN FROM THE SOUTHWEST TODAY. FOLLOWED SREF POP GUIDANCE STARTING WITH CATEGORICAL POPS EARLY...DROPPING TO SLIGHT CHANCE WEST OF A KCLE TO KMFD LINE BY 15Z. BY 18Z WILL DROP FAR EASTERN COUNTIES TO CHANCE AND MUCH OF THE REST OF THE AREA TO SLIGHT CHANCE OR LOWER. HIGHS WILL BE VERY TRICKY TODAY AND HAVE USED THE HRRR WHICH IS ABLE TO BEST GRAPHICALLY HANDLE MOVING THE TIGHT GRADIENT ACROSS THE AREA. IN SHORT...EXPECT TEMPS IN THE EAST AND CENTRAL COUNTIES TO RECOVER WITH THE MILD AIR LIFTING TO THE LAKESHORE AGAIN EARLY WHILE THE WEST WILL REMAIN COOL. DURING THE AFTERNOON THE COOLER AIR WILL SWEEP SOUTHEAST. WILL CONTINUE WITH THE FLOOD WATCH AS IS. MEDIA REMIND YOUR VIEWERS AND LISTENERS NOT TO DRIVE THROUGH FLOODED AREAS. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... SHOULD GET A BIT OF A BREAK TONIGHT AS THE DRY SLOT CONTINUE THROUGH THE AREA ALTHOUGH BY MORNING MONDAY 850MB TEMPS WILL BE DOWN TO -7 TO -9 ON THE LAKE. WHILE THIS WILL NOT BE ENOUGH FOR LAKE EFFECT TEMPS CONTINUE TO FALL TO -12C OR SO THROUGH THE AFTERNOON SO WOULD EXPECT CHANCES FOR SNOW WILL INCREASE AS THE DAY WEARS ON. WILL HAVE CHANCE POPS ACROSS THE SNOW BELT IN THE MORNING INCREASING TO LIKELY IN THE AFTERNOON. TEMPS CONTINUE TO DROP TO -14C BY 12Z TUESDAY WHILE THE CORE OF THE COLD AIR (-20C) THANKFULLY DROPS ACROSS SOUTHERN AND CENTRAL OHIO. STILL HOWEVER...-14C WILL BE LOW ENOUGH FOR LAKE EFFECT TO CONTINUE AND IN FACT WILL HAVE CATEGORICAL POPS FOR THE OVERNIGHT MONDAY NIGHT...DROPPING BACK TO LIKELY TUESDAY. TUESDAY NIGHT HIGH PRESSURE AND DRIER AIR WILL MOVE QUICKLY ACROSS THE AREA COUNTERING THE -16C TEMPS ON THE LAKE. WILL DROP POPS THROUGH LIKELY TO CHANCE THROUGH THE NIGHT. WEDNESDAY A WARM FRONT WILL MOVE THROUGH THE WESTERN LAKE WITH OVERRUNNING MOISTURE BRUSHING THE AREA. AM CONCERNED THAT A LIGHT SNOW DEVELOPS SO WILL HAVE LOW CHANCE POPS IN PLACE FOR THE DAY. WEDNESDAY NIGHT HEIGHTS DROP AS AN UPPER LOW/TROF MOVES BACK INTO THE GREAT LAKES REGION SO WILL CONTINUE WITH LOW CHANCE POPS. && .LONG TERM /THURSDAY THROUGH SATURDAY/... THURSDAY COLD FRONT MOVES THROUGH THE AREA HOWEVER THERE ARE DIFFERENCES BETWEEN THE GFS AND ECMWF TIMING WITH THE ECMWF SLOWER OF THE TWO. WILL FOLLOW WPC/ECMWF GUIDANCE THROUGH THE LONG TERM PERIOD GENERALLY BRINGING BACK A SHOT AT LAKE EFFECT SNOW THURSDAY THROUGH FRIDAY...DRYING IT OUT FOR SATURDAY AS HIGH PRESSURE BUILDS IN. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... LOW PRESSURE IS NOW IN SOUTHWEST OHIO WITH A WARM FRONT EXTENDING NORTHEAST THROUGH MANSFIELD TO MEADVILLE. THE LOW WILL CONTINUE TO MOVE NORTHEAST ALONG THE FRONT AND KEEP THE RAIN GOING THROUGH MUCH OF THE NIGHT. A LINE OF SHOWERS AND MINIMAL THUNDERSTORMS WILL MOVE THROUGH MANSFIELD AND AKRON CANTON AREA AND WILL PRODUCE GUSTY WINDS AS IT MOVES THROUGH THE AREA. WE WILL CONTINUE TO SEE SOME VERY LOW CEILINGS THROUGH THE NIGHT DUE TO THE PROXIMITY OF THE FRONTAL BOUNDARY AND LOW PRESSURE SYSTEM. POCKETS OF HEAVY RAIN COULD DROP VISIBILITIES CONSIDERABLY FOR BRIEF PERIODS. EXPECTING RAIN TO FINALLY END FROM WEST TO EAST BEGINNING AROUND 12Z AS RAIN PULLS OUT OF THE REGION. WINDS WILL BE VARIABLE THROUGH THE FORECAST PERIOD DUE TO THE LOW PRESSURE SYSTEM TRACKING ACROSS THE AREA. .OUTLOOK...SPOTTY NON VFR LINGERS INTO MONDAY...IMPROVING BY TUESDAY NIGHT. BY WEDNESDAY MOSTLY VFR CONDITIONS. && .MARINE... EXPECTING A VARIABLE WIND EARLY TODAY AS LOW PRESSURE TRACKS ACROSS THE REGION. WINDS WILL TURN SOUTHWEST 15 TO 25 KNOTS BEHIND THE LOW HOWEVER FOR MUCH OF TODAY. HIGH PRESSURE WILL BUILD IN FOR LATE MONDAY AND TUESDAY TURNING WINDS NORTHWEST AT 10 TO 20 KNOTS OR SO. MID WEEK THE HIGH MOVES EAST AND WINDS TURN SOUTH TO SOUTHWEST AT 15 TO 25 KNOTS REACHING NEAR 30 KNOTS THURSDAY. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...FLOOD WATCH THROUGH THIS AFTERNOON FOR OHZ003-006>014-017>023- 027>033-036>038-047-089. PA...FLOOD WATCH THROUGH THIS AFTERNOON FOR PAZ001>003. MARINE...NONE. && $$ SYNOPSIS...TK NEAR TERM...TK SHORT TERM...TK LONG TERM...TK AVIATION...LOMBARDY MARINE...TK
AREA FORECAST DISCUSSION
NWS TULSA OK
911 PM CST MON DEC 23 2013 ...UPDATE... .DISCUSSION... UPDATED THE FORECAST EARLIER IN THE EVENING TO REMOVE POPS. THE MAIN VARIABLE FOR THE REMAINDER OF THE NIGHT IS THE EXTENT OF LOW CLOUDS AND THE EFFECT ON MINIMUM TEMPERATURES. THE RUC KEEPS PLENTY OF MOISTURE/CLOUDS OVERNIGHT... ALTHOUGH CURRENT SATELLITE IMAGES SHOW PARTIAL CLEARING ACROSS THE AREA. WAS TEMPTED TO RAISE MINIMUM TEMPERATURES A FEW DEGREES BASED ON ANTICIPATED CLOUDS. HOWEVER... WITH AREAS OF CLEAR SKIES OUT THERE CURRENTLY... HAVE ENOUGH DOUBT THAT RADIATIONAL COOLING WILL BE INHIBITED ALL THAT MUCH. THE BOTTOM LINE IS THAT FORECAST MINIMUM TEMPERATURES HAVE BEEN LEFT UNCHANGED. THEREFORE... WILL UPDATE PRODUCTS AT THIS TIME. && .TSA WATCHES/WARNINGS/ADVISORIES... OK...NONE. AR...NONE. && $$ SHORT TERM...06
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
723 PM EST MON DEC 23 2013 .SYNOPSIS... A SLOW-MOVING FRONTAL BOUNDARY ALONG THE EAST COAST WILL PUSH OUT TO SEA TONIGHT. NOTICEABLY COLDER AIR WILL RETURN TO THE AREA BY CHRISTMAS EVE AND CONTINUE INTO THE END OF THE WEEK. ASIDE FROM THE POSSIBILITY OF A COUPLE OF WEAK CLIPPER TYPE SYSTEMS DROPPING OUT OF THE GREAT LAKES...NO SIGNIFICANT STORMS ARE EXPECTED FOR THE UPCOMING WEEK. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... WEAK WAVE OF LOW PRES NR VIRGINIA BEACH SLOWING EXIT OF SFC FRONT ALONG THE E COAST THIS EVENING. RAIN CONTINUES TO FALL EARLY THIS EVENING WELL WEST OF THE FRONT IN REGION OF FGEN FORCING BENEATH RIGHT ENTRANCE TO POWERFUL UPPER JET. LATEST RAP OUTPUT CAPTURES THIS FORCING THE THE 8-7H LVL AND IMPLIES THE LAST OF THE RAIN WILL EXIT LANCASTER CO BY 00Z. THE UPPER TROF AXIS IS STILL WELL TO THE WEST AND WILL BE APPROACHING TONIGHT AND TUESDAY. THE DEEP MOISTURE WILL HAVE PUSHED OFF WELL TO THE EAST BY OVERNIGHT...BUT BETWEEN GR LAKES MOISTURE AND THE INCREASE IN UPPER FORCING...IT WILL BE ENOUGH TO TRIGGER SOME SNOW SHOWERS OVER THE AREAS DOWNWIND OF LAKE ERIE INTO NW PA. AT THIS POINT AMOUNTS LOOK TO AVERAGE LESS THAN ADVISORY LEVELS IN MOST AREAS...BUT WOULD NOT BE SURPRISED TO SEE A FEW REPORTS OF 3 INCHES ACROSS THE SNOWBELT OF NW WARREN CO THROUGH LATE TUESDAY. LOWS TONIGHT WILL END THE RECENT SPELL OF VERY MILD WEATHER WITH TEENS AND 20S GETTING BACK VERY CLOSE TO NORMAL. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/... THE UPPER TROF WILL PASS BY EARLY TUESDAY AFTERNOON WITH THE ACCOMPANYING POCKET OF COLD AIR ALOFT HELPING SUPPORT FAIRLY WIDESPREAD SNOW SHOWERS AND FLURRIES. THE BEST CHANCE OF SEEING A COATING TO A COUPLE OF INCHES OF NEW SNOW WILL BE OVER THE HIGH TERRAIN OF THE NORTH AND WEST...WITH LITTLE CHANCE FOR A WHITE CHRISTMAS ELSEWHERE. FORCING FOR THE SNOW SHOWERS WILL BE WANING RAPIDLY IN THE AFTERNOON AS A SHORTWAVE UPPER RIDGE HURRIES TO FILL IN BEHIND OUR DEPARTING TROUGH. HIGH TEMPS FROM NEAR 20 IN THE NORTH TO NEAR 49 IN THE SE WILL REPRESENT A RETURN TO BELOW NORMAL TEMPS FOR THE REGION. && .LONG TERM /TUESDAY NIGHT THROUGH MONDAY/... UPPER LEVEL TROFFING WILL PERSIST THROUGH MUCH OF THE LONG TERM PERIOD OVER THE EASTERN TWO THIRDS OF CONUS AS MODERATE TO STRONG NORTHERN STREAM JET STREAM DIRECTS SEVERAL WAVES OF COLD AIR INTO THE NORTHEASTERN U.S. BRIEF PERIOD OF SHORT WAVE RIDGING ON WEDNESDAY WILL SUPPORT STRONG SFC HIGH WITH A PERIOD OF QUIET WEATHER EXPECTED FOR CHRISTMAS DAY. IN GENERA...MOST OF THE LONG TERM PERIOD SHOULD BE RELATIVELY QUIET WEATHER-WISE DESPITE SEVERAL FRONTAL PASSAGES...AS SYSTEMS WILL BE MOISTURE LIMITED AND NOT ABLE TO PRODUCE MUCH PCPN. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... FEW SNOW SHOWERS TO THE WEST...BUT ON THE DECREASE. LOWER CIGS ACROSS THE MOUNTAINS TONIGHT. MAIN ISSUE WILL BE SNOW SHOWERS ON TUE...AS A STRONG UPPER LVL SYSTEM AND COLD FRONT MOVES ACROSS THE REGION. THINK THAT BURST OF HEAVIER SNOW WILL BE POSSIBLE ACROSS CENTRAL AND WESTERN AREAS...ALONG WITH GUSTY WINDS. IMPROVING CONDITIONS FOR TUESDAY NIGHT AND CHRISTMAS DAY. NEXT SYSTEM MOVES ACROSS THE AREA ON THU...FOLLOWED BY ANOTHER SYSTEM ON FRIDAY. NW FLOW WILL SUPPORT SOME SNOW SHOWER ACTIVITY...ESPECIALLY AT BFD. OUTLOOK... WED...VFR HIGH PRES. THU-FRI...OCNL SNOW SHOWERS/MVFR CIGS WEST. VFR CENTRAL AND EASTERN AREAS. SAT...NO SIG WX. && .CLIMATE... RECORD DAILY MAXIMUM TEMPERATURES WERE SET AT OUR OFFICIAL CLIMATE SITES /HARRISBURG AND WILLIAMSPORT/ YESTERDAY. THERE WERE ALSO SEVERAL "UNOFFICIAL" RECORD HIGHS SET AT NON-LCD SITES SUCH AS ALTOONA AND BRADFORD. A RECORD HIGH TEMPERATURE OF 70 DEGREES WAS SET AT HARRISBURG YESTERDAY. THIS BROKE THE OLD RECORD HIGH OF 64 DEGREES SET BACK IN 1949. A CONTINUOUS WEATHER RECORD HAS BEEN KEPT AT HARRISBURG SINCE 1888. A RECORD HIGH TEMPERATURE OF 64 DEGREES WAS SET AT WILLIAMSPORT YESTERDAY. THIS BROKE THE OLD RECORD OF 60 DEGREES SET BACK IN 1949. A CONTINUOUS WEATHER RECORD HAS BEEN KEPT AT WILLIAMSPORT SINCE 1895. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...FITZGERALD/LA CORTE NEAR TERM...FITZGERALD/LA CORTE SHORT TERM...LA CORTE LONG TERM...LAMBERT/GARTNER AVIATION...MARTIN CLIMATE...STEINBUGL
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1141 AM CST SUN DEC 22 2013 .AVIATION... NO THREAT TO VFR CONDITIONS THROUGH MONDAY AS SURFACE HIGH PRESSURE PASSES THROUGH THE REGION. LIGHT NLY WINDS TODAY WILL VEER S-SWLY BY TONIGHT. && PREV DISCUSSION... /ISSUED 331 AM CST SUN DEC 22 2013/ SHORT TERM... WINTER DOES NOT WANT TO LET UP FOR THE REGION WITH RENEWED CHANCES FOR LIGHT PRECIPITATION THIS MORNING. ANOTHER TROUGH AXIS HAS STILL TO PASS LATER THIS MORNING. WEAK Q-VECTOR CONVERGENCE IS CURRENTLY MOVING OVER THE AREA. THIS WAS COUPLED WITH WEAK FRONTOGENETICAL FORCING AROUND 750-700MB EDGING INTO THE SOUTHWESTERN TEXAS PANHANDLE. MODELS WERE IN GOOD AGREEMENT SHOWING LIFT PEAKING AROUND 12Z UNDER SATURATED SOUNDINGS. ALTHOUGH...THE ONLY DIFFERENCE BETWEEN MODEL RAP AND NAM SOUNDINGS IS A DRY NEAR SURFACE LAYER DEPICTED BY THE NAM. THIS CAN CERTAINLY MAKE A DIFFERENCE IN SNOW TOTALS WITH THE MORE MOIST RAP SHOWING MORE SNOWFALL. LONG TERM... WITH THE EXIT EAST OF THE CURRENT LONG-WAVE TROUGH MONDAY...LESSER AMPLITUDE AND DRY NORTHWEST FLOW WILL BECOME DOMINANT THROUGH MUCH OF THE WEEK. NEXT SHORT-WAVE UPPER TROUGH WILL SKIM BY TO THE NORTH WEDNESDAY DRAGGING A SLIGHTLY WEAKER FRONT INTO THE AREA EARLY WEDNESDAY THAN PREVIOUSLY ADVERTISED. FLATTER WESTERLY FLOW APPEARS IN THE WORKS EARLY NEXT WEEKEND WITH BACKING AND INCREASING SOUTHWEST FLOW ALOFT LATER IN THE WEEKEND...ALTHOUGH SPREAD IN THE DEVELOPING INTER-MOUNTAIN UPPER TROUGH WILL BE ON THE RISE. THIS PATTERN WILL YIELD MODEST WARMING MONDAY...A WEAK BACK-DOOR FRONT WILL SLIP IN MONDAY AFTERNOON AND EVENING...WITH BETTER WARMING AND GUSTY SOUTHWEST WINDS TUESDAY. THEN THE SLIGHT CHRISTMAS DAY COOL-DOWN WITH SLOW WARMING THURSDAY AND FRIDAY. BIGGER BOOST IN TEMPERATURES AND MORE GUSTY SOUTHWEST BREEZES EXPECTED SATURDAY BEFORE NEXT COOLING THE FOLLOWING SUNDAY. MINOR CHANGES. RMCQUEEN && .PRELIMINARY POINT TEMPS/POPS... FRIONA 37 19 42 24 55 / 10 0 0 0 0 TULIA 38 20 42 24 56 / 10 0 0 0 0 PLAINVIEW 40 21 46 25 56 / 10 0 0 0 0 LEVELLAND 42 22 49 26 56 / 10 0 0 0 0 LUBBOCK 42 23 49 26 57 / 10 0 0 0 0 DENVER CITY 44 24 50 28 55 / 10 0 0 0 0 BROWNFIELD 44 24 51 27 56 / 10 0 0 0 0 CHILDRESS 40 22 46 24 57 / 10 0 0 0 0 SPUR 45 23 50 27 57 / 10 0 0 0 0 ASPERMONT 45 24 51 29 58 / 0 0 0 0 0 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 93
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
536 AM CST SUN DEC 22 2013 .AVIATION... VFR IS EXPECTED THROUGH THE TAF PERIOD. THERE EXISTS A VERY SMALL CHANCE AT SNOW FLURRIES AT KLBB DURING THE MORNING HOURS BUT CHANCES ARE TOO LOW TO MENTION IN THE TAF. && .PREV DISCUSSION... /ISSUED 331 AM CST SUN DEC 22 2013/ SHORT TERM... WINTER DOES NOT WANT TO LET UP FOR THE REGION WITH RENEWED CHANCES FOR LIGHT PRECIPITATION THIS MORNING. ANOTHER TROUGH AXIS HAS STILL TO PASS LATER THIS MORNING. WEAK Q-VECTOR CONVERGENCE IS CURRENTLY MOVING OVER THE AREA. THIS WAS COUPLED WITH WEAK FRONTOGENETICAL FORCING AROUND 750-700MB EDGING INTO THE SOUTHWESTERN TEXAS PANHANDLE. MODELS WERE IN GOOD AGREEMENT SHOWING LIFT PEAKING AROUND 12Z UNDER SATURATED SOUNDINGS. ALTHOUGH...THE ONLY DIFFERENCE BETWEEN MODEL RAP AND NAM SOUNDINGS IS A DRY NEAR SURFACE LAYER DEPICTED BY THE NAM. THIS CAN CERTAINLY MAKE A DIFFERENCE IN SNOW TOTALS WITH THE MORE MOIST RAP SHOWING MORE SNOWFALL. LONG TERM... WITH THE EXIT EAST OF THE CURRENT LONG-WAVE TROUGH MONDAY...LESSER AMPLITUDE AND DRY NORTHWEST FLOW WILL BECOME DOMINANT THROUGH MUCH OF THE WEEK. NEXT SHORT-WAVE UPPER TROUGH WILL SKIM BY TO THE NORTH WEDNESDAY DRAGGING A SLIGHTLY WEAKER FRONT INTO THE AREA EARLY WEDNESDAY THAN PREVIOUSLY ADVERTISED. FLATTER WESTERLY FLOW APPEARS IN THE WORKS EARLY NEXT WEEKEND WITH BACKING AND INCREASING SOUTHWEST FLOW ALOFT LATER IN THE WEEKEND...ALTHOUGH SPREAD IN THE DEVELOPING INTER-MOUNTAIN UPPER TROUGH WILL BE ON THE RISE. THIS PATTERN WILL YIELD MODEST WARMING MONDAY...A WEAK BACK-DOOR FRONT WILL SLIP IN MONDAY AFTERNOON AND EVENING...WITH BETTER WARMING AND GUSTY SOUTHWEST WINDS TUESDAY. THEN THE SLIGHT CHRISTMAS DAY COOL-DOWN WITH SLOW WARMING THURSDAY AND FRIDAY. BIGGER BOOST IN TEMPERATURES AND MORE GUSTY SOUTHWEST BREEZES EXPECTED SATURDAY BEFORE NEXT COOLING THE FOLLOWING SUNDAY. MINOR CHANGES. RMCQUEEN && .PRELIMINARY POINT TEMPS/POPS... FRIONA 37 19 46 24 55 / 10 0 0 0 0 TULIA 38 20 46 24 56 / 10 0 0 0 0 PLAINVIEW 40 21 49 25 56 / 10 0 0 0 0 LEVELLAND 42 23 51 26 56 / 10 0 0 0 0 LUBBOCK 42 23 52 26 57 / 0 0 0 0 0 DENVER CITY 44 23 52 28 55 / 10 0 0 0 0 BROWNFIELD 44 23 52 27 56 / 0 0 0 0 0 CHILDRESS 40 22 49 24 57 / 0 0 0 0 0 SPUR 45 22 53 27 57 / 0 0 0 0 0 ASPERMONT 45 23 53 29 58 / 0 0 0 0 0 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 01
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
331 AM CST SUN DEC 22 2013 .SHORT TERM... WINTER DOES NOT WANT TO LET UP FOR THE REGION WITH RENEWED CHANCES FOR LIGHT PRECIPITATION THIS MORNING. ANOTHER TROUGH AXIS HAS STILL TO PASS LATER THIS MORNING. WEAK Q-VECTOR CONVERGENCE IS CURRENTLY MOVING OVER THE AREA. THIS WAS COUPLED WITH WEAK FRONTOGENETICAL FORCING AROUND 750-700MB EDGING INTO THE SOUTHWESTERN TEXAS PANHANDLE. MODELS WERE IN GOOD AGREEMENT SHOWING LIFT PEAKING AROUND 12Z UNDER SATURATED SOUNDINGS. ALTHOUGH...THE ONLY DIFFERENCE BETWEEN MODEL RAP AND NAM SOUNDINGS IS A DRY NEAR SURFACE LAYER DEPICTED BY THE NAM. THIS CAN CERTAINLY MAKE A DIFFERENCE IN SNOW TOTALS WITH THE MORE MOIST RAP SHOWING MORE SNOWFALL. && .LONG TERM... WITH THE EXIT EAST OF THE CURRENT LONG-WAVE TROUGH MONDAY...LESSER AMPLITUDE AND DRY NORTHWEST FLOW WILL BECOME DOMINANT THROUGH MUCH OF THE WEEK. NEXT SHORT-WAVE UPPER TROUGH WILL SKIM BY TO THE NORTH WEDNESDAY DRAGGING A SLIGHTLY WEAKER FRONT INTO THE AREA EARLY WEDNESDAY THAN PREVIOUSLY ADVERTISED. FLATTER WESTERLY FLOW APPEARS IN THE WORKS EARLY NEXT WEEKEND WITH BACKING AND INCREASING SOUTHWEST FLOW ALOFT LATER IN THE WEEKEND...ALTHOUGH SPREAD IN THE DEVELOPING INTER-MOUNTAIN UPPER TROUGH WILL BE ON THE RISE. THIS PATTERN WILL YIELD MODEST WARMING MONDAY...A WEAK BACK-DOOR FRONT WILL SLIP IN MONDAY AFTERNOON AND EVENING...WITH BETTER WARMING AND GUSTY SOUTHWEST WINDS TUESDAY. THEN THE SLIGHT CHRISTMAS DAY COOL-DOWN WITH SLOW WARMING THURSDAY AND FRIDAY. BIGGER BOOST IN TEMPERATURES AND MORE GUSTY SOUTHWEST BREEZES EXPECTED SATURDAY BEFORE NEXT COOLING THE FOLLOWING SUNDAY. MINOR CHANGES. RMCQUEEN && .PRELIMINARY POINT TEMPS/POPS... FRIONA 37 19 46 24 55 / 10 0 0 0 0 TULIA 38 20 46 24 56 / 10 0 0 0 0 PLAINVIEW 40 21 49 25 56 / 10 0 0 0 0 LEVELLAND 42 23 51 26 56 / 10 0 0 0 0 LUBBOCK 43 23 52 26 57 / 0 0 0 0 0 DENVER CITY 44 23 52 28 55 / 10 0 0 0 0 BROWNFIELD 44 23 52 27 56 / 0 0 0 0 0 CHILDRESS 40 22 49 24 57 / 0 0 0 0 0 SPUR 45 22 53 27 57 / 0 0 0 0 0 ASPERMONT 45 23 53 29 58 / 0 0 0 0 0 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 01/05
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
203 AM EST SUN DEC 22 2013 .SYNOPSIS... A VERY MILD AND MOIST AIRMASS WILL REMAIN IN PLACE THROUGH THE WEEKEND AHEAD OF AN APPROACHING COLD FRONT. SIGNIFICANT RAINFALL IS POSSIBLE IN MANY LOCATIONS AHEAD OF THE FRONT SUNDAY INTO PARTS OF MONDAY. THE FRONT WILL MOVE THROUGH THE AREA ON MONDAY...AND WITH IT WILL COME AN ABRUPT END TO OUR VERY MILD WEATHER. COLDER HIGH PRESSURE BUILDS OVER THE REGION BY THE MIDDLE OF THE WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 200 AM EST SUNDAY... ADDED MORE COUNTIES TO WIND ADVISORY FOR THIS MORNING. WATCHING CONVECTION TO THE WEST MOVING EAST. MORE CHANGES AS MORNING PROGRESSES. AS OF 101 AM EST SUNDAY... ADJUSTED POPS FOR LATEST RADAR TRENDS WITH SCATTERED STORMS FORMING AHEAD OF THE MAIN BAND OF CONVECTION TO OUR WEST IN THE OHIO VALLEY. LOW PRESSURE WAS LOCATED IN INDIANA THIS MORNING WITH COLD FRONT EXTENDING SOUTHWARD ACROSS WESTERN KENTUCKY AND WESTERN TENNESSEE. COLD FRONT AND ASSOCIATED CONVECTION WILL CONTINUE TO MOVE EAST TODAY. STRONG SOUTHERN WINDS ADVECTING PLENTY OF MOISTURE INTO OUR REGION. WIND ADVISORIES REMAIN IN EFFECT FOR ELEVATION ABOVE 3000 FEET TO CAPTURE LOW LEVEL JET. MORE ADJUSTMENTS LATER THIS MORNING WITH ACTIVE WEATHER... AS OF 1040 PM EST SATURDAY... A SLOW MOVING COLD FRONT WILL CONTINUE INCHING EASTWARD THROUGH THE MID-MISSISSIPPI AND LOWER OHIO RIVER VALLEYS. AHEAD OF THE FRONT...S-SW LOW LEVEL FLOW WILL INCREASE TO 50 TO 60 KTS AT 850 MB AND ADVECT PLENTY OF GULF OF MEXICO MOISTURE INTO THE REGION. THIS MOISTURE WILL BE REALIZED IN ABUNDANT CLOUD COVER...VERY HIGH SURFACE DEW POINTS FOR LATE DECEMBER. HAVE RAISED PROBABILITY OF PRECIPITATION ALONG THE CREST OF THE BLUE RIDGE FROM NEAR FLOYD SOUTHWEST INTO THE NORTHERN MOUNTAINS OF NORTH CAROLINA. ANOTHER REGION TO WATCH FOR PRECIPITATION IS SOUTHEAST WEST VIRGINIA. THIS AREA WILL BE CLOSEST TO THE ACTUALLY FRONT...AND WEAK DISTURBANCES ALONG THE FRONT WILL HELP TO BRING PERIODIC WIDELY SCATTERED COVERAGE TO THIS PART OF THE FORECAST AREA OVERNIGHT. MAIN AREA OF PRECIPITATION CLOSER TO THE FRONT IS NOT EXPECTED TO ARRIVE IN THE WESTERN COUNTY WARNING AREA UNTIL AFTER 12Z/7AM. THIS TIMING IS SUPPORT BY THE LATEST HRRR AND RAP MODELS AS WELL AS THE 18Z LOCAL WRF. THE HIGH DEW POINTS WILL ALLOW FOR EQUALLY MILD OVERNIGHT LOW TEMPERATURES. WE ARE EXPECTING NEW RECORD HIGH MINIMUM TEMPERATURES EVERYWHERE TONIGHT. LOWS WILL RANGE FROM THE UPPER 50S TO NEAR 60 IN THE MOUNTAINS WITH LOWER 60S ACROSS THE PIEDMONT. && .SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/... AS OF 350 PM EST SATURDAY... SUNDAY BEGINS WITH MILD TEMPS AND HEALTHY SOUTH TO SOUTHWEST FLOW UP ALONG BLUE RIDGE WITH VISIBILITIES SOCKED IN ALONG BLUE RIDGE...LIGHT SHOWERS...AND WITH HEAVIER BAND OF RAIN SHOWERS JUST ENTERING FAR SOUTHWEST VA AND NW NC AROUND DAYBREAK MODELS HAVE DEFINITELY SLOWED THIS DOWN. SEEING EXTREMELY LIMITED INSTABILITY FOR THUNDER...BUT WENT AHEAD ADDED SLIGHT CHC OF THUNDER BY NOON FOR MUCH OF SW VA AND NW NC. SHALLOW LINE OF CONVECTION MAY HAVE VERY GUSTY WINDS WITH IT AS IT ENTERS FAR WESTERN PORTION OF FCST AREA...BUT MOST MODELS HAVE THIS WEAKENING QUICKLY AS IT ENTERS DURING THE MID MORNING HOURS. CANT RULE OUT SOME DAMAGING WINDS WEST OF I-81 AND SOUTH OF 460...MAYBE INTO NW NC. GENERALLY SW WINDS WILL BE GUSTY AHEAD OF THIS...AND MAY REACH ADVISORY CRITERIA AT VERY HIGHEST RIDGES...BUT SHOULD BE ISOLATED ENOUGH...AND NOT HIGH ENOUGH POTENTIAL WITH CONVECTIVE LINE OF SHOWERS...TO ISSUE A WIND ADVISORY AT THIS TIME. BY AFTERNOON...PARTS OF THIS LINE OF SHALLOW CONVECTION SHOULD SNEAK INTO PIEDMONT...BUT THIS MAY NOT OCCUR UNTIL VERY LATE IN AFTERNOON ACCORDING TO LATEST TRENDS. STILL UPSLOPE FLOW FROM SOUTH ALONG BLUE RIDGE SHOULD BE ENHANCING PRECIP AMOUNTS THERE REGARDLESS OF TIMING OF THIS HEAVIER BAND OF SHOWERS...POSSIBLE ISOLATED THUNDER. NAM STILL IS SLOWEST AND LARGELY DUE TO STRONGLY INFLUENCE OF THIS WAVE RIDING UP FROM THE SOUTHWEST...AND SPREADS MORE PRECIP BACK TOWARD THE WEST AGAIN SUNDAY NIGHT AND MONDAY. SOME HINTS OF THIS IN GFS BUT IT STILL REMAINS MOST PROGRESSIVE. HEAVIEST RAINFALL FROM NAM AND SOME HIGH RES MODELS SUGGESTED ALONG BLUE RIDGE...WHILE GFS AND ECMWF MORE OUT INTO PIEDMONT THROUGH SUNDAY NIGHT AND MONDAY. GENERALLY GOING CLOSER TO GFS/ECMWF IDEA...AND NOT QUITE AS WET AS GFS...BUT DID ENHANCE THE RAINFALL ALONG BLUE RIDGE MORE SO THAN WHAT THESE MODELS HAVE. THUS HAVE INCREASED OVERALL STORM QPF SIGNIFICANTLY...WITH 2.5 TO 3 INCHES FROM BLUE RIDGE EAST. PLEASE READ THE HYDROLOGY SECTION BELOW FOR MORE DISCUSSION ON THE RAINFALL AND FLOODING POTENTIAL...BUT FOR NOW HAVE NOT GONE WITH ANY FLOOD HEADLINES...BUT WILL HIGHLIGHT IN THE HWO. AS FAR AS TEMPERATURES...STILL LOOKING AT A RECORD BREAKING MILD AFTERNOON, DESPITE EXTENSIVE CLOUD COVER AND RAIN ACROSS THE WEST...BUT WITH THE PIEDMONT HOLDING OFF ON RAIN UNTIL LATE...LIKELY TO SEE MID 70S. JUST ABOUT ALL LOCATIONS SHOULD TIE OR BREAK A RECORD MAX TEMP FOR THE DATE. SEE CLIMATE SECTION BELOW FOR RECORDS. ON MONDAY THE COLDER AIR BEHIND THE FRONT BEGINS TO FILTER IN...BUT NOT AS FAST AS PREVIOUSLY THOUGHT...AS EVEN THE MORE PROGRESSIVE GFS HAS SLOWED THINGS DOWN WITH THIS WAVE. COLD AIR MAY BEGIN TO RUSH IN LATE IN THE DAY IN THE WEST...BUT WILL PROBABLY NOT ARRIVE IN THE EAST UNTIL MONDAY EVENING. AGAIN...SOME MODEL DIFFERENCES STILL IN TERMS OF HOW FAR WEST THIS WAVE WILL SPREAD OR DEVELOP MORE PRECIP...AND HAVE NOT DROPPED POPS TOO LOW ACROSS THE FAR WEST FOR THIS REASON...BUT THERE COULD BE A BREAK MOST OF MONDAY FOR MUCH OF THE WEST WHILE SHOWERS STILL PLAGUE THE BLUE RIDGE AND THE PIEDMONT MOST OF THE DAY BEFORE FINALLY PUSHING EAST AFTER THE WAVE GOES BY LATE IN THE DAY. WITH WESTERLY FLOW...SOME UPSLOPE SHOWERS COULD LINGER IN TYPICAL UPSLOPE FAVORED AREAS OF THE WEST...BUT CHANCES INCREASE FOR MEASURABLE PRECIP BY LATE MONDAY NIGHT OR EARLY TUES MORNING WITH STRONG UPPER TROUGH AND SHORT WAVE DIGGING QUICKLY ACROSS THE AREA. STRONG COLD ADVECTION BY THIS TIME...AND WHILE LOW LEVEL WINDS MORE WESTERLY...NOT IDEAL FOR BEST UPSLOPE SNOWS...THE ADVECTION OVER VERY MOIST GROUND JUST UPSTREAM IS STILL A CONCERN. STILL LEANING MORE TOWARD THE MODELS THAT PRODUCE SOME LIGHT UPSLOPE ACCUMULATIONS MONDAY NIGHT INTO EARLY TUES MORNING. RIGHT NOW THINKING A VERY LIGHT ACCUM IN NW NC MTNS...WITH AN INCH OR TWO IN WESTERN GREENBRIER WV. NAM STILL STINGY ON THIS...BUT THINKING GFS HAS BEST HANDLE...AND COULD EVEN BE MORE. THIS WAVE MOVES QUICKLY THROUGH AND SHOULD DRY OUT QUICKLY DURING THE DAY TUES..WITH CONTINUED STRONG COLD ADVECTION...DOESN`T LOOK LIKE WIND ADV CRITERIA WIND SPEEDS AT THE MOMENT...AND MUCH COLDER TEMPS WITH MANY AREAS OF THE WEST REMAINING BELOW FREEZING FOR THE DAY. WENT WITH COLDER ECMWF MOS-BASED GUIDANCE. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... AS OF 320 PM EST SATURDAY... STRONG DRY ARCTIC HIGH PRESSURE WILL LEAD TO SOME VERY COLD MORNINGS NEXT WEEK...POSSIBLY SINGLE DIGITS IN THE DEEPEST COLDEST VALLEYS WEDNESDAY MORNING. OTHERWISE A RATHER BENIGN PATTERN WITH A DRY COLD FRONT CROSSING THURSDAY NIGHT. ANOTHER BOUNDARY DROPPING THROUGH THE UPPER MIDWEST LATE NEXT WEEKEND WILL MEAN SW SURFACE FLOW...POTENTIALLY PUSHING H85 TEMPS TO NEAR +5C. A COLDER PATTERN COULD ARRIVE PAST NEXT WEEKEND AS THE POLAR VORTEX DIVES SOUTH THANKS TO AN UPPER RIDGE POTENTIALLY LINKING FROM GREENLAND TO ALASKA. && .AVIATION /07Z SUNDAY THROUGH THURSDAY/... AS OF 1155 PM EST SATURDAY... IFR STRATUS COVERED MUCH OF THE SOUTHERN BLUE RIDGE THIS EVENING. MODERATE CONFIDENCE THAT CEILINGS WILL REMAIN ABOVE IFR AT KLYH/KDAN/KROA/KBCB THROUGH MIDNIGHT. OVERNIGHT...MOISTURE TRANSPORT INCREASES ACROSS THE AREA ON 50 TO 60 KT 850 MB WINDS. ANTICIPATE A TREND TOWARD MORE MVFR CIGS ACROSS THE REGION WITH LOCALIZED IFR CIGS AND MVFR VSBYS. LIGHT RAIN SHOWERS WILL BECOME MORE NUMEROUS...ESPECIALLY ALONG THE CREST OF THE BLUE RIDGE AND ALSO NEAR A KLWB-KBLF LINE. WIND GUSTS UP TO 30 KNOTS ARE POSSIBLE...ESPECIALLY FROM 1AM THROUGH 8AM. ON SUNDAY MORNING THE SURFACE COLD FRONT MOVES INTO THE MOUNTAINS...AND MOISTURE WILL CONTINUE TO STREAM ACROSS THE REGION. LOW CONFIDENCE CONCERNING HOW LOW CEILINGS WILL GET IN THE AFTERNOON AND EVENING AFTER THE FIRST STRONG BAND OF SHOWERS AND ISOLATED THUNDERSTORMS GOES THROUGH BUT BEFORE THE FRONT ARRIVES. FOR NOW HAVE LOWERED INTO THE MVFR TO IFR RANGE. A REINFORCING WAVE WILL MOVE NORTH ALONG THE FRONT AND DELAY THE FRONTAL PASSAGE EAST OF THE BLUE RIDGE UNTIL MONDAY. EXPECT A SHARP WIND SHIFT AS A COLD FRONT COMES THROUGH...THEN GUSTY NORTHWEST WINDS ON MONDAY. UPSLOPE SNOW SHOWERS ARE EXPECTED ACROSS SE WV MONDAY NIGHT THROUGH TUESDAY. LOCALIZED MVFR CONDITIONS ARE EXPECTED. VFR CEILINGS AND VISIBILITIES RETURN ON WEDNESDAY AND THURSDAY AS HIGH PRESSURE AND DRIER AIR COME INTO THE REGION. && .HYDROLOGY... AS OF 335 PM EST SATURDAY... MODEL TRENDS TOWARD HIGHER PRECIP AMOUNTS SUNDAY NIGHT AND MONDAY...AND THIS NOT SURPRISING GIVEN SECOND WAVE RIDING UP ALONG FRONT SLOWING IT DOWN..WITH STRONG FETCH OF MOISTURE ADVECTION FROM GULF. FORECAST PRECIPITABLE WATER VALUES OF 1.5 TO 1.7 INCHES WOULD BE RECORD OR NEAR RECORD VALUES FOR DECEMBER. WHILE SOME HIGH RESOLUTION MODELS ARE LIKELY OVERDOING THE MAXIMUM PRECIP OUTPUT...SOME SIGNS THAT TWO AREAS OF CONCERN ARE ALONG THE BLUE RIDGE SUNDAY THROUGH EARLY MONDAY...AND ALSO OUT IN THE PIEDMONT MAINLY SUNDAY NIGHT AND MONDAY. CURRENT FORECAST AMOUNTS ARE BETWEEN 2 AND JUST OVER 3 INCHES...AND THIS MAY BE ENOUGH TO CAUSE NOT ONLY LOCALIZED FLOODING OF SMALL STREAMS AND CREEKS...BUT COULD BRING THE DAN RIVER UP TO ACTION OR MINOR FLOOD STAGE BY TUESDAY FROM UPSTREAM AND LOCAL RUNOFF. MAY ALSO HAVE TO WATCH THE HEADWATERS OF THE NEW RIVER IN NW NC FOR SUNDAY NIGHT...AS WELL AS ROANOKE RIVER FOR MON/TUES TIME FRAME. IF HIGHER RESOLUTION MODELS ARE CORRECT...THERE COULD BE MUCH MORE SIGNIFICANT FLOODING PROBLEMS...BOTH FLASH FLOOD AND RIVER FLOOD. NOT CONFIDENT ENOUGH YET TO GO WITH A WATCH OF ANY KIND YET. && .CLIMATE... RECORDS FOR THE WARMEST LOW TEMPERATURE AT EACH CLIMATE SITE FOR THE MONTH OF DECEMBER ARE AT RISK OF BEING TIED OR BROKEN...ESPECIALLY ACROSS THE PIEDMONT. HIGHEST LOW TEMPERATURES FOR THE MONTH OF DECEMBER... BLACKSBURG 55/DEC 23 1990 ROANOKE 60/DEC 14 1927 LYNCHBURG 62/DEC 16 1971 DANVILLE 60/DEC 6 2011 BLUEFIELD 58/DEC 22 1990 LEWISBURG 58/DEC 28 1982 && .RNK WATCHES/WARNINGS/ADVISORIES... VA...WIND ADVISORY UNTIL NOON EST TODAY FOR VAZ007-009>011-015- 018>020-022>024-034-035. NC...WIND ADVISORY UNTIL NOON EST TODAY FOR NCZ001-018. WV...WIND ADVISORY UNTIL NOON EST TODAY FOR WVZ042>045. && $$ SYNOPSIS...KK/SK NEAR TERM...AMS/DS/KK SHORT TERM...SK LONG TERM...KM AVIATION...AMS/DS HYDROLOGY...SK CLIMATE...CF/DS/SK
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
112 AM EST SUN DEC 22 2013 .SYNOPSIS... A VERY MILD AND MOIST AIRMASS WILL REMAIN IN PLACE THROUGH THE WEEKEND AHEAD OF AN APPROACHING COLD FRONT. SIGNIFICANT RAINFALL IS POSSIBLE IN MANY LOCATIONS AHEAD OF THE FRONT SUNDAY INTO PARTS OF MONDAY. THE FRONT WILL MOVE THROUGH THE AREA ON MONDAY...AND WITH IT WILL COME AN ABRUPT END TO OUR VERY MILD WEATHER. COLDER HIGH PRESSURE BUILDS OVER THE REGION BY THE MIDDLE OF THE WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 101 AM EST SUNDAY... ADJUSTED POPS FOR LATEST RADAR TRENDS WITH SCATTERED STORMS FORMING AHEAD OF THE MAIN BAND OF CONVECTION TO OUR WEST IN THE OHIO VALLEY. LOW PRESSURE WAS LOCATED IN INDIANA THIS MORNING WITH COLD FRONT EXTENDING SOUTHWARD ACROSS WESTERN KENTUCKY AND WESTERN TENNESSEE. COLD FRONT AND ASSOCIATED CONVECTION WILL CONTINUE TO MOVE EAST TODAY. STRONG SOUTHERN WINDS ADVECTING PLENTY OF MOISTURE INTO OUR REGION. WIND ADVISORIES REMAIN IN EFFECT FOR ELEVATION ABOVE 3000 FEET TO CAPTURE LOW LEVEL JET. MORE ADJUSTMENTS LATER THIS MORNING WITH ACTIVE WEATHER... AS OF 1040 PM EST SATURDAY... A SLOW MOVING COLD FRONT WILL CONTINUE INCHING EASTWARD THROUGH THE MID-MISSISSIPPI AND LOWER OHIO RIVER VALLEYS. AHEAD OF THE FRONT...S-SW LOW LEVEL FLOW WILL INCREASE TO 50 TO 60 KTS AT 850 MB AND ADVECT PLENTY OF GULF OF MEXICO MOISTURE INTO THE REGION. THIS MOISTURE WILL BE REALIZED IN ABUNDANT CLOUD COVER...VERY HIGH SURFACE DEW POINTS FOR LATE DECEMBER. HAVE RAISED PROBABILITY OF PRECIPITATION ALONG THE CREST OF THE BLUE RIDGE FROM NEAR FLOYD SOUTHWEST INTO THE NORTHERN MOUNTAINS OF NORTH CAROLINA. ANOTHER REGION TO WATCH FOR PRECIPITATION IS SOUTHEAST WEST VIRGINIA. THIS AREA WILL BE CLOSEST TO THE ACTUALLY FRONT...AND WEAK DISTURBANCES ALONG THE FRONT WILL HELP TO BRING PERIODIC WIDELY SCATTERED COVERAGE TO THIS PART OF THE FORECAST AREA OVERNIGHT. MAIN AREA OF PRECIPITATION CLOSER TO THE FRONT IS NOT EXPECTED TO ARRIVE IN THE WESTERN COUNTY WARNING AREA UNTIL AFTER 12Z/7AM. THIS TIMING IS SUPPORT BY THE LATEST HRRR AND RAP MODELS AS WELL AS THE 18Z LOCAL WRF. THE HIGH DEW POINTS WILL ALLOW FOR EQUALLY MILD OVERNIGHT LOW TEMPERATURES. WE ARE EXPECTING NEW RECORD HIGH MINIMUM TEMPERATURES EVERYWHERE TONIGHT. LOWS WILL RANGE FROM THE UPPER 50S TO NEAR 60 IN THE MOUNTAINS WITH LOWER 60S ACROSS THE PIEDMONT. && .SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/... AS OF 350 PM EST SATURDAY... SUNDAY BEGINS WITH MILD TEMPS AND HEALTHY SOUTH TO SOUTHWEST FLOW UP ALONG BLUE RIDGE WITH VISIBILITIES SOCKED IN ALONG BLUE RIDGE...LIGHT SHOWERS...AND WITH HEAVIER BAND OF RAIN SHOWERS JUST ENTERING FAR SOUTHWEST VA AND NW NC AROUND DAYBREAK MODELS HAVE DEFINITELY SLOWED THIS DOWN. SEEING EXTREMELY LIMITED INSTABILITY FOR THUNDER...BUT WENT AHEAD ADDED SLIGHT CHC OF THUNDER BY NOON FOR MUCH OF SW VA AND NW NC. SHALLOW LINE OF CONVECTION MAY HAVE VERY GUSTY WINDS WITH IT AS IT ENTERS FAR WESTERN PORTION OF FCST AREA...BUT MOST MODELS HAVE THIS WEAKENING QUICKLY AS IT ENTERS DURING THE MID MORNING HOURS. CANT RULE OUT SOME DAMAGING WINDS WEST OF I-81 AND SOUTH OF 460...MAYBE INTO NW NC. GENERALLY SW WINDS WILL BE GUSTY AHEAD OF THIS...AND MAY REACH ADVISORY CRITERIA AT VERY HIGHEST RIDGES...BUT SHOULD BE ISOLATED ENOUGH...AND NOT HIGH ENOUGH POTENTIAL WITH CONVECTIVE LINE OF SHOWERS...TO ISSUE A WIND ADVISORY AT THIS TIME. BY AFTERNOON...PARTS OF THIS LINE OF SHALLOW CONVECTION SHOULD SNEAK INTO PIEDMONT...BUT THIS MAY NOT OCCUR UNTIL VERY LATE IN AFTERNOON ACCORDING TO LATEST TRENDS. STILL UPSLOPE FLOW FROM SOUTH ALONG BLUE RIDGE SHOULD BE ENHANCING PRECIP AMOUNTS THERE REGARDLESS OF TIMING OF THIS HEAVIER BAND OF SHOWERS...POSSIBLE ISOLATED THUNDER. NAM STILL IS SLOWEST AND LARGELY DUE TO STRONGLY INFLUENCE OF THIS WAVE RIDING UP FROM THE SOUTHWEST...AND SPREADS MORE PRECIP BACK TOWARD THE WEST AGAIN SUNDAY NIGHT AND MONDAY. SOME HINTS OF THIS IN GFS BUT IT STILL REMAINS MOST PROGRESSIVE. HEAVIEST RAINFALL FROM NAM AND SOME HIGH RES MODELS SUGGESTED ALONG BLUE RIDGE...WHILE GFS AND ECMWF MORE OUT INTO PIEDMONT THROUGH SUNDAY NIGHT AND MONDAY. GENERALLY GOING CLOSER TO GFS/ECMWF IDEA...AND NOT QUITE AS WET AS GFS...BUT DID ENHANCE THE RAINFALL ALONG BLUE RIDGE MORE SO THAN WHAT THESE MODELS HAVE. THUS HAVE INCREASED OVERALL STORM QPF SIGNIFICANTLY...WITH 2.5 TO 3 INCHES FROM BLUE RIDGE EAST. PLEASE READ THE HYDROLOGY SECTION BELOW FOR MORE DISCUSSION ON THE RAINFALL AND FLOODING POTENTIAL...BUT FOR NOW HAVE NOT GONE WITH ANY FLOOD HEADLINES...BUT WILL HIGHLIGHT IN THE HWO. AS FAR AS TEMPERATURES...STILL LOOKING AT A RECORD BREAKING MILD AFTERNOON, DESPITE EXTENSIVE CLOUD COVER AND RAIN ACROSS THE WEST...BUT WITH THE PIEDMONT HOLDING OFF ON RAIN UNTIL LATE...LIKELY TO SEE MID 70S. JUST ABOUT ALL LOCATIONS SHOULD TIE OR BREAK A RECORD MAX TEMP FOR THE DATE. SEE CLIMATE SECTION BELOW FOR RECORDS. ON MONDAY THE COLDER AIR BEHIND THE FRONT BEGINS TO FILTER IN...BUT NOT AS FAST AS PREVIOUSLY THOUGHT...AS EVEN THE MORE PROGRESSIVE GFS HAS SLOWED THINGS DOWN WITH THIS WAVE. COLD AIR MAY BEGIN TO RUSH IN LATE IN THE DAY IN THE WEST...BUT WILL PROBABLY NOT ARRIVE IN THE EAST UNTIL MONDAY EVENING. AGAIN...SOME MODEL DIFFERENCES STILL IN TERMS OF HOW FAR WEST THIS WAVE WILL SPREAD OR DEVELOP MORE PRECIP...AND HAVE NOT DROPPED POPS TOO LOW ACROSS THE FAR WEST FOR THIS REASON...BUT THERE COULD BE A BREAK MOST OF MONDAY FOR MUCH OF THE WEST WHILE SHOWERS STILL PLAGUE THE BLUE RIDGE AND THE PIEDMONT MOST OF THE DAY BEFORE FINALLY PUSHING EAST AFTER THE WAVE GOES BY LATE IN THE DAY. WITH WESTERLY FLOW...SOME UPSLOPE SHOWERS COULD LINGER IN TYPICAL UPSLOPE FAVORED AREAS OF THE WEST...BUT CHANCES INCREASE FOR MEASURABLE PRECIP BY LATE MONDAY NIGHT OR EARLY TUES MORNING WITH STRONG UPPER TROUGH AND SHORT WAVE DIGGING QUICKLY ACROSS THE AREA. STRONG COLD ADVECTION BY THIS TIME...AND WHILE LOW LEVEL WINDS MORE WESTERLY...NOT IDEAL FOR BEST UPSLOPE SNOWS...THE ADVECTION OVER VERY MOIST GROUND JUST UPSTREAM IS STILL A CONCERN. STILL LEANING MORE TOWARD THE MODELS THAT PRODUCE SOME LIGHT UPSLOPE ACCUMULATIONS MONDAY NIGHT INTO EARLY TUES MORNING. RIGHT NOW THINKING A VERY LIGHT ACCUM IN NW NC MTNS...WITH AN INCH OR TWO IN WESTERN GREENBRIER WV. NAM STILL STINGY ON THIS...BUT THINKING GFS HAS BEST HANDLE...AND COULD EVEN BE MORE. THIS WAVE MOVES QUICKLY THROUGH AND SHOULD DRY OUT QUICKLY DURING THE DAY TUES..WITH CONTINUED STRONG COLD ADVECTION...DOESN`T LOOK LIKE WIND ADV CRITERIA WIND SPEEDS AT THE MOMENT...AND MUCH COLDER TEMPS WITH MANY AREAS OF THE WEST REMAINING BELOW FREEZING FOR THE DAY. WENT WITH COLDER ECMWF MOS-BASED GUIDANCE. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... AS OF 320 PM EST SATURDAY... STRONG DRY ARCTIC HIGH PRESSURE WILL LEAD TO SOME VERY COLD MORNINGS NEXT WEEK...POSSIBLY SINGLE DIGITS IN THE DEEPEST COLDEST VALLEYS WEDNESDAY MORNING. OTHERWISE A RATHER BENIGN PATTERN WITH A DRY COLD FRONT CROSSING THURSDAY NIGHT. ANOTHER BOUNDARY DROPPING THROUGH THE UPPER MIDWEST LATE NEXT WEEKEND WILL MEAN SW SURFACE FLOW...POTENTIALLY PUSHING H85 TEMPS TO NEAR +5C. A COLDER PATTERN COULD ARRIVE PAST NEXT WEEKEND AS THE POLAR VORTEX DIVES SOUTH THANKS TO AN UPPER RIDGE POTENTIALLY LINKING FROM GREENLAND TO ALASKA. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... AS OF 1155 PM EST SATURDAY... IFR STRATUS COVERED MUCH OF THE SOUTHERN BLUE RIDGE THIS EVENING. MODERATE CONFIDENCE THAT CEILINGS WILL REMAIN ABOVE IFR AT KLYH/KDAN/KROA/KBCB THROUGH MIDNIGHT. OVERNIGHT...MOISTURE TRANSPORT INCREASES ACROSS THE AREA ON 50 TO 60 KT 850 MB WINDS. ANTICIPATE A TREND TOWARD MORE MVFR CIGS ACROSS THE REGION WITH LOCALIZED IFR CIGS AND MVFR VSBYS. LIGHT RAIN SHOWERS WILL BECOME MORE NUMEROUS...ESPECIALLY ALONG THE CREST OF THE BLUE RIDGE AND ALSO NEAR A KLWB-KBLF LINE. WIND GUSTS UP TO 30 KNOTS ARE POSSIBLE...ESPECIALLY FROM 1AM THROUGH 8AM. ON SUNDAY MORNING THE SURFACE COLD FRONT MOVES INTO THE MOUNTAINS...AND MOISTURE WILL CONTINUE TO STREAM ACROSS THE REGION. LOW CONFIDENCE CONCERNING HOW LOW CEILINGS WILL GET IN THE AFTERNOON AND EVENING AFTER THE FIRST STRONG BAND OF SHOWERS AND ISOLATED THUNDERSTORMS GOES THROUGH BUT BEFORE THE FRONT ARRIVES. FOR NOW HAVE LOWERED INTO THE MVFR TO IFR RANGE. A REINFORCING WAVE WILL MOVE NORTH ALONG THE FRONT AND DELAY THE FRONTAL PASSAGE EAST OF THE BLUE RIDGE UNTIL MONDAY. EXPECT A SHARP WIND SHIFT AS A COLD FRONT COMES THROUGH...THEN GUSTY NORTHWEST WINDS ON MONDAY. UPSLOPE SNOW SHOWERS ARE EXPECTED ACROSS SE WV MONDAY NIGHT THROUGH TUESDAY. LOCALIZED MVFR CONDITIONS ARE EXPECTED. VFR CEILINGS AND VISIBILITIES RETURN ON WEDNESDAY AND THURSDAY AS HIGH PRESSURE AND DRIER AIR COME INTO THE REGION. && .HYDROLOGY... AS OF 335 PM EST SATURDAY... MODEL TRENDS TOWARD HIGHER PRECIP AMOUNTS SUNDAY NIGHT AND MONDAY...AND THIS NOT SURPRISING GIVEN SECOND WAVE RIDING UP ALONG FRONT SLOWING IT DOWN..WITH STRONG FETCH OF MOISTURE ADVECTION FROM GULF. FORECAST PRECIPITABLE WATER VALUES OF 1.5 TO 1.7 INCHES WOULD BE RECORD OR NEAR RECORD VALUES FOR DECEMBER. WHILE SOME HIGH RESOLUTION MODELS ARE LIKELY OVERDOING THE MAXIMUM PRECIP OUTPUT...SOME SIGNS THAT TWO AREAS OF CONCERN ARE ALONG THE BLUE RIDGE SUNDAY THROUGH EARLY MONDAY...AND ALSO OUT IN THE PIEDMONT MAINLY SUNDAY NIGHT AND MONDAY. CURRENT FORECAST AMOUNTS ARE BETWEEN 2 AND JUST OVER 3 INCHES...AND THIS MAY BE ENOUGH TO CAUSE NOT ONLY LOCALIZED FLOODING OF SMALL STREAMS AND CREEKS...BUT COULD BRING THE DAN RIVER UP TO ACTION OR MINOR FLOOD STAGE BY TUESDAY FROM UPSTREAM AND LOCAL RUNOFF. MAY ALSO HAVE TO WATCH THE HEADWATERS OF THE NEW RIVER IN NW NC FOR SUNDAY NIGHT...AS WELL AS ROANOKE RIVER FOR MON/TUES TIME FRAME. IF HIGHER RESOLUTION MODELS ARE CORRECT...THERE COULD BE MUCH MORE SIGNIFICANT FLOODING PROBLEMS...BOTH FLASH FLOOD AND RIVER FLOOD. NOT CONFIDENT ENOUGH YET TO GO WITH A WATCH OF ANY KIND YET. && .CLIMATE... RECORDS FOR THE WARMEST LOW TEMPERATURE AT EACH CLIMATE SITE FOR THE MONTH OF DECEMBER ARE AT RISK OF BEING TIED OR BROKEN...ESPECIALLY ACROSS THE PIEDMONT. HIGHEST LOW TEMPERATURES FOR THE MONTH OF DECEMBER... BLACKSBURG 55/DEC 23 1990 ROANOKE 60/DEC 14 1927 LYNCHBURG 62/DEC 16 1971 DANVILLE 60/DEC 6 2011 BLUEFIELD 58/DEC 22 1990 LEWISBURG 58/DEC 28 1982 && .RNK WATCHES/WARNINGS/ADVISORIES... VA...WIND ADVISORY UNTIL NOON EST TODAY FOR VAZ007-009-015-018>020- 022>024-034-035. NC...WIND ADVISORY UNTIL NOON EST TODAY FOR NCZ001-018. WV...WIND ADVISORY UNTIL NOON EST TODAY FOR WVZ043>045. && $$ SYNOPSIS...KK/SK NEAR TERM...AMS/DS/KK SHORT TERM...SK LONG TERM...KM AVIATION...AMS/DS HYDROLOGY...SK CLIMATE...CF/DS/SK
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1158 PM EST SAT DEC 21 2013 .SYNOPSIS... A VERY MILD AND MOIST AIRMASS WILL REMAIN IN PLACE THROUGH THE WEEKEND AHEAD OF AN APPROACHING COLD FRONT. SIGNIFICANT RAINFALL IS POSSIBLE IN MANY LOCATIONS AHEAD OF THE FRONT SUNDAY INTO PARTS OF MONDAY. THE FRONT WILL MOVE THROUGH THE AREA ON MONDAY...AND WITH IT WILL COME AN ABRUPT END TO OUR VERY MILD WEATHER. COLDER HIGH PRESSURE BUILDS OVER THE REGION BY THE MIDDLE OF THE WEEK. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... AS OF 1040 PM EST SATURDAY... A SLOW MOVING COLD FRONT WILL CONTINUE INCHING EASTWARD THROUGH THE MID-MISSISSIPPI AND LOWER OHIO RIVER VALLEYS. AHEAD OF THE FRONT...S-SW LOW LEVEL FLOW WILL INCREASE TO 50 TO 60 KTS AT 850 MB AND ADVECT PLENTY OF GULF OF MEXICO MOISTURE INTO THE REGION. THIS MOISTURE WILL BE REALIZED IN ABUNDANT CLOUD COVER...VERY HIGH SURFACE DEW POINTS FOR LATE DECEMBER. HAVE RAISED PROBABILITY OF PRECIPITATION ALONG THE CREST OF THE BLUE RIDGE FROM NEAR FLOYD SOUTHWEST INTO THE NORTHERN MOUNTAINS OF NORTH CAROLINA. ANOTHER REGION TO WATCH FOR PRECIPITATION IS SOUTHEAST WEST VIRGINIA. THIS AREA WILL BE CLOSEST TO THE ACTUALLY FRONT...AND WEAK DISTURBANCES ALONG THE FRONT WILL HELP TO BRING PERIODIC WIDELY SCATTERED COVERAGE TO THIS PART OF THE FORECAST AREA OVERNIGHT. MAIN AREA OF PRECIPITATION CLOSER TO THE FRONT IS NOT EXPECTED TO ARRIVE IN THE WESTERN COUNTY WARNING AREA UNTIL AFTER 12Z/7AM. THIS TIMING IS SUPPORT BY THE LATEST HRRR AND RAP MODELS AS WELL AS THE 18Z LOCAL WRF. THE HIGH DEW POINTS WILL ALLOW FOR EQUALLY MILD OVERNIGHT LOW TEMPERATURES. WE ARE EXPECTING NEW RECORD HIGH MINIMUM TEMPERATURES EVERYWHERE TONIGHT. LOWS WILL RANGE FROM THE UPPER 50S TO NEAR 60 IN THE MOUNTAINS WITH LOWER 60S ACROSS THE PIEDMONT. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/... AS OF 350 PM EST SATURDAY... SUNDAY BEGINS WITH MILD TEMPS AND HEALTHY SOUTH TO SOUTHWEST FLOW UP ALONG BLUE RIDGE WITH VISIBILITIES SOCKED IN ALONG BLUE RIDGE...LIGHT SHOWERS...AND WITH HEAVIER BAND OF RAIN SHOWERS JUST ENTERING FAR SOUTHWEST VA AND NW NC AROUND DAYBREAK MODELS HAVE DEFINITELY SLOWED THIS DOWN. SEEING EXTREMELY LIMITED INSTABILITY FOR THUNDER...BUT WENT AHEAD ADDED SLIGHT CHC OF THUNDER BY NOON FOR MUCH OF SW VA AND NW NC. SHALLOW LINE OF CONVECTION MAY HAVE VERY GUSTY WINDS WITH IT AS IT ENTERS FAR WESTERN PORTION OF FCST AREA...BUT MOST MODELS HAVE THIS WEAKENING QUICKLY AS IT ENTERS DURING THE MID MORNING HOURS. CANT RULE OUT SOME DAMAGING WINDS WEST OF I-81 AND SOUTH OF 460...MAYBE INTO NW NC. GENERALLY SW WINDS WILL BE GUSTY AHEAD OF THIS...AND MAY REACH ADVISORY CRITERIA AT VERY HIGHEST RIDGES...BUT SHOULD BE ISOLATED ENOUGH...AND NOT HIGH ENOUGH POTENTIAL WITH CONVECTIVE LINE OF SHOWERS...TO ISSUE A WIND ADVISORY AT THIS TIME. BY AFTERNOON...PARTS OF THIS LINE OF SHALLOW CONVECTION SHOULD SNEAK INTO PIEDMONT...BUT THIS MAY NOT OCCUR UNTIL VERY LATE IN AFTERNOON ACCORDING TO LATEST TRENDS. STILL UPSLOPE FLOW FROM SOUTH ALONG BLUE RIDGE SHOULD BE ENHANCING PRECIP AMOUNTS THERE REGARDLESS OF TIMING OF THIS HEAVIER BAND OF SHOWERS...POSSIBLE ISOLATED THUNDER. NAM STILL IS SLOWEST AND LARGELY DUE TO STRONGLY INFLUENCE OF THIS WAVE RIDING UP FROM THE SOUTHWEST...AND SPREADS MORE PRECIP BACK TOWARD THE WEST AGAIN SUNDAY NIGHT AND MONDAY. SOME HINTS OF THIS IN GFS BUT IT STILL REMAINS MOST PROGRESSIVE. HEAVIEST RAINFALL FROM NAM AND SOME HIGH RES MODELS SUGGESTED ALONG BLUE RIDGE...WHILE GFS AND ECMWF MORE OUT INTO PIEDMONT THROUGH SUNDAY NIGHT AND MONDAY. GENERALLY GOING CLOSER TO GFS/ECMWF IDEA...AND NOT QUITE AS WET AS GFS...BUT DID ENHANCE THE RAINFALL ALONG BLUE RIDGE MORE SO THAN WHAT THESE MODELS HAVE. THUS HAVE INCREASED OVERALL STORM QPF SIGNIFICANTLY...WITH 2.5 TO 3 INCHES FROM BLUE RIDGE EAST. PLEASE READ THE HYDROLOGY SECTION BELOW FOR MORE DISCUSSION ON THE RAINFALL AND FLOODING POTENTIAL...BUT FOR NOW HAVE NOT GONE WITH ANY FLOOD HEADLINES...BUT WILL HIGHLIGHT IN THE HWO. AS FAR AS TEMPERATURES...STILL LOOKING AT A RECORD BREAKING MILD AFTERNOON, DESPITE EXTENSIVE CLOUD COVER AND RAIN ACROSS THE WEST...BUT WITH THE PIEDMONT HOLDING OFF ON RAIN UNTIL LATE...LIKELY TO SEE MID 70S. JUST ABOUT ALL LOCATIONS SHOULD TIE OR BREAK A RECORD MAX TEMP FOR THE DATE. SEE CLIMATE SECTION BELOW FOR RECORDS. ON MONDAY THE COLDER AIR BEHIND THE FRONT BEGINS TO FILTER IN...BUT NOT AS FAST AS PREVIOUSLY THOUGHT...AS EVEN THE MORE PROGRESSIVE GFS HAS SLOWED THINGS DOWN WITH THIS WAVE. COLD AIR MAY BEGIN TO RUSH IN LATE IN THE DAY IN THE WEST...BUT WILL PROBABLY NOT ARRIVE IN THE EAST UNTIL MONDAY EVENING. AGAIN...SOME MODEL DIFFERENCES STILL IN TERMS OF HOW FAR WEST THIS WAVE WILL SPREAD OR DEVELOP MORE PRECIP...AND HAVE NOT DROPPED POPS TOO LOW ACROSS THE FAR WEST FOR THIS REASON...BUT THERE COULD BE A BREAK MOST OF MONDAY FOR MUCH OF THE WEST WHILE SHOWERS STILL PLAGUE THE BLUE RIDGE AND THE PIEDMONT MOST OF THE DAY BEFORE FINALLY PUSHING EAST AFTER THE WAVE GOES BY LATE IN THE DAY. WITH WESTERLY FLOW...SOME UPSLOPE SHOWERS COULD LINGER IN TYPICAL UPSLOPE FAVORED AREAS OF THE WEST...BUT CHANCES INCREASE FOR MEASURABLE PRECIP BY LATE MONDAY NIGHT OR EARLY TUES MORNING WITH STRONG UPPER TROUGH AND SHORT WAVE DIGGING QUICKLY ACROSS THE AREA. STRONG COLD ADVECTION BY THIS TIME...AND WHILE LOW LEVEL WINDS MORE WESTERLY...NOT IDEAL FOR BEST UPSLOPE SNOWS...THE ADVECTION OVER VERY MOIST GROUND JUST UPSTREAM IS STILL A CONCERN. STILL LEANING MORE TOWARD THE MODELS THAT PRODUCE SOME LIGHT UPSLOPE ACCUMULATIONS MONDAY NIGHT INTO EARLY TUES MORNING. RIGHT NOW THINKING A VERY LIGHT ACCUM IN NW NC MTNS...WITH AN INCH OR TWO IN WESTERN GREENBRIER WV. NAM STILL STINGY ON THIS...BUT THINKING GFS HAS BEST HANDLE...AND COULD EVEN BE MORE. THIS WAVE MOVES QUICKLY THROUGH AND SHOULD DRY OUT QUICKLY DURING THE DAY TUES..WITH CONTINUED STRONG COLD ADVECTION...DOESN`T LOOK LIKE WIND ADV CRITERIA WIND SPEEDS AT THE MOMENT...AND MUCH COLDER TEMPS WITH MANY AREAS OF THE WEST REMAINING BELOW FREEZING FOR THE DAY. WENT WITH COLDER ECMWF MOS-BASED GUIDANCE. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... AS OF 320 PM EST SATURDAY... STRONG DRY ARCTIC HIGH PRESSURE WILL LEAD TO SOME VERY COLD MORNINGS NEXT WEEK...POSSIBLY SINGLE DIGITS IN THE DEEPEST COLDEST VALLEYS WEDNESDAY MORNING. OTHERWISE A RATHER BENIGN PATTERN WITH A DRY COLD FRONT CROSSING THURSDAY NIGHT. ANOTHER BOUNDARY DROPPING THROUGH THE UPPER MIDWEST LATE NEXT WEEKEND WILL MEAN SW SURFACE FLOW...POTENTIALLY PUSHING H85 TEMPS TO NEAR +5C. A COLDER PATTERN COULD ARRIVE PAST NEXT WEEKEND AS THE POLAR VORTEX DIVES SOUTH THANKS TO AN UPPER RIDGE POTENTIALLY LINKING FROM GREENLAND TO ALASKA. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... AS OF 1155 PM EST SATURDAY... IFR STRATUS COVERED MUCH OF THE SOUTHERN BLUE RIDGE THIS EVENING. MODERATE CONFIDENCE THAT CEILINGS WILL REMAIN ABOVE IFR AT KLYH/KDAN/KROA/KBCB THROUGH MIDNIGHT. OVERNIGHT...MOISTURE TRANSPORT INCREASES ACROSS THE AREA ON 50 TO 60 KT 850 MB WINDS. ANTICIPATE A TREND TOWARD MORE MVFR CIGS ACROSS THE REGION WITH LOCALIZED IFR CIGS AND MVFR VSBYS. LIGHT RAIN SHOWERS WILL BECOME MORE NUMEROUS...ESPECIALLY ALONG THE CREST OF THE BLUE RIDGE AND ALSO NEAR A KLWB-KBLF LINE. WIND GUSTS UP TO 30 KNOTS ARE POSSIBLE...ESPECIALLY FROM 1AM THROUGH 8AM. ON SUNDAY MORNING THE SURFACE COLD FRONT MOVES INTO THE MOUNTAINS...AND MOISTURE WILL CONTINUE TO STREAM ACROSS THE REGION. LOW CONFIDENCE CONCERNING HOW LOW CEILINGS WILL GET IN THE AFTERNOON AND EVENING AFTER THE FIRST STRONG BAND OF SHOWERS AND ISOLATED THUNDERSTORMS GOES THROUGH BUT BEFORE THE FRONT ARRIVES. FOR NOW HAVE LOWERED INTO THE MVFR TO IFR RANGE. A REINFORCING WAVE WILL MOVE NORTH ALONG THE FRONT AND DELAY THE FRONTAL PASSAGE EAST OF THE BLUE RIDGE UNTIL MONDAY. EXPECT A SHARP WIND SHIFT AS A COLD FRONT COMES THROUGH...THEN GUSTY NORTHWEST WINDS ON MONDAY. UPSLOPE SNOW SHOWERS ARE EXPECTED ACROSS SE WV MONDAY NIGHT THROUGH TUESDAY. LOCALIZED MVFR CONDITIONS ARE EXPECTED. VFR CEILINGS AND VISIBILITIES RETURN ON WEDNESDAY AND THURSDAY AS HIGH PRESSURE AND DRIER AIR COME INTO THE REGION. && .HYDROLOGY... AS OF 335 PM EST SATURDAY... MODEL TRENDS TOWARD HIGHER PRECIP AMOUNTS SUNDAY NIGHT AND MONDAY...AND THIS NOT SURPRISING GIVEN SECOND WAVE RIDING UP ALONG FRONT SLOWING IT DOWN..WITH STRONG FETCH OF MOISTURE ADVECTION FROM GULF. FORECAST PRECIPITABLE WATER VALUES OF 1.5 TO 1.7 INCHES WOULD BE RECORD OR NEAR RECORD VALUES FOR DECEMBER. WHILE SOME HIGH RESOLUTION MODELS ARE LIKELY OVERDOING THE MAXIMUM PRECIP OUTPUT...SOME SIGNS THAT TWO AREAS OF CONCERN ARE ALONG THE BLUE RIDGE SUNDAY THROUGH EARLY MONDAY...AND ALSO OUT IN THE PIEDMONT MAINLY SUNDAY NIGHT AND MONDAY. CURRENT FORECAST AMOUNTS ARE BETWEEN 2 AND JUST OVER 3 INCHES...AND THIS MAY BE ENOUGH TO CAUSE NOT ONLY LOCALIZED FLOODING OF SMALL STREAMS AND CREEKS...BUT COULD BRING THE DAN RIVER UP TO ACTION OR MINOR FLOOD STAGE BY TUESDAY FROM UPSTREAM AND LOCAL RUNOFF. MAY ALSO HAVE TO WATCH THE HEADWATERS OF THE NEW RIVER IN NW NC FOR SUNDAY NIGHT...AS WELL AS ROANOKE RIVER FOR MON/TUES TIME FRAME. IF HIGHER RESOLUTION MODELS ARE CORRECT...THERE COULD BE MUCH MORE SIGNIFICANT FLOODING PROBLEMS...BOTH FLASH FLOOD AND RIVER FLOOD. NOT CONFIDENT ENOUGH YET TO GO WITH A WATCH OF ANY KIND YET. && .CLIMATE... RECORDS FOR THE WARMEST LOW TEMPERATURE AT EACH CLIMATE SITE FOR THE MONTH OF DECEMBER ARE AT RISK OF BEING TIED OR BROKEN...ESPECIALLY ACROSS THE PIEDMONT. HIGHEST LOW TEMPERATURES FOR THE MONTH OF DECEMBER... BLACKSBURG 55/DEC 23 1990 ROANOKE 60/DEC 14 1927 LYNCHBURG 62/DEC 16 1971 DANVILLE 60/DEC 6 2011 BLUEFIELD 58/DEC 22 1990 LEWISBURG 58/DEC 28 1982 && .RNK WATCHES/WARNINGS/ADVISORIES... VA...WIND ADVISORY UNTIL NOON EST SUNDAY FOR VAZ007-009-015-018>020- 022>024-034-035. NC...WIND ADVISORY UNTIL NOON EST SUNDAY FOR NCZ001-018. WV...WIND ADVISORY UNTIL NOON EST SUNDAY FOR WVZ043>045. && $$ SYNOPSIS...KK/SK NEAR TERM...AMS/DS SHORT TERM...SK LONG TERM...KM AVIATION...AMS/DS HYDROLOGY...SK CLIMATE...CF/DS/SK
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
829 PM CST MON DEC 23 2013 .UPDATE... IMPRESSIVE LAKE EFFECT SNOW SHOWING UP ON RADAR ABOUT 20 MILES OFF SHORE...OUT OVER THE LAKE. IT IS A BATTLE BETWEEN THE NORTHEAST WINDS IN THE 4-7KFT LAYER THAT ARE PUSHING TOWARD SHORE...AND THE BRISK AND EXTREMELY DRY WESTERLY SURFACE WINDS TRYING TO BEAT IT BACK. THE HRRR SAYS IT WILL NEVER MAKE IT TO SHORE. IT GETS CLOSE...THEN HEADS EAST SOUTHEAST WITH TIME. REALITY WOULD SUGGEST SOME OF THOSE HIGHER RETURNS WILL MAKE IT TO SHORE...BUT IT APPEARS THEY WILL TEMPERED DUE TO THE DRY LOW LEVELS. WOULDN/T BE SURPRISED IF SOME SHORELINE AREAS SOUTH OF SHEBOYGAN GET A SNEAKY INCH OF SNOW ACCUM OUT OF THIS. THE SHEBOYGAN AREA HAS ALREADY GOTTEN 1-3 INCHES TODAY...IT/S BEEN SNOWING UP THERE NEARLY ALL DAY. THE MAIN UPPER LEVEL TROF HELPING TO DRIVE ALL THIS DOES DRIFT SOUTHEAST OF US BY MORNING...SO I EXPECT THE SNOW TO GRADUALLY DIMINISH OVERNIGHT. MAYBE NOT AS FAST AS THE PREV FORECAST THOUGHT HOWEVER. THE OTHER MAIN STORY IS THE COLD. TEMPS DROPPED EARLY AND FAST IN THE SOUTH WHERE SKIES CLEARED FOR A TIME. WITH WINDS STILL ELEVATED SOUTHWEST OF MADISON...WIND CHILL READINGS WERE HITTING -20 ALREADY. EXPECT THESE COLD WIND CHILLS THERE THROUGH THE NIGHT SO A WIND CHILL ADVISORY IS IN EFFECT UNTIL 9 AM FOR IOWA/LAFAYETTE AND GREEN COUNTIES. && .AVIATION/06Z TAFS/... MVFR CIGS/VSBYS WITH LIGHT SNOW EXPECTED THROUGH ABOUT 3-4 AM TONIGHT AS THE MAIN UPPER LEVEL TROF SLOWLY EXITS TO THE SOUTHEAST OVERNIGHT. EXPECT SKIES TO GRADUALLY CLEAR AFTER 12-13Z TUESDAY. THE NEXT ROUND OF SNOW WILL BRING SIMILAR MVFR CIGS/VSBYS DUE TO SNOW AFTER 02Z WED AT MADISON AND 04Z AT MILWAUKEE. && .PREV DISCUSSION... /ISSUED 339 PM CST MON DEC 23 2013/ TONIGHT...FORECAST CONFIDENCE IS MEDIUM. MAIN ISSUES WILL BE ENDING THE LIGHT SNOW...SUBSEQUENT CLEARING... FRIGID TEMPS AND POTENTIAL WIND CHILL ISSUES. WITH LIGHT SNOW PIVOTING NORTHEAST AROUND CIRCULATION NEAR KARX...EXPECT THE STEADIEST SNOW INTO THE EVENING TO BE ACROSS THE NE 1/2 OF THE CWA. THE CIRCULATION DOES DRIFT ESE WITH TIME SO SOME AREAS THAT CLEARED OUT IN SW CWA MAY STILL SEE SOME CLOUDS/FLURRIES THIS EVENING. ATTENTION THEN TURNS TO LOW TEMPS. 925 TEMPS DROP TO -14 TO -16C. TEMPS ALREADY DROPPING OFF QUITE QUICKLY IN THE SW CWA. RIDGE AXIS DRAWS CLOSER AND 925 MB WINDS REALLY DROP OFF ESPECIALLY IN THE WESTERN CWA. SO WILL DROP TEMPS A BIT FURTHER. WITH UPPER TROUGH AXIS SHIFTING EAST OF THE CWA AFTER 06Z...POTENTIAL FOR REST OF CWA TO CLEAR OUT AS WELL. 925/850 MB RH PROGS ARE SHOWING A DECREASING TREND IN THIS REGARD...SO NO REAL REASON NOT TO EXPECT A DECENT TEMP DROPOFF CWA WIDE. WIND CHILL GETS TO NEAR -20 IN THE SOUTHWEST CWA LATE IN THE NIGHT THOUGH TEMPORAL AND AREAL EXTENT NOT GREAT...SO AFTER COLLAB WITH KARX WILL HOLD OFF ON ADVISORY THERE...BUT CWA WIDE WIND CHILLS TO EVENTUALLY DROP INTO THAT BITTER -10 TO 20 RANGE. TUESDAY...FORECAST CONFIDENCE IS MEDIUM. AFTER A FRIGID START...SURFACE/850 RIDGE AXES SHIFT EAST OF WI. 850 MB WARM ADVECTION BEGINS IN THE AFTERNOON. BUFKIT SOUNDINGS SHOW SOME MOISTURE AOA 10K FEET ARRIVING INTO THE WESTERN CWA DURING THE AFTERNOON. 925 MB TEMPS REBOUND TO -11 OR -12C...HOWEVER EXPECT A MIXING OUT TO LOWER THAN THAT SO GOING WITH ONLY TEENS FOR HIGHS. SHORT TERM...TUESDAY NIGHT THROUGH THURSDAY...FORECAST CONFIDENCE IS HIGH. SHORT TERM MODELS ARE STILL IN GOOD AGREEMENT WITH LIGHT SNOW MOVING THROUGH THE AREA TUESDAY NIGHT...LINGERING THROUGH CHRISTMAS DAY INTO WEDNESDAY NIGHT. BEST SHOT WILL BE TUESDAY NIGHT...AS 500 MB SHORTWAVE TROUGH AND WARM AIR ADVECTION MOVE THROUGH THE AREA. MODERATE TO STRONG UPWARD VERTICAL MOTION SEEN WITH DEEP LAYER Q VECTOR CONVERGENCE. THIS OCCURS WITHIN SATURATED AIR COLUMN TAPPING DENDRITE SNOW GROWTH ZONE. HIGH POPS CONTINUE FOR TUESDAY NIGHT. HIGH SNOW TO LIQUID RATIOS OF 17/19 TO 1 GIVES AMOUNTS OF 2 TO 3 INCHES ACROSS THE AREA TUESDAY NIGHT. WINDS INCREASING DURING THIS TIME MAY LEAD TO DRIFTING ON EAST TO WEST ROADS. NO ADVISORY WAS ISSUED...BUT MAY NEED TO BE CONSIDERED IF SNOW AMOUNTS INCREASE IN LATER FORECASTS. KEPT POPS GOING FOR CHRISTMAS DAY INTO WEDNESDAY NIGHT...AS MODELS BRING ANOTHER 500MB SHORTWAVE TROUGH THROUGH THE REGION. NAM IS A BIT SLOWER THAN THE GFS/ECMWF/CANADIAN WITH THE SHORTWAVE PASSAGE. MOISTURE IS MODEST THROUGH THE AIR COLUMN...BUT ENOUGH TO LEAVE POPS GOING. MAY SEE ANOTHER 1/2 TO 1 INCH DURING THIS PERIOD. COLD TEMPERATURES WILL RETURN WEDNESDAY NIGHT. LEFT THURSDAY DRY FOR NOW...AS HIGH AXIS SLIDES TO THE EAST. MORE 500 MB SHORTWAVES APPROACH THE AREA IN THE AFTERNOON...BUT FORECAST SOUNDINGS ARE SLOW TO SATURATE. COLD TEMPERATURES WILL CONTINUE. LONG TERM...THURSDAY NIGHT THROUGH MONDAY...FORECAST CONFIDENCE IS MEDIUM. SEVERAL 500 MB VORTICITY MAXIMA CONTINUE TO SHIFT SOUTHEAST THROUGH THE AREA PER ECWMF AND GFS MODELS. AIRMASS SEEMS FAIRLY DRY THROUGH SATURDAY...SO KEPT FORECAST DRY PER CONSENSUS BLEND OF POPS. KEPT POPS IN LATER ON...AS MORE MOISTURE MOVES INTO THE AREA. MAINTAINED CONSENSUS BLEND OF TEMPERATURES DURING THE LONG TERM PERIOD...WHICH KEEPS THE AREA COLD. AVIATION/00Z TAFS/... NW-SE ORIENTED MVFR SNOW AREA ASSOCIATED WITH LOW LEVEL TROUGH AND UPPER CYCLONIC FLOW. A FEW IFR VSBYS IN THIS BAND. RADAR ANIMATION SHOWS CIRCULATION CENTER NEAR KLSE. BAND OF SNOW PIVOTING AROUND THIS FEATURE. EXPECT SNOW TO PERSIST MAINLY IN THE NE 1/2 OF CWA THIS EVENING BUT WILL HAVE TO KEEP AN EYE ON ANY DEF ZONE PCPN DROPPING SOUTHEAST FROM NEAR KLSE. DRYING THEN WORKS IN AS THE NIGHT WEARS ON. HIGH PRESSURE RIDGE ACROSS THE CWA AT 18Z TUESDAY...SHIFTING INTO THE OH VLY BY 00Z. SOUTHERLY WIND FLOW SETS UP THOUGH PRECIP ASSOCIATED WITH NEXT DISTURBANCE HOLDS OFF UNTIL TUESDAY NIGHT. MARINE... GRADIENT WILL TIGHTEN UP TUESDAY NIGHT AHEAD OF NEXT LOW PRESSURE. WINDS TURN WESTERLY AND REMAIN GUSTY CHRISTMAS DAY AND REMAIN SO INTO WEDNESDAY NIGHT. SMALL CRAFT GUSTS EXPECTED WITH HIGHEST WAVES LIKELY TOWARDS OPEN WATER. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...WIND CHILL ADVISORY UNTIL 9 AM CST TUESDAY FOR WIZ062-067-068. LM...NONE. && $$ UPDATE...DAVIS TONIGHT/TUESDAY AND AVIATION/MARINE...COLLAR TUESDAY NIGHT THROUGH MONDAY...WOOD
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
300 PM CST SUN DEC 22 2013 .SHORT TERM...(TONIGHT THROUGH MONDAY NIGHT) ISSUED AT 300 PM CST SUN DEC 22 2013 MAIN FORECAST CONCERNS THIS PACKAGE...CONTINUING LIGHT SNOW TONIGHT/MON...LOWS/WIND CHILLS MON NIGHT. 18Z DATA ANALYSIS HAD A BROAD AREA OF LOW PRESSURE NEAR LAKE ERIE WITH TROUGHING NORTHWEST THRU LOWER MI/WI INTO NORTHERN MN. MAIN SNOW AREA WITH THE SHORTWAVE THAT TRACKED NORTHEAST ACROSS NORTHERN IL EARLY THIS MORNING WAS ALREADY EXITING NORTHEAST WI. WARNINGS/ ADVISORIES IN/AROUND THE AREA BEFORE 18Z DUE TO THE RAPID EXIT OF THIS SNOW AREA.. LIGHT SNOW FALLING OVER WESTERN WI/MUCH OF MN AT MID-DAY WAS ASSOCIATED WITH STRONG TROUGHING/SHORTWAVE ENERGY DIGGING SOUTHEAST INTO THE UPPER MIDWEST. VISIBILITIES IN MUCH OF THIS SNOW VARIED FROM 1 TO 7 MILES. INITIALIZATIONS OF 22.12Z MODELS GENERALLY GOOD WITH SOLUTIONS VERY SIMILAR FOR TONIGHT THRU MON NIGHT...THOUGH NO 22.12Z CAN-GEM DATA AVAILABLE THIS CYCLE. THIS AS NORTHERN STREAM ENERGY CARVES OUT A RATHER DEEP MID LEVEL TROUGH OVER THE UPPER MIDWEST TONIGHT/MON THEN SHORTWAVE RIDGING BUILDS IN MON NIGHT. TREND CONTINUES TO FAVOR STRONGER/SLOWER WITH THE TROUGH THRU THE PERIOD. CHECK OF OBS VS. MODEL DATA AT 18Z SHOWED ALL TO BE QUITE REASONABLE WITH THE LK ERIE SFC LOW AND TROUGHING BACK INTO MN/WI. BLEND OF THE MODELS LOOKED BEST WITH THE 12-18Z PRECIP OVER THE CENTRAL/EASTERN CONUS THOUGH INDIVIDUALLY ALL WERE VERY SIMILAR WITH THIS. PER WV IMAGERY ALL LOOKED QUITE GOOD WITH THE SHORTWAVE DETAILS OVER NOAM. NO ONE FAVORITE AND WITH SOLUTIONS TRENDING TOWARD AN EVEN TIGHTER CONSENSUS...FAVORED THE MODEL/ENSEMBLE CONSENSUS. SHORT-TERM FCST CONFIDENCE IS GOOD THIS CYCLE. FOR THE SHORT TERM...ATTENTION IS FOCUSED ON THE UPSTREAM SHORTWAVE ENERGY/SHORTWAVES OVER THE DAKOTAS TO SASKAT/ALB TO CARVE OUT A DEEP MID LEVEL TROUGH OVER THE UPPER MIDWEST THE NEXT 24HRS. FALLING HGTS AND DIVERGENCE ALOFT WITH PV ADVECTION AHEAD OF THE SHORTWAVES WORK TO DEEPEN AN 850-700MB LOW/CIRCULATION OVER WESTERN WI/EASTERN MN TONIGHT...TO DRIFT SOUTHEAST ACROSS THE AREA MON. THE INCREASING LOWER LEVEL CYCLONIC CONVERGENCE WORKS WITH THE DIVERGENCE ALOFT TO CONTINUE WRINGING OUT SOME OF THE PLENTIFUL SFC-700MB AND ABOVE MOISTURE IN THE COLUMN. DEEPEST OF THE MOISTURE/STRONGER OF THE CONVERGENCE/LIFT IS OVER THE NORTHEAST 3/4 OR SO OF THE FCST AREA TONIGHT/MON AS THE WEAK 850-700MB LOW DEVELOPS/MOVES SOUTHEAST ACROSS THE AREA. CONTINUED 70-100 PERCENT -SN CHANCES FOR THE NORTHEAST 3/4 OF THE FCST AREA TONIGHT...THEN TREND THESE SLOWLY EASTWARD AND DOWNWARD MONDAY AS THE 850-500MB TROUGH AXIS GRADUALLY PASSES. GIVEN THE COOLING COLUMN AND THE DENDRITIC GROWTH ZONE ABOUT HALF THE DEPTH OF THE SFC-700MB LAYER SNOW-WATER RATIOS LOOKING TO BE MORE IN THE 15-20 TO 1 RANGE. MODEL CONSENSUS PRODUCES 0.05 TO 0.15 INCH OF QPF OVER THE NORTHEAST 2/3 OF THE FCST AREA TONIGHT... THUS 1 TO 2 INCHES OF SNOWFALL EXPECTED ACROSS THAT PORTION OF THE FCST AREA TONIGHT THRU EARLY MONDAY AFTERNOON. COLDER AIR FILTERS IN TONIGHT WITH TEMPS REACHING NEAR OR JUST BELOW ZERO ACROSS THE WEST END OF THE FCST AREA LATE TONIGHT. THIS WITH NORTHWEST WINDS IN THE 10-15 MPH RANGE. WIND CHILLS AT SITES LIKE KTOB/KAUM/KCCY DIP TO AROUND -20 LATE TONIGHT/MON MORNING. WILL ISSUE A WIND CHILL ADVISORY FOR 06Z-18Z MON FOR THE WESTERN 6 COUNTIES OF THE FCST AREA. RATHER SHARP SFC-850MB RIDGE AXIS BUILDS EAST INTO THE FCST AREA MON NIGHT...TO NEAR THE MS RIVER BY 12Z TUE. HOWEVER MODEL CONSENSUS RELUCTANT TO CLEAR OUT THE LOWER LEVEL MOISTURE OVER WI EAST OF THIS RIDGE AXIS. WITH LIGHTER WINDS MON NIGHT...CLOUDS OR NO CLOUDS WILL HAVE AS MUCH AS A 5F TO 10F IMPACT ON LOW TEMPS...WARMER UNDER THE CLOUDS. GIVEN THE CLOUD UNCERTAINTIES STAYED WITH THE MODEL/ENSEMBLE CONSENSUS FOR LOWS MON NIGHT...WITH LOWS IN THE -5F TO -15F RANGE. THESE TEMPS COMBINED WITH EVEN THE LIGHTER NORTHWEST WINDS TO PRODUCE WINDS CHILLS OF -20 TO -30 MON NIGHT INTO TUE MORNING. TO AVOID THE /DOUBLE HEADLINE/ WILL HOLD OFF ON A WIND CHILL ADVISORY FOR THIS TIME PERIOD FOR NOW. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 300 PM CST SUN DEC 22 2013 MAIN FORECAST CONCERNS FOR THE TUE THRU WED NIGHT PERIOD ARE LIGHT SNOW CHANCES/AMOUNTS LATE TUE THRU WED NIGHT. TIGHTENING CONSENSUS AMONG THE 22.12Z MODELS CONTINUES IN THE TUE THRU WED NIGHT PERIOD...ESPECIALLY TUE/TUE NIGHT AS THE SHORTWAVE RIDGING QUICKLY PASSES AND THE NEXT STRONG NORTHWEST FLOW SHORTWAVE DROPS INTO THE UPPER MIDWEST. SOME DIFFERENCES BY LATER WED/WED NIGHT WITH GFS LOOKING TO BE A FAST OUTLIER WITH A SECONDARY SHORTWAVE TO DROP INTO/ACROSS THE REGION. FCST CONFIDENCE REMAINS QUITE GOOD TUE/TUE NIGHT...THEN AVERAGE FOR WED/WED NIGHT. SFC-700MB RIDGE AXIS TRANSLATES QUICKLY ACROSS THE AREA TUE...WITH RATHER STRONG 925-700MB WARM ADVECTION AND SFC-500MB MOISTURE SPREADING QUICKLY ACROSS THE AREA. PV ADVECTION AHEAD OF THE LEAD SHORTWAVE PLUS THE STRONG LOW LEVEL WARM ADVECTION/ISENTROPIC LIFT PROVIDE RATHER DEEP UPWARD FORCING THRU THE COLUMN CENTERED ON TUESDAY EVENING. DEEP DENDRITIC GROWTH ZONE INDICATED LATE TUE AFTERNOON/NIGHT...FOR WHAT SHOULD BE RATHER FLUFFY CHRISTMAS EVE SNOW. BASED ON MODEL CONSENSUS QPF PRODUCTION...1 TO 3 INCHES OF SNOW LOOKS QUITE LIKELY FOR THE FCST AREA FROM LATE TUE AFTERNOON INTO WED MORNING. IF NAM/ECMWF ARE MORE CORRECT WITH A RATHER STRONG SECONDARY SHORTWAVE TO DROP ACROSS THE AREA...ANOTHER ROUND OF LIFT MOVES BY TO SQUEEZE OUT MORE LIGHT SNOW LATER WED INTO WED NIGHT. FOR NOW LEFT -SN CHANCES WED AFTERNOON/NIGHT IN THE 20-40 PERCENT RANGE. USED THE MODEL/ENSEMBLE BLEND FOR HIGHS/LOWS TUE THRU WED NIGHT. FOR THURSDAY THROUGH SUNDAY.../DAYS 4 TO 7/... MEDIUM RANGE MODEL RUNS OF 22.00Z/22.12Z SHOW GOOD BETWEEN MODEL AND RUN-TO-RUN AGREEMENT WITH THE LARGER SCALE FEATURES OF LONGWAVE TROUGHING OVER THE EASTERN HALF OF NOAM THU/FRI...WITH NORTHWEST FLOW ALOFT OVER THE UPPER MIDWEST. HOWEVER PLENTY OF DETAIL DIFFERENCES WITH SMALL SCALE SHORTWAVES RIPPLING ACROSS THE REGION THRU THIS FLOW. ACTUALLY GOOD AGREEMENT FOR HGTS OVER THE REGION TO RISE A BIT SAT AS THE THU/FRI TROUGH PROGRESSES EAST AND STRONGER TROUGHING DIGS INTO THE NORTHERN ROCKIES. ANY RISE OF HGTS/WEAK RIDGING ALOFT OVER THE REGION LOOKS SHORT LIVED AS MODELS MAINTAIN GOOD CONSENSUS FOR RENEWED TROUGHING TO DIG INTO THE NORTH-CENTRAL CONUS SUNDAY. WITH THE BETTER BETWEEN MODEL CONSISTENCY THIS CYCLE THE DAY 4-7 FCST CONFIDENCE IS ON THE PLUS SIDE OF AVERAGE. SOME GFS/ECMWF CONSISTENCY FOR A STRONGER SHORTWAVE/TROUGH TO BE ROTATING EAST OF THE FCST AREA AT 12Z THU. DRIER CAN HIGH PRESSURE TO BUILD IN BEHIND IT FOR THU INTO FRI...FOR WHAT SHOULD BE A BREAK FROM THE LIGHT SNOW CHANCES OF MUCH OF THE TONIGHT THRU WED NIGHT PERIOD. THE HIGH MOVES QUICKLY SOUTHEAST OF THE REGION FRI AS LOW PRESSURE TRACKS ACROSS SOUTHERN CAN. THU NIGHT SHAPING UP TO BE A NIGHT OF SUB-ZERO LOWS ACROSS THE FCST AREA WITH THE SFC RIDGE AXIS/LIGHT WINDS ACROSS THE THE AREA THAT NIGHT. MDT/STRONG LOWER LEVEL WARM ADVECTION SPREADS ACROSS THE AREA FRI/FRI NIGHT. APPEARS MUCH OF THIS GOES INTO WARMING...WITH SFC- 700MB MOISTURE REMAINING SCANT AND LITTLE IN THE WAY OF UPWARD MOTION GENERATED. 850MB TEMPS PROGGED TO GO FROM AROUND -8C TO -12C AT 12Z FRI TO 0C TO +6C BY 12Z SAT AS WESTERLY SFC-700MB FLOW BECOMES MORE WESTERLY ACROSS THE REGION. WILL LEAVE FRI NIGHT/SAT DRY FOR NOW WITH THE STRONG UPWARD TREND IN TEMPS FOR THE WEEKEND. GOOD GFS/ECMWF CONSISTENCY FOR A STRONGER SFC THRU 700MB TROUGH TO SLIDE SOUTHEAST ACROSS THE AREA SAT NIGHT INTO SUN. LOWER LEVEL COLD ADVECTION AND AN INCREASE OF LOWER LEVEL MOISTURE TO FOLLOW THE TROUGH AXIS. IF PRESENT TIMING/ CONSENSUS MAINTAINS...WHAT SMALL MODEL CONSENSUS -SN CHANCES ARE IN THE FCST GRIDS FOR SAT NIGHT/SUN WOULD HAVE TO BE RAISED. MODEL/ ENSEMBLE CONSENSUS FOR THU THRU SUN HIGHS/LOWS APPEAR REASONABLE. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1122 AM CST SUN DEC 22 2013 SOME UNCERTAINTY ON WHAT THE CEILINGS ARE GOING TO DO THROUGH THE PERIOD. POCKET OF VFR CONDITIONS HAS DEVELOPED IN THE WAKE OF THE SNOW BAND AND IS OVER BOTH TAF SITES. HOWEVER...OFF TO THE NORTHWEST...LARGE AREA OF MVFR CEILINGS IN PLACE AHEAD OF THE NEXT SHORT WAVE TROUGH THAT WAS ACROSS THE EASTERN DAKOTAS. EXPECT THAT AS THE SHORT WAVE TROUGH MOVES IN THAT THE CEILINGS SHOULD GO DOWN TO MVFR AND HAVE TRENDED THE FORECAST THAT WAY. FOR THE MOST PART...EXPECT THE VISIBILITY TO REMAIN VFR DESPITE HAVING LIGHT SNOW FALLING THROUGH THE ENTIRE FORECAST PERIOD. THE 22.16Z RAP INDICATES THE BETTER CHANCES FOR VISIBILITY RESTRICTIONS IN THE LIGHT SNOW TO EXTEND FROM ABOUT THE TWIN CITIES INTO CENTRAL WISCONSIN STAYING NORTH OF BOTH TAF SITES. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST MONDAY FOR MNZ086-094. IA...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST MONDAY FOR IAZ008-009-018-019. && $$ SHORT TERM...RRS LONG TERM....RRS AVIATION.....04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1128 PM CST SAT DEC 21 2013 .UPDATE... ISSUED AT 900 PM CST SAT DEC 21 2013 THE MAIN FOCUS THIS EVENING HAS BEEN WITH WHETHER OR NOT A TIER OF COUNTIES NEEDS TO BE ADDED ONTO THE CURRENT ADVISORY/WARNING. CURRENTLY...SOME VERY LIGHT FREEZING DRIZZLE HAS BEEN FALLING ACROSS PORTIONS OF THE AREA IN RESPONSE TO SOME WEAK 280-290K ISENTROPIC LIFT THAT IS OCCURRING AHEAD OF THE MAIN TROUGH. BEFORE WE SEE ANY SNOW DEVELOP LOCALLY...THE DRY LAYER BETWEEN 800-600MB WILL HAVE TO SATURATE OUT. THE 22.01 RAP RH FIELDS SHOW SOME INCREASING RH IN THAT COLUMN COMING IN FROM THE SOUTHEAST AND SOUTH AROUND AND AFTER 6Z. THIS COINCIDES FAIRLY WELL WITH WHAT 22.00Z HRRR REFLECTIVITY GRAPHICS SHOW WITH THE SNOW MOVING UP INTO NORTHEAST IOWA AROUND/AFTER 6Z. BASED ON THE PATH OF THE 500MB VORT MAX THROUGH NORTHERN ILLINOIS AND THE CURRENT HEAVY SNOW THAT IS FALLING ACROSS PORTIONS OF KANSAS...CONFIDENCE IS STILL HIGH IN THE HEAVY SNOW THAT IS FORECAST TO OCCUR OVERNIGHT INTO TOMORROW MORNING ACROSS THE WINTER STORM WARNING AREA. IT STILL LOOKS LIKE THE 2AM TO 10AM TIME FRAME IS WHEN THE HEAVIEST SNOW WILL COME THROUGH WITH SOME 1...MAYBE 2...INCH PER HOUR SNOWFALL RATES IN THIS BAND. FURTHER TO THE NORTHWEST...THE 22.00Z AND PRIOR RUNS HAVE BEEN HINTING AT A SECONDARY DEFORMATION BAND SETTING UP ALONG THE ADVISORY COUNTIES AND POSSIBLE JUST TO THE WEST OF IT. THIS LIFT IS COMING IN THE 500-300MB LEVELS AND IS OVER THE DRY LAYER BETWEEN 800-600MB...SO THERE IS THE QUESTION OF WHETHER THE DRY LAYER WILL BE DEEP ENOUGH TO KEEP ANY SNOW/ICE FROM MAKING IT TO THE GROUND. 22.01Z RAP SOUNDINGS SHOW THIS DRY LAYER WINNING OUT THROUGH MUCH OF THE OVERNIGHT HOURS BEFORE BRIEFLY SATURATING UP ENOUGH TO ALLOW FOR SOME SNOW TO FINALLY OCCUR TOWARD DAYBREAK. DUE TO THE SHORT LENGTH OF WHEN THIS SNOW COULD FALL...HAVE DECIDED TO NOT MAKE ANY CHANGES TO THE CURRENT ADVISORY...BUT WILL UP THE TOTALS AN INCH OR TWO FROM CHARLES CITY IOWA NORTH NORTHEAST TOWARD BLACK RIVER FALLS WISCONSIN FOR WHERE IT LOOKS LIKE THIS BAND COULD SET UP. WILL CONTINUE TO WATCH DOWNSTREAM OBS FOR WHETHER ANY FUTURE ADJUSTMENTS NEED TO BE MADE TO THIS AREA. && .SHORT TERM...(TONIGHT THROUGH SUNDAY NIGHT) ISSUED AT 300 PM CST SAT DEC 21 2013 MAIN FORECAST CONCERNS THIS PACKAGE...WINTER STORM TO MOVE ACROSS THE AREA TONIGHT/SUN...LINGERING SNOW CHANCES SUN NIGHT. DATA ANALYSIS AT 18Z HAD A BROAD AREA OF HIGH PRESSURE OVER CENTRAL CANADA AND DEEPENING LOW PRESSURE OVER ARKANSAS. PER WV IMAGERY... SHORTWAVE OF INTEREST FOR TONIGHT/SUNDAY HAS ROUNDED THE BASE OF THE TROUGH AND COULD BE SEEN LIFTING NORTHEAST ACROSS TX AT MID-DAY. UPPER MIDWEST UNDER THE INFLUENCE OF THE HIGH TODAY...WITH GENERALLY QUIET WEATHER BUT MOSTLY CLOUDY TO CLOUDY SKIES WITH ABUNDANT LOW LEVEL MOISTURE TRAPPED UNDER AN INVERSION NEAR 850MB. MID-DAY TEMPS ACROSS MUCH OF THE REGION NEAR SEASONAL NORMALS. 21.12Z MODELS LOOK TO HAVE INITIALIZED WITHOUT LARGE ERRORS. MODELS CONTINUE TO CONVERGE TOWARD A TIGHTER/COMMON CONSENSUS THRU SUN NIGHT...TOWARD THE EARLIER ECMWF/CAN-GEM RUNS. THIS AS THE AZ/ NORTHERN MEX/WEST TX SHORTWAVE ENERGY LIFTS QUICKLY NORTHEAST TONIGHT/SUN TO WESTERN QUEBEC BY 00Z MON...AND ENERGY OVER BC/ALB CARVES OUT A RATHER DEEP TROUGH OVER THE REGION LATER SUN NIGHT. MODEL DIFFERENCES THAT DO REMAIN IMPACT SNOW AMOUNTS TONIGHT/SUNDAY. CHECK OF OBS VS. MODEL DATA AT 18Z SHOWED MODELS ALL REASONABLE ON THE SFC MASS FIELDS ACROSS THE CENTRAL CONUS. PER WV IMAGERY... MODELS ALL APPEAR GOOD WITH THE SOUTHERN PLAINS SHORTWAVE ENERGY. BLEND OF THE MODELS LOOKED GOOD WITH THE 12-18Z PRECIP ASSOCIATED WITH THE MID LEVEL TROUGH AND SFC TROUGH/FRONT FROM THE SOUTHERN PLAINS LOW THRU OHIO VALLEY. WITH MODELS TRENDING MORE SIMILAR... TOWARD A TIGHTER COMPROMISE SOLUTION...FAVORED THE MODEL/ENSEMBLE CONSENSUS. GIVEN THE SNOW AMOUNT DIFFERENCES...AND A SLIGHT TREND TOWARD DRIER/LESS SNOW...SHORT-TERM FCST CONFIDENCE IS SHY OF GOOD THIS CYCLE. IN THE SHORT TERM...MODEL SOUNDINGS SHOWING SATURATION TO ABOUT 800MB AND CLOUD TOP TEMPS IN THE -5C TO -10C RANGE THIS AFTERNOON. FALLING PRESSURES/DIVERGENCE ALOFT STARTING TO SPREAD ACROSS THE AREA...PROVIDING A LITTLE LIFT TO THE LOWER LEVELS AND GETTING FEW REPORTS OF -FZDZ. MODEL SOUNDINGS SHOWING IT TAKES THRU MUCH OF THE EVENING FOR THE COLUMN TO SATURATE FOR ICE IN THE LOWER CLOUD/ MOISTURE LAYER. AVIATION FORECASTER DID ADD MENTION OF -FZDZ WITH THE -SN CHANCES TO MUCH OF THE FCST AREA THRU THE EVENING. VIGOROUS TX SHORTWAVE LIFTS TO NEAR THE IA/MO/IL INTERSECTION BY 12Z SUN...WHILE THE SFC LOW LIFTS TO THE VICINITY OF NORTHWEST OH. 850MB LOW LIFTS ACROSS MO TO NEAR OR EAST OF CHICAGO BY 12Z SUN. ON THIS TRACK...MUCH OF THE STRONGER/DEEPER LOWER LEVEL THERMO- DYNAMIC FORCING JUST CLIPS THE SOUTHEAST END OF THE FCST AREA. BULK OF THE FORCING/LIFT TO PASS ACROSS THE REST OF THE FCST AREA WILL BE FROM UPPER LEVEL PV ADVECTION/DIVERGENCE/LIFT AHEAD OF THE VIGOROUS SHORTWAVE AND DIVERGENCE ALOFT BETWEEN AT LEAST SEMI- COUPLED JET MAXES. PLENTY OF MOIST/UNSTABLE AIR BEING LIFTED NORTH OF THIS SYSTEM...WITH DYNAMICS/LIFT AHEAD OF THE ADVANCING TROUGH PRODUCING ABUNDANT CONVECTION/PRECIP NEAR THE SFC TROUGH/FRONT ACROSS THE MID MS TO OH VALLEYS. THE SLIGHT DROP IN PRECIP PRODUCTION ACROSS THE AREA TONIGHT/SUN MAY BE TIED TO THIS WALL OF CONVECTION ROBBING MUCH OF THE INCOMING MOISTURE BEFORE IT WOULD REACH THE AREA. GFS/ECMWF/NAM NOW BARELY PRODUCE ENOUGH QPF FOR ADVISORY SNOW AMOUNTS OVER THE SOUTHEAST END OF THE FCST AREA WHILE CAN-GEM STILL HOLDS ONTO WARNING/ADVISORY AMOUNTS ACROSS THE SOUTHEAST 1/3 TO HALF OF THE FCST AREA. WITH MUCH OF THE LIFT ABOVE 850MB AND EVEN 700MB...AND VERTICAL MOTIONS NOT OVERLY STRONG EXCEPT OVER THE SOUTHEAST END OF THE FCST AREA...HAVING A HARD TIME SEEING SNOW-WATER RATIOS IN THE 15 TO 20 TO 1 RANGED TO PRODUCE THE HIGHER SNOWFALL TOTALS. LOWERED SNOW AMOUNTS A BIT...BUT LEFT THEM IN RANGES TO SUPPORT THE CURRENT ADVISORIES/ WARNINGS...WHICH WILL BE LEFT AS FOR NOW. TIGHTER PRESSURE GRADIENT AND BRISK NORTHWEST WINDS FOR SOME BLOWING/DRIFTING OF NEW SNOW WILL ADD THAT TO THE WINTER WEATHER HEADLINES FOR LATER TONIGHT/MUCH OF SUNDAY. FORCING/LIFT WITH THIS SHORTWAVE EXITS DURING THE MORNING WITH ATTENTION QUICKLY TURNING TO THE NORTHERN STREAM SHORTWAVE DROPPING TOWARD THE AREA. STRONG HGT FALLS TO MOVE ACROSS THE AREA LATER SUN/ SUN NIGHT WITH ANOTHER ROUND OF STRONG PV ADVECTION AND DIVERGENCE/ LIFT ALOFT. MUCH COLDER COLUMN OVER THE AREA BY SUN NIGHT WITH THE DENDRITIC GROWTH ZONE LOWER...IN THE 850-700MB RANGE. INCREASING MODEL SIGNAL/CONSENSUS FOR THE FEATURE TO PRODUCE 1 TO PERHAPS 2 INCHES OF SNOW ACROSS THE NORTHEAST 2/3 OF THE FCST AREA SUN AFTERNOON/NIGHT AND RAISED SNOW CHANCES THESE PERIODS INTO THE 70-80 PERCENT RANGE OVER THAT PORTION OF THE FCST AREA. USED THE MODEL/ ENSEMBLE CONSENSUS FOR LOWS/HIGHS TONIGHT THRU SUN NIGHT...PLENTY OF CLOUDS THRU SUN NIGHT AND BY LATER TONIGHT STRONGER GRADIENT SFC WINDS TO KEEP THE BOUNDARY LAYER STIRRED. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 300 PM CST SAT DEC 21 2013 MAIN FORECAST CONCERNS FOR MONDAY THROUGH TUESDAY NIGHT...SNOW CHANCES WITH NORTHWEST FLOW SHORTWAVES AND TEMPERATURES THRU THE PERIOD. 21.12Z MODELS IN IMPROVING AGREEMENT AS THE DEEP MID LEVEL TROUGH MOVES ACROSS THE REGION MONDAY THEN HGTS RISING QUICKLY WITH ITS PASSAGE AND SHORTWAVE RIDGING BUILDING IN MON NIGHT. CONSENSUS REMAINS RATHER TIGHT AS THE SHORTWAVE RIDGE QUICKLY PASSES TUE... THEN THE NEXT STRONG NORTHWEST FLOW TROUGH DROPS INTO THE REGION AND SENDS MID LEVEL HGTS CRASHING AGAIN. TREND THRU THE PERIOD FAVORS STRONGER/SLOWER OF THE EARLIER RUNS. FCST CONFIDENCE IN THE MON THRU TUE NIGHT PERIOD IS AVERAGE TO GOOD THIS CYCLE. PLENTY OF SFC-600MB MOISTURE...A COLD COLUMN...DEEP/TIGHT CYCLONIC CONVERGENCE AND A SFC TROUGH COMBINE TO CONTINUE WRINGING OUT SOME LIGHT SNOW ACROSS MUCH OF THE FCST AREA ON MON...RAISED -SN CHANCE TO THE 50-70 PERCENT RANGE OVER THE EAST HALF OF THE FCST AREA... MAINLY DURING THE MORNING AHEAD OF THE MID LEVEL TROUGH AXIS. -SN CHANCES WANE MON AFTERNOON WITH PASSAGE OF THE 700-500MB TROUGH AXIS. RATHER SHARP SFC-700MB RIDGE AXIS AND SUBSIDENCE WITHIN IT BUILDING EAST LATE MON/MON NIGHT SHOULD HELP CLEAR OUT THE CLOUDS BUT WITH THE SLOWING TREND AMONG THE MODELS...THIS MAY NOT OCCUR UNTIL LATE MON NIGHT OVER THE EAST END OF THE FCST AREA. MORE CLOUDS FOR MORE OF THE NIGHT MON NIGHT TO HAVE AN IMPACT ON LOW TEMPS. WARMER MODEL CONSENSUS LOWS MON ESPECIALLY OVER THE EAST HALF OF THE FCST AREA LOOK GOOD. ANY SHOT AT CLEAR SKIES/SOME SUNSHINE APPEAR SHORT LIVED AS SFC-700MB RIDGE AXIS PASSES QUICKLY WITH INCREASING LOWER LEVEL WARM ADVECTION AND DEEPER MOISTURE AHEAD OF THE NEXT TROUGH SPREADING RAPIDLY ACROSS THE REGION ON TUE. GIVEN THE DEPTH/ STRENGTH OF THE UPWARD MOTION AND MOISTURE INCREASE SIGNAL...-SN CHANCES MOVE QUICKLY BACK INTO THE FCST AREA TUE AFTERNOON. WITH THE TIGHTER MODEL CONSENSUS...RAISED -SN CHANCES INTO THE 40-60 PERCENT RANGE FOR TUE NIGHT...WITH 1 TO 2 INCHES OF LIGHT SNOW LOOKING LIKELY FOR MUCH OF THE FCST AREA CHRISTMAS EVE NIGHT. USED A BLEND OF THE NUMERICAL TEMPS GUIDANCE FOR HIGHS/LOWS MON-TUE NIGHT. FOR CHRISTMAS DAY THROUGH SATURDAY.../DAYS 4 TO 7/... 21.00S AND 21.12Z MEDIUM RANGE MODELS IN DECENT AGREEMENT FOR A RATHER VIGOROUS SHORTWAVE TROUGH TO BE MOVING ACROSS THE UPPER MIDWEST ON WED WITH AN INCREASING SIGNAL FOR A SECONDARY SHORTWAVE TO DROP ACROSS THE REGION WED NIGHT. GOOD CONSENSUS FOR BROAD LONGWAVE TROUGHING TO REMAIN OVER CENTRAL/EASTERN NOAM FRI/SAT... WITH PLENTY OF DIFFERENCES ON SMALLER SCALE SHORTWAVES EMBEDDED IN THE FLOW. SOME CONSENSUS FOR A STRONGER/TRACKABLE SHORTWAVE TROUGH TO BE DROPPING INTO THE NORTHERN PLAINS SAT. ALL IN ALL...DAY 4-7 FCST IS AVERAGE. LIGHT SNOW REMAINS IN THE FCST FOR CHRISTMAS DAY/WED NIGHT. THE MAIN LOWER LEVEL THERMO-DYNAMIC FORCING AND DIVERGENCE ALOFT FROM THE TUE NIGHT SHORTWAVE WILL BE PASSING EAST OF THE AREA WED MORNING...WITH DECREASING -SN CHANCES THRU THE DAY. GFS/ECMWF THEN DROP A RATHER VIGOROUS SECONDARY SHORTWAVE SOUTHEAST ACROSS THE AREA WED NIGHT WITH ANOTHER ROUND OF STRONGER DIVERGENCE/LIFT ALOFT. SOUNDINGS/X- SECTIONS SHOWING PLENTY OF MOISTURE IN THE COLUMN FOR THIS LIFT TO WRING OUT SOME -SN...EVEN WITH LESSER LOW LEVEL SUPPORT/LIFT AND LOWER OVERALL PW VALUES. APPEARS THE AREA GETS A BREAK FROM THE PRECIP/-SN BY LATER THU AND FOR FRI AS HGTS RISE A BIT AND A LARGER/DRY/COLD SFC HIGH PRESSURE RIDGE BUILDS ACROSS THE REGION. THIS HIGH MOVES EAST RATHER QUICKLY FRI. A MDT/STRONG ROUND OF LOWER LEVEL WARM ADVECTION TO SPREAD INTO/ACROSS THE AREA LATER FRI THRU SAT...AHEAD OF THE NEXT STRONGER SFC-MID LEVEL TROUGH PROGGED TO DROP INTO THE NORTHERN PLAINS. LOWER LEVEL MOISTURE INCREASE IN THIS FLOW APPEARS DELAYED INTO FRI NIGHT/SAT. MAY YET NEED A -SN CHANCE AGAIN BY SAT BUT WILL STAY WITH THE DRY MODEL/ENSEMBLE CONSENSUS FOR NOW UNTIL A CLEARER SIGNAL IS SEEN. TEMPS TO REMAIN BELOW NORMAL FOR WED-SAT WITH THE AREA UNDER THE NORTHWEST FLOW ALOFT. SOME WELL BELOW NORMAL TEMPS WITH THE LARGER/COLD HIGH FOR THU/FRI. MODEL/ ENSEMBLE CONSENSUS FOR HIGHS/LOWS IN THE WED-SAT PERIOD LOOKS TO HAVE THIS WELL TRENDED. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1128 PM CST SAT DEC 21 2013 THE MAIN FOCUS IS ON THE SNOW THAT WILL MOVE IN TONIGHT AND HOW LOW CONDITIONS WILL GET. FLIGHT CONDITIONS ARE CURRENTLY MVFR...BUT WILL DROP TO IFR ONCE THE SNOW BEGINS SHORTLY AFTER MIDNIGHT. LSE HAS THE HIGHER CHANCE OF SEEING THE LOWER VISIBILITY SNOW WITH THE MAIN BAND OF HEAVY SNOW TRACKING THROUGH SOUTHWEST WISCONSIN. VISIBILITIES ARE CURRENTLY IN THE HALF TO 2 MILE RANGE DOWN IN IOWA UPSTREAM FROM LSE. EXPECT THAT THE MAIN TIME FRAME FOR SEEING THE HEAVIER SNOW WILL BE BETWEEN 11-14Z WITH THE MODERATE SNOW ENDING BY LATE MORNING. SOME LIGHT SNOW LOOKS LIKE IT WILL HOLD ON THROUGH THE AFTERNOON AND EVENING HOURS AT LSE/RST...SO KEPT CEILINGS DOWN THROUGH THE REST OF THE PERIOD. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...WINTER WEATHER ADVISORY UNTIL 6 PM CST SUNDAY FOR WIZ034-041-042- 053. WINTER STORM WARNING UNTIL 6 PM CST SUNDAY FOR WIZ043-044-054- 055-061. MN...WINTER WEATHER ADVISORY UNTIL 6 PM CST SUNDAY FOR MNZ096. IA...WINTER WEATHER ADVISORY UNTIL 6 PM CST SUNDAY FOR IAZ010-011-019. WINTER STORM WARNING UNTIL 6 PM CST SUNDAY FOR IAZ029-030. && $$ UPDATE...HALBACH SHORT TERM...RRS LONG TERM....RRS AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
405 AM CST Tue Dec 24 2013 ...Updated for long term discussion... .SYNOPSIS... ISSUED AT 1117 PM CST MON DEC 23 2013 At 00z Tuesday a -31c 500mb trough was located over southern British Columbia and the Pacific Northwest. An upper level ridge axis was located downstream of this 500mb trough, and extended from Wyoming into southwest Manitoba. Across the Central Plains a northwest flow was present at the 700mb and 500mb level. A 850mb temperature gradient at 00z Tuesday was located across western Nebraska and central Kansas. 850mb temperatures earlier this evening ranged from -19c at Omaha and -16c at Topeka to -8c at North Platte, -4c at Dodge City, and +2c at Amarillo. At the surface an area of high pressure was located across eastern Kansas and a trough of low pressure was located across eastern Colorado. && .SHORT TERM...(Today and tonight) ISSUED AT 132 AM CST TUE DEC 24 2013 A trough of low pressure at the surface will deepen along the lee of the Rockies early today as an upper level trough, which was located over the Pacific Northwest at 00z Tuesday, approaches the Rockies. By late day/early evening this upper level trough will cross the Rockies and move out into the plains. At this time given the track of this upper trough, the 00z NAM and GFS model soundings indicating only mid level moisture will accompany this upper level disturbance, and given the dry layer forecast to be present in the 850mb-700mb level the chances for precipitation still appears small. Increasing clouds however can be expected which may initially limit the cooling early tonight behind a cold front that will be crossing western Kansas. Still given some clearing behind this upper trough after midnight the lows tonight should still fall back into the teens by early Christmas day. Colder temperatures overnight will be over the snow pack from roughly Larned to Minneola. As for temperatures today, westerly downslope flow will improve and 850mb temperatures ahead of the approaching cold front are forecast to range from 5c to near 10c during the afternoon across western Kansas. This continues to suggest afternoon temperatures climbing in the lower 50s for areas that did not receive snow over the past weekend. Will however trim a few degrees off from these warm 850mb mix down temperatures in north central Kansas given the increase in cloud cover late today. In areas that continue to have snow on the ground will stay close to the previous forecast with highs today only in the 30s. .LONG TERM...(Wednesday through Monday) ISSUED AT 403 AM CST TUE DEC 24 2013 The large scale pattern through Friday will be characterized by mid to high level flow from the eastern pacific into southwest Canada and the northern Rockies. At the surface, pressures will generally be falling in this pattern due to the increased low to mid level cross mountain flow, leading to fairly mild maximum temperatures at least 1 standard deviation above average. This means highs in the 50s, except for the areas that received heavy snow on December 21st, which may stay 5 to 15 degrees cooler depending on how fast the snow melts. By Saturday through Monday, the upper level flow will amplify again, leading to mid level flow more parallel to the Rockies and directed over land from western Canada into the northern and central plains. This will lead to a cold air surge at low levels into the plains, although not as cold as some of the airmasses we have experienced already this cold season. Highs by Sunday will fall back into the 30s, with lows falling back into the teens. The global models that go out beyond 7 days (ECMWF, GFS and GEM) indicate some degree of upper level troughing approaching the plains around January 1st. The GFS is the most amplified, the ECMWF in the middle and the GEM the weakest. Therefore, some sort of precipitation event cannot be ruled out, and precipitation type is also in question. && .AVIATION...(For the 06Z TAFS through 06Z Tuesday night) ISSUED AT 1117 PM CST MON DEC 23 2013 Low status and patchy freezing fog had developed earlier this evening as a southeast wind developed. SREF and HRRR were both in decent agreement with keeping the IFR/low MVFR status around through at least 12z Tuesday as this south/southeasterly flow continues. Area more favorable for the lower cigs lasting longer early this morning will be at HYS and DDC. At GCK the winds are forecast to veer more to the southwest between 12z and 15z allowing for some drier air in the lower levels to advect in from the west. In addition to the low clouds some MVFR/IFR visibilities will also be possible, mainly in the DDC area through early Tuesday morning. Given the low level winds from the NAM BUFR soundings do not think widespread dense freezing fog will be an issue at any taf site. && .PRELIMINARY POINT TEMPS/POPS... DDC 39 15 38 16 / 10 10 0 0 GCK 51 15 47 18 / 10 10 0 0 EHA 52 18 47 22 / 0 10 0 0 LBL 41 17 45 18 / 10 0 0 0 HYS 47 17 46 18 / 10 10 0 0 P28 35 16 39 15 / 10 10 0 0 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...Burgert SHORT TERM...Burgert LONG TERM...Finch AVIATION...Burgert
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
136 AM CST Tue Dec 24 2013 ...Updated short term discussion... .SYNOPSIS... ISSUED AT 1117 PM CST MON DEC 23 2013 At 00z Tuesday a -31c 500mb trough was located over southern British Columbia and the Pacific Northwest. An upper level ridge axis was located downstream of this 500mb trough, and extended from Wyoming into southwest Manitoba. Across the Central Plains a northwest flow was present at the 700mb and 500mb level. A 850mb temperature gradient at 00z Tuesday was located across western Nebraska and central Kansas. 850mb temperatures earlier this evening ranged from -19c at Omaha and -16c at Topeka to -8c at North Platte, -4c at Dodge City, and +2c at Amarillo. At the surface an area of high pressure was located across eastern Kansas and a trough of low pressure was located across eastern Colorado. && .SHORT TERM...(Today and tonight) ISSUED AT 132 AM CST TUE DEC 24 2013 A trough of low pressure at the surface will deepen along the lee of the Rockies early today as an upper level trough, which was located over the Pacific Northwest at 00z Tuesday, approaches the Rockies. By late day/early evening this upper level trough will cross the Rockies and move out into the plains. At this time given the track of this upper trough, the 00z NAM and GFS model soundings indicating only mid level moisture will accompany this upper level disturbance, and given the dry layer forecast to be present in the 850mb-700mb level the chances for precipitation still appears small. Increasing clouds however can be expected which may initially limit the cooling early tonight behind a cold front that will be crossing western Kansas. Still given some clearing behind this upper trough after midnight the lows tonight should still fall back into the teens by early Christmas day. Colder temperatures overnight will be over the snow pack from roughly Larned to Minneola. As for temperatures today, westerly downslope flow will improve and 850mb temperatures ahead of the approaching cold front are forecast to range from 5c to near 10c during the afternoon across western Kansas. This continues to suggest afternoon temperatures climbing in the lower 50s for areas that did not receive snow over the past weekend. Will however trim a few degrees off from these warm 850mb mix down temperatures in north central Kansas given the increase in cloud cover late today. In areas that continue to have snow on the ground will stay close to the previous forecast with highs today only in the 30s. .LONG TERM...(Tuesday night through Monday) ISSUED AT 205 PM CST MON DEC 23 2013 Tuesday night will begin with a northwest flow aloft over western Kansas. Some of the snowpack will remain from Sat-Sun`s snow storm, and temperatures will show cold bias in the eastern sections of our CWA, in the Larned, Stafford, and Pawnee counties, where 14 to 15 inches of snow fell and will slow to melt. Mostly clear skies are anticipated through the day 5.5 forecast, with clouds moving in next Sunday. Wednesday will see an east to west temperature gradient, with MaxT`s ranging from around 33F degrees in St. John to 38F degrees in Dodge City, to 47F degrees near the Colorado border. This same temperature pattern will exist from Wednesday into Saturday, rising to the 43F degree to 56F degree range by both Friday and Saturday. Winds will basically be from the west or northwest and not over the 10 to 20 mph range. At night, winds will tend to drop off to less than 10 mph, allowing the mercury to fall significantly. Lows on Wednesday will dip into the teens to near 12F degrees in the deepest snow between Kinsley and Larned, and range upward to around 21F degrees near Hays and Liberal. Lows will increase each day through Saturday and Sunday mornings, leveling off in the mid 20s to around 30F degrees by Sat. On Sunday, both the ECMWF and GFS models are forecasting an arctic outbreak of cold air to plunge south through the plains and invade central Kansas Sunday afternoon. Clouds will increase to cloudy and probably be thick stratus. We could have another non-diurnal temperature pattern on Sunday, with highs occurring in the mid day, then falling in the afternoon. Since Sunday is day 7, will not put the hourly temps in the grids, but it may be something we have to watch as the Sunday period approaches. && .AVIATION...(For the 06Z TAFS through 06Z Tuesday night) ISSUED AT 1117 PM CST MON DEC 23 2013 Low status and patchy freezing fog had developed earlier this evening as a southeast wind developed. SREF and HRRR were both in decent agreement with keeping the IFR/low MVFR status around through at least 12z Tuesday as this south/southeasterly flow continues. Area more favorable for the lower cigs lasting longer early this morning will be at HYS and DDC. At GCK the winds are forecast to veer more to the southwest between 12z and 15z allowing for some drier air in the lower levels to advect in from the west. In addition to the low clouds some MVFR/IFR visibilities will also be possible, mainly in the DDC area through early Tuesday morning. Given the low level winds from the NAM BUFR soundings do not think widespread dense freezing fog will be an issue at any taf site. && .PRELIMINARY POINT TEMPS/POPS... DDC 39 15 38 16 / 10 10 0 0 GCK 51 15 45 18 / 10 10 0 0 EHA 52 18 47 22 / 0 10 0 0 LBL 41 17 45 18 / 10 0 0 0 HYS 47 17 44 18 / 10 10 0 0 P28 35 16 39 15 / 10 10 0 0 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...Burgert SHORT TERM...Burgert LONG TERM...Burke AVIATION...Burgert
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1121 PM CST Mon Dec 23 2013 ...Updated synopsis and aviation discussion... .SYNOPSIS... ISSUED AT 1117 PM CST MON DEC 23 2013 At 00z Tuesday a -31c 500mb trough was located over southern British Columbia and the Pacific Northwest. An upper level ridge axis was located downstream of this 500mb trough, and extended from Wyoming into southwest Manitoba. Across the Central Plains a northwest flow was present at the 700mb and 500mb level. A 850mb temperature gradient at 00z Tuesday was located across western Nebraska and central Kansas. 850mb temperatures earlier this evening ranged from -19c at Omaha and -16c at Topeka to -8c at North Platte, -4c at Dodge City, and +2c at Amarillo. At the surface an area of high pressure was located across eastern Kansas and a trough of low pressure was located across eastern Colorado. && .SHORT TERM...(This evening through Tuesday) ISSUED AT 1234 PM CST MON DEC 23 2013 Tonight: Low level stratus is expected to be pretty much gone by this afternoon, however, there still will be some mid to high level clouds that will stick around through the overnight. These clouds are ahead of a synoptic system coming out of the northern Rockies and eventually across the Central/Northern Plains tomorrow. Otherwise, the forecast will remain free of precipitation through the overnight hours. Minimums will be in the lower teens (F). Tomorrow: The aforementioned synoptic system will result in continuation of scattered mid to high level clouds tomorrow. The NAM suggests potential for flurries, but not buying into this solution, as low levels are fairly dry and "warm". Will keep precipitation probabilities at or below 10 percent. Kind of a moot point anyway, because flurries typically don`t measure (0.01" or higher). Anyway, there will be a gradient of temperatures across the forecast area of responsibility. The 23.12Z NAM breaks the inversion across west-central Kansas and advertises upper 50sF. The rest of the mesoscale/global models (WRF, EC, etc) suggest lower maximums. The ongoing max temp forecast still looks on track and will continue as is. Farther east, deep snowpack will have a meso-alpha perhaps beta influence on temperatures with values struggling to get higher than the freezing mark, if that. .LONG TERM...(Tuesday night through Monday) ISSUED AT 205 PM CST MON DEC 23 2013 Tuesday night will begin with a northwest flow aloft over western Kansas. Some of the snowpack will remain from Sat-Sun`s snow storm, and temperatures will show cold bias in the eastern sections of our CWA, in the Larned, Stafford, and Pawnee counties, where 14 to 15 inches of snow fell and will slow to melt. Mostly clear skies are anticipated through the day 5.5 forecast, with clouds moving in next Sunday. Wednesday will see an east to west temperature gradient, with MaxT`s ranging from around 33F degrees in St. John to 38F degrees in Dodge City, to 47F degrees near the Colorado border. This same temperature pattern will exist from Wednesday into Saturday, rising to the 43F degree to 56F degree range by both Friday and Saturday. Winds will basically be from the west or northwest and not over the 10 to 20 mph range. At night, winds will tend to drop off to less than 10 mph, allowing the mercury to fall significantly. Lows on Wednesday will dip into the teens to near 12F degrees in the deepest snow between Kinsley and Larned, and range upward to around 21F degrees near Hays and Liberal. Lows will increase each day through Saturday and Sunday mornings, leveling off in the mid 20s to around 30F degrees by Sat. On Sunday, both the ECMWF and GFS models are forecasting an arctic outbreak of cold air to plunge south through the plains and invade central Kansas Sunday afternoon. Clouds will increase to cloudy and probably be thick stratus. We could have another non-diurnal temperature pattern on Sunday, with highs occurring in the mid day, then falling in the afternoon. Since Sunday is day 7, will not put the hourly temps in the grids, but it may be something we have to watch as the Sunday period approaches. && .AVIATION...(For the 06Z TAFS through 06Z Tuesday night) ISSUED AT 1117 PM CST MON DEC 23 2013 Low status and patchy freezing fog had developed earlier this evening as a southeast wind developed. SREF and HRRR were both in decent agreement with keeping the IFR/low MVFR status around through at least 12z Tuesday as this south/southeasterly flow continues. Area more favorable for the lower cigs lasting longer early this morning will be at HYS and DDC. At GCK the winds are forecast to veer more to the southwest between 12z and 15z allowing for some drier air in the lower levels to advect in from the west. In addition to the low clouds some MVFR/IFR visibilities will also be possible, mainly in the DDC area through early Tuesday morning. Given the low level winds from the NAM BUFR soundings do not think widespread dense freezing fog will be an issue at any taf site. && .PRELIMINARY POINT TEMPS/POPS... DDC 11 39 16 38 / 20 10 10 0 GCK 12 49 17 45 / 10 10 10 0 EHA 15 49 19 47 / 0 0 10 0 LBL 11 45 20 45 / 20 10 0 0 HYS 11 43 20 44 / 0 10 10 0 P28 10 35 15 39 / 20 10 10 0 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...Burgert SHORT TERM...Sugden LONG TERM...Burke AVIATION...Burgert
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1116 PM CST Mon Dec 23 2013 ...Updated synopsis and aviation discussion... .SYNOPSIS... ISSUED AT 1110 PM CST MON DEC 23 2013 At 00z Tuesday a -31c 500mb trough was located over southern British Columbia and the Pacific Northwest. An upper level ridge axis was located downstream of this 500mb trough, and extended from Wyoming into southwest Manitoba. Across the Central Plains a northwest flow was present at the 700mb and 500mb level. A 850mb temperature gradient at 00z Tuesday was located across western Nebraska and central Kansas. 850mb temperatures earlier this evening ranged from -19c at Omaha and -16c at Topeka to -8c at North Platte, -4c at Dodge City, and +2c at Amarillo. At the surface an area of high pressure was located across eastern Kansas and a trough of low pressure was located across eastern Colorado. && .SHORT TERM...(This evening through Tuesday) ISSUED AT 1234 PM CST MON DEC 23 2013 Tonight: Low level stratus is expected to be pretty much gone by this afternoon, however, there still will be some mid to high level clouds that will stick around through the overnight. These clouds are ahead of a synoptic system coming out of the northern Rockies and eventually across the Central/Northern Plains tomorrow. Otherwise, the forecast will remain free of precipitation through the overnight hours. Minimums will be in the lower teens (F). Tomorrow: The aforementioned synoptic system will result in continuation of scattered mid to high level clouds tomorrow. The NAM suggests potential for flurries, but not buying into this solution, as low levels are fairly dry and "warm". Will keep precipitation probabilities at or below 10 percent. Kind of a moot point anyway, because flurries typically don`t measure (0.01" or higher). Anyway, there will be a gradient of temperatures across the forecast area of responsibility. The 23.12Z NAM breaks the inversion across west-central Kansas and advertises upper 50sF. The rest of the mesoscale/global models (WRF, EC, etc) suggest lower maximums. The ongoing max temp forecast still looks on track and will continue as is. Farther east, deep snowpack will have a meso-alpha perhaps beta influence on temperatures with values struggling to get higher than the freezing mark, if that. .LONG TERM...(Tuesday night through Monday) ISSUED AT 205 PM CST MON DEC 23 2013 Tuesday night will begin with a northwest flow aloft over western Kansas. Some of the snowpack will remain from Sat-Sun`s snow storm, and temperatures will show cold bias in the eastern sections of our CWA, in the Larned, Stafford, and Pawnee counties, where 14 to 15 inches of snow fell and will slow to melt. Mostly clear skies are anticipated through the day 5.5 forecast, with clouds moving in next Sunday. Wednesday will see an east to west temperature gradient, with MaxT`s ranging from around 33F degrees in St. John to 38F degrees in Dodge City, to 47F degrees near the Colorado border. This same temperature pattern will exist from Wednesday into Saturday, rising to the 43F degree to 56F degree range by both Friday and Saturday. Winds will basically be from the west or northwest and not over the 10 to 20 mph range. At night, winds will tend to drop off to less than 10 mph, allowing the mercury to fall significantly. Lows on Wednesday will dip into the teens to near 12F degrees in the deepest snow between Kinsley and Larned, and range upward to around 21F degrees near Hays and Liberal. Lows will increase each day through Saturday and Sunday mornings, leveling off in the mid 20s to around 30F degrees by Sat. On Sunday, both the ECMWF and GFS models are forecasting an arctic outbreak of cold air to plunge south through the plains and invade central Kansas Sunday afternoon. Clouds will increase to cloudy and probably be thick stratus. We could have another non-diurnal temperature pattern on Sunday, with highs occurring in the mid day, then falling in the afternoon. Since Sunday is day 7, will not put the hourly temps in the grids, but it may be something we have to watch as the Sunday period approaches. && .AVIATION...(For the 06Z TAFS through 06Z Tuesday night) ISSUED AT 1110 PM CST MON DEC 23 2013 Low status and areas of freezing fog had developed earlier this evening as a southeast wind developed. SREF and HRRR were both in decent agreement with keeping the IFR/low MVFR status around through at least 12z Tuesday as this south/southeasterly flow continues. Area more favorable for the lower cigs lasting longer early this morning will be at HYS and DDC. At GCK the winds are forecast to veer more to the southwest between 12z and 15z allowing for some drier air in the lower levels to advect in from the west. In addition to the low clouds some MVFR/IFR visibilities will also be possible, mainly in the DDC area through early Tuesday morning. Given the low level winds from the NAM BUFR soundings do not think widespread dense fog will be an issue at any taf site. && .PRELIMINARY POINT TEMPS/POPS... DDC 11 39 16 38 / 20 10 10 0 GCK 12 49 17 45 / 10 10 10 0 EHA 15 49 19 47 / 0 0 10 0 LBL 11 45 20 45 / 20 10 0 0 HYS 11 43 20 44 / 0 10 10 0 P28 10 35 15 39 / 20 10 10 0 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...Burgert SHORT TERM...Sugden LONG TERM...Burke AVIATION...Burgert
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1213 AM EST TUE DEC 24 2013 .SYNOPSIS... WEAK LOW PRESSURE WILL MOVE EAST INTO THE MARITIMES OVERNIGHT. COLD HIGH PRESSURE WILL THEN MOVE IN TUESDAY AND WEDNESDAY. && .NEAR TERM /THROUGH TUESDAY/... UPDATE...IT LOOKS LIKE FREEZING PRECIP HAS GONE OVER TO SOME LIGHT SNOW ACROSS THE INTERIOR DOWNEAST WHILE THE COAST STILL SHOWED SOME LIGHT FREEZING DRIZZLE OR PLAIN RAIN MIXING W/SNOW. THIS IS MOST EVIDENT FROM THE LAPS SOUNDINGS SHOWING THAT DRY WEDGE IN THE MID LEVELS AND DEEP MOISTURE IN THE LLVLS. LAST 3HR TRENDS FROM THE OBS IN BAR HARBOR SHOW JUST RAIN W/TEMPERATURES AROUND 34F. ANY FREEZING PRECIP SHOULD MOVE E AN END BY 3 AM. ADJUSTED THE PRECIP CHANCES TOWARD MORNING DOWN TO 20-30% USING THE HRRR GUIDANCE AS THE HRRR INDICATED PRECIP SHIELD PULLING OFF THE COAST AND TO THE E. COLDER AIR WITH CLRG TO PRTL CLRG SKIES ARE SLATED FOR THE FA LATE TNGT WITH INCREASING NW WINDS. A SIG NW BREEZE IS LIKELY TO CONT ON TUE...WITH POTENTIAL IMPLICATIONS FOR FURTHER DAMAGE IN THE MAX ICE ACCRETION ZONE DOWNEAST IN THE ABSENCE OF ANNY MELTING...WHICH DOES NOT APPEAR LIKELY N OF THE IMMEDIATE COAST. DUE TO MDTLY STRONG LLVL COLD ADVCN ON TUE...HI TEMPS TUE WILL ONLY RECOVER A FEW DEGREES AT BEST FROM OVRNGT LOWS UNDER MSLY CLR TO PTLY CLDY SKIES. && .SHORT TERM /TONIGHT THROUGH THURSDAY/... ARCTIC HIGH PRESSURE BUILDS INTO NEW ENGLAND FOR A BITTERLY COLD CHRISTMAS DAY. A WIND CHILL ADVISORY MAY BE NECESSARY LATE TUESDAY NIGHT INTO CHRISTMAS DAY MORNING. AFTER ANOTHER CHILLY NIGHT...TEMPERATURES WARM SIGNIFICANTLY ON THURSDAY AHEAD OF A CLIPPER SYSTEM. LIGHT SNOW SHOULD DEVELOP IN THE AFTERNOON AS THIS SYSTEM APPROACHES. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... A CLIPPER SYSTEM MOVES ACROSS THE GULF OF MAINE AND INTO THE MARITIMES THURSDAY NIGHT INTO EARLY FRIDAY. A COUPLE INCHES OF SNOWFALL WILL BE POSSIBLE WITH THE PASSAGE OF THIS SYSTEM...ESPECIALLY NEAR THE NEW BRUNSWICK BORDER. MORE ARCTIC AIR SPILLS INTO THE REGION BEHIND THIS SYSTEM. THE GFS AND ECMWF DIFFER ON YET ANOTHER LOW PRESSURE SYSTEM FORECAST TO APPROACH NORTHERN NEW ENGLAND ON SUNDAY. THE ECMWF IS FARTHER SOUTH WITH THE TRAJECTORY OF THIS SYSTEM WHICH RESULTS IN HIGHER QPF/SNOWFALL AMOUNTS. && .AVIATION /05Z TUESDAY THROUGH SATURDAY/... NEAR TERM: CONDITIONS AT THE TERMINALS ACROSS NORTHERN AND EASTERN MAINE VARY CONSIDERABLY LATE THIS EVENING FROM IFR TO VFR. PATCHES OF LOWER STRATUS WILL MOVE IN AND OUT MAKING THE CEILING FORECAST A CHALLENGE AND WILL LIKELY BE HIGHLY VARIABLE OVER THE NEXT SEVERAL HOURS. CONDITIONS SHOULD IMPROVE TO VFR BY DAYBREAK TUE ACROSS ALL TAF SITES...WITH VFR CONTG THRU THE DAY TUE. A PERIOD OF MVFR POSSIBLE AT THE NORTHERN TERMINALS TUE EVENING IN SNOW SHOWERS. SHORT TERM: IFR CIGS AND VSBYS WILL BE POSSIBLE LATE THURSDAY THROUGH EARLY FRIDAY DUE TO SNOW AND FOG. OTHERWISE VFR CONDITIONS ARE EXPECTED. && .MARINE... NEAR TERM: SEAS RUNNING AROUND 5 FT AT THE EASTERN MAINE SHELF LATE THIS EVENING AND WILL CONT WITH SCA FOR HAZ SEAS FOR THE OUTER WATERS INTO TUE AFTN BASED ON BLENDED FCST WW3/SWAN NAM/SWAN GFS WV HTS WHICH ALSO HAD TO BE ADJUSTED UPWARDS BY 1 TO 2 FT THRU TNGT GIVEN THE LATEST LOW BIAS COMPARED TO BUOY OBS. SHORT TERM: AN SCA MAY BE NEEDED ON CHRISTMAS DAY FOR WIND GUSTS IN EXCESS OF 25 KNOTS AND FOR WAVE HEIGHTS 5-7 FEET THURSDAY AFTERNOON AND EVENING. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM EST THIS AFTERNOON FOR ANZ050-051. && $$ NEAR TERM...HEWITT
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1227 AM EST TUE DEC 24 2013 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 343 PM EST MON DEC 23 2013 LATEST WV SATELLITE IMAGERY AND RUC ANALYSIS SHOWS BROAD 5H TROUGH SLOWLY PUSHING E ACROSS THE WRN GREAT LAKES THIS AFTERNOON. WEAK 850-500MB Q-VECTOR CONVERGENCE ASSOC WITH THIS TROUGH OVER LAKE SUPERIOR WILL TRANSITION TO Q-VECTOR DIVERGENCE THIS EVENING. VIS IMAGERY SHOWS NE WIND PARALLEL LAKE EFFECT SNOW BANDS ACROSS LAKE SUPERIOR IMPACTING MAINLY FAR WESTERN AND NORTH CENTRAL UPPER MI. A FEW OF THE MORE INTENSE BANDS HAVE PRODUCED PERIODS OF MODERATE SNOW. LES HAS BEEN VERY FLUFFY WITH SNOW RATIOS 40-50/1. MAIN FORECAST CONCERN IS CONTINUING LES EVENT FOR FAR WESTERN AND NORTH CENTRAL COUNTIES INTO THIS EVENING AND THEN DIMINISHING LES OVERNIGHT INTO TUE MORNING. EXPECT ADDITIONAL SNOWFALL AMOUNTS OF 2 TO 5 INCHES THROUGH THIS EVENING. BEST LOW-LVL CONVERGENCE SUGGESTS MORE INTENSE LES BANDS AND THUS GREATEST SNOW AMOUNTS WILL BE OVER ERN HALF OF MQT COUNTY INTO PERHAPS WRN ALGER COUNTY. GIVEN EXPECTATION OF CONTINUING LES ACCUMULATION INTO AT LEAST THE EVENING HRS WILL CONTINUE ADVISORIES FOR GOGEBIC-ONTONAGON AND MQT-BARAGA INTO THE EARLY OVERNIGHT. LES SHOULD GENERALLY BE WINDING DOWN BY LATE EVENING INTO OVERNIGHT HRS WITH Q-VECT DIVERGENCE ACROSS THE AREA AND WEAKENING WIND FIELDS. LOW-LVL CONVERGENCE MAY STRENGTHEN DUE TO WEAKENING WINDS AND DEVELOPING LAND BREEZES TO ALLOW MORE LOCALLY INTENSE LES BANDS TO FORM AND PERHAPS EVEN A MESOLOW OR TWO OFF THE PORCUPINE MOUNTAINS AND OVER MQT BAY AS DEPICTED BY LOCAL AND REGIONAL MESOSCALE MODELS. HOWEVER...WINDS BACKING TO THE WEST/SOUTHWEST OVERNIGHT AHEAD OF ADVANCING SFC RDG AXIS SHOULD KEEP LES BANDS OR MESOLOW FEATURES MOVING ENOUGH EASTWARD TO EFFECTIVELY LIMIT ACCUMULATIONS FOR THE OVERNIGHT HRS. DECREASING CLOUD COVER OVERNIGHT AND LIGHT WINDS WILL ALLOW TEMPERATURES TO FALL OFF OUTSIDE OF THOSE AREAS WHERE THE LAKE EFFECT SNOWS LINGER. COLDEST TEMPERATURES ARE EXPECTED OVER THE FAR EAST AND INTERIOR WEST SECTIONS. THE WRN INTERIOR ALONG THE WI BDR WITH LIKELY SEE A FEW LOCATIONS PLUMMET TO 10 BELOW OR COLDER WHERE TYPICAL COLD SPOTS OVER LUCE COUNTY COULD ALSO DIP NEAR 10 BELOW ZERO. GENERALLY FOLLOWED A BLEND OF THE BETTER PERFORMING CANADIAN REGIONAL GEM AND ECMWF FOR MIN TEMPS. TUESDAY...DECENT MODEL AGREEMENT THAT LINGERING LAKE EFFECT OVER NCNTRL CWA WILL BE PUSHED OUT OVR SOUTH CENTRAL LK SUPERIOR THROUGH THE MORNING AS WINDS BECOME SSW AHEAD OF APPROACHING SHORTWAVE AND SFC TROUGH OVER THE NRN PLAINS. MAY BE ABLE TO SNEAK IN SOME SUNSHINE OVER MUCH OF THE CWA INTO EARLY AFTN BEFORE HIGH CLOUDS START INCREASING AHEAD OF SHORTWAVE TROUGH DROPPING ACROSS THE NORTHERN PLAINS. WARM ADVECTION SSW FLOW WILL ALLOW FOR MAX TEMPS TO REBOUND INTO THE TEENS ACROSS MUCH OF THE AREA. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 310 PM EST MON DEC 23 2013 UPPER AIR PATTERN WILL CONSIST OF A 500 MB RIDGE ON THE WEST COAST AND A TROUGH OVER THE NORTHERN PLAINS 00Z WED. NAM ALSO SHOWS A CLOSED 500 MB LOW OVER NORTHERN ALBERTA 00Z WED. BOTH THE LOW AND THE TROUGH MOVE TO THE EAST WITH THE REMAINS OF THE LOW HELPING TO DIG A DEEP UPPER TROUGH INTO THE UPPER GREAT LAKES ON WED. NAM SHOWS SOME 850-500 MB Q-VECTOR CONVERGENCE OVER THE CWA WITH DEEPER MOISTURE TUE NIGHT LASTING INTO WED BEFORE BOTH MOVE OUT WED NIGHT INTO THU. GFS AND ECMWF SHOW ABOUT THE SAME THING. DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST. CLIPPER TYPE SYSTEM COMES IN FOR TUE NIGHT INTO WED AND WILL HAVE SOME LAKE MICHIGAN LAKE ENHANCEMENT OVER THE ERN CWA WHICH WAS ALREADY COVERED IN THE PREVIOUS FORECAST. COULD SEE UP TO 8 INCHES IN ERN SCHOOLCRAFT AND LUCE COUNTIES FOR TUE NIGHT AND WED. DID LOWER TEMPERATURES A BIT THOUGH EACH DAY FOR LOWS AND HIGHS TUE NIGHT THROUGH THU AS THE TEMPERATURES SEEMED A BIT TOO WARM CONSIDERING THE PERSISTENT COLD PATTERN WE HAVE BEEN IN. IN THE EXTENDED...GFS AND ECMWF SHOW A 500 MB TROUGH OVER THE CENTRAL U.S. 12Z FRI WITH A RIDGE OVER THE WESTERN U.S. UPPER FLOW BECOMES MORE ZONAL OVER THE NORTHERN PLAINS AND UPPER GREAT LAKES 12Z SAT WHICH WILL MEAN A BRIEF WARMING TREND IS STARTING. A BROAD 500 MB TROUGH THEN MOVES INTO THE UPPER GREAT LAKES 12Z SUN AND INTO MONDAY WITH COLD AIR ONCE AGAIN OVER THE AREA WITH THE DEEP UPPER TROUGH. LAKE EFFECT SNOW WILL BE THE MAIN RULE FOR MOST OF THIS FORECAST PERIOD WITH TEMPERATURES GOING BACK BELOW NORMAL SUNDAY INTO MONDAY. CLIPPER SYSTEM MOVES THROUGH FOR SAT AND THIS WOULD BE THE WARMEST DAY OF THE WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1222 AM EST TUE DEC 24 2013 MAINLY MVFR CONDITIONS ARE EXPECTED TONIGHT WITH LINGERING LIGHT LAKE EFFECT SNOW SHOWERS MOVING THROUGH NORTHERN UPPER MICHIGAN ON LIGHT NRLY WINDS. EXPECT CIGS AND VSBYS TO IMPROVE TO VFR LATE TONIGHT AT IWD AND TUE MORNING AT CMX AND SAW AS LAKE EFFECT COMES TO AN ENDS WITH WINDS BACKING TO THE SOUTHWEST. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 343 PM EST MON DEC 23 2013 NORTHEAST WINDS WILL GRADUALLY DIMINISH THROUGH THE DAY. HEAVY FREEZING SPRAY WILL REMAIN A PROBLEM OVER THE WEST AND NORTH CENTRAL PORTIONS OF LAKE SUPERIOR UNTIL THE PRESSURE GRADIENT RELAXES A BIT MORE IN THE AFTERNOON. AFTER A BRIEF RESPITE...SOUTH WINDS PICK UP AGAIN AHEAD OF THE NEXT SYSTEM MOVING THROUGH TO THE NORTH OF LAKE SUPERIOR TUESDAY NIGHT WITH GALE FORCE WINDS TO 35 KNOTS EXPECTED THEN...MAINLY FOR THE EASTERN PORTION OF THE LAKE. WINDS DIMINISH WEDNESDAY AND REMAIN BELOW 20 KNOTS THROUGH FRIDAY. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... LAKE EFFECT SNOW ADVISORY UNTIL 3 AM EST EARLY THIS MORNING FOR MIZ004-005. LAKE SUPERIOR... GALE WATCH FROM LATE TONIGHT THROUGH WEDNESDAY MORNING FOR LSZ266. LAKE MICHIGAN... NONE. && $$ SHORT TERM...VOSS LONG TERM...07 AVIATION...JLB MARINE...VOSS
AREA FORECAST DISCUSSION...RETRANSMITTED
NWS RALEIGH NC
300 AM EST TUE DEC 24 2013 .SYNOPSIS...BEHIND A COLD FRONT MOVING OFF OF THE CAROLINA COAST THROUGH EARLY AFTERNOON...HIGH PRESSURE BUILDS OVER THE REGION. HIGH PRESSURE REMAINS AT LEAST THROUGH CHRISTMAS NIGHT. WEAK LOW PRESSURE DEVELOPS OFF OF THE CAROLINA COAST THURSDAY. && .NEAR TERM /THROUGH TODAY/... AS OF 255 AM TUESDAY... THE SURFACE COLD FRONT CONTINUES TO MAKE GRADUAL EASTWARD PROGRESS OFFSHORE OF THE CAROLINAS...THOUGH WEAK SURFACE CYCLONIC FLOW CONTINUES ON THE LATEST SURFACE ANALYSIS OVER THE SOUTHEAST PART OF THE STATE. PATCHES OF LIGHT RAIN PERSISTED THERE UNDERNEATH THE SOUTHWEST FLOW ALOFT...BUT DURING THE MORNING THE MORE MOIST FLOW ALOFT WILL ALSO SHIFT EAST AS THE UPPER TROUGH ON WATER VAPOR... MOVING INTO THE TENNESSEE VALLEY...MOVES INTO AND THEN ACROSS THE STATE. THE HRRR WRF HAS BEEN CONSISTENT WITH ITSELF...AND WITH THE DIMINISHING MOISTURE NOTED ON GFS BUFR SOUNDINGS...THAT MUCH OF THE PATCHY LIGHT RAIN SHOULD BE MOVING OFF TO THE EAST OF CENTRAL NORTH CAROLINA BY AROUND 12Z. WILL RETAIN A SLIGHT CHANCE OF RAIN EAST OF INTERSTATE 95 FOR THE EARLY DAYLIGHT HOURS...THEN WILL SHOW DRY CONDITIONS FOR THE REST OF THE DAY WITH CHANCES LESS THAN SLIGHT. EVEN THOUGH THE UPPER TROUGH IS WELL DEFINED ON WATER VAPOR IMAGERY...THE GUIDANCE CONSENSUS IS DRIER THAN 24 HOURS AGO...MAKING THE CHANCES FOR SPRINKLES WITH THE APPROACH OF THE TROUGH ALOFT REMOTE. TOO MUCH MID-LEVEL DRY AIR IS FORECAST...COINCIDENT WITH DRY AIR TO OUR WEST AS NOTED ON THE 00Z UPPER-AIR ANALYSIS. EVEN THE TREND IS DRIER IN THE LOWER LEVELS...THOUGH EXPECT LINGERING STRATOCU INTO THE MORNING IN MANY AREAS. THE SURFACE GRADIENT TIGHTENS TODAY AS HIGH PRESSURE BUILDS IN BEHIND THE DEPARTING FRONT. BUFR SOUNDINGS SUGGEST ENOUGH MIXING THAT FOR A PERIOD THIS AFTERNOON WIND GUSTS SHOULD REACH INTO THE UPPER TEENS TO LOWER 20S KNOTS...WITH NORTHERLY WINDS BACKING MORE NORTHWEST WITH MIXING. 1000-850MB THICKNESSES WILL BE FALLING DURING THE DAY...BUT THEIR VALUES SUGGEST HIGHS CLOSE TO MOS GUIDANCE BUT WITH ONLY MINIMAL RECOVERY FROM LATE NIGHT TEMPERATURES...FOR HIGHS IN THE MID 40S TO AROUND 50. && .SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/... AS OF 255 AM TUESDAY... HIGH PRESSURE REMAINS FOR MUCH OF THIS PERIOD...WITH PRECIPITABLE WATER VALUES MOSTLY BELOW A QUARTER-INCH AND K INDICES HIGHLY NEGATIVE. DRY SURFACE DEW POINTS MOVE IN AS WELL. BUFR SOUNDINGS AND RELATIVE HUMIDITY FORECASTS ARE DRY...SUGGESTIVE OF CLEAR OR MOSTLY CLEAR CONDITIONS INTO WEDNESDAY NIGHT. LOWS TONIGHT IN THE 20S...WITH HIGHS WEDNESDAY IN THE LOWER TO MID 40S...NEARER THE SLIGHTLY WARMER MAV MOS GUIDANCE WHICH IS CLOSER TO EXPECTED VALUES BASED ON 1000-850MB THICKNESSES. WEDNESDAY NIGHT...THERE IS SOME GUIDANCE DIFFERENCE ON THE AMOUNT OF HIGH CLOUDS THAT COULD MOVE INTO CENTRAL NORTH CAROLINA WITH THE APPROACH OF A JET AXIS ALOFT...AND LOWERING HEIGHTS. THE NAM IS CERTAINLY DRIER THAN THE GFS...WHICH IS DEEPER WITH THE ENERGY ALOFT AND LOWERS PRESSURES MORE OFF OF THE CAROLINA COAST BY 12Z THURSDAY. THE 00Z ECMWF OFFERS A GOOD COMPROMISE...SHOWING A FEW HIGH CLOUDS STARTING TO ENCROACH ON CENTRAL NORTH CAROLINA FROM THE SOUTH LATE IN THE DAY WEDNESDAY...AND SLOWLY SPREADING NORTH OVER MUCH OF THE AREA WEDNESDAY NIGHT...LIKELY MORE OPAQUE SOUTH. WILL GO CLOSER TO THE COLDER MET GUIDANCE WEDNESDAY NIGHT IN THE TRIAD AND NEAR THE VIRGINIA BORDER...WITH A BLEND IN THE MIDDLE INCLUDING THE TRIANGLE AND KRWI...AND CLOSER TO THE WARMER MAV GUIDANCE TOWARD KFAY. THIS RESULTS IN LOWS IN THE LOWER 20S TOWARD KTDF...25 TO 30 OVER THE SANDHILLS AND SOUTHERN COASTAL PLAIN...AND MID 20S IN BETWEEN. && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 300 AM TUESDAY... A SOUTHERN STREAM WAVE WILL TRACK ACROSS THE SOUTHEAST ON THURSDAY...WITH A NORTHERN STREAM CLIPPER ON ITS HEELS. MODELS INDICATE A WEAK SURFACE LOW MAY DEVELOP OFF THE NC/SC COAST IN RESPONSE TO THE WEAK DPVA AND UPPER DIVERGENCE IN THE RIGHT FRONT ENTRANCE REGION OF AN INTENSIFYING UPPER JET OVER THE MID-ATLANTIC STATES. HOWEVER...FORECAST SOUNDINGS SHOW LIMITED MID-LEVEL MOISTURE INLAND AND THUS DONT PRODUCE ANY QPF OVER THE RAH CWA. CIRRUS SHOULD BE RATHER ABUNDANT...AT LEAST EARLY IN THE DAY...BEFORE BEING SHUNTED EASTWARD WITH THE PASSING NORTHERN STREAM TROUGH AXIS. THIS WILL LIMIT SOME OF THE MODERATION OF TEMPS....THOUGH HIGHS SHOULD STILL REACH SEASONAL NORMS...48-52. LOWS THURSDAY NIGHT 26-31. THE REMAINDER OF THE EXTENDED PERIOD WILL BE MOSTLY DOMINATED BY THE NORTHERN STREAM AS SHORTWAVES MOVING ACROSS THE GREAT LAKES REGION SLOWLY CARVE OUT A LONGWAVE TROUGH OVER THE EASTERN US. THIS IS SUPPORTED BY A TREND TOWARD NEGATIVE NAO/AO PHASES IN THE MEDIUM RANGE. ANOTHER SOUTHERN STREAM SHORTWAVE AND ASSOCIATED POTENTIAL SURFACE LOW SHOULD REMAINED SUPPRESSED OFFSHORE SUNDAY/MONDAY...THOUGH THE 00Z ECMWF TRENDED FURTHER WEST WITH MOISTURE ON SUNDAY. WILL LEAVE THE FORECAST DRY AT THIS TIME. PERIODS OF CIRRUS WILL LIKELY PLAGUE THE AREA OVER THE WEEKEND...WITH HIGHS REBOUNDING A BIT...INTO THE LOW TO MID 50S... BEFORE WHAT APPEARS TO BE A MOSTLY DRY COLD FRONT CROSSES THE AREA EARLY NEXT WEEK. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... AS OF 1250 AM TUESDAY... VFR CONDITIONS OVER THE WESTERN PIEDMONT...INCLUDING THE TRIAD... WILL GRADUALLY SPREAD EAST OVER CENTRAL NORTH CAROLINA DURING THIS EARLY MORNING...WITH KRWI LIKELY THE LAST TAF SITE TO BECOME VFR AROUND 12Z...COINCIDENT WITH AREAS OF LIGHT RAIN MOVING OFF TO THE EAST. WHILE THE NAM MODEL DRIES OUT THE LOW LEVELS FASTER THAN THE GFS...EVEN THE GFS WOULD SUGGEST BROKEN VFR-LEVEL CEILINGS ENDING BY AFTERNOON. WITH MIXING TODAY...WINDS SHOULD BACK MORE TO THE NORTHWEST WITH GUSTS IN THE 20S KNOTS AS THE SURFACE GRADIENT TIGHTENS. WINDS WILL DIMINISH THIS EVENING AS HIGH PRESSURE CONTINUES TO BUILD OVER THE AREA. BEYOND THE 06Z VALID TAF PERIOD...EXPECT VFR CONDITIONS. BASED ON THE LATEST GFS MODEL GUIDANCE...THERE IS A LOW PROBABILITY OF SUB- VFR CONDITIONS AT KFAY AND KRWI LATE WEDNESDAY NIGHT INTO EARLY THURSDAY AS WEAK LOW PRESSURE DEVELOPS OFF OF THE CAROLINA COAST. OTHER GUIDANCE APPEARS DRIER AS OF THIS WRITING. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DJF NEAR TERM...DJF SHORT TERM...DJF LONG TERM...SMITH AVIATION...DJF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
256 AM EST TUE DEC 24 2013 .SYNOPSIS...BEHIND A COLD FRONT MOVING OFF OF THE CAROLINA COAST THROUGH EARLY AFTERNOON...HIGH PRESSURE BUILDS OVER THE REGION. HIGH PRESSURE REMAINS AT LEAST THROUGH CHRISTMAS NIGHT. WEAK LOW PRESSURE DEVELOPS OFF OF THE CAROLINA COAST THURSDAY. && .NEAR TERM /THROUGH TODAY/... AS OF 255 AM TUESDAY... THE SURFACE COLD FRONT CONTINUES TO MAKE GRADUAL EASTWARD PROGRESS OFFSHORE OF THE CAROLINAS...THOUGH WEAK SURFACE CYCLONIC FLOW CONTINUES ON THE LATEST SURFACE ANALYSIS OVER THE SOUTHEAST PART OF THE STATE. PATCHES OF LIGHT RAIN PERSISTED THERE UNDERNEATH THE SOUTHWEST FLOW ALOFT...BUT DURING THE MORNING THE MORE MOIST FLOW ALOFT WILL ALSO SHIFT EAST AS THE UPPER TROUGH ON WATER VAPOR... MOVING INTO THE TENNESSEE VALLEY...MOVES INTO AND THEN ACROSS THE STATE. THE HRRR WRF HAS BEEN CONSISTENT WITH ITSELF...AND WITH THE DIMINISHING MOISTURE NOTED ON GFS BUFR SOUNDINGS...THAT MUCH OF THE PATCHY LIGHT RAIN SHOULD BE MOVING OFF TO THE EAST OF CENTRAL NORTH CAROLINA BY AROUND 12Z. WILL RETAIN A SLIGHT CHANCE OF RAIN EAST OF INTERSTATE 95 FOR THE EARLY DAYLIGHT HOURS...THEN WILL SHOW DRY CONDITIONS FOR THE REST OF THE DAY WITH CHANCES LESS THAN SLIGHT. EVEN THOUGH THE UPPER TROUGH IS WELL DEFINED ON WATER VAPOR IMAGERY...THE GUIDANCE CONSENSUS IS DRIER THAN 24 HOURS AGO...MAKING THE CHANCES FOR SPRINKLES WITH THE APPROACH OF THE TROUGH ALOFT REMOTE. TOO MUCH MID-LEVEL DRY AIR IS FORECAST...COINCIDENT WITH DRY AIR TO OUR WEST AS NOTED ON THE 00Z UPPER-AIR ANALYSIS. EVEN THE TREND IS DRIER IN THE LOWER LEVELS...THOUGH EXPECT LINGERING STRATOCU INTO THE MORNING IN MANY AREAS. THE SURFACE GRADIENT TIGHTENS TODAY AS HIGH PRESSURE BUILDS IN BEHIND THE DEPARTING FRONT. BUFR SOUNDINGS SUGGEST ENOUGH MIXING THAT FOR A PERIOD THIS AFTERNOON WIND GUSTS SHOULD REACH INTO THE UPPER TEENS TO LOWER 20S KNOTS...WITH NORTHERLY WINDS BACKING MORE NORTHWEST WITH MIXING. 1000-850MB THICKNESSES WILL BE FALLING DURING THE DAY...BUT THEIR VALUES SUGGEST HIGHS CLOSE TO MOS GUIDANCE BUT WITH ONLY MINIMAL RECOVERY FROM LATE NIGHT TEMPERATURES...FOR HIGHS IN THE MID 40S TO AROUND 50. && .SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/... AS OF 255 AM TUESDAY... HIGH PRESSURE REMAINS FOR MUCH OF THIS PERIOD...WITH PRECIPITABLE WATER VALUES MOSTLY BELOW A QUARTER-INCH AND K INDICES HIGHLY NEGATIVE. DRY SURFACE DEW POINTS MOVE IN AS WELL. BUFR SOUNDINGS AND RELATIVE HUMIDITY FORECASTS ARE DRY...SUGGESTIVE OF CLEAR OR MOSTLY CLEAR CONDITIONS INTO WEDNESDAY NIGHT. LOWS TONIGHT IN THE 20S...WITH HIGHS WEDNESDAY IN THE LOWER TO MID 40S...NEARER THE SLIGHTLY WARMER MAV MOS GUIDANCE WHICH IS CLOSER TO EXPECTED VALUES BASED ON 1000-850MB THICKNESSES. WEDNESDAY NIGHT...THERE IS SOME GUIDANCE DIFFERENCE ON THE AMOUNT OF HIGH CLOUDS THAT COULD MOVE INTO CENTRAL NORTH CAROLINA WITH THE APPROACH OF A JET AXIS ALOFT...AND LOWERING HEIGHTS. THE NAM IS CERTAINLY DRIER THAN THE GFS...WHICH IS DEEPER WITH THE ENERGY ALOFT AND LOWERS PRESSURES MORE OFF OF THE CAROLINA COAST BY 12Z THURSDAY. THE 00Z ECMWF OFFERS A GOOD COMPROMISE...SHOWING A FEW HIGH CLOUDS STARTING TO ENCROACH ON CENTRAL NORTH CAROLINA FROM THE SOUTH LATE IN THE DAY WEDNESDAY...AND SLOWLY SPREADING NORTH OVER MUCH OF THE AREA WEDNESDAY NIGHT...LIKELY MORE OPAQUE SOUTH. WILL GO CLOSER TO THE COLDER MET GUIDANCE WEDNESDAY NIGHT IN THE TRIAD AND NEAR THE VIRGINIA BORDER...WITH A BLEND IN THE MIDDLE INCLUDING THE TRIANGLE AND KRWI...AND CLOSER TO THE WARMER MAV GUIDANCE TOWARD KFAY. THIS RESULTS IN LOWS IN THE LOWER 20S TOWARD KTDF...25 TO 30 OVER THE SANDHILLS AND SOUTHERN COASTAL PLAIN...AND MID 20S IN BETWEEN. && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 110 PM MONDAY... ON THURSDAY...A SOUTHERN STREAM WAVE OVER NRN FL AND SRN GA EARLY IN THE DAY WILL MOVE NE ALONG THE COAST...EXITING NE OF THE CAROLINAS BY MID-EVENING. LATEST MODEL RUNS NOW SUGGEST THE BEST MOISTURE WILL REMAIN WELL EAST OF I-95...SO WITH THIS FORECAST CYCLE WILL LIKELY KEEP POPS BELOW 15 PERCENT FOR OUR EASTERN ZONES FOR THURSDAY. HIGHS THURSDAY IN THE MID-UPR 40S. THEREAFTER...HIGH PRESSURE WILL BUILD BACK OVER OUR REGION THURSDAY NIGHT AND REMAIN OVER US THROUGH EARLY SUNDAY...RESULTING IN FAIR WEATHER AND TEMPS NEAR TO SLIGHTLY BELOW NORMAL. DURING THE DAY SUNDAY...THE HIGH WILL MOVE EAST AS THE NEXT COLD FRONT APPROACHES FROM THE WEST LATE IN THE DAY. LOOK FOR TEMPS TO CLIMB TO A FEW DEGREES ABOVE NORMAL ON SUNDAY AS THE RETURN FLOW SETS UP BEHIND THE DEPARTING HIGH. OTHERWISE...CLOUDS WILL SLOWLY INCREASE DURING THE DAY SUNDAY AS THE FRONT APPROACHES...BUT ANY RAIN WITH THE FRONT SHOULD HOLD OFF UNTIL FROPA ON MONDAY. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... AS OF 1250 AM TUESDAY... VFR CONDITIONS OVER THE WESTERN PIEDMONT...INCLUDING THE TRIAD... WILL GRADUALLY SPREAD EAST OVER CENTRAL NORTH CAROLINA DURING THIS EARLY MORNING...WITH KRWI LIKELY THE LAST TAF SITE TO BECOME VFR AROUND 12Z...COINCIDENT WITH AREAS OF LIGHT RAIN MOVING OFF TO THE EAST. WHILE THE NAM MODEL DRIES OUT THE LOW LEVELS FASTER THAN THE GFS...EVEN THE GFS WOULD SUGGEST BROKEN VFR-LEVEL CEILINGS ENDING BY AFTERNOON. WITH MIXING TODAY...WINDS SHOULD BACK MORE TO THE NORTHWEST WITH GUSTS IN THE 20S KNOTS AS THE SURFACE GRADIENT TIGHTENS. WINDS WILL DIMINISH THIS EVENING AS HIGH PRESSURE CONTINUES TO BUILD OVER THE AREA. BEYOND THE 06Z VALID TAF PERIOD...EXPECT VFR CONDITIONS. BASED ON THE LATEST GFS MODEL GUIDANCE...THERE IS A LOW PROBABILITY OF SUB- VFR CONDITIONS AT KFAY AND KRWI LATE WEDNESDAY NIGHT INTO EARLY THURSDAY AS WEAK LOW PRESSURE DEVELOPS OFF OF THE CAROLINA COAST. OTHER GUIDANCE APPEARS DRIER AS OF THIS WRITING. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DJF NEAR TERM...DJF SHORT TERM...DJF LONG TERM...NP AVIATION...DJF
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1232 AM EST TUE DEC 24 2013 .SYNOPSIS... A SLOW MOVING COLD FRONT APPROACHING FROM THE WEST WILL MOVE OFF THE COAST TONIGHT. DRIER AND COOLER AIR WILL SPREAD ACROSS THE REGION IN THE WAKE OF THE COLD FRONT. A MOSTLY DRY COLD FRONT WILL PASS ACROSS THE AREA FRIDAY...MAINTAINING SEASONABLE TEMPERATURES INTO THE WEEKEND. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... AS OF 1015 PM MONDAY...THE SFC COLD FRONT HAS BEEN MAKING PROGRESS TO THE SOUTHEAST THIS EVENING...AND NOW EXTENDS ACROSS THE EASTERN CAROLINAS...HAVING PUSHED EAST OF THE I-95 CORRIDOR. THE COLD FRONT WILL PUSH ACROSS THE REMAINING PORTIONS OF THE FA LATE THIS EVENING OR EARLY ON DURING THE PRE-DAWN TUE HOURS. THE POST COLD FRONTAL SENSIBLE WX CONDITIONS ACROSS THE FA WILL EXPERIENCE A WIND DIRECTION CHANGE VEERING TO THE NW-N AT 5 TO 15 MPH...COLD AIR ADVECTION ACCOMPANIED BY LOWER DEWPOINTS. LATEST PROGS CONTINUE WITH POST-FRONTAL LIGHT RAIN AND SHOWERS PERSISTING OVERNIGHT INTO DAYLIGHT TUESDAY B4 FINALLY BEING PUSHED OFF THE COAST AND OFFSHORE FROM A PROGRESSIVE UPPER S/W TROF. OVERNITE LOWS HAVE BEEN TWEAKED...WITH MINS OCCURRING AROUND SUNRISE TUESDAY. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/... AS OF 240 PM MONDAY...A DRIER COLUMN WILL BUILD ACROSS THE AREA EARLY ON IN THE SHORT TERM PERIOD AS THE SUBTROPICAL MOISTURE PLUME SHIFTS AWAY FROM THE COAST. LINGERING LOW CLOUDS IN THE MORNING...BUT RAINFALL WILL COME TO AN END WITH THE DEPARTURE OF THE AFOREMENTIONED PLUME AND AS STRONG SUBSIDENCE DEVELOPS IN THE H85-H5 LAYER. THUS THE TREND FOR TUESDAY IS CLEARING SKIES AND MUCH COOLER TEMPERATURES COMPARED TO THE RECENT WARM SPELL. COLDER AIR ARRIVES TUESDAY NIGHT INTO WEDNESDAY MORNING (LOWS IN THE MID TO UPPER 20S) WITH COLD AIR ADVECTION LEADING TO HIGHS ONLY IN THE 40S FOR CHRISTMAS DAY. INCREASING CLOUDS WEDNESDAY NIGHT WILL RESULT IN SLIGHTLY WARMER MINS...BUT THEY WILL STILL BE AT OR JUST BELOW FREEZING ACROSS THE FORECAST AREA. && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 240 PM MONDAY...THE EXTENDED FORECAST CONTINUES TO LOOK RATHER UNEVENTFUL WITH THE OVERALL MID LEVEL PATTERN DEPICTING A MODEST TROUGH OVER THE EASTERN THIRD OF THE U.S. AND MODEST RIDGING ACROSS THE SOUTHWEST. AT THE SURFACE THERE WILL BE TWO FRONTS THAT MOVE ACROSS THE AREA THAT WILL ONLY SERVE TO RESET ANY TEMPERATURE MODIFICATION. TEMPERATURES THURSDAY AND FRIDAY WILL BE SLIGHTLY BELOW CLIMATOLOGY AS THE COLD AIR MASS THAT FOLLOWS THE SYSTEM MOVING THROUGH TODAY AND TONIGHT LINGERS. THERE IS A SLIGHT MODIFICATION OF TEMPERATURES SATURDAY AND SUNDAY VIA AIRMASS MODIFICATION. THIS BRIEF WARMUP IS SHORT LIVED AS ANOTHER DRY FRONT MOVES ACROSS MONDAY. THE TRENDS ARE RATHER CONSISTENT AND THE CONSOLATION IS THAT THE WILD TEMPERATURE SWINGS WE HAVE EXPERIENCED THE PAST FEW WEEKS ARE AT LEAST TEMPORARILY A THING OF THE PAST. FINALLY THE ONLY POPS IN THE FORECAST ARE THURSDAY INTO EARLY FRIDAY FROM WHAT APPEARS TO BE MORE OF A WEAK WAVE MOVING IN FROM THE SOUTHWEST FLOW ALOFT THAT SKIRTS THE AREA. THE SURFACE COASTAL TROUGH PATTERN SEEMS TO HAVE DISAPPEARED. REGARDLESS OF THE FORCING MECHANISMS...POPS REMAIN LOW AND MOSTLY CONFINED TO THE COASTAL AREAS. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... AS OF 06Z...A COLD FRONT HAS CLEARED ALL THE TERMINALS. KFLO/KMYR SHOULD BE PREDOMINATELY MVFR DUE TO CIGS...BECOMING VFR IN THE PRE-DAWN HOURS...THEN SCATTER OUT BY MID MORNING. THERE IS A HIGHER POTENTIAL FOR IFR OR LOWER FLIGHT CONDITIONS AT THE COASTAL TERMINALS. THESE CONDITIONS SHOULD RISE TO MVFR JUST AFTER SUNRISE...THEN SCATTER OUT BY MID TO LATE MORNING. NW-N WINDS WILL CONTINUE THROUGHOUT THE DAY...WITH OCCASIONAL GUSTS TO AROUND 20 KNOTS. VFR WITH LIGHT N WINDS AFTER SUNSET. EXTENDED OUTLOOK...VFR THROUGH THE PERIOD. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1030 PM MONDAY...SCA WILL CONTINUE FOR THE ILM NC WATERS THROUGH 7 AM TUESDAY. SCEC HAS REPLACED THE SCA FOR THE ILM SC WATERS...AND WILL REMAIN IN EFFECT THRU 7 AM TUESDAY. SW-WSW AROUND 15 KT LATE THIS EVENING...WILL VEER TO THE NW AROUND 15 KT IMMEDIATELY AFTER THE COLD FRONTAL PASSAGE...AND FURTHER VEER TO THE NORTH AT 10-20 KT DURING THE PRE-DAWN TUE HOURS. THE LATEST NAM AND HRRR WIND PROGS ILLUSTRATE THIS NICELY. SIGNIFICANT SEAS WILL BE GOVERNED BY A 7 TO 8 SECOND PERIOD SSE BORDERLINE SWELL...AND A 10 SECOND PERIOD SE GROUND SWELL. COMBINED WITH LOCALLY PRODUCED WIND DRIVEN WAVES...SIGNIFICANT SEAS WILL RANGE BETWEEN 3 AND 5 FT FOR THE ILM SC WATERS...AND 4 TO 7 FT ACROSS THE ILM NC WATERS. THE 7 FOOTERS WILL OCCUR ACROSS THE OUTER WATERS OFF CAPE FEAR. AREAL COVERAGE OF SEA FOG HAS DECREASED...AND WILL FURTHER DECREASE OVERNIGHT ESPECIALLY ONCE THE POST FRONTAL LOWER DEWPOINTS ADVECT ACROSS THE LOCAL WATERS. SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 240 PM MONDAY...N TO NW FLOW WILL PREVAIL IN THE WAKE OF THE COLD FRONT TUESDAY AND TUESDAY NIGHT...THEN THE WIND WILL VEER TO THE NE DURING WEDNESDAY. WINDS WILL DIMINISH TO AROUND 10 KT OR LESS BY WEDNESDAY NIGHT AS WEAKENING RIDGE OF HIGH PRESSURE BUILD INTO THE VICINITY. THE OFFSHORE TRAJECTORY WILL RESULT IN A RANGE OF SEAS THAT WILL BE FETCH LIMITED NEAR THE COAST. FOR THE MOST PART SEAS WILL APPROACH 5 FT CLOSER TO 20 NM OFFSHORE THROUGH MOST OF THE PERIOD WITH 1-2 FT SEAS NEAR THE COAST. LONG TERM /THURSDAY THROUGH SATURDAY/... AS OF 240 PM MONDAY...ONCE AGAIN THE CENTRAL THEME FOR THE EXTENDED COASTAL WATERS FORECAST IS A NORTHERLY COMPONENT TO THE WINDS. FOR THURSDAY THE FLOW WILL BE 10-15 KNOTS WITH A COUPLE OF ROGUE GUSTS OVER 15 POSSIBLE. AS A DRY FRONT MOVES ACROSS FRIDAY SPEEDS WILL INCREASE TO 15-20 KNOTS. SATURDAY WINDS DROP BACK DOWN TO 10-15 KNOTS...AGAIN FROM THE NORTH. SEAS WILL FOLLOW THE WIND SPEED TRENDS WITH 2-4 FEET THURSDAY AND SATURDAY WITH 3-5 FEET FOR FRIDAY. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST TUESDAY FOR AMZ250-252. && $$ SYNOPSIS...SRP NEAR TERM...DCH SHORT TERM...SRP LONG TERM...SHK AVIATION...MRR/RJD
AREA FORECAST DISCUSSION
NWS TULSA OK
1102 PM CST MON DEC 23 2013 .AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM. FORECAST SITES CURRENTLY RESIDE BETWEEN TWO REGION OF LOWER CEILINGS BOTH TO THE EAST AND WEST. THE EASTERN LOW CLOUDS MAY BRUSH FAR NW AR WITHIN THE NEXT FEW HOURS...HOWEVER THE TREND WILL BE TOWARD FEWER CLOUDS ACROSS THIS REGION. FURTHER WEST...MVFR CEILINGS ARE LIKELY TO REMAIN VERY NEAR THE HIGHWAY 75 CORRIDOR INCREASING THE UNCERTAINTY FOR IMPACTS OK SITES. THIS REGION OF LOWER CLOUDS SHOULD ERODE AFTER SUNRISE WITH VFR CONDITIONS EVENTUALLY PREVAILING. && .PREV DISCUSSION... /ISSUED 911 PM CST MON DEC 23 2013/ ..UPDATE... DISCUSSION... UPDATED THE FORECAST EARLIER IN THE EVENING TO REMOVE POPS. THE MAIN VARIABLE FOR THE REMAINDER OF THE NIGHT IS THE EXTENT OF LOW CLOUDS AND THE EFFECT ON MINIMUM TEMPERATURES. THE RUC KEEPS PLENTY OF MOISTURE/CLOUDS OVERNIGHT... ALTHOUGH CURRENT SATELLITE IMAGES SHOW PARTIAL CLEARING ACROSS THE AREA. WAS TEMPTED TO RAISE MINIMUM TEMPERATURES A FEW DEGREES BASED ON ANTICIPATED CLOUDS. HOWEVER... WITH AREAS OF CLEAR SKIES OUT THERE CURRENTLY... HAVE ENOUGH DOUBT THAT RADIATIONAL COOLING WILL BE INHIBITED ALL THAT MUCH. THE BOTTOM LINE IS THAT FORECAST MINIMUM TEMPERATURES HAVE BEEN LEFT UNCHANGED. THEREFORE... WILL UPDATE PRODUCTS AT THIS TIME. && .PRELIMINARY POINT TEMPS/POPS... TUL 14 40 26 46 / 0 0 10 10 FSM 20 44 26 49 / 10 0 0 10 MLC 17 46 28 49 / 0 0 0 10 BVO 9 40 23 46 / 0 0 10 10 FYV 12 38 24 46 / 10 0 10 10 BYV 11 36 27 46 / 10 0 10 10 MKO 15 43 25 47 / 0 0 0 10 MIO 10 40 25 46 / 10 0 10 10 F10 16 44 27 47 / 0 0 0 10 HHW 21 46 27 50 / 0 0 0 10 && .TSA WATCHES/WARNINGS/ADVISORIES... OK...NONE. AR...NONE. && $$ AVIATION...07
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AREA FORECAST DISCUSSION
NWS NEW YORK NY
1023 AM EST TUE DEC 24 2013 .SYNOPSIS... A COLD FRONT MOVES THROUGH THE REGION THIS EVENING FOLLOWED BY CANADIAN HIGH PRESSURE FOR CHRISTMAS. A WEAK COLD FRONT MOVES ACROSS THE REGION THURSDAY FOLLOWED BY MORE HIGH PRESSURE BUILDING IN FROM THE SOUTH AND WEST THROUGH THE WEEKEND. A STRONG COLD FRONT MOVES ACROSS THE REGION LATE SUNDAY INTO MONDAY. && .NEAR TERM /UNTIL 4 PM THIS AFTERNOON/... TRICKY NEAR TERM CLOUD COVER FCST TODAY. MID/HIGH CLOUDS OVER LONG ISLAND MOVING EAST QUICKLY AS UPPER TROF INDUCED CLOUDS OVER PA MOVE EAST. THIS LEAVES A SUNNY PERIOD FOR THE LUNCH HOUR. WITH CLOUDS COMING QUICKLY BACK FOR THE AFTERNOON FROM WEST TO EAST. USED LATEST HRRR AND NSSL WRF CLOUD FIELDS TO DEPICT THIS IN THE GRIDS. COLD FRONT NOW RACING THROUGH WEST CENTRAL PA WITH INSTABILITY SNOW SHOWERS. TIME OF ARRIVAL FOR OUR AREA IS SET FOR EARLY EVENING. ATMOSPHERE SUPPORTS SNOW, THOUGH SFC TEMPS ABOVE FREEZING ALONG THE COAST WILL LIKELY PRESENT ISSUES...SEE SHORT TERM SECTION. WITH SUNSHINE...HAVE RAISED MAX TEMPS SLIGHTLY WITH MAXES AROUND 40 ALONG THE COAST. && .SHORT TERM /4 PM THIS AFTERNOON THROUGH 6 PM WEDNESDAY/... LOW LEVEL INSTABILITY IS SIGNIFICANT THIS EVENING WITH SFC TO 950 HPA LAPSE RATES IN EXCESS OF 9 C / KM ALONG WITH NARROW CAPE UP TO 600 HPA. THINK WE`RE LOOKING AT SNOW SQUALLS. UNFORTUNATELY, WITH TEMPS EARLY THIS EVENING ABOVE FREEZING ALONG THE COAST, WE HAVE POTENTIAL FOR A FLASH FREEZE AS TEMPS DROP QUICKLY. THE UNCERTAINTY REVOLVES ON THE AMOUNT AND LOCATION OF SNOW. CURRENTLY, HAVE POPS AT 40% AS THINKING COVERAGE WILL BE AROUND THIS AMOUNT. TOTALS OF A FEW HUNDREDTHS THOUGH COULD RESULT IS A SERIOUS TRAVEL ISSUE AS TEMPS FALL RAPIDLY ON STRONG NW FLOW IN THE WAKE OF THE FRONT. PLANNING ON ISSUING AN SPS EARLY THIS AFTERNOON. COLD AIR REMAINS THROUGH MUCH OF CHRISTMAS DAY. THE GFS IS TOO SLOW TO BRING THE ARCTIC AIR IN AND LEANED TOWARD THE COLDER NAM GUIDANCE FOR LOWS TONIGHT AND HIGHS CHRISTMAS DAY. WARM ADVECTION QUICKLY SETS UP LATE IN THE DAY...HOWEVER TOO LATE FOR TEMPERATURES TO RISE OUT OF THE 20S. TEMPERATURES CHRISTMAS NIGHT POSSIBLY START TO CLIMB. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... A WEAK COLD FRONT WILL PUSH ACROSS THE TRI-STATE AREA DURING THE DAY ON THURSDAY. THIS FRONT WILL BRING THE REGION SOME CLOUDY SKIES AND A SLIGHT CHANCE OF SOME SNOW SHOWERS DURING THE DAYTIME. THE FRONT MOVES EAST OF THE AREA THURSDAY NIGHT AND HIGH PRESSURE OVER THE SOUTHWEST WILL START TO BUILD INTO THE AREA. THIS HIGH WILL REMAIN OVER THE AREA THROUGH THE END OF THE WEEK AND FOR MUCH OF THE WEEKEND BEFORE SLIDING EAST OVER THE ATLANTIC. AN AREA OF LOW PRESSURE WILL PASS WELL NORTH OF THE REGION SUNDAY AND MONDAY. ITS ASSOCIATED COLD FRONT WITH APPROACH THE REGION LATE SUNDAY AND MOVE ACROSS THE AREA LATE SUNDAY INTO MONDAY MORNING. TEMPERATURES WILL BE RIGHT AROUND NORMAL THURSDAY THROUGH SATURDAY...THEN RISE SLIGHTLY ABOVE NORMAL ON SUNDAY...BEFORE FALLING BACK TO NEAR OR BELOW NORMAL ON MONDAY. EXPECT HIGHS IN THE UPPER 30S AND LOWER 40S EACH DAY...EXCEPT SUNDAY WHEN HIGHS WILL REACH THE MIDDLE AND UPPER 40S. && .AVIATION /15Z TUESDAY THROUGH SATURDAY/... AA TROUGH OF LOW PRESSURE WILL MOVE ACROSS THE AREA LATE THIS AFTERNOON AND INTO EARLY THIS EVENING. VFR FOR MUCH OF THE DAY AS A BAND OF MID AND HIGH LEVEL CLOUDS EXITS TO THE EAST THIS MORNING. THERE IS THE POTENTIAL FOR A BRIEF PERIOD OF IFR CONDITIONS IN SNOW SHOWERS FROM 21Z TO 03Z. RIGHT NOW...THE NYC METRO TERMINALS...KSWF...KHPN...AND KISP ARE THE MOST FAVORED LOCATIONS. NORTH/NORTHWEST WINDS THIS MORNING REMAIN BETWEEN 10 TO 15 KTS. WINDS WILL BACK 30 TO 50 DEGREES BY LATE THIS AFTERNOON/EARLY THIS EVENING AHEAD OF THE TROUGH. THE WINDS WILL THEN VEER BACK TO THE NORTH/NORTHWEST BEHIND THE TROF LATER THIS EVENING AND WILL INCREASE TO 15 TO 25 KTS LATE THIS EVENING AND OVERNIGHT. GUSTS UP TO 30 KT POSSIBLE FOR A TIME TONIGHT. NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KEWR FCSTER COMMENTS: WINDS TO THE RIGHT OF 310 MAGNETIC THIS MORNING. AMENDMENTS POSSIBLE FOR A SLIGHT WIND SHIFT BACK TO THE WEST/NORTHWEST AROUND 310 MAGNETIC LATE THIS AFTERNOON. AMENDMENTS FOR POSSIBLE SNOW SHOWERS LATE THIS AFTERNOON AND EVENING. THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD. KJFK FCSTER COMMENTS: WINDS TO THE RIGHT OF 310 MAGNETIC THIS MORNING. AMENDMENTS POSSIBLE FOR A SLIGHT WIND SHIFT BACK TO THE WEST/NORTHWEST AROUND 310 MAGNETIC LATE THIS AFTERNOON. AMENDMENTS FOR POSSIBLE SNOW SHOWERS LATE THIS AFTERNOON AND EVENING. KLGA FCSTER COMMENTS: WINDS TO THE RIGHT OF 310 MAGNETIC THIS MORNING. AMENDMENTS POSSIBLE FOR A SLIGHT WIND SHIFT BACK TO THE WEST/NORTHWEST AROUND 310 MAGNETIC LATE THIS AFTERNOON. AMENDMENTS FOR POSSIBLE SNOW SHOWERS LATE THIS AFTERNOON AND EVENING. KTEB FCSTER COMMENTS: AMENDMENTS FOR POSSIBLE SNOW SHOWERS LATE THIS AFTERNOON AND EVENING. KHPN FCSTER COMMENTS: AMENDMENTS FOR POSSIBLE SNOW SHOWERS LATE THIS AFTERNOON AND EVENING. KISP FCSTER COMMENTS: AMENDMENTS FOR POSSIBLE SNOW SHOWERS THIS EVENING. .OUTLOOK FOR 12Z WEDNESDAY THROUGH SATURDAY... .WED...VFR. DIMINISHING WINDS. .THU...MAINLY VFR...EXCEPT BRIEF SUB-VFR POSSIBLE IN AFTERNOON SNOW SHOWERS. .THU NIGHT-SAT...VFR. && .MARINE... WITH A SURGE OF ARCTIC COLD AIR THIS EVENING....GUSTS INCREASE TO SMALL CRAFT LEVELS...AND MAY BRIEFLY APPROACH GALE FORCE ON THE OUTER WATERS WITH THE INITIAL SURGE OF THE COLD AIR. SO WILL LEAVE THE ADVISORY ON THE OCEAN WATERS THROUGH TONIGHT. SMALL CRAFT GUSTS ARE LIKELY ON THE REMAINDER OF THE FORECAST WATERS TONIGHT...AND ISSUED AN ADVISORY JUST FOR TONIGHT. MAY BE A BIT TOO LONG AS THE COLD ADVECTION WEAKENS LATE TONIGHT AND WINDS ALOFT DIMINISH. THEN WINDS AND SEAS WILL BE BELOW SMALL CRAFT WEDNESDAY. ALTHOUGH SEAS ON THE OCEAN MAY STILL BE AROUND 5 FT EAST OF MORICHES INLET EARLY IN THE MORNING. A WEAK COLD FRONT WILL PUSH ACROSS THE AREA WATERS DURING THE DAY ON THURSDAY...WHICH COULD POSSIBLY BRING SOME SMALL CRAFT STRENGTH GUSTS TO THE AREA WATERS. BEHIND THIS FRONT...HIGH PRESSURE WILL BUILD OVER THE AREA WATERS PROVIDING A PERIOD OF SUB-SCA CONDITIONS FROM THURSDAY NIGHT THROUGH SATURDAY. ANOTHER CHANCE OF SMALL CRAFT CONDITIONS RETURNS ON SUNDAY WITH THE APPROACH OF ANOTHER COLD FRONT. && .HYDROLOGY... NO SIGNIFICANT WIDESPREAD PRECIP EXPECTED TUESDAY THROUGH THE END OF THE WEEK. && .EQUIPMENT... THE NEW YORK CITY NOAA ALL HAZARDS WEATHER RADIO STATION KWO35 IS OUT OF SERVICE. DUE TO INTERFERENCE ISSUES WITH THE U.S. COAST GUARD EMERGENCY BROADCAST CHANNEL...THE NEW YORK CITY NOAA ALL HAZARDS WEATHER RADIO STATION KWO35 IS OUT OF SERVICE. DURING THE TIME...THE TRANSMITTER MAY BE RETURNED TO SERVICE INTERMITTENTLY FOR USE OF THE NOAA ALL HAZARDS WEATHER RADIO DURING POTENTIALLY DANGEROUS WEATHER SITUATIONS...FOR ROUTINE WEEKLY TEST OF THE WARNING SYSTEM...AND TO DETERMINE IF THE INTERFERENCE ISSUE HAS BEEN RESOLVED. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 AM EST WEDNESDAY FOR ANZ330-335-338-340-345. SMALL CRAFT ADVISORY UNTIL 6 AM EST WEDNESDAY FOR ANZ350-353- 355. && $$ SYNOPSIS...BC/MET NEAR TERM...TONGUE SHORT TERM...MET LONG TERM...BC AVIATION...DW MARINE...BC/MET HYDROLOGY...BC/MET EQUIPMENT...
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
611 AM CST TUE DEC 24 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 403 AM CST TUE DEC 24 2013 ARCTIC HIGH PRESSURE WAS DRIFTING ACROSS THE EASTERN CWA EARLY THIS MORNING WITH THE COLDEST TEMPERATURES SO FAR THIS WINTER. LOWS ARE APPROACHING 30 BELOW ZERO ACROSS CENTRAL MN WITH 15 BELOW INTO SOUTHERN MN AND NW WISCONSIN. STUBBORN CLOUDINESS ASSOCIATED WITH THE UPPER WAVE OVERHEAD YESTERDAY MORNING WAS STILL CIRCULATING AROUND ACROSS PARTS OF WEST CENTRAL WISCONSIN. SURFACE WINDS HAVE ALREADY BECOME SOUTHERLY IN FAR WESTERN MN WITH SPEEDS OF 10 TO 15 MPH. THE WIND CHILL WARNING AND ADVISORY HEADLINES LOOK GOOD FOR THIS MORNING WITH THE APPARENT TEMPERATURE FORECAST DROPPING OUT OF THE ADVISORY/WARNING CRITERIA AROUND NOON TODAY...WHICH IS WHEN THE CURRENT PRODUCTS EXPIRE. FORECAST HIGHS FOR THIS AFTERNOON REMAIN IN THE SINGLE DIGITS TO LOW TEENS WITH LOWS TONIGHT ONLY A FEW DEGREES BELOW THE HIGHS. OUR NEXT ADVENTURE IN THE SHORT TERM FORECAST IS THE WAVE OF LOW PRESSURE THAT WILL MOVE ACROSS THE FORECAST AREA THIS AFTERNOON AND TONIGHT. OVERNIGHT MODEL RUNS ARE A LITTLE RICHER WITH THE SPECIFIC HUMIDITY ON THE NAM/GFS 290K THETA SURFACES. WE ARE NOW SEEING 2.5 TO 3.5 G/KG FOR A SHORT PERIOD DURING THE AFTERNOON AND EVENING ALONG WITH STRONG ADIABATIC OMEGA. THERE IS AN ALIGNMENT OF ABOUT 2 HOURS WHERE MAXIMUM OMEGA IS IN THE DENDRITIC GROWTH ZONE. THIS WILL BE THE BEST PERIOD OF ACCUMULATING SNOW WITH SNOWFALL RATES APPROACHING 1 INCH PER HOUR. THE OVERALL IDEA ON THE SNOW FORECAST HAS NOT CHANGED MUCH WITH THE LEADING EDGE OF THE SNOW PUSHING INTO WEST CENTRAL MN LATE THIS MORNING...REACHING THE I-35 CORRIDOR IN THE 3-4 PM TIME FRAME AND EAU CLAIRE TO LADYSMITH BETWEEN 6 AND 7 PM. THE PRECIPITATION PLACEMENT AND AMOUNTS ARE VERY SIMILAR TO THE PREVIOUS FORECAST PACKAGE. THE SNOW ACCUMULATION FORECAST WORKS OUT TO BE 3 TO 4 INCHES GENERALLY ALONG AND NORTH OF A LINE FROM REDWOOD FALLS THROUGH RED WING TO EAU CLAIRE WITH 2 TO 3 INCHES SOUTH OF THIS LINE. THE ACCUMULATING SNOW SHOULD END EARLY THIS EVENING ACROSS WEST CENTRAL MN...ALONG THE I-35 CORRIDOR BY MIDNIGHT...AND IN THE EAU CLAIRE TO LADYSMITH AREAS AROUND 4 AM WEDNESDAY MORNING. ONE CONCERN TODAY AS THAT AS THE SNOW SPREADS INTO WEST CENTRAL MN SURFACE WINDS WILL BE SOUTHERLY AT 15 TO 20 MPH. THIS COULD LEAD TO A COUPLE HOUR PERIOD OF POOR VISIBILITY IN SNOW/BLOWING SNOW. ON THE PLUS SIDE...WINDS WILL SUBSIDE DURING THE AFTERNOON AS THE PRESSURE GRADIENT WEAKENS. HENCE...A WINTER WEATHER ADVISORY REMAINS IN EFFECT FOR ALL OF THE CWA THIS AFTERNOON AND TONIGHT. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 403 AM CST TUE DEC 24 2013 I FEEL LIKE I AM BEGINNING TO SOUND LIKE A BROKEN RECORD HERE...BUT VERY LITTLE CHANGE IS EXPECTED WITH OUR WEATHER PATTERN OVER THE NEXT WEEK...WITH NW FLOW EXPECTED TO BE THE DOMINATE FEATURE AS WE MAINTAIN A MEAN RIDGE OVER THE ERN PAC AND MEAN TROUGH OVER ERN NOAM AS THE POLAR VORTEX OVER HUDSON BAY DEEPENS/EXPANDS THIS WEEKEND INTO NEXT WEEK. ALTHOUGH LITTLE CHANGE IS EXPECTED IN THE WEATHER PATTERN...DID MAKE SOME BIG CHANGES TO POPS IN THE UPWARD DIRECTION WEDNESDAY AND THURSDAY...WITH LIKELY POPS NOW INDICATED FOR WEDNESDAY AND 40S INTRODUCED FOR THURSDAY. WEDNESDAY IS THE RESULT OF A RATHER STRONG UPPER WAVE DROPPING DOWN ON THE BACK SIDE OF TODAY/S SYSTEM. THE NAM CONTINUES TO SHOW A 5 PVU POTENTIAL VORTICITY ANOMALY WORKING DOWN I-94 DURING THE DAY. TRACK RECORDS FOR WAVES OF THIS STRENGTH SO FAR THIS MONTH HAS BEEN FOR A HEALTHY AMOUNT OF LIGHT FLUFFY SNOW...AND WITH THIS EXPECTED...INCREASED POPS SIGNIFICANTLY FOR CHRISTMAS DAY. NOT EXPECTING MUCH MORE THAN A HALF TO ONE INCH OF SNOW...BUT LOOKS GOOD FOR YET ANOTHER HIGH POP/VERY LOW QPF EVENT. FOR THURSDAY...THE 24.00 MODELS ACTUALLY CAME IN SIGNIFICANTLY DIFFERENT THAN PREVIOUS RUNS IN TERMS OF TEMPERATURES AND DEWPS...WITH BOTH ABOUT 10 DEGREES WARMER THAN PREVIOUS RUNS. FOR THOSE VARIABLES...DID A BLEND OF 00Z GUIDANCE WITH THE GOING FORECAST TO KEEP FROM HAVING A HUGE CHANGE IN THE FORECAST. THE BIG IMPACT OF THIS IS THAT AS THE NEXT UPPER WAVE MOVES ACROSS THE AREA THURSDAY AFTERNOON...IT HAS SIGNIFICANTLY MORE MOISTURE TO WORK WITH THAN WHAT MODELS HAD BEEN SHOWING PREVIOUSLY. IN THE WARM SECTOR WORKING OUT AHEAD OF THIS WAVE...THE GFS/NAM ARE SHOWING SFCS DEWPS UP AROUND 20...WITH SPEC HUMIDITY ON THE 295K SFC UP AROUND 2.5 G/KG. MOST GUIDANCE PAINTS THIS BAND COMING DOWN ALONG/NORTH OF I-94...SO THIS IS WHERE WE STARTED WITH THE INTRODUCTION OF 40 POPS. GIVEN THE HIGHER MOISTURE...THIS WAVE MAY HAVE THE POTENTIAL TO PRODUCE A WHOLE WHOPPING 1-2 INCHES OF LIGHT FLUFFY SNOW. FROM THE SNOW END OF THINGS...WE ACTUALLY LOOK TO GET A BREAK FRIDAY AND SATURDAY AS RIDGING NUDGES INTO THE PLAINS...PUSHING THESE PESKY NW FLOW WAVES NORTH OF THE MPX AREA. OF COURSE THE ADVANTAGE TO THIS IS THAT WE WILL HAVE A COUPLE OF BRIEF WARM DAYS FRIDAY AND LEAST THE FIRST HALF OF SATURDAY BEFORE ARCTIC AIR RETURNS. STILL LOOKS LIKE SOME HIGHS IN THE 30S FOR SOUTHERN MN LOOK LIKE A POSSIBILITY FRIDAY AND SATURDAY. ALTHOUGH NOT IN THE FORECAST NOW...THE NEXT CHANCE FOR LIGHT SNOW WILL LIKELY BE SATURDAY NIGHT INTO SUNDAY AS THE NEXT POWERFUL BLAST OF ARCTIC AIR RETURNS. MORE WORRISOME THAN THE LIGHT SNOW THOUGH ARE THE WINDS THE ECMWF/GEM/GFS SHOW DEVELOPING IN THE COLD ADVECTION BEHIND THE FRONT. GFS BUFKIT SOUNDINGS OUT IN WRN AND SRN MN SUNDAY NIGHT ARE SHOWING MID CHANEL MIXING WINDS OF AROUND 35 KTS...WITH TOP OF THE CHANNEL OF 45 KTS. THIS WOULD SUGGEST THE POTENTIAL FOR BLIZZARD CONDITIONS SATURDAY NIGHT AS THIS COLD AIR ARRIVES...SO THIS WILL NEED TO WATCHED CLOSELY IN THE COMING DAYS. AS FOR WHAT COMES BEHIND THIS FRONT...WELL LETS JUST SAY IT/S NOT PRETTY IF YOU HAVE HAD ENOUGH OF THE ARCTIC AIR! BOTH THE GFS/ECMWF SHOW SUNDAY THROUGH AT LEAST WEDNESDAY NEXT WEEK BEING THE COLDEST STRETCH OF DAYS WE HAVE SEEN YET. COULD VERY WELL END UP SEEING A 2 TO 4 DAY STRETCH WHERE MUCH OF THE AREA STRUGGLES TO SEE HIGHS GET ABOVE ZERO WITH LOWS AGAIN GOING DOUBLE DIGITS BELOW ZERO ACROSS MUCH OF THE AREA. ENJOY! && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 611 AM CST TUE DEC 24 2013 IFR CEILINGS HAVE BLOSSOMED EARLY THIS MORNING ACROSS WEST CENTRAL WI...JUST NICKING KRNH WITH KEAU NEARLY IN THE CENTER. RAP 0.5KM CONDENSATION PRESSURE DEFICITS SHOW THE SATURATION MOVING NORTHEAST OF THESE TWO TAFS SITES BY 15Z. MOVEMENT FROM SATELLITE WOULD SUPPORT THIS TREND. BACK TO THE WEST...STRONG SOUTH TO SOUTHEAST WINDS HAVE DEVELOPED ALONG THE MN/DAKOTA BORDER AS THE PRESSURE GRADIENT TIGHTENS AHEAD OF AN INCOMING LOW PRESSURE SYSTEM. WHERE THE SNOW HAS DEVELOPED WELL BACK IN WESTERN NORTH DAKOTA...CEILINGS DROP QUICKLY TO LOW MVFR WITH SOME IFR. FOLLOWED THE LATEST HOPWRF REFLECTIVITY FORECAST FOR THE TIMING ON BRINGING THE SNOW INTO THE TAF SITES. THIS WAS VERY CLOSE TO THE PREVIOUS SET WITH ONLY MINOR CHANGES MADE. MOST SHORT TERM SOLUTIONS POINT TO A 3 TO 4 HOUR PERIOD OF MODERATE SNOW AS THE BEST FORCING MOVES THROUGH DURING THE AFTERNOON AND EVENING. CURRENT THINKING IS THAT MVFR CEILINGS WILL PREVAIL IN THE WAKE OF THE SNOW OVERNIGHT AND ON CHRISTMAS. LIGHT SNOW SHOULD SPREAD BACK IN FROM THE NORTHWEST DURING THE DAY ON CHRISTMAS AS THE ARCTIC WAVE TRAIN CONTINUES. KMSP... NO CONCERNS UNTIL LATE AFTERNOON WHEN SNOW AND MVFR CEILINGS ARRIVE. A PERIOD OF IFR OR LOWER CEILINGS/VSBYS IN MODERATE SNOW FORECAST IN THE 23Z-03Z TIME FRAME. SNOW ACCUMULATION REACHING 3 INCHES BY LATE IN THE EVENING WITH THE SNOW TAPERING OF SIGNIFICANTLY AFTER 06Z. SE WINDS INCREASING TO 12-15 KNOTS THIS MORNING AND CONTINUING INTO THIS EVENING. WINDS LOWERING BELOW 10 KNOTS LATE IN THE EVENING AND VEERING W OVERNIGHT. /OUTLOOK FOR KMSP/ WED...MVFR WITH -SN POSSIBLE. WINDS W 10-15KTS. THU...VFR. CHANCE MVFR CIGS/VSBYS IN -SN. WINDS S AT 5 KTS. FRI...VFR. WINDS SW 5-10 KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...WINTER WEATHER ADVISORY FROM NOON TODAY TO MIDNIGHT CST TONIGHT FOR MNZ042>045-049>052-057>062-065>069-073>076-082>084-091- 092. WIND CHILL ADVISORY UNTIL NOON CST TODAY FOR MNZ043>045-050>053- 059>063-068>070-076>078-084-085-091>093. WINTER WEATHER ADVISORY FROM 9 AM THIS MORNING TO 9 PM CST THIS EVENING FOR MNZ041-047-048-054>056-064. WIND CHILL WARNING UNTIL 9 AM CST THIS MORNING FOR MNZ041-047- 048-054>056-064. WIND CHILL WARNING UNTIL NOON CST TODAY FOR MNZ042-049-057-058- 065>067-073>075-082-083. WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO 3 AM CST WEDNESDAY FOR MNZ053-063-070-077-078-085-093. WI...WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO 3 AM CST WEDNESDAY FOR WIZ014>016-023>028. && $$ SHORT TERM...RAH LONG TERM...MPG AVIATION...RAH
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
958 AM CST TUE DEC 24 2013 .SYNOPSIS... ISSUED AT 327 AM CST TUE DEC 24 2013 POTENT VORT MAX NOTED ON WATER VAPOR ACROSS MONTANA MOVING SOUTHEAST.ASSOCIATED WITH THE VORT MAX WAS A 1010MB LOW PRESSURE CENTER ACROSS CENTRAL MONTANA. A STRONG ARCTIC HIGH PRESSURE CENTER OF 1039MB WAS LOCATED ACROSS NORTHERN MISSOURI. OTHERWISE A WEAK LOW PRESSURE TROUGH WAS ORIENTED NORTH TO SOUTH ALONG THE EAST COAST...WITH HIGH PRESSURE LOCATED ALONG THE WEST COAST. && .UPDATE... ISSUED AT 958 AM CST TUE DEC 24 2013 UPDATED FORECAST TO REFINE PRECIP TYPE ACROSS NORTHERN NEBRASKA THROUGH THE MORNING HOURS. VISIBLE SATELLITE SHOWS SOME WEAK CONVECTIVE ENHANCEMENT ASSOCIATED WITH ECHOES COMING SOUTHEAST INTO NW CHERRY COUNTY. THIS IS SOMEWHAT SUPPORTED BY CROSS SECTIONS OF INSTABILITY PARAMETERS IN THAT AREA...ALTHOUGH ASOS REPORTS ARE INCONCLUSIVE. IR SATELLITE AND RAP MID LEVEL DEFORMATION VECTORS INDICATE INCREASING FRONTOGENESIS IN THIS REGION WHICH THE MODELS HAVE ADVERTISED WELL. STILL...SOUNDINGS SUGGEST SOME DRY AIR TO BE OVERCOME AND CURRENT ECHO COVERAGE SUPPORTS THAT. IF WEAK CONVECTION IS INDEED A POSSIBILITY...SLEET POTENTIAL WILL INCREASE AND HENCE MENTION OF SLEET IS INCLUDED FOR THE NORTHERN MOST FORECAST AREA. FURTHER SOUTH...FCST REMAINS CLOSE TO WHERE IT WAS. TEMPERATURES ARE TRICKY FOR TODAY AS WARM AIR SURGES EASTWARD AHEAD OF SOUTHWARD ADVANCING COLD FRONT. MIXING POTENTIAL IS IN QUESTION WITH EXISTING SNOW COVER...SO TEMPS WERE ONLY LOWERED SLIGHTLY IN THE NORTH WHERE CLOUD COVER AND PRECIP SHOULD LIMIT POTENTIAL. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 327 AM CST TUE DEC 24 2013 THE MAIN FORECAST CHALLENGES OVER THE NEXT 24 HOURS DEAL WITH PRECIPITATION CHANCES AND WINDS IN ASSOCIATION WITH A CLIPPER SYSTEM. ATTM...SURFACE LOW PRESSURE WAS LOCATED OVER NERN WYOMING PER 09Z SFC ANALYSIS WITH A WARM FRONT EXTENDING SOUTH FROM THIS FEATURE THROUGH EASTERN WYOMING...AND AN ARCTIC COLD FRONT EXTENDING NORTHWEST OF THE SURFACE LOW INTO NORTH CENTRAL MONTANA. OVER THE NEXT 12 HOURS...SURFACE LOW PRESSURE WILL TRACK TO THE EAST SOUTHEAST FROM NERN WYOMING INTO NERN NEBRASKA. EAST OF THE APPG WARM FRONT THIS MORNING...THERE WILL BE AN INCREASED THREAT FOR PRECIPITATION AS MID LEVEL LIFT INCREASES PER MID LEVEL FRONTOGENESIS AND OMEGA. TEMPERATURE PROFILES PER BUFKIT SOUNDING DATA ARE INDICATIVE OF A VERY SHALLOW...ABOVE FREEZING LAYER ABOVE THE SUBZERO SURFACE LATER THIS MORNING. GIVEN THE VERY SHALLOW NATURE OF THE ARCTIC AIR THIS MORNING...DECIDED TO KEEP A MENTION OF SLEET ALONG WITH LIGHT SNOW THIS MORNING. ONCE THE COLD FRONT CLEARS LATER THIS AFTERNOON...THE THREAT FOR PCPN WILL SHIFT TO ALL SNOW. MID LEVEL LIFT CONTINUES TO BE MOST FAVORABLE ACROSS THE NORTH CENTRAL AND NERN CWA LATER TODAY AND WILL CONTINUE HIGHEST POPS IN THESE AREAS. UTILIZING A BLEND OF THE MET AND MAV SOLNS YIELDED QPFS OF UNDER A TENTH OF AN INCH TDY IN THE NORTH...AND WILL KEEP CORRESPONDING SNOW ACCUMS TO AN INCH OR LESS. THEN THERE IS THE WIND BEHIND THE FRONT. THE LATEST NAM BUFKIT SOUNDINGS HAVE A TIGHT WINDOW OF NEAR ADVISORY WINDS IN THE PANHANDLE COUNTIES AROUND 1 PM THIS AFTERNOON...WITH WINDS FALLING BACK INTO THE 20 TO 30 MPH RANGE BY EARLY EVENING. DECIDED TO FORGO AN ADVISORY FOR THE PANHANDLE COUNTIES ATTM AS THE NAM BUFKIT SOUNDINGS WINDS ARE NOT SUPPORTED WITH THE MAV GUIDANCE WHICH KEEPS WINDS BELOW ADVISORY CRITERIA THIS AFTERNOON. FOR TONIGHT...WINDS WILL DECREASE SOMEWHAT...BUT REMAIN IN THE 10 TO 15 MPH RANGE...WITH EXCEPTION IN THE VALLEY...WHERE WINDS WILL BE BELOW 10 MPH. WITH A LIGHT BREEZE CONTINUING INTO THE OVERNIGHT...TEMPS WILL BE MILD WITH READINGS IN THE TEENS EXPECTED. LOWS WILL BOTTOM OUT IN THE HIGH SINGLE DIGITS IN THE PLATTE RIVER VALLEY WITH LIGHT WESTERLY WINDS FORECAST. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 327 AM CST TUE DEC 24 2013 VERY LITTLE CHANGE IS EXPECTED THE REST OF THE WEEK AND INTO THE UPCOMING WEEKEND...AS A PROGRESSIVE NORTHWEST FLOW ALOFT WILL CONTINUE. SEVERAL MID LEVEL DISTURBANCES WILL BE LOCATED WITHIN THE FLOW...BUT ANY LIGHT PRECIPITATION WITH THESE DISTURBANCES SHOULD REMAIN NORTH OF OUR AREA. CHRISTMAS DAY THROUGH FRIDAY WILL BE DOMINATED BY A PACIFIC AIRMASS AND DOWNSLOPE WESTERLY WINDS. HIGH TEMPERATURES WILL WARM FROM THE 30S TO LOWER 40S CHRISTMAS DAY...TO THE MID 40S TO MID 50S BY FRIDAY. AN ARCTIC COLD FRONT WILL DIVE SOUTH THROUGH THE NORTHERN PLAINS SATURDAY...ENTERING NEBRASKA SATURDAY AFTERNOON. THIS WILL BRING COLDER CONDITIONS TO THE AREA SUNDAY. LATEST INDICATIONS ARE THAT THE COLDEST AIR BEHIND THE FRONT WILL SLIDE FROM THE NORTHERN PLAINS INTO THE MISSISSIPPI VALLEY. MILD CONDITIONS SHOULD THEN RETURN FOR AT LEAST WESTERN NEBRASKA BY MONDAY. THE ECMWF IS MOST SUPPORTIVE OF THIS SCENARIO...WITH THE GFS KEEPING THE COLDER AIR A BIT FARTHER WEST. EVEN THE COLDER GFS SCENARIO SUPPORTS HIGHS WELL INTO THE 30S BY MONDAY ACROSS WESTERN NEBRASKA...WITH MID TO UPPER 20S FARTHER EAST. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 600 AM CST TUE DEC 24 2013 A FAST MOVING CLIPPER SYSTEM WILL SPREAD LIGHT SNOW OR FREEZING PRECIPITATION TO NORTHERN NEBRASKA TODAY WITH GUSTY WINDS EXPECTED ACROSS THE REMAINDER OF WESTERN AND NORTH CENTRAL NEBRASKA. FOR THE KLBF TERMINAL...EXPECT INCREASING CLOUDINESS TODAY WITH CIGS DROPPING DOWN TO 5000 FT AGL. WINDS WILL BE FROM THE NORTHWEST AT 15 TO 25 KTS TODAY...DIMINISHING TO UNDER 10 KTS TONIGHT. FOR THE KVTN TERMINAL...LIGHT SNOW OR FREEZING PRECIPITATION IS POSSIBLE LATER THIS MORNING INTO THE AFTERNOON HOURS WITH VISBYS DOWN TO 1SM. CIGS WILL LOWER TO 2000 FT AGL BY MIDDAY. WINDS WILL BE FROM THE NORTHWEST OR NORTH AT 15 TO 25 KTS TODAY...DECREASING TO 10 TO 15 KTS TONIGHT. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JWS SYNOPSIS...TAYLOR SHORT TERM...CLB LONG TERM...TAYLOR AVIATION...CLB
AREA FORECAST DISCUSSION
NWS RALEIGH NC
645 AM EST TUE DEC 24 2013 .SYNOPSIS...BEHIND A COLD FRONT MOVING OFF OF THE CAROLINA COAST THROUGH EARLY AFTERNOON...HIGH PRESSURE BUILDS OVER THE REGION. HIGH PRESSURE REMAINS AT LEAST THROUGH CHRISTMAS NIGHT. WEAK LOW PRESSURE DEVELOPS OFF OF THE CAROLINA COAST THURSDAY. && .NEAR TERM /THROUGH TODAY/... AS OF 255 AM TUESDAY... THE SURFACE COLD FRONT CONTINUES TO MAKE GRADUAL EASTWARD PROGRESS OFFSHORE OF THE CAROLINAS...THOUGH WEAK SURFACE CYCLONIC FLOW CONTINUES ON THE LATEST SURFACE ANALYSIS OVER THE SOUTHEAST PART OF THE STATE. PATCHES OF LIGHT RAIN PERSISTED THERE UNDERNEATH THE SOUTHWEST FLOW ALOFT...BUT DURING THE MORNING THE MORE MOIST FLOW ALOFT WILL ALSO SHIFT EAST AS THE UPPER TROUGH ON WATER VAPOR... MOVING INTO THE TENNESSEE VALLEY...MOVES INTO AND THEN ACROSS THE STATE. THE HRRR WRF HAS BEEN CONSISTENT WITH ITSELF...AND WITH THE DIMINISHING MOISTURE NOTED ON GFS BUFR SOUNDINGS...THAT MUCH OF THE PATCHY LIGHT RAIN SHOULD BE MOVING OFF TO THE EAST OF CENTRAL NORTH CAROLINA BY AROUND 12Z. WILL RETAIN A SLIGHT CHANCE OF RAIN EAST OF INTERSTATE 95 FOR THE EARLY DAYLIGHT HOURS...THEN WILL SHOW DRY CONDITIONS FOR THE REST OF THE DAY WITH CHANCES LESS THAN SLIGHT. EVEN THOUGH THE UPPER TROUGH IS WELL DEFINED ON WATER VAPOR IMAGERY...THE GUIDANCE CONSENSUS IS DRIER THAN 24 HOURS AGO...MAKING THE CHANCES FOR SPRINKLES WITH THE APPROACH OF THE TROUGH ALOFT REMOTE. TOO MUCH MID-LEVEL DRY AIR IS FORECAST...COINCIDENT WITH DRY AIR TO OUR WEST AS NOTED ON THE 00Z UPPER-AIR ANALYSIS. EVEN THE TREND IS DRIER IN THE LOWER LEVELS...THOUGH EXPECT LINGERING STRATOCU INTO THE MORNING IN MANY AREAS. THE SURFACE GRADIENT TIGHTENS TODAY AS HIGH PRESSURE BUILDS IN BEHIND THE DEPARTING FRONT. BUFR SOUNDINGS SUGGEST ENOUGH MIXING THAT FOR A PERIOD THIS AFTERNOON WIND GUSTS SHOULD REACH INTO THE UPPER TEENS TO LOWER 20S KNOTS...WITH NORTHERLY WINDS BACKING MORE NORTHWEST WITH MIXING. 1000-850MB THICKNESSES WILL BE FALLING DURING THE DAY...BUT THEIR VALUES SUGGEST HIGHS CLOSE TO MOS GUIDANCE BUT WITH ONLY MINIMAL RECOVERY FROM LATE NIGHT TEMPERATURES...FOR HIGHS IN THE MID 40S TO AROUND 50. && .SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/... AS OF 255 AM TUESDAY... HIGH PRESSURE REMAINS FOR MUCH OF THIS PERIOD...WITH PRECIPITABLE WATER VALUES MOSTLY BELOW A QUARTER-INCH AND K INDICES HIGHLY NEGATIVE. DRY SURFACE DEW POINTS MOVE IN AS WELL. BUFR SOUNDINGS AND RELATIVE HUMIDITY FORECASTS ARE DRY...SUGGESTIVE OF CLEAR OR MOSTLY CLEAR CONDITIONS INTO WEDNESDAY NIGHT. LOWS TONIGHT IN THE 20S...WITH HIGHS WEDNESDAY IN THE LOWER TO MID 40S...NEARER THE SLIGHTLY WARMER MAV MOS GUIDANCE WHICH IS CLOSER TO EXPECTED VALUES BASED ON 1000-850MB THICKNESSES. WEDNESDAY NIGHT...THERE IS SOME GUIDANCE DIFFERENCE ON THE AMOUNT OF HIGH CLOUDS THAT COULD MOVE INTO CENTRAL NORTH CAROLINA WITH THE APPROACH OF A JET AXIS ALOFT...AND LOWERING HEIGHTS. THE NAM IS CERTAINLY DRIER THAN THE GFS...WHICH IS DEEPER WITH THE ENERGY ALOFT AND LOWERS PRESSURES MORE OFF OF THE CAROLINA COAST BY 12Z THURSDAY. THE 00Z ECMWF OFFERS A GOOD COMPROMISE...SHOWING A FEW HIGH CLOUDS STARTING TO ENCROACH ON CENTRAL NORTH CAROLINA FROM THE SOUTH LATE IN THE DAY WEDNESDAY...AND SLOWLY SPREADING NORTH OVER MUCH OF THE AREA WEDNESDAY NIGHT...LIKELY MORE OPAQUE SOUTH. WILL GO CLOSER TO THE COLDER MET GUIDANCE WEDNESDAY NIGHT IN THE TRIAD AND NEAR THE VIRGINIA BORDER...WITH A BLEND IN THE MIDDLE INCLUDING THE TRIANGLE AND KRWI...AND CLOSER TO THE WARMER MAV GUIDANCE TOWARD KFAY. THIS RESULTS IN LOWS IN THE LOWER 20S TOWARD KTDF...25 TO 30 OVER THE SANDHILLS AND SOUTHERN COASTAL PLAIN...AND MID 20S IN BETWEEN. && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 300 AM TUESDAY... A SOUTHERN STREAM WAVE WILL TRACK ACROSS THE SOUTHEAST ON THURSDAY...WITH A NORTHERN STREAM CLIPPER ON ITS HEELS. MODELS INDICATE A WEAK SURFACE LOW MAY DEVELOP OFF THE NC/SC COAST IN RESPONSE TO THE WEAK DPVA AND UPPER DIVERGENCE IN THE RIGHT FRONT ENTRANCE REGION OF AN INTENSIFYING UPPER JET OVER THE MID-ATLANTIC STATES. HOWEVER...FORECAST SOUNDINGS SHOW LIMITED MID-LEVEL MOISTURE INLAND AND THUS DONT PRODUCE ANY QPF OVER THE RAH CWA. CIRRUS SHOULD BE RATHER ABUNDANT...AT LEAST EARLY IN THE DAY...BEFORE BEING SHUNTED EASTWARD WITH THE PASSING NORTHERN STREAM TROUGH AXIS. THIS WILL LIMIT SOME OF THE MODERATION OF TEMPS....THOUGH HIGHS SHOULD STILL REACH SEASONAL NORMS...48-52. LOWS THURSDAY NIGHT 26-31. THE REMAINDER OF THE EXTENDED PERIOD WILL BE MOSTLY DOMINATED BY THE NORTHERN STREAM AS SHORTWAVES MOVING ACROSS THE GREAT LAKES REGION SLOWLY CARVE OUT A LONGWAVE TROUGH OVER THE EASTERN US. THIS IS SUPPORTED BY A TREND TOWARD NEGATIVE NAO/AO PHASES IN THE MEDIUM RANGE. ANOTHER SOUTHERN STREAM SHORTWAVE AND ASSOCIATED POTENTIAL SURFACE LOW SHOULD REMAINED SUPPRESSED OFFSHORE SUNDAY/MONDAY...THOUGH THE 00Z ECMWF TRENDED FURTHER WEST WITH MOISTURE ON SUNDAY. WILL LEAVE THE FORECAST DRY AT THIS TIME. PERIODS OF CIRRUS WILL LIKELY PLAGUE THE AREA OVER THE WEEKEND...WITH HIGHS REBOUNDING A BIT...INTO THE LOW TO MID 50S... BEFORE WHAT APPEARS TO BE A MOSTLY DRY COLD FRONT CROSSES THE AREA EARLY NEXT WEEK. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... AS OF 645 AM TUESDAY... VFR CONDITIONS OVER THE WESTERN PIEDMONT WERE SLOWLY SPREADING EAST AND THEY WILL GRADUALLY SPREAD OVER CENTRAL NORTH CAROLINA DURING THIS EARLY MORNING...WITH KFAY LIKELY BEING PREDOMINANTLY VFR BY 14Z. THEN...CURRENTLY EXPECT BROKEN VFR-LEVEL CEILINGS ENDING BY EARLY AFTERNOON. WITH MIXING TODAY...WINDS SHOULD BACK MORE TO THE NORTHWEST WITH GUSTS IN THE 20S KNOTS AS THE SURFACE GRADIENT TIGHTENS. WINDS WILL DIMINISH THIS EVENING AS HIGH PRESSURE CONTINUES TO BUILD OVER THE AREA...THOUGH NORTHERLY WINDS TOWARD KRWI AND KFAY MAY BE MORE NOTICEABLE A LITTLE LONGER INTO THE OVERNIGHT HOURS DUE TO THE TIGHTER GRADIENT IN PLACE THERE COMPARED TO THE REST OF CENTRAL NORTH CAROLINA. BEYOND THE 12Z VALID TAF PERIOD...EXPECT VFR CONDITIONS. BASED ON THE LATEST GFS MODEL GUIDANCE...THERE IS A LOW PROBABILITY OF SUB- VFR CONDITIONS AT KFAY AND KRWI LATE WEDNESDAY NIGHT INTO EARLY THURSDAY AS WEAK LOW PRESSURE DEVELOPS OFF OF THE CAROLINA COAST. OTHER GUIDANCE APPEARS DRIER AS OF THIS WRITING. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DJF NEAR TERM...DJF SHORT TERM...DJF LONG TERM...SMITH AVIATION...DJF
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
651 AM CST TUE DEC 24 2013 .UPDATE... ISSUED AT 651 AM CST TUE DEC 24 2013 CURRENT RADAR IMAGERY INDICATES AN AREA OF HEAVIER PRECIP ACROSS NORTHWEST SOUTH DAKOTA (LIKELY ASSOCIATED WITH STRONGER FORCING FROM UPPER WAVE)...AND A BAND OF PRECIP EXTENDING TO THE NORTH (LIKELY ASSOCIATED WITH 850MB WARM AIR ADVECTION). THE WARM AIR ADVECTION SNOWFALL SHOULD LEAD TO MOSTLY 1-2 INCHES...POSSIBLY UP TO 3. THE SOUTHERN AND HEAVIER AREA OF PRECIP WILL LIKELY LEAD TO 2-4 INCHES...POSSIBLY UP TO 5. THE MAIN QUESTION IS WHERE WILL THIS STRONGER AREA OF PRECIP TRACK. THE RAP INITIALIZED THIS AREA TOO FAR NORTH...AND WILL THROW OUT THIS SOLUTION. THE REMAINDER OF THE GUIDANCE HAS COME INTO SOME SORT OF AGREEMENT...INDICATING ACROSS THE SOUTHERN VALLEY AND INTO THE WADENA AREA. SLIGHTLY ADJUSTED THE SNOWFALL FORECAST TO ACCOUNT FOR THE ABOVE THINKING...MOSTLY LIMITING THE 3+ TOTALS ALONG AND SOUTH OF A LIDGERWOOD TO PARK RAPIDS LINE. THE ONLY CHANGE MADE TO THE WINTER WEATHER ADVISORY WAS TO END THE NORTHERN VALLEY AT 19Z AS IT APPEARS SNOW WILL BE OVER BY THIS TIME. THE ADVISORY LOOKS GOOD FOR AREAS ACROSS THE SOUTH EXPECTED TO RECEIVE 3+ INCHES OF SNOW. TO THE NORTH...1-3 INCHES OF SNOW NOT REALLY ADVISORY CRITERIA...AND WINDS ARE NOT QUITE STRONG ENOUGH TO CAUSE BLOWING SNOW. HOWEVER...GIVEN THE 20-30 MPH WINDS COMBINED WITH HIGHER SNOWFALL RATES...WILL LET IT RIDE (THIS WILL CAUSE SOME TRAVEL HAZARDS). && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 345 AM CST TUE DEC 24 2013 THE MAIN CONCERN WILL BE WIND SPEEDS AND SNOW AMOUNTS TODAY. 00Z MODELS ARE IN POOR AGREEMENT...MAKING CONFIDENCE WITH DETAILS QUITE LOW. THE ECMWF IS THE FURTHEST SOUTH WITH THE HEAVIEST BAND OF SNOWFALL (JUST SOUTH OF THE FA)...WHILE THE GFS/NAM/GEM/RAP/HRRR BRING THE HEAVIER BAND THROUGH THE SOUTHERN FA (WITH LIGHTER AMOUNTS TO THE NORTH). THE HIGH-RES GUIDANCE IS INDICATING QPF AROUND 0.40 INCHES WITHIN THE HEAVIER BAND (AND AROUND 0.10 INCHES ELSEWHERE)...WHICH WOULD EQUATE TO 4-6 INCHES. THE 06Z NAM HAS TRENDED FURTHER SOUTH...AND CURRENT RADAR IMAGERY SEEMS TO SUPPORT THE SOUTHERN SOLUTION. GIVEN THE LOW CONFIDENCE...WILL MONITOR OBSERVATIONAL TRENDS AND INCOMING MODEL GUIDANCE OVER THE NEXT FEW HOURS BEFORE MAKING ANY RADICAL CHANGES TO THE FORECAST...AND STICK TO THE ONGOING FORECAST UNTIL THEN. THE ONLY CHANGE WAS TO DELAY THE ONSET OF SNOWFALL THIS MORNING. LATEST GUIDANCE IS INDICATING COLDER TEMPERATURES FOR TODAY...AND SHALLOWER MIXING POTENTIAL. THIS MEANS WINDS MAY NOT BE QUITE AS STRONG...BUT STILL LIKELY 20-30MPH THIS MORNING (WHICH COMBINED WITH FALLING SNOW COULD STILL LEAD TO POOR VISIBILITY). TONIGHT-WEDNESDAY...EXPECT NORTHWEST FLOW ALOFT...ALONG WITH HARD TO TIME UPPER WAVES. MOST GUIDANCE INDICATES A WEAK WAVE TONIGHT INTO WEDNESDAY MORNING...AND INCREASED POPS INTO THE 30%-40% RANGE FOR THIS FEATURE. WINDS FROM THE NW COULD BE BREEZY AT TIMES BEHIND THE UPPER WAVE...BUT SHOULD NOT BE STRONG ENOUGH FOR DRIFTING AND/OR BLOWING SNOW. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 345 AM CST TUE DEC 24 2013 WEDNESDAY NIGHT-THURSDAY NIGHT...NORTHWEST FLOW ALOFT...ALONG WITH HARD TO TIME SHORTWAVES...WILL CONTINUE. MOST GUIDANCE AGREES ON THE NEXT WAVE LATE WED NIGHT INTO THURSDAY...AND INCREASED POPS INTO THE 30-40% RANGE FOR THIS FEATURE. FRIDAY-MONDAY...FRIDAY LOOKS DOWNRIGHT BALMY COMPARED TO RECENT DAYS AS RISING HEIGHTS AHEAD OF WEEKEND SYSTEM CAUSE BROAD SOUTHWEST FLOW AT THE SURFACE. FRONTAL BOUNDARY/THERMAL RIBBON IS NORTH OF CWFA ON FRIDAY. HOWEVER MID LEVEL MOISTURE AND LIFT GENERATED BY EXIT REGION OF 300MB JET JUSTIFY LOW POPS SAGGING INTO NORTHERN THIRD CWFA AFTER 00Z SATURDAY. BASED ON CURRENT AND PREVIOUS GUIDANCE WILL CONTINUE TO SPREAD POPS SOUTH WITH APPROACHING SHORT WAVE...INCREASING CYCLONIC FLOW AND LIFT IN LEFT REAR QUAD OF JET. 00Z SUITE OF MODELS IN PRETTY GOOD AGREEMENT WITH THE TIMING OF THE NEXT COLD SURGE. THE TEMPERATURE WILL PROBABLY PEAK EARLY SATURDAY THEN BEGIN ANOTHER DOWNWARD SPIRAL BEHIND THE FRONT. SUBSIDENCE BEHIND THE SHORTWAVE...MODEST PRESSURE RISE/FALL COUPLET...DEEP LAYERED COLD ADVECTION AND ORIENTATION OF ISOBARS SUGGEST QUITE BREEZY CONDITIONS POST FRONTAL FOR SATURDAY. HAVE UPPED WIND SPEEDS ON SATURDAY INTO EVENING USING GFS/BCMOS BLEND. BEYOND THAT THE LAST FEW DAYS OF 2013 ARE COLD AND DRY AS ARCTIC RIDGE SLIDES ALONG AND WEST OF CWFA. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 651 AM CST TUE DEC 24 2013 THE MAIN CONCERN WILL BE SNOWFALL MOVING THROUGH THE REGION TODAY. THIS REGION OF SNOWFALL WILL BE ASSOCIATED WITH MOSTLY MVFR CIGS/VSBY...AND POSSIBLY PERIODS OF IFR CONDITIONS. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...WINTER WEATHER ADVISORY UNTIL 7 PM CST THIS EVENING FOR NDZ039- 053. WINTER WEATHER ADVISORY UNTIL 1 PM CST THIS AFTERNOON FOR NDZ008- 016-027-029-030. MN...WINTER WEATHER ADVISORY UNTIL 7 PM CST THIS EVENING FOR MNZ002- 003-005-006-008-009-013>017-022>024-027>032-040. WINTER WEATHER ADVISORY UNTIL 1 PM CST THIS AFTERNOON FOR MNZ001- 004-007. && $$ UPDATE...TG SHORT TERM...TG LONG TERM...EWENS/TG AVIATION...TG
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1005 AM MST TUE DEC 24 2013 .UPDATE... && .SHORT TERM...OVERALL...CURRENT FORECASTS LOOK ON TRACK. CHINOOK WINDS FAIRLY STRONG IN AND NEAR FOOTHILLS...WITH SOME RECENT GUSTS TO 60 MPH ALONG HIGHWAY 93 FROM BOULDER TO GOLDEN. GUSTY WINDS TO 50 MPH OVER THE HIGHER MOUNTAIN PASSES AS WELL. FAIRLY DECENT MOUNTAIN TOP INVERSION COMBINING WITH GOOD MOUNTAIN WAVE TO PRODUCE THE GUSTY AND ERRATIC CHINOOK WINDS. ACROSS THE PLAINS AWAY FROM THE FOOTHILL...WINDS LIGHTER WITH SOME SORT OF A ANTICYCLONE IN THE DENVER AREA. SNOW ACROSS MOUNTAINS BEGINNING TO INCREASE IN COVERAGE AS MID LEVEL ASCENT INCREASES AHEAD OF THE SHORTWAVE MOVING INTO WYOMING. SPATIAL CROSS SECTIONS STILL INDICATING A DECREASE IN THE WINDS BY EARLY AFTERNOON...AS CROSS MOUNTAIN FLOW DECREASES TO AROUND 40 KTS IN RESPONSE TO THE INCREASING ASCENT. THIS ASCENT WILL HELP BREAK DOWN THE INVERSION. LATEST MODELS SHOWING ADDITIONAL SNOW AMOUNTS OF AROUND 2 TO 4 INCHES THROUGH THIS AFTERNOON...MAINLY WEST AND NORTHWEST FACING SLOPES. GUSTY WINDS OVER HIGHER PASSES WILL PRODUCE SOME BLOWING SNOW. ACROSS PLAINS...APPEARS COLD FRONT IS JUST NORTH OF CHEYENNE. THERE ARE SOME PRESSURE RISES ACROSS SOUTHERN WYOMING AND NORTHERN COLORADO. MODELS SHOW FRONT RACING SOUTH BY 20Z..A BIT SLOWER THAN EARLIER THINKING. WINDS TO BE GUSTY WITH THE FRONTAL PASSAGE...SOME GUSTS AROUND 40 MPH POSSIBLE EAST OF DENVER AREA. STILL SOME QUESTION WHETHER THERE WILL BE ENOUGH LOW LEVEL MOISTURE TO GENERATE SOME LIGHT RAIN OR SNOW SHOWERS. PRECIPITATION NEAR THE CHEYENNE AREA SHOWINGS SIGNS OF DECREASING. LATEST RAP AND HRRR DOES SHOW SOME LIGHT QPF ACROSS THE PLAINS EAST OF DENVER AS WELL AS THE PALMER DIVIDE. CURRENT THINKING IS THAT THERE WILL BE SUFFICIENT MID LEVEL ASCENT TO PERHAPS SQUEEZE OUT A FEW SHOWERS BY THE EVENING. THIS STILL SEEMS REASONABLE... LOW POPS LOOK GOOD FOR NOW. NO ACCUMULATION IS EXPECTED...WITH PERHAPS A LIGHT DUSTING ALONG THE PALMER DIVIDE. SUBSIDENCE AND DRIER AIR BEHIND DISTURBANCE THIS EVENING WITH DECREASING SNOW ACROSS MOUNTAINS. THOUGH WINDS EXPECTED TO DECREASE ACROSS PLAINS...CROSS SECTIONS SHOW CROSS MOUNTAIN FLOW INCREASING TO 50 KTS AT MOUNTAIN TOP BY MIDNIGHT. WITH THE INCREASING SUBSIDENCE... WINDS TO INCREASE AGAIN ACROSS THE RIDGES AND EAST SLOPES OVERNIGHT. .AVIATION...WEAK CYCLONE DEVELOPING NEAR THE DENVER AREA WITH LIGHT EASTERLY WINDS AT KDEN AND KAPA. GUSTY WESTERLY WINDS ONGOING AT KBJC. FRONT JUST NORTH OF CHEYENNE...AND SHOULD RACE SOUTH ACROSS THE AREA BY 20Z. WILL BACK OFF THE TIMING OF THE FRONT TO 19Z FOR THE LATEST TAF ISSUANCE. OTHERWISE...REST OF TAF TRENDS LOOK REASONABLE. GUSTY NORTHERLY WINDS FOR A FEW HOURS AFTER FROPA THEN DECREASING WITH A GRADUAL CLOCKWISE SHIFT TO SOUTHERLY THROUGH THE EVENING. STILL A SLIGHT CHANCE FOR A FEW RAIN/SNOW SHOWERS BETWEEN 20Z AND 02Z WITH PERHAPS CEILINGS AROUND 7000 FEET AGL. NO ACCUMULATION EXPECTED. VFR TO PREVAIL. && .PREV DISCUSSION... /ISSUED 705 AM MST TUE DEC 24 2013/ UPDATE... AVIATION...UPDATED DENVER AREA TAFS TO REFLECT AN EARLIER ARRIVAL TIME FOR THE COLD FRONT AND ITS WIND SHIFT. FRONT AT PRESENT TIME WAS JUST PASSING TORRINGTON IN SOUTHEAST WYOMING. WITHIN THE PAST 30 MINUTES...THE FRONT BLEW THROUGH CASPER WITH IFR CIGS...MODERATE SNOW AND GUSTY NORTHERN WINDS TO 31 KTS. AT ITS PRESENT SPEED... COULD SEE THIS FRONTAL BOUNDARY ARRIVING IN THE DENVER AREA BY 18Z OR EVEN 17Z. THAT WOULD BE 2 TO 3 HOURS EARLIER THAN WHAT MODELS INDICATE. FURTHERMORE...IT MAY BE NECESSARY LATER THIS MORNING SHOULD IT APPEAR CIGS WILL BE LOWER THAN WHAT IS NOW INDICATED IN TAFS. HOWEVER...MODELS PRESENTLY DO NOT INDICATE THIS HAPPENING. PREV DISCUSSION... /ISSUED 550 AM MST TUE DEC 24 2013/ RESENT... SHORT TERM...TODAY-TONIGHT: FROM A SYNOPTIC PERSPECTIVE... 700-500 MB TROUGH MOVING ALONG IN STRONG NORTHWEST FLOW STREAM AND PRESENTLY PASSING OVER IDAHO AND WESTERN MONTANA. AT THE SURFACE...A PACIFIC COLD FRONT EXTENDS FROM SOUTHERN IDAHO ACROSS NORTHWEST WYOMING AND SOUTHEAST MONTANA AS OF 09Z. AIRMASS BEHIND THIS FRONTAL BOUNDARY NOT ALL THAT COLD AS REVEALED BY THE RAIN...NOT SNOW...FALLING FROM THE CLOUD BAND ALONG THE FRONT CROSSING SOUTHERN MONTANA. LOWER ELEVATION TEMPERATURES BEHIND THE FRONT AT THIS HOURS IN THE RELATIVELY MILD 20S AND 30S. MEANWHILE CLOSER TO HOME...STRONG NORTHWEST FLOW ALOFT COMBINING WITH A MOUNTAIN WAVE AND INCREASING MTN TOP STABILITY TO CRANK CHINOOK WIND MACHINE ALONG THE OVER AND NEAR THE FRONT RANGE. GUSTS DURING THE PAST COUPLE OF HOURS IN THE HIGHER FOOTHILLS OF BOULDER AND GILPIN COUNTIES IN THE 40-50 MPH RANGE. MODEL SPATIAL CROSS SECTIONS INDICATE AN INCREASE IN CROSS BARRIER FLOW OVER THE NEXT FEW HOURS AS THE UPPER TROUGH AND FRONT NEAR. THOSE HIGH WIND PRONE AREAS...SUCH AS UP AROUND WONDERVU... GEORGETOWN...WARD AND NEDERLAND IN THE FOOTHILLS WEST OF DENVER AND BOULDER COULD SEE GUSTS APPROACHING 65 MPH PRIOR TO 12Z. FURTHERMORE A MOUNTAIN WAVE CLOUD SHIELD HAVE FORMED IN THE LEE OF THE FRONT RANGE WHICH HAS ALSO HELPED TO PRODUCE MILD OVERNIGHT TEMPERATURES ALONG THE BASE OF THE FOOTHILLS. TODAY...STRONG/GUSTY CHINOOK WINDS ARE FORECAST TO EASE THROUGH THE MORNING AS THE MOUNTAIN WAVE AND CROSS MOUNTAIN PRESSURE GRADIENT RELAX. UPPER TROUGH AND SFC FRONT WILL RACE SOUTHEAST ACROSS WYOMING THIS MORNING WITH WHAT LOOKS TO BE A SHRINKING CLOUD/PRECIP BAND AS THIS SYSTEM ADVANCES INTO A DRIER ENVIRONMENT. THE COLD FRONT IS TIMED TO REACH THE NORTHEAST COLORADO BORDER BY ABOUT 18Z TODAY... WHERE IT THEN RACES SOUTH WITH GUSTY NORTHERLY WINDS OF 25-40 MPH DURING THE AFTERNOON. WRF...HRRR AND NAM MODELS SHOW THE FRONT AND ITS GUSTY NORTHERLY WINDS REACHING DENVER AND THE I-70 CORRIDOR EAST OF THE METRO AREA AROUND 21Z (2 PM MST)...AND EXITING SOUTHERN SECTIONS OF THE CWFA AN HOUR OR SO LATER. GUSTS TO 35-40 MPH WITH THE FRONT AND FOR AN HOUR OR SO AFTER FROPA...WITH THE STRONGEST WINDS STAYING EAST OF I-25. WINDS SHOULD DIE DOWN IN THE SOUTHERN FOOTHILLS WITH FROPA...BUT STRENGTHEN AGAIN OVER NORTHERN SECTIONS OF THE FRONT RANGE FOOTHILLS WITH STRONG SFC TO MILD-LEVEL SUBSIDENCE BEHIND THE UPPER TROUGH AXIS FORECAST TO PASS OVER THE AREA NOT LONG AFTER FRONTAL PASSAGE. COULD ONCE AGAIN SEE NORTHWEST WINDS GUSTING TO AROUND 50 MPH UP NEAR THE WYOMING BORDER LATE TODAY. AS FOR PRECIPITATION...WEAK SFC-500 MB QG ASCENT WITH TROUGH AND FRONT STILL NECESSITATES MENTIONING AT LEAST A SLIGHT CHANCE OF RAIN/SNOW ON THE PLAINS LATE THIS AFTERNOON. LOOKS TOO DRY FOR ANY ACCUMULATION...EVEN ON THE PALMER DIVIDE. MOUNTAIN AREAS...SPECIALLY ALONG AND WEST OF THE CONTINENTAL DIVIDE IN LINE TO SEE SEVERAL HOURS OF LIGHT TO AT TIMES MODERATE SNOWFALL LATE MORNING THROUGH EARLY THIS EVENING WITH TROUGH PASSAGE. NEW SNOW AMOUNTS PROBABLY NO MORE THAN 3-4 INCHES ON HIGHEST WEST-NORTHWEST SLOPES. SNOWFALL SHOULD QUICKLY SHUT DOWN THROUGH THE EVENING WITH DRYING AND STRONG SUBSIDENCE. AT THE SAME TIME...RIDGES AND EAST SLOPES COULD SEE WESTERLY WINDS RAMPING UP AGAIN WITH GUSTS APPROACHING 50 MPH IN WIND PRONE AREAS OVERNIGHT. LONG TERM...A RELATIVELY QUIET WEATHER WEAK ACROSS COLORADO AS HIGH PRESSURE RIDGE ALOFT BUILDS INLAND INTO THE GREAT BASIN THROUGH FRIDAY. THE RESULT WILL BE A DECREASING NORTHWEST FLOW PATTERN WITH GENERALLY DRY CONDITIONS AND WARMING TEMPERATURES FOR WEDNESDAY AND THURSDAY. THERE IS A WEAK RIPPLE IN THE FLOW THAT BRUSHES FAR NORTHEAST COLORADO LATE THURSDAY BUT THIS FEATURE LOOKS RATHER DRY EXCEPT FOR SOME MID LEVEL CLOUDINESS. TEMPERATURES WILL WARM TO WELL ABOVE NORMALS FOR THURSDAY AND FRIDAY WITH READINGS INTO THE 50S OVER THE PLAINS. THE NEXT FEATURE WITH POTENTIAL WEATHER AND COOLER TEMPERATURES WILL MOVE ACROSS COLORADO SATURDAY NIGHT AND EARLY SUNDAY. THE GFS IS THE DRIER MODEL WHILE THE EUROPEAN HAS MORE MOISTURE AND SOME LIGHT SNOWFALL OVER COLORADO. GIVEN THE DIFFERENCES AT THIS TIME WILL KEEP LOW CHANCES OF SNOW FOR THE MOUNTAINS AND PLAINS. TEMPERATURES WILL BE COOLER AS WELL. AVIATION...SOUTH-SOUTHWEST WINDS 8-15KTS IN THE DENVER AREA THIS MORNING...EXCEPT WEST-SOUTHWEST 10-20 KTS WITH OCNL GUSTS TO 30KTS NEAR THE FOOTHILLS SUCH AS AT BJC. THIS AFTERNOON COLD FRONT RACES SOUTH THROUGH THE DENVER METRO AREA WITH NORTH WINDS OF 15-25KTS. HIGHER GUSTS POSSIBLE EAST OF I-25 AROUND 21Z. GUSTY NORTHWESTERLY WINDS LAST AN HOUR OR SO AFTER FRONTAL PASSAGE...THEN LIGHTEN UP AS THEY TURN CLOCKWISE THROUGH EARLY EVENING...AND BECOMING SOUTHERLY 5-10KTS BEFORE 06Z. THERE IS A SLIGHT CHANCE OF A LIGHT RAN/SNOW SHOWER IN THE DENVER AREA SHORTLY AFTER FRONTAL PASSAGE. NO SNOW ACCUMULATION WITH PREVAILING VFR CONDITIONS. THEN CLEARING IN THE EVENING. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...D-L LONG TERM....ENTREKIN AVIATION...D-L
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
440 PM EST TUE DEC 24 2013 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 438 PM EST TUE DEC 24 2013 12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOWS SHRTWV RDG AXIS MOVING INTO THE WRN LKS BTWN DEPARTING TROF IN THE SE GRT LKS RESPONSIBLE FOR LES THE PAST FEW DAYS AND A PAIR OF SHRTWVS DIGGING SEWD THRU SCENTRAL CANADA/THE NRN ROCKIES E OF MEAN RDG NEAR THE W COAST. WITH SFC HI PRES BLDG ACRS THE AREA...LINGERING LES NEAR LK SUP HAS DIMINISHED AND PUSHED INTO THE OPEN WATERS AS THE FLOW IS SHIFTING TO THE SSW IN ADVANCE OF THE SFC LO PRES TROF IN THE NRN PLAINS ASSOCIATED WITH THE TWO CLIPPER SHRTWVS. THE 12Z INL/MPX RAOBS SHOWED A VERY DRY AIRMASS WITH PWATS UNDER 0.10 INCH...SO SKIES ARE TURNING MOSUNNY AT MOST PLACES AS THE SSW FLOW SHIFTS LINGERING LO CLDS BACK OUT OVER LK SUP. MID CLDS IN ADVANCE OF APRCHG CLIPPER SHRTWVS/SFC TROF ARE PUSHING EWD THRU MN...WITH SN FALLING OVER NW MN AND THE ERN DAKOTAS. ALTHOUGH THIS SN HAS BEEN MDT AT SOME PLACES UNDER THE SHARPER H85-5 QVECTOR CVNGC...THE COVERAGE APPEARS TO BE LIMITED BY ABSENCE OF SGNFT MSTR INFLOW. MAIN FCST CONCERNS IN THE SHORT TERM ARE EXPECTED POPS/SN AMOUNTS LATE TNGT AND XMAS MRNG ASSOCIATED WITH UPSTREAM CLIPPER SHRTWVS AND GOING WINTER STORM WATCH OVER THE ERN CWA/NEED FOR ANY NEW HEADLINES. TNGT INTO XMAS DAY...UPR TROF TO THE NW IS FCST TO SHIFT TO THE SE AND STRETCH FM NW ONTARIO THRU MN AND INTO THE CENTRAL PLAINS BY 12Z WED. MODELS SHOW PCPN IN ADVANCE OF THIS TROF ARRIVING OVER THE WRN CWA LATE THIS EVNG AND PUSHING TO THE E...WITH A 6-9 PERIOD OF SN AT MOST LOCATIONS BEFORE THE SN DIMINISHES OVER THE W 09-12Z WED AND BY ABOUT 18Z WED OVER THE ERN CWA FOLLOWING DEPARTURE OF DEEP LYR QVECTOR CNVGC. MAIN NEGATIVES FOR SGNFT SN FALL INCLUDE FCST SHARPER H85-5 QVECTOR CNVGC/SHARPER H7 UVV ASSOCIATED WITH INCOMING OUT OF PHASE SHRTWVS FOCUSING TO THE S OF UPR MI... LACK OF SGNFT MSTR INFLOW WITH ONLY ABOUT 1.5-2 G/KG SPECIFIC HUMIDITY NEAR H7...AND LIMITED RESIDENCE OF TIME OF PCPN. ONE FACTOR IN FAVOR OF SOMEWHAT HIER SN AMOUNTS IS FCST DEEP DGZ THAT MAY BOOST SN/WATER RATIOS AS HI AS 20-25:1. CONSIDERING MODEL QPF 0.05-0.15 INCH...EXPECT 1 TO 3 INCHES OF SN. THE ONE EXCEPTION WL BE OVER THE ERN CWA DOWNWIND OF LK MI...WHERE INCRSG SSW FLOW UP THE LENGTH OF LK MI IN THE PRESENCE OF DEEP MSTR/H85 TEMPS ARND -15C WL BRING A PERIOD OF HEAVIER LK ENHANCED SN. PRESENCE OF LINGERING BAND IN NRN LK MI AS SHOWN ON RECENT STLT IMAGERY EARLY THIS AFTN INCREASES CONFIDENCE IN THIS FCST. BULK OF HIER RES MODELS SHOW THE HEAVIER LES BAND IMPACTING FAR SE SCHOOLCRAFT COUNTY/SRN LUCE COUNTY IN THE 09Z-15Z WED TIME FRAME. WITH MODEL QPF RANGING FM 0.25 INCH TO AS MUCH AS 0.40 INCH AND DEEP DGZ SHOWN ON THE FCST SDNGS...EXPECT AT LEAST A HI END ADVY SNFALL IN THIS AREA. FCST SDNGS ALSO SHOW A PERIOD OF NEARLY UNIDIRECTIONAL SSW FLOW WITHIN THE MIXED LYR FOR A FEW HRS DURING TIME OF PEAK SN INTENSITY. GIVEN THESE FVRBL CONDITIONS...OPTED TO UPGRADE WATCH TO A WRNG FOR LUCE COUNTY...WHERE HEAVIER LES BAND IS MOST LIKELY TO RESIDE THE LONGEST AND DROP UP TO 9 TO PERHAPS 10 INCHES ALONG M-28 E OF ERY. WENT WITH AN ADVY FOR SCHOOLCRAFT COUNTY WITH POTENTIAL FOR SOME LK ENHANCEMENT...ESPECIALLY E OF SENEY AND MANISTIQUE. AS FOR TEMPS...ARRIVAL OF THICKER CLDS/STEADY S WIND WL ALLOW FOR ONLY A RELATIVELY SMALL TEMP DIP EARLY OVER THE W HALF. BUT TO THE E...EXPECT TEMPS TO FALL QUICKLY OVER THE INTERIOR ERN CWA THIS EVNG BEFORE THE CLDS AND STEADY S WINDS ARRIVE LATER. LATER ON XMAS DAY...AS THE UPR TROF AND SFC REFLECTION SHIFT SLOWLY THRU THE UPR GREAT LKS...THE LLVL FLOW IS PROGGED TO VEER TOWARD THE W. THIS WSHFT TO A MORE WSW DIRECTION WL END THE THREAT OF LK ENHANCED SHSN OVER THE E BY EARLY AFTN BUT CAUSE SOME LES TO DVLP OVER THE W IN THE AFTN AS H85 TEMPS DIP BACK NEAR -18C BY 00Z THU. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 438 PM EST TUE DEC 24 2013 WEDNESDAY NIGHT...LOW LEVEL CONV ALONG A COLD FRONT AND 850 MB TEMPS DROPPING FROM -15C TO -19C WILL BRING AN INCREASE IN LES INTO NORTHWEST UPPER MICHIGAN WED EVENING AND OVER ERN CWA OVERNIGHT. EVEN WITH A FAVORABLE PLACEMENT OF THE DGZ IN THE CONVECTIVE LAYER GIVING SLR VALUES NEAR 25/1...INVERSION HEIGHTS NEAR 6K FT AND STEADILY VEERING WINDS SHOULD KEEP ACCUMULATIONS IN THE 2 TO 4 INCH RANGE...WITH THE GREATEST AMOUNTS IN THE HIGHER TERRAIN FROM CALUMET TO TWIN LAKES AND NORTH OF M-28 EAST OF MUNISING. THU INTO THU NIGHT...NW FLOW LES WILL GRADUALLY DIMINISH AS A WEAK SFC RIDGE BUILDS FROM THE UPPER MS VALLEY INTO THE WRN LAKES BRINGING BACKING WINDS AND LOWERING INVERSION HEIGHTS. THE STRONGEST FORCING AND MOST FAVORABLE WAA/ISENTROPIC LIFT ASSOCIATED WITH A WEAK CLIPPER SHORTWAVE TROUGH IS EXPECTED TO REMAIN SOUTH OF THE UPPER MICHIGAN. FRI...THE ECMWF WAS MORE AGGRESSIVE WITH POTENTIAL FOR SOME LIGHT SNOW BY LATE FRI WITH THE WAA/ISENTROPIC LIFT PATTERN DEVELOPING AHEAD OF THE NEXT CLIPPER SHRTWV AND SFC LOW MOVING TOWARD NW ONTARIO COMPARED TO THE GFS/GEM. WITH LOW CONFIDENCE IN ANY PCPN...ONLY SLIGHT/CHANCE POPS WERE INCLUDED...MAINLY OVER THE EAST. SAT INTO SAT NIGHT...A BRIEF WARMUP IS EXPECTED SATURDAY AS UPPER MI WILL BE IN THE WARMER SECTOR AHEAD OF THE NEXT LOW. TEMPS SHOULD CLIMB ABOVE NORMAL WITH HIGHS AROUND 30. MODEL DIFFERENCES WERE EVEN GREATER BY SATURDAY NIGHT...AS THE ECMWF WAS SLOWER/DEEPER WITH SHRTWV AND SFC LOW MOVING THROUGH THE NRN GREAT LAKES. REGARDLESS OF MODEL DIFFERENCES...A COLD FRONT MOVING THROUGH WITH WINDS VEERING SHARPLY TO THE NNW SHOULD BRING LES OR LAKE ENHANCED SNOW INTO NRN UPPER SAT NIGHT. SUN-TUE...ANOTHER VERY COLD ARCTIC AIRMASS WILL DOMINATE THE REGION THROUGH THE PERIOD WITH LES EXPECTED FOR NW WIND FAVORED SNOWBELTS. WIND CHILL VALUES NEAR ADVISORY WILL BE POSSIBLE OVER THE WEST HALF BOTH EARLY MONDAY AND TUESDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1231 PM EST TUE DEC 24 2013 AS THE PRES GRADIENT OVER UPR MI TIGHTENS BTWN A DEPARTING SFC HI PRES RDG AND AN APRCHG LO PRES TROF...EXPECT GUSTY S WINDS TO DVLP LATE THIS AFTN/EVNG AT THE MORE EXPOSED IWD/SAW LOCATIONS. OTRW... VFR CONDITIONS WL GIVE WAY TO MVFR AND PERHAPS IFR CONDITIONS BY LATE EVNG AS SN IN ADVANCE OF THE TROF MOVES W-E INTO UPR MI. THE BEST CHC FOR THE IFR VSBYS WL BE AT SAW...WHERE THE LLVL S WIND WL NOT DOWNSLOPE. EVEN AFTER THE SN DIMINISHES W-E BY SUNRISE ON WED... MVFR SC CIGS WL LINGER. AS THE WEAKER FLOW VEERS TOWARD THE W LATER ON WED MRNG...MORE SHSN/IFR VSBYS MAY IMPACT CMX LATE IN THE TAF PERIOD. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 438 PM EST TUE DEC 24 2013 AS THE PRES GRADIENT TIGHTENS OVER LAKE SUPERIOR THIS EVENING BETWEEN DEPARTING SURFACE HI PRES RIDGE AND AN APPROACHING LO PRES TROF...OPTED TO MAINTAIN GOING GALE WARNING FOR THE ECENTRAL PORTIONS OF THE LAKE. AWAY FROM THIS FAVORED AREA...SOME GALE FORCE GUSTS WILL BE POSSIBLE. CLOSER APPROACH AND THEN PASSAGE OF LO PRES TROF AND WEAKER GRADIENT ON WED WILL CAUSE THE GALES TO DIMINISH AS THE WINDS VEER TOWARD THE W-NW. NORTHWEST TO NORTH GALES WILL AGAIN BE POSSIBLE SATURDAY NIGHT BEHIND AN ARCTIC COLD FRONT. HEAVY FREEZING SPRAY IS ALSO EXPECTED INTO EARLY NEXT WEEK. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... WINTER WEATHER ADVISORY FROM 1 AM TO 10 AM EST WEDNESDAY FOR MIZ014-085. WINTER STORM WARNING FROM 1 AM TO 1 PM EST WEDNESDAY FOR MIZ007. LAKE SUPERIOR... GALE WARNING FROM 11 PM THIS EVENING TO 7 AM EST WEDNESDAY FOR LSZ266. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...JLB AVIATION...KC MARINE...KC
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1137 AM CST TUE DEC 24 2013 .SYNOPSIS... ISSUED AT 327 AM CST TUE DEC 24 2013 POTENT VORT MAX NOTED ON WATER VAPOR ACROSS MONTANA MOVING SOUTHEAST.ASSOCIATED WITH THE VORT MAX WAS A 1010MB LOW PRESSURE CENTER ACROSS CENTRAL MONTANA. A STRONG ARCTIC HIGH PRESSURE CENTER OF 1039MB WAS LOCATED ACROSS NORTHERN MISSOURI. OTHERWISE A WEAK LOW PRESSURE TROUGH WAS ORIENTED NORTH TO SOUTH ALONG THE EAST COAST...WITH HIGH PRESSURE LOCATED ALONG THE WEST COAST. && .UPDATE... ISSUED AT 958 AM CST TUE DEC 24 2013 UPDATED FORECAST TO REFINE PRECIP TYPE ACROSS NORTHERN NEBRASKA THROUGH THE MORNING HOURS. VISIBLE SATELLITE SHOWS SOME WEAK CONVECTIVE ENHANCEMENT ASSOCIATED WITH ECHOES COMING SOUTHEAST INTO NW CHERRY COUNTY. THIS IS SOMEWHAT SUPPORTED BY CROSS SECTIONS OF INSTABILITY PARAMETERS IN THAT AREA...ALTHOUGH ASOS REPORTS ARE INCONCLUSIVE. IR SATELLITE AND RAP MID LEVEL DEFORMATION VECTORS INDICATE INCREASING FRONTOGENESIS IN THIS REGION WHICH THE MODELS HAVE ADVERTISED WELL. STILL...SOUNDINGS SUGGEST SOME DRY AIR TO BE OVERCOME AND CURRENT ECHO COVERAGE SUPPORTS THAT. IF WEAK CONVECTION IS INDEED A POSSIBILITY...SLEET POTENTIAL WILL INCREASE AND HENCE MENTION OF SLEET IS INCLUDED FOR THE NORTHERN MOST FORECAST AREA. FURTHER SOUTH...FCST REMAINS CLOSE TO WHERE IT WAS. TEMPERATURES ARE TRICKY FOR TODAY AS WARM AIR SURGES EASTWARD AHEAD OF SOUTHWARD ADVANCING COLD FRONT. MIXING POTENTIAL IS IN QUESTION WITH EXISTING SNOW COVER...SO TEMPS WERE ONLY LOWERED SLIGHTLY IN THE NORTH WHERE CLOUD COVER AND PRECIP SHOULD LIMIT POTENTIAL. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 327 AM CST TUE DEC 24 2013 THE MAIN FORECAST CHALLENGES OVER THE NEXT 24 HOURS DEAL WITH PRECIPITATION CHANCES AND WINDS IN ASSOCIATION WITH A CLIPPER SYSTEM. ATTM...SURFACE LOW PRESSURE WAS LOCATED OVER NERN WYOMING PER 09Z SFC ANALYSIS WITH A WARM FRONT EXTENDING SOUTH FROM THIS FEATURE THROUGH EASTERN WYOMING...AND AN ARCTIC COLD FRONT EXTENDING NORTHWEST OF THE SURFACE LOW INTO NORTH CENTRAL MONTANA. OVER THE NEXT 12 HOURS...SURFACE LOW PRESSURE WILL TRACK TO THE EAST SOUTHEAST FROM NERN WYOMING INTO NERN NEBRASKA. EAST OF THE APPG WARM FRONT THIS MORNING...THERE WILL BE AN INCREASED THREAT FOR PRECIPITATION AS MID LEVEL LIFT INCREASES PER MID LEVEL FRONTOGENESIS AND OMEGA. TEMPERATURE PROFILES PER BUFKIT SOUNDING DATA ARE INDICATIVE OF A VERY SHALLOW...ABOVE FREEZING LAYER ABOVE THE SUBZERO SURFACE LATER THIS MORNING. GIVEN THE VERY SHALLOW NATURE OF THE ARCTIC AIR THIS MORNING...DECIDED TO KEEP A MENTION OF SLEET ALONG WITH LIGHT SNOW THIS MORNING. ONCE THE COLD FRONT CLEARS LATER THIS AFTERNOON...THE THREAT FOR PCPN WILL SHIFT TO ALL SNOW. MID LEVEL LIFT CONTINUES TO BE MOST FAVORABLE ACROSS THE NORTH CENTRAL AND NERN CWA LATER TODAY AND WILL CONTINUE HIGHEST POPS IN THESE AREAS. UTILIZING A BLEND OF THE MET AND MAV SOLNS YIELDED QPFS OF UNDER A TENTH OF AN INCH TDY IN THE NORTH...AND WILL KEEP CORRESPONDING SNOW ACCUMS TO AN INCH OR LESS. THEN THERE IS THE WIND BEHIND THE FRONT. THE LATEST NAM BUFKIT SOUNDINGS HAVE A TIGHT WINDOW OF NEAR ADVISORY WINDS IN THE PANHANDLE COUNTIES AROUND 1 PM THIS AFTERNOON...WITH WINDS FALLING BACK INTO THE 20 TO 30 MPH RANGE BY EARLY EVENING. DECIDED TO FORGO AN ADVISORY FOR THE PANHANDLE COUNTIES ATTM AS THE NAM BUFKIT SOUNDINGS WINDS ARE NOT SUPPORTED WITH THE MAV GUIDANCE WHICH KEEPS WINDS BELOW ADVISORY CRITERIA THIS AFTERNOON. FOR TONIGHT...WINDS WILL DECREASE SOMEWHAT...BUT REMAIN IN THE 10 TO 15 MPH RANGE...WITH EXCEPTION IN THE VALLEY...WHERE WINDS WILL BE BELOW 10 MPH. WITH A LIGHT BREEZE CONTINUING INTO THE OVERNIGHT...TEMPS WILL BE MILD WITH READINGS IN THE TEENS EXPECTED. LOWS WILL BOTTOM OUT IN THE HIGH SINGLE DIGITS IN THE PLATTE RIVER VALLEY WITH LIGHT WESTERLY WINDS FORECAST. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 327 AM CST TUE DEC 24 2013 VERY LITTLE CHANGE IS EXPECTED THE REST OF THE WEEK AND INTO THE UPCOMING WEEKEND...AS A PROGRESSIVE NORTHWEST FLOW ALOFT WILL CONTINUE. SEVERAL MID LEVEL DISTURBANCES WILL BE LOCATED WITHIN THE FLOW...BUT ANY LIGHT PRECIPITATION WITH THESE DISTURBANCES SHOULD REMAIN NORTH OF OUR AREA. CHRISTMAS DAY THROUGH FRIDAY WILL BE DOMINATED BY A PACIFIC AIRMASS AND DOWNSLOPE WESTERLY WINDS. HIGH TEMPERATURES WILL WARM FROM THE 30S TO LOWER 40S CHRISTMAS DAY...TO THE MID 40S TO MID 50S BY FRIDAY. AN ARCTIC COLD FRONT WILL DIVE SOUTH THROUGH THE NORTHERN PLAINS SATURDAY...ENTERING NEBRASKA SATURDAY AFTERNOON. THIS WILL BRING COLDER CONDITIONS TO THE AREA SUNDAY. LATEST INDICATIONS ARE THAT THE COLDEST AIR BEHIND THE FRONT WILL SLIDE FROM THE NORTHERN PLAINS INTO THE MISSISSIPPI VALLEY. MILD CONDITIONS SHOULD THEN RETURN FOR AT LEAST WESTERN NEBRASKA BY MONDAY. THE ECMWF IS MOST SUPPORTIVE OF THIS SCENARIO...WITH THE GFS KEEPING THE COLDER AIR A BIT FARTHER WEST. EVEN THE COLDER GFS SCENARIO SUPPORTS HIGHS WELL INTO THE 30S BY MONDAY ACROSS WESTERN NEBRASKA...WITH MID TO UPPER 20S FARTHER EAST. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1136 AM CST TUE DEC 24 2013 TRICKY FORECAST IN TIMING ONSET OF PRECIPITATION AND INCREASES IN WIND. COLD FRONT IS PROGRESSING SOUTHWARD AND HAS MADE IT THROUGH THE NORTHWESTERN PORTION OF THE FORECAST AREA AND KVTN WINDS HAVE INCREASED IN THE LAST HOUR. IN ADDITION...IR SAT PICS AND RAP MODEL MID LEVEL DEFORMATION VECTORS CONTINUE TO INDICATE FRONTOGENETIC FORCING ACROSS SD AND INTO FAR NRN NEBRASKA. HOWEVER...DRY AIR AND MORE OF A FRONTOLYTICAL STRUCTURE SUGGEST LESSER CHANCES FOR RAIN OR SNOW SHOWERS AS THE AFTERNOON PROGRESSES IN SOUTHWEST NEBRASKA...WHICH IS IN LINE WITH CURRENT RADAR RETURNS. THE TAF FOR KVTN INCLUDES THE MENTION AND CIGS NEARING IFR FOR THE AFTERNOON HOURS BEFORE THE FORCING AND ASSOCIATED UPPER LEVEL SUPPORT MOVES QUICKLY OUT OF THE AREA THIS EVENING. AS FOR KLBF...NO MENTION OF PRECIP IN THE TAF BECAUSE OF THE PREVIOUSLY MENTIONED DRY AIR IN THE MID LEVELS AND LESSER MID LEVEL FORCING FOR ASCENT. CONFIDENCE IS ONLY MODERATE ON THIS IDEA AND WITH A WEAK CONVECTIVE NATURE TO THE PRECIPITATION WILL HAVE TO MONITOR TRENDS THIS AFERNOON. SOME CONCERN FOR LIGHT FOG DURING THE EARLY MORNING HOURS FOR KLBF...BUT HAVE NOT INCLUDED AT THIS TIME DUE TO A LACK OF CONFIDENCE IN LOW LEVEL SATURATION. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JWS SYNOPSIS...TAYLOR SHORT TERM...CLB LONG TERM...TAYLOR AVIATION...JWS
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
112 PM CST TUE DEC 24 2013 .UPDATE... ISSUED AT 112 PM CST TUE DEC 24 2013 BACK EDGE OF SNOW BAND NOW EXTENDS FROM NEAR BAUDETTE TO FARGO TO LISBON...MOVING TO THE EAST-SOUTHEAST AROUND 25 MPH. WILL ALLOW THE NORTHERN VALLEY PORTION OF THE ADVISORY TO EXPIRE AT 1 PM AND WILL ALSO CANCEL THE WESTERN TIER OF COUNTIES FOR THE PORTION SET TO EXPIRE AT 7 PM. RADAR REFLECTIVITY HAS DIMINISHED ACROSS MUCH OF THE FORECAST AREA WITH THE HIGHER RETURNS/HEAVIER SNOW COAGULATING ACROSS NORTHEAST SD ALONG TRACK OF 850 HPA LOW. SNOW AMOUNTS ACROSS NORTHWEST AND WEST CENTRAL MN LIKELY TO BE ON THE LOW END OF PREVIOUSLY FORECAST RANGE (1-2 INCHES)...BUT WILL MAINTAIN ADVISORY GIVEN SOME BLOWING SNOW AND REDUCED VISIBLITY. HOWEVER...LOCALIZED HIGHER POCKETS OF 3-4 INCHES STILL NOT OUT THE QUESTION. MADE SOME MINOR ADJUSTMENTS TO THE REST OF THE GRIDS TO FALL IN-LINE WITH CURRENT OBSERVATIONS. OTHERWISE...CURRENT FORECAST LOOKS GOOD. UPDATE ISSUED AT 1014 AM CST TUE DEC 24 2013 CONCERNS THIS MORNING INCLUDE SNOW/WIND AND ASSOCIATED ADVISORY HEADLINES. WILL FOLLOW CURRENT OBSERVATIONS AND LATEST RAP/HRRR OUTPUT FOR UPDATE DETAILS. WSR-88D SHOWING A LINE OF LIGHT TO MODERATE SNOW FROM ROSEAU/ HALLOCK THROUGH GRAND FORKS/THIEF RIVER FALLS AND INTO SOUTHEAST ND. STRONGEST WIND IS CONFINED MAINLY TO THE NORTHERN VALLEY INTO NORTHWEST MN WHERE RAP IS SHOWING 925 HPA WINDS AROUND 50 KTS. VERY STRONG INVERSION IS KEEPING MUCH OF THIS FROM MIXING TO THE SURFACE...BUT STILL SEEING SOME OBSERVATIONS SUSTAINED AROUND 20 MPH WITH GUSTS TO 25 MPH. THESE WINDS...COMBINED WITH SNOW IS RESULTING IN SOME REDUCTION IN VISIBILITY BETWEEN 1/4 AND 1/2 MILE. WITH THIS IN MIND AND GIVEN THE BUSY TRAVEL DAY BEFORE CHRISTMAS... CURRENT ADVISORY LOOKS GOOD. TOTAL SNOW ACCUMULATION FROM 1 TO 4 INCHES IS STILL REASONABLE WITH THE HIGHER AMOUNTS ALONG THE ND/SD BORDER INTO WEST CENTRAL MN COINCIDENT WITH 850 HPA LOW TRACK. DID ADD RANSOM/SARGENT COUNTIES TO THE ADVISORY UNTIL 01 UTC AS THERE IS AN AREA OF LIGHT TO MODERATE SNOW MAKING ITS WAY THROUGH LAMOURE/ DICKEY COUNTIES. WINDS NOT AS STRONG IN THIS AREA...BUT A QUICK 2 TO 4 INCHES OF FRESH SNOW ARE POSSIBLE. A WELL-DEFINED BACK EDGE OF THE SNOW HAS DEVELOPED FROM HALLOCK TO COOPERSTOWN TO JAMESTOWN...SO MAY BE ABLE TO CANCEL PORTIONS OF THE ADVISORY AT THE 1 PM UPDATE. FOR NOW...UPDATED POPS TO REMOVE ALL SNOW MENTION ACROSS THE DEVILS LAKE BASIN. ALL OTHER GRIDS GOOD WITH ONLY SMALL ADJUSTMENTS TO ACCOUNT FOR LATEST OBSERVATIONS. UPDATE ISSUED AT 651 AM CST TUE DEC 24 2013 CURRENT RADAR IMAGERY INDICATES AN AREA OF HEAVIER PRECIP ACROSS NORTHWEST SOUTH DAKOTA (LIKELY ASSOCIATED WITH STRONGER FORCING FROM UPPER WAVE)...AND A BAND OF PRECIP EXTENDING TO THE NORTH (LIKELY ASSOCIATED WITH 850MB WARM AIR ADVECTION). THE WARM AIR ADVECTION SNOWFALL SHOULD LEAD TO MOSTLY 1-2 INCHES...POSSIBLY UP TO 3. THE SOUTHERN AND HEAVIER AREA OF PRECIP WILL LIKELY LEAD TO 2-4 INCHES...POSSIBLY UP TO 5. THE MAIN QUESTION IS WHERE WILL THIS STRONGER AREA OF PRECIP TRACK. THE RAP INITIALIZED THIS AREA TOO FAR NORTH...AND WILL THROW OUT THIS SOLUTION. THE REMAINDER OF THE GUIDANCE HAS COME INTO SOME SORT OF AGREEMENT...INDICATING ACROSS THE SOUTHERN VALLEY AND INTO THE WADENA AREA. SLIGHTLY ADJUSTED THE SNOWFALL FORECAST TO ACCOUNT FOR THE ABOVE THINKING...MOSTLY LIMITING THE 3+ TOTALS ALONG AND SOUTH OF A LIDGERWOOD TO PARK RAPIDS LINE. THE ONLY CHANGE MADE TO THE WINTER WEATHER ADVISORY WAS TO END THE NORTHERN VALLEY AT 19Z AS IT APPEARS SNOW WILL BE OVER BY THIS TIME. THE ADVISORY LOOKS GOOD FOR AREAS ACROSS THE SOUTH EXPECTED TO RECEIVE 3+ INCHES OF SNOW. TO THE NORTH...1-3 INCHES OF SNOW NOT REALLY ADVISORY CRITERIA...AND WINDS ARE NOT QUITE STRONG ENOUGH TO CAUSE BLOWING SNOW. HOWEVER...GIVEN THE 20-30 MPH WINDS COMBINED WITH HIGHER SNOWFALL RATES...WILL LET IT RIDE (THIS WILL CAUSE SOME TRAVEL HAZARDS). && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 345 AM CST TUE DEC 24 2013 THE MAIN CONCERN WILL BE WIND SPEEDS AND SNOW AMOUNTS TODAY. 00Z MODELS ARE IN POOR AGREEMENT...MAKING CONFIDENCE WITH DETAILS QUITE LOW. THE ECMWF IS THE FURTHEST SOUTH WITH THE HEAVIEST BAND OF SNOWFALL (JUST SOUTH OF THE FA)...WHILE THE GFS/NAM/GEM/RAP/HRRR BRING THE HEAVIER BAND THROUGH THE SOUTHERN FA (WITH LIGHTER AMOUNTS TO THE NORTH). THE HIGH-RES GUIDANCE IS INDICATING QPF AROUND 0.40 INCHES WITHIN THE HEAVIER BAND (AND AROUND 0.10 INCHES ELSEWHERE)...WHICH WOULD EQUATE TO 4-6 INCHES. THE 06Z NAM HAS TRENDED FURTHER SOUTH...AND CURRENT RADAR IMAGERY SEEMS TO SUPPORT THE SOUTHERN SOLUTION. GIVEN THE LOW CONFIDENCE...WILL MONITOR OBSERVATIONAL TRENDS AND INCOMING MODEL GUIDANCE OVER THE NEXT FEW HOURS BEFORE MAKING ANY RADICAL CHANGES TO THE FORECAST...AND STICK TO THE ONGOING FORECAST UNTIL THEN. THE ONLY CHANGE WAS TO DELAY THE ONSET OF SNOWFALL THIS MORNING. LATEST GUIDANCE IS INDICATING COLDER TEMPERATURES FOR TODAY...AND SHALLOWER MIXING POTENTIAL. THIS MEANS WINDS MAY NOT BE QUITE AS STRONG...BUT STILL LIKELY 20-30MPH THIS MORNING (WHICH COMBINED WITH FALLING SNOW COULD STILL LEAD TO POOR VISIBILITY). TONIGHT-WEDNESDAY...EXPECT NORTHWEST FLOW ALOFT...ALONG WITH HARD TO TIME UPPER WAVES. MOST GUIDANCE INDICATES A WEAK WAVE TONIGHT INTO WEDNESDAY MORNING...AND INCREASED POPS INTO THE 30%-40% RANGE FOR THIS FEATURE. WINDS FROM THE NW COULD BE BREEZY AT TIMES BEHIND THE UPPER WAVE...BUT SHOULD NOT BE STRONG ENOUGH FOR DRIFTING AND/OR BLOWING SNOW. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 345 AM CST TUE DEC 24 2013 WEDNESDAY NIGHT-THURSDAY NIGHT...NORTHWEST FLOW ALOFT...ALONG WITH HARD TO TIME SHORTWAVES...WILL CONTINUE. MOST GUIDANCE AGREES ON THE NEXT WAVE LATE WED NIGHT INTO THURSDAY...AND INCREASED POPS INTO THE 30-40% RANGE FOR THIS FEATURE. FRIDAY-MONDAY...FRIDAY LOOKS DOWNRIGHT BALMY COMPARED TO RECENT DAYS AS RISING HEIGHTS AHEAD OF WEEKEND SYSTEM CAUSE BROAD SOUTHWEST FLOW AT THE SURFACE. FRONTAL BOUNDARY/THERMAL RIBBON IS NORTH OF CWFA ON FRIDAY. HOWEVER MID LEVEL MOISTURE AND LIFT GENERATED BY EXIT REGION OF 300MB JET JUSTIFY LOW POPS SAGGING INTO NORTHERN THIRD CWFA AFTER 00Z SATURDAY. BASED ON CURRENT AND PREVIOUS GUIDANCE WILL CONTINUE TO SPREAD POPS SOUTH WITH APPROACHING SHORT WAVE...INCREASING CYCLONIC FLOW AND LIFT IN LEFT REAR QUAD OF JET. 00Z SUITE OF MODELS IN PRETTY GOOD AGREEMENT WITH THE TIMING OF THE NEXT COLD SURGE. THE TEMPERATURE WILL PROBABLY PEAK EARLY SATURDAY THEN BEGIN ANOTHER DOWNWARD SPIRAL BEHIND THE FRONT. SUBSIDENCE BEHIND THE SHORTWAVE...MODEST PRESSURE RISE/FALL COUPLET...DEEP LAYERED COLD ADVECTION AND ORIENTATION OF ISOBARS SUGGEST QUITE BREEZY CONDITIONS POST FRONTAL FOR SATURDAY. HAVE UPPED WIND SPEEDS ON SATURDAY INTO EVENING USING GFS/BCMOS BLEND. BEYOND THAT THE LAST FEW DAYS OF 2013 ARE COLD AND DRY AS ARCTIC RIDGE SLIDES ALONG AND WEST OF CWFA. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 112 PM CST TUE DEC 24 2013 SNOW BAND ALONG A ROX-GFK-JMS LINE PROPAGATING EAST AT 25 KTS AND USED THIS SPEED TO TIME BAND ACROSS FA. WILL BE LATE AFTERNOON WHEN SNOW MOVES EAST OF ROUGHLY A KFAR-KFSE LINE AND EARLY EVENING FOR THE REMAINDER OF THE FA. VSBY GENERALLY FROM 3/4 TO 2 MILES IN SNOW BAND WITH GENERALLY MVFR CIGS. MORE MVFR CIGS DROPPING IN BEHIND SNOW BAND SO WILL LIKELY BE THIS EVENING BEFORE CIGS LIFT INTO VFR CONDITIONS. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...WINTER WEATHER ADVISORY UNTIL 7 PM CST THIS EVENING FOR NDZ052- 053. MN...WINTER WEATHER ADVISORY UNTIL 7 PM CST THIS EVENING FOR MNZ003- 006-009-016-017-022>024-027>032-040. && $$ UPDATE...ROGERS SHORT TERM...TG LONG TERM...EWENS/TG AVIATION...VOELKER
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
1014 AM CST TUE DEC 24 2013 .UPDATE... ISSUED AT 1014 AM CST TUE DEC 24 2013 CONCERNS THIS MORNING INCLUDE SNOW/WIND AND ASSOCIATED ADVISORY HEADLINES. WILL FOLLOW CURRENT OBSERVATIONS AND LATEST RAP/HRRR OUTPUT FOR UPDATE DETAILS. WSR-88D SHOWING A LINE OF LIGHT TO MODERATE SNOW FROM ROSEAU/ HALLOCK THROUGH GRAND FORKS/THIEF RIVER FALLS AND INTO SOUTHEAST ND. STRONGEST WIND IS CONFINED MAINLY TO THE NORTHERN VALLEY INTO NORTHWEST MN WHERE RAP IS SHOWING 925 HPA WINDS AROUND 50 KTS. VERY STRONG INVERSION IS KEEPING MUCH OF THIS FROM MIXING TO THE SURFACE...BUT STILL SEEING SOME OBSERVATIONS SUSTAINED AROUND 20 MPH WITH GUSTS TO 25 MPH. THESE WINDS...COMBINED WITH SNOW IS RESULTING IN SOME REDUCTION IN VISIBILITY BETWEEN 1/4 AND 1/2 MILE. WITH THIS IN MIND AND GIVEN THE BUSY TRAVEL DAY BEFORE CHRISTMAS... CURRENT ADVISORY LOOKS GOOD. TOTAL SNOW ACCUMULATION FROM 1 TO 4 INCHES IS STILL REASONABLE WITH THE HIGHER AMOUNTS ALONG THE ND/SD BORDER INTO WEST CENTRAL MN COINCIDENT WITH 850 HPA LOW TRACK. DID ADD RANSOM/SARGENT COUNTIES TO THE ADVISORY UNTIL 01 UTC AS THERE IS AN AREA OF LIGHT TO MODERATE SNOW MAKING ITS WAY THROUGH LAMOURE/ DICKEY COUNTIES. WINDS NOT AS STRONG IN THIS AREA...BUT A QUICK 2 TO 4 INCHES OF FRESH SNOW ARE POSSIBLE. A WELL-DEFINED BACK EDGE OF THE SNOW HAS DEVELOPED FROM HALLOCK TO COOPERSTOWN TO JAMESTOWN...SO MAY BE ABLE TO CANCEL PORTIONS OF THE ADVISORY AT THE 1 PM UPDATE. FOR NOW...UPDATED POPS TO REMOVE ALL SNOW MENTION ACROSS THE DEVILS LAKE BASIN. ALL OTHER GRIDS GOOD WITH ONLY SMALL ADJUSTMENTS TO ACCOUNT FOR LATEST OBSERVATIONS. UPDATE ISSUED AT 651 AM CST TUE DEC 24 2013 CURRENT RADAR IMAGERY INDICATES AN AREA OF HEAVIER PRECIP ACROSS NORTHWEST SOUTH DAKOTA (LIKELY ASSOCIATED WITH STRONGER FORCING FROM UPPER WAVE)...AND A BAND OF PRECIP EXTENDING TO THE NORTH (LIKELY ASSOCIATED WITH 850MB WARM AIR ADVECTION). THE WARM AIR ADVECTION SNOWFALL SHOULD LEAD TO MOSTLY 1-2 INCHES...POSSIBLY UP TO 3. THE SOUTHERN AND HEAVIER AREA OF PRECIP WILL LIKELY LEAD TO 2-4 INCHES...POSSIBLY UP TO 5. THE MAIN QUESTION IS WHERE WILL THIS STRONGER AREA OF PRECIP TRACK. THE RAP INITIALIZED THIS AREA TOO FAR NORTH...AND WILL THROW OUT THIS SOLUTION. THE REMAINDER OF THE GUIDANCE HAS COME INTO SOME SORT OF AGREEMENT...INDICATING ACROSS THE SOUTHERN VALLEY AND INTO THE WADENA AREA. SLIGHTLY ADJUSTED THE SNOWFALL FORECAST TO ACCOUNT FOR THE ABOVE THINKING...MOSTLY LIMITING THE 3+ TOTALS ALONG AND SOUTH OF A LIDGERWOOD TO PARK RAPIDS LINE. THE ONLY CHANGE MADE TO THE WINTER WEATHER ADVISORY WAS TO END THE NORTHERN VALLEY AT 19Z AS IT APPEARS SNOW WILL BE OVER BY THIS TIME. THE ADVISORY LOOKS GOOD FOR AREAS ACROSS THE SOUTH EXPECTED TO RECEIVE 3+ INCHES OF SNOW. TO THE NORTH...1-3 INCHES OF SNOW NOT REALLY ADVISORY CRITERIA...AND WINDS ARE NOT QUITE STRONG ENOUGH TO CAUSE BLOWING SNOW. HOWEVER...GIVEN THE 20-30 MPH WINDS COMBINED WITH HIGHER SNOWFALL RATES...WILL LET IT RIDE (THIS WILL CAUSE SOME TRAVEL HAZARDS). && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 345 AM CST TUE DEC 24 2013 THE MAIN CONCERN WILL BE WIND SPEEDS AND SNOW AMOUNTS TODAY. 00Z MODELS ARE IN POOR AGREEMENT...MAKING CONFIDENCE WITH DETAILS QUITE LOW. THE ECMWF IS THE FURTHEST SOUTH WITH THE HEAVIEST BAND OF SNOWFALL (JUST SOUTH OF THE FA)...WHILE THE GFS/NAM/GEM/RAP/HRRR BRING THE HEAVIER BAND THROUGH THE SOUTHERN FA (WITH LIGHTER AMOUNTS TO THE NORTH). THE HIGH-RES GUIDANCE IS INDICATING QPF AROUND 0.40 INCHES WITHIN THE HEAVIER BAND (AND AROUND 0.10 INCHES ELSEWHERE)...WHICH WOULD EQUATE TO 4-6 INCHES. THE 06Z NAM HAS TRENDED FURTHER SOUTH...AND CURRENT RADAR IMAGERY SEEMS TO SUPPORT THE SOUTHERN SOLUTION. GIVEN THE LOW CONFIDENCE...WILL MONITOR OBSERVATIONAL TRENDS AND INCOMING MODEL GUIDANCE OVER THE NEXT FEW HOURS BEFORE MAKING ANY RADICAL CHANGES TO THE FORECAST...AND STICK TO THE ONGOING FORECAST UNTIL THEN. THE ONLY CHANGE WAS TO DELAY THE ONSET OF SNOWFALL THIS MORNING. LATEST GUIDANCE IS INDICATING COLDER TEMPERATURES FOR TODAY...AND SHALLOWER MIXING POTENTIAL. THIS MEANS WINDS MAY NOT BE QUITE AS STRONG...BUT STILL LIKELY 20-30MPH THIS MORNING (WHICH COMBINED WITH FALLING SNOW COULD STILL LEAD TO POOR VISIBILITY). TONIGHT-WEDNESDAY...EXPECT NORTHWEST FLOW ALOFT...ALONG WITH HARD TO TIME UPPER WAVES. MOST GUIDANCE INDICATES A WEAK WAVE TONIGHT INTO WEDNESDAY MORNING...AND INCREASED POPS INTO THE 30%-40% RANGE FOR THIS FEATURE. WINDS FROM THE NW COULD BE BREEZY AT TIMES BEHIND THE UPPER WAVE...BUT SHOULD NOT BE STRONG ENOUGH FOR DRIFTING AND/OR BLOWING SNOW. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 345 AM CST TUE DEC 24 2013 WEDNESDAY NIGHT-THURSDAY NIGHT...NORTHWEST FLOW ALOFT...ALONG WITH HARD TO TIME SHORTWAVES...WILL CONTINUE. MOST GUIDANCE AGREES ON THE NEXT WAVE LATE WED NIGHT INTO THURSDAY...AND INCREASED POPS INTO THE 30-40% RANGE FOR THIS FEATURE. FRIDAY-MONDAY...FRIDAY LOOKS DOWNRIGHT BALMY COMPARED TO RECENT DAYS AS RISING HEIGHTS AHEAD OF WEEKEND SYSTEM CAUSE BROAD SOUTHWEST FLOW AT THE SURFACE. FRONTAL BOUNDARY/THERMAL RIBBON IS NORTH OF CWFA ON FRIDAY. HOWEVER MID LEVEL MOISTURE AND LIFT GENERATED BY EXIT REGION OF 300MB JET JUSTIFY LOW POPS SAGGING INTO NORTHERN THIRD CWFA AFTER 00Z SATURDAY. BASED ON CURRENT AND PREVIOUS GUIDANCE WILL CONTINUE TO SPREAD POPS SOUTH WITH APPROACHING SHORT WAVE...INCREASING CYCLONIC FLOW AND LIFT IN LEFT REAR QUAD OF JET. 00Z SUITE OF MODELS IN PRETTY GOOD AGREEMENT WITH THE TIMING OF THE NEXT COLD SURGE. THE TEMPERATURE WILL PROBABLY PEAK EARLY SATURDAY THEN BEGIN ANOTHER DOWNWARD SPIRAL BEHIND THE FRONT. SUBSIDENCE BEHIND THE SHORTWAVE...MODEST PRESSURE RISE/FALL COUPLET...DEEP LAYERED COLD ADVECTION AND ORIENTATION OF ISOBARS SUGGEST QUITE BREEZY CONDITIONS POST FRONTAL FOR SATURDAY. HAVE UPPED WIND SPEEDS ON SATURDAY INTO EVENING USING GFS/BCMOS BLEND. BEYOND THAT THE LAST FEW DAYS OF 2013 ARE COLD AND DRY AS ARCTIC RIDGE SLIDES ALONG AND WEST OF CWFA. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 651 AM CST TUE DEC 24 2013 THE MAIN CONCERN WILL BE SNOWFALL MOVING THROUGH THE REGION TODAY. THIS REGION OF SNOWFALL WILL BE ASSOCIATED WITH MOSTLY MVFR CIGS/VSBY...AND POSSIBLY PERIODS OF IFR CONDITIONS. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...WINTER WEATHER ADVISORY UNTIL 7 PM CST THIS EVENING FOR NDZ039- 049-052-053. WINTER WEATHER ADVISORY UNTIL 1 PM CST THIS AFTERNOON FOR NDZ008- 016-027-029-030. MN...WINTER WEATHER ADVISORY UNTIL 7 PM CST THIS EVENING FOR MNZ002- 003-005-006-008-009-013>017-022>024-027>032-040. WINTER WEATHER ADVISORY UNTIL 1 PM CST THIS AFTERNOON FOR MNZ001- 004-007. && $$ UPDATE...ROGERS SHORT TERM...TG LONG TERM...EWENS/TG AVIATION...TG
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
603 PM EST TUE DEC 24 2013 .SYNOPSIS... HIGH PRESSURE FROM THE CENTRAL LAKES TO THE LOWER OHIO VALLEY WILL MOVE TO THE MIDDLE ATLANTIC STATES ON CHRISTMAS DAY. A COLD FRONT WILL MOVE EAST ACROSS THE AREA THURSDAY. HIGH PRESSURE WILL BUILD OVER THE REGION THURSDAY NIGHT. THE HIGH PRESSURE AREA WILL DRIFT SOUTH TO THE TENNESSEE VALLEY BY SATURDAY AND ALLOW FOR MODERATING TEMPERATURES. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... LAKE EFFECT SNOWS ARE WINDING DOWN THIS AFTERNOON AS THE UPPER TROUGH MOVES EAST THE AREA AND THE INVERSION LOWERS ACROSS THE REGION. THE FLOW HAS VEERED TO NORTHWEST DECREASING THE FETCH ACROSS LAKE ERIE. VISIBLE IMAGERY SHOWS CUMULUS CLOUDS GRADUALLY CLEARING OVER THE WESTERN SECTION OF THE LAKE. LAKE EFFECT BANDS SHOULD CONTINUE TO DIMINISH. ONE TO TWO MORE INCHES OF SNOW ARE POSSIBLE THIS EVENING OVER FAR NE OHIO AND NW PA SO WILL CONTINUE THE LAKE EFFECT HEADLINES WITH NO CHANGES. WILL KEEP LIKELY POPS IN NW PA FOR THIS EVENING WITH DRY CONDITIONS OVER THE WESTERN 2/3 OF THE FORECAST AREA. WITH FRESH SNOW COVER EAST OF CLE AND SOME CLEARING EXPECTED ALONG WITH LIGHT WINDS...SOME RADIATIONAL COOLING IS EXPECTED ESPECIALLY IN GEAUGA COUNTY. THE HRRR MODEL SURFACE TEMPERATURES DROP INTO THE SINGLE DIGITS IN THIS AREA AND THIS SEEMS VERY REASONABLE. ELSEWHERE SLIGHTLY WARMER CONDITIONS ARE EXPECTED GIVEN SLIGHTLY MORE WIND AND EITHER SLOWER CLEARING THIS EVENING OR AN INCREASE IN CLOUDS AFTER MIDNIGHT. STILL READING WILL BE RATHER COLD AND BE AROUND 10. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY NIGHT/... ANOTHER SHORT WAVE WILL MOVE EAST ACROSS THE GREAT LAKES CHRISTMAS DAY AND PRODUCE MODEST ISENTROPIC LIFT ACROSS THE AREA. THE AIRMASS IS QUITE DRY SO LITTLE SNOWFALL IS EXPECTED AND WILL BE MAINLY NEAR LAKE ERIE WITH LITTLE MORE THAN A DUSTING. TEMPERATURES WILL MODERATE TO THE MID TO UPPER 20S. ANOTHER IMPULSE WILL DEEPEN THE TROUGH WEDNESDAY EVENING AND EARLY THURSDAY WITH A COLD FRONTAL PASSAGE TOWARD MORNING. THE LOW LEVEL FLOW VEERS TO A MORE WESTERLY DIRECTION WITH 850 MB TEMPERATURES COOLING TO NEAR -12C SO SOME LAKE EFFECT/ENHANCED SNOW IS EXPECTED IN THE SNOWBELT THURSDAY. THE FLOW WILL BACK TO A SOUTHWESTERLY DIRECTION THURSDAY NIGHT ALONG WITH WARMING CONDITIONS SO ANY LAKE EFFECT SNOWBANDS WILL SHIFT OFFSHORE AND DIMINISH. FAIR MODERATING CONDITIONS ARE EXPECTED FRIDAY AS 850 MB TEMPERATURES WARM TO NEAR 0C AS A SOUTHWESTERLY FLOW DEVELOPS. && .LONG TERM /SATURDAY THROUGH TUESDAY/... DRY WEATHER IS EXPECTED ON SATURDAY AS A FRONT APPROACHES FOR SUNDAY. THE AMOUNT OF MOISTURE ASSOCIATED WITH THE FRONT IS NOT THAT IMPRESSIVE SO WILL CONTINUE CHANCE POPS ON SUNDAY INTO SUNDAY NIGHT. PRECIPITATION TYPE IS IN QUESTION. THE ECMWF IS A LITTLE WARMER...SO WILL MENTION A MIX FOR SUNDAY. FOR SUNDAY NIGHT IT WILL BE COLD ENOUGH JUST FOR SNOW SHOWERS. SNOW SHOWERS WILL LINGER INTO MONDAY NIGHT...LOW CHANCE WITH MOISTURE LIMITED EVEN THOUGH THE LAKE AND 850 MB TEMPERATURE DIFFERENCE WILL BE NEAR 20C. ANOTHER FRONTAL SYSTEM WILL BE MOVING IN ON TUESDAY. SOME TIMING QUESTIONS WITH THAT...SO WILL LEAVE THE POPS LOW FOR THE TIME BEING. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... HIGH PRESSURE MOVING OVER THE AREA THRU MIDNIGHT WILL HELP TO END THE LAKE EFFECT SHSN AROUND ERI WHILE THE MVFR STRATO CU OVER ALL BUT THE WESTERN AREA WILL RECEDE TO THE EAST. HIGH AND MID LEVEL CLOUDS WILL SPREAD BACK IN FROM THE WEST LATER TONIGHT THRU MIDDAY WED. SOME LIGHT SHSN MAY BE SPREADING ACROSS THE AREA AROUND AND NEAR LERI BY LATE IN THE DAY WED BUT SINCE THE OVERALL POP FOR ANYTHING MEASURABLE IS ONLY 30% WILL JUST CARRY 6SM SHSN OR VCSH IN TAFS LATE WED AFTERNOON. .OUTLOOK...NON VFR POSSIBLE WEDNESDAY NIGHT AND THURSDAY IN SNOW SHOWERS. && .MARINE... SMALL CRAFT ADVISORIES WILL BE NEEDED FREQUENTLY INTO EARLY NEXT WEEK...ESPECIALLY ON THE EAST END OF THE LAKE. A RIDGE IS BUILDING IN TONIGHT...SO THE WINDS AND WAVES WILL CONTINUE TO DECREASE. WILL LET THE SMALL CRAFT ADVISORY EXPIRE AT 9 PM ON THE EAST END...IT WILL BE CLOSE. THE NEXT THREAT FOR A SMALL CRAFT ADVISORY WILL BE LATE WEDNESDAY NIGHT INTO THURSDAY AFTER ANOTHER FRONT MOVES THROUGH. ANOTHER FRONT MOVES THROUGH LATE FRIDAY AND SATURDAY NIGHT INTO SUNDAY. THIS FRONT WILL PROMPT THE NEED FOR A SMALL CRAFT ADVISORY THAT MAY LAST INTO EARLY NEXT WEEK AS THE WEST TO NORTHWEST FLOW WILL BE PERSISTENT. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...LAKE EFFECT SNOW ADVISORY UNTIL 10 PM EST THIS EVENING FOR OHZ014-089. PA...LAKE EFFECT SNOW ADVISORY UNTIL 10 PM EST THIS EVENING FOR PAZ003. LAKE EFFECT SNOW WARNING UNTIL 10 PM EST THIS EVENING FOR PAZ001-002. MARINE...SMALL CRAFT ADVISORY UNTIL 9 PM EST THIS EVENING FOR LEZ146>149. && $$ SYNOPSIS...LAPLANTE NEAR TERM...LAPLANTE SHORT TERM...LAPLANTE LONG TERM...KIELTYKA AVIATION...ADAMS MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
357 PM EST TUE DEC 24 2013 .SYNOPSIS... HIGH PRESSURE FROM THE CENTRAL LAKES TO THE LOWER OHIO VALLEY WILL MOVE TO THE MIDDLE ATLANTIC STATES ON CHRISTMAS DAY. A COLD FRONT WILL MOVE EAST ACROSS THE AREA THURSDAY. HIGH PRESSURE WILL BUILD OVER THE REGION THURSDAY NIGHT. THE HIGH PRESSURE AREA WILL DRIFT SOUTH TO THE TENNESSEE VALLEY BY SATURDAY AND ALLOW FOR MODERATING TEMPERATURES. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... LAKE EFFECT SNOWS ARE WINDING DOWN THIS AFTERNOON AS THE UPPER TROUGH MOVES EAST THE AREA AND THE INVERSION LOWERS ACROSS THE REGION. THE FLOW HAS VEERED TO NORTHWEST DECREASING THE FETCH ACROSS LAKE ERIE. VISIBLE IMAGERY SHOWS CUMULUS CLOUDS GRADUALLY CLEARING OVER THE WESTERN SECTION OF THE LAKE. LAKE EFFECT BANDS SHOULD CONTINUE TO DIMINISH. ONE TO TWO MORE INCHES OF SNOW ARE POSSIBLE THIS EVENING OVER FAR NE OHIO AND NW PA SO WILL CONTINUE THE LAKE EFFECT HEADLINES WITH NO CHANGES. WILL KEEP LIKELY POPS IN NW PA FOR THIS EVENING WITH DRY CONDITIONS OVER THE WESTERN 2/3 OF THE FORECAST AREA. WITH FRESH SNOW COVER EAST OF CLE AND SOME CLEARING EXPECTED ALONG WITH LIGHT WINDS...SOME RADIATIONAL COOLING IS EXPECTED ESPECIALLY IN GEAUGA COUNTY. THE HRRR MODEL SURFACE TEMPERATURES DROP INTO THE SINGLE DIGITS IN THIS AREA AND THIS SEEMS VERY REASONABLE. ELSEWHERE SLIGHTLY WARMER CONDITIONS ARE EXPECTED GIVEN SLIGHTLY MORE WIND AND EITHER SLOWER CLEARING THIS EVENING OR AN INCREASE IN CLOUDS AFTER MIDNIGHT. STILL READING WILL BE RATHER COLD AND BE AROUND 10. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY NIGHT/... ANOTHER SHORT WAVE WILL MOVE EAST ACROSS THE GREAT LAKES CHRISTMAS DAY AND PRODUCE MODEST ISENTROPIC LIFT ACROSS THE AREA. THE AIRMASS IS QUITE DRY SO LITTLE SNOWFALL IS EXPECTED AND WILL BE MAINLY NEAR LAKE ERIE WITH LITTLE MORE THAN A DUSTING. TEMPERATURES WILL MODERATE TO THE MID TO UPPER 20S. ANOTHER IMPLUSE WILL DEEPEN THE TROUGH WEDNESDAY EVENING AND EARLY THURSDAY WITH A COLD FRONTAL PASSAGE TOWARD MORNING. THE LOW LEVEL FLOW VEERS TO A MORE WESTERLY DIRECTION WITH 850 MB TEMPERATURES COOLING TO NEAR -12C SO SOME LAKE EFFECT/ENHANCED SNOW IS EXPECTED IN THE SNOWBELT THURSDAY. THE FLOW WILL BACK TO A SOUTHWESTERLY DIRECTION THURSDAY NIGHT ALONG WITH WARMING CONDITIONS SO ANY LAKE EFFECT SNOWBANDS WILL SHIFT OFFSHORE AND DIMINISH. FAIR MODERATING CONDITIONS ARE EXPECTED FRIDAY AS 850 MB TEMPERATURES WARM TO NEAR 0C AS A SOUTHWESTERLY FLOW DEVELOPS. && .LONG TERM /SATURDAY THROUGH TUESDAY/... DRY WEATHER IS EXPECTED ON SATURDAY AS A FRONT APPROACHES FOR SUNDAY. THE AMOUNT OF MOISTURE ASSOCIATED WITH THE FRONT IS NOT THAT IMPRESSIVE SO WILL CONTINUE CHANCE POPS ON SUNDAY INTO SUNDAY NIGHT. PRECIPITATION TYPE IS IN QUESTION. THE ECMWF IS A LITTLE WARMER...SO WILL MENTION A MIX FOR SUNDAY. FOR SUNDAY NIGHT IT WILL BE COLD ENOUGH JUST FOR SNOW SHOWERS. SNOW SHOWERS WILL LINGER INTO MONDAY NIGHT...LOW CHANCE WITH MOISTURE LIMITED EVEN THOUGH THE LAKE AND 850 MB TEMPERATURE DIFFERENCE WILL BE NEAR 20C. ANOTHER FRONTAL SYSTEM WILL BE MOVING IN ON TUESDAY. SOME TIMING QUESTIONS WITH THAT...SO WILL LEAVE THE POPS LOW FOR THE TIME BEING. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... THE FIRST BATCH OF SYNOPTIC SNOW IS MOVING EAST BUT THE TROUGH OVER LAKE ERIE WILL DROP SOUTHEAST ACROSS NE OH/NW PA AND EXPECT ADDITIONAL LAKE ENHANCED SNOW SHOWERS TO CONTINUE THROUGH LATE MORNING OR EARLY AFTERNOON WITH MVFR CEILINGS AND OCCASIONAL IFR VISIBILITIES IN THE HEAVIER SNOW SHOWERS. THE SNOW SHOWERS COULD LAST INTO THE EVENING AT KERI IF LAKE HURON SNOW BANDS CAN GET INTO NW PA. THE AIR MASS WILL REALLY DRY OUT TODAY AS ARCTIC AIR OVERSPREADS THE AREA. EXPECT CEILINGS TO IMPROVE TO VFR FROM WEST TO EAST WITH CLEARING TONIGHT AS THE RIDGE AXIS PASSES TO THE EAST. MID AND HIGH CLOUDS WILL SPREAD IN LATER TONIGHT. .OUTLOOK...NON VFR POSSIBLE WEDNESDAY NIGHT AND THURSDAY IN SNOW SHOWERS. && .MARINE... SMALL CRAFT ADVISORIES WILL BE NEEDED FREQUENTLY INTO EARLY NEXT WEEK...ESPECIALLY ON THE EAST END OF THE LAKE. A RIDGE IS BUILDING IN TONIGHT...SO THE WINDS AND WAVES WILL CONTINUE TO DECREASE. WILL LET THE SMALL CRAFT ADVISORY EXPIRE AT 9 PM ON THE EAST END...IT WILL BE CLOSE. THE NEXT THREAT FOR A SMALL CRAFT ADVISORY WILL BE LATE WEDNESDAY NIGHT INTO THURSDAY AFTER ANOTHER FRONT MOVES THROUGH. ANOTHER FRONT MOVES THROUGH LATE FRIDAY AND SATURDAY NIGHT INTO SUNDAY. THIS FRONT WILL PROMPT THE NEED FOR A SMALL CRAFT ADVISORY THAT MAY LAST INTO EARLY NEXT WEEK AS THE WEST TO NORTHWEST FLOW WILL BE PERSISTENT. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...LAKE EFFECT SNOW ADVISORY UNTIL 10 PM EST THIS EVENING FOR OHZ014-089. PA...LAKE EFFECT SNOW ADVISORY UNTIL 10 PM EST THIS EVENING FOR PAZ003. LAKE EFFECT SNOW WARNING UNTIL 10 PM EST THIS EVENING FOR PAZ001-002. MARINE...SMALL CRAFT ADVISORY UNTIL 9 PM EST THIS EVENING FOR LEZ146>149. && $$ SYNOPSIS...LAPLANTE NEAR TERM...LAPLANTE SHORT TERM...LAPLANTE LONG TERM...KIELTYKA AVIATION...KIELTYKA MARINE...KIELTYKA
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1140 AM CST TUE DEC 24 2013 .UPDATE... SEE THE UPDATED AVIATION DISCUSSION BELOW. HAD SEVERAL REPORTS OF FREEZING RAIN/SLEET ACROSS THE WEST THIS MORNING WITH SNOW MOVING EAST. THE BAND OF ECHOES IS NOT THAT WIDE THIS MORNING AS IT WAS MOVING EAST. THE HRRR MODEL SHOWED THIS BAND WELL. THUS...IT LOOKS LIKE THE PRECIPITATION WILL END EARLY THIS AFTERNOON AND MAY CANCEL ADVISORY EARLY OUT WEST. THE EAST MAY YET HAVE BETTER DEVELOPMENT THIS AFTERNOON WITH THE SNOWFALL. THE LATEST NAM AND GFS SHOW MORE DEVELOPMENT AND QPF THROUGH 00Z THIS EVENING ACROSS THE EASTERN CWA. && .PREVIOUS DISCUSSION... .SHORT TERM...TODAY AND TONIGHT PRIMARY FORECAST CHALLENGES ARE P-TYPE AND SNOW AMOUNTS THROUGH THIS EVENING. FORECASTER CONFIDENCE: LOW TO MEDIUM VERY CHALLENGING FORECAST SHAPING UP OVER THE AREA...WITH PLENTY OF ISSUES. 00Z UPPER AIR ANALYSIS AND WATER VAPOR ANALYSIS INDICATED A VERY POTENT UPPER SHORTWAVE/PV ANOMALY SLIDING E/SEWD ACROSS THE NRN ROCKIES. VERY IMPRESSIVE H5 HEIGHT FALLS ON THE ORDER OF 150 METERS NOTED OVER THE PAC NW. IN CONJUNCTION...VERY STRONG LOW LEVEL WAA SIGNAL NOTED ON REGIONAL RAOBS...WITH A SIGNIFICANT INCREASE IN PWATS. AT THE SFC...MSAS ANALYSIS AT 10Z SHOWED A DEEPENING SFC LOW OVER MT/WY WITH A STRONG SLY SFC FLOW OVER THE CWA. INITIAL CONCERN IS WIND CHILL VALUES. WITH ABOVE MENTIONED WAA PATTERN...TEMPS HAVE BEEN STEADILY RISING OVERNIGHT WITH READINGS IN THE CWA NOW IN THE SINGLE DIGITS ABOVE AND BELOW ZERO. STILL FLIRTING WITH WIND CHILL ADV CRITERIA /ESP IN THE FAR EAST/...BUT BELIEVE WE WILL BE ABLE TO CANCEL AS SCHEDULED AROUND 12Z /6AM CST/. ATTENTION THEN TURNS TO THE P-TYPE AND SNOW AMOUNTS WITH THE NEXT UPPER DISTURBANCE. RADAR ECHOES ARE ALREADY EXPANDING ACROSS PORTIONS OF MT AND WRN SD AS OF 10Z AND THIS LINE OF PCPN IS MOVING EWD. FORECAST SOUNDINGS INDICATE A WELL DEFINED WARM LAYER TO IMPACT AT LEAST THE WRN CWA...SO EXPECTING AN WINTRY MIX OF FREEZING RAIN...SLEET...AND SNOW THROUGH MID-MORNING. ICE ACCUMS STILL EXPECTED TO BE LIGHT...GENERALLY LESS THAN A TENTH OF AN INCH. HIGHEST ICE AMOUNTS ARE CURRENTLY FORECAST ALONG AND WEST OF THE MISSOURI RIVER NEAR KPIR. WILL BE INTERESTING TO SEE HOW LONG ANY ICING CAN PERSIST...AS THE MODELS DO INDICATE QUITE A BIT OF DRY AIR WHICH MAY ACT TO WET BULB THE COLUMN BELOW FREEZING RELATIVELY QUICKLY. FURTHER EAST...EXPECTING SNOW TO BE THE DOMINANT PTYPE AS THE WARM NOSE FOLDS S/SE. BIG QUESTIONS STILL REMAIN ON STRENGTH AND LONGEVITY OF FORCING. 00Z GFS WAS THE MOST BULLISH WITH QPF IN OUR AREA...WITH 00Z NAM/GEM SHOWING BEST FORCING/SATURATION OVER ND. DURING THIS FORECAST CYCLE...USED A MODEL BLEND OF GFS/ECMWF WHICH APPEARED MOST REASONABLE. IT SHOULD BE NOTED THAT A NUMBER OF THE HI-RES MODELS REMAIN VERY PROGRESSIVE WITH THE MOVEMENT OF THIS FRONTAL BAND. THIS WOULD SUGGEST A RATHER SHORT LIVED...BUT INTENSE BURST OF SNOWFALL. ALL IN ALL...HAVE SNOW AMOUNTS IN THE EAST RANGING FROM AROUND 4 INCHES IN OUR MN COUNTIES TO AROUND 2 INCHES WEST OF ABERDEEN. ONCE THE EVOLUTION OF THIS SYSTEM BECOMES CLEARER...THE AXIS OF HEAVIEST QPF MAY NEED TO BE ADJUSTED. WINTER WX ADVISORY WILL RUN TO 00Z WED. TEMPERATURES TODAY WILL BE MUCH MILDER...WITH READINGS GENERALLY IN THE TEENS TO LOW 30S. COULD SEE SOME LINGERING SNOW IN THE FAR EAST THIS EVENING...BEFORE YET ANOTHER SHORTWAVE DROPS SWD LATE TONIGHT. WILL SEE ANOTHER CHANCE FOR LIGHT SNOW WITH THIS LOBE OF ENERGY...AND SOME POTENTIAL FOR WINDS IN THE WAKE OF THE SYSTEM. .LONG TERM...WEDNESDAY THROUGH MONDAY TRACKING S/W ENERGY OVER ALBERTA/SASKATCHEWAN EMBEDDED WITHIN THE LONGWAVE TROF...SAID S/W ENERGY SHOULD BE SWEEPING SEWD THROUGH THE FAR NORTHEASTERN CWA ON WEDNESDAY...POTENTIALLY DRAGGING SOME LIGHT SNOW UP OVER THE PRAIRIE COTEAU. LOW LEVEL CAA ON WEDNESDAY AND SOME SUBSIDENCE PROMOTING STEEP LOW LEVEL LAPSE RATES/BETTER MIXING ENVIRONMENT AND A BETTER POTENTIAL FOR HAZARDOUS BLOWING SNOW CONCERNS COMING LESS THAN 24 HOURS AFTER AN EXPECTED LIGHT SNOW EVENT. MAY NEED TO CONSIDER A WINT WX ADV FOR BLOWING SNOW. OTHERWISE...STILL MONITORING NORTHWEST FLOW THROUGHOUT THE REMAINDER OF THE FORECAST. STILL LOOKS LIKE THE CAA WEDNESDAY/WEDNESDAY NIGHT WILL BE QUICKLY REPLACED BY WARMER PACIFIC-MODIFIED AIRMASS FROM THURSDAY THROUGH SATURDAY MORNING BEFORE THE NEXT NW FLOW SYSTEM PUSHES THE POLAR FRONT BACK SOUTHWARD ACROSS THE REGION DURING THE DAY SATURDAY...WITH ANOTHER MULTIPLE-DAY PERIOD OF ARCTIC COLD AIR AROUND HEADING INTO NEXT WEEK. THE 00Z GFS/ECMWF SOLUTIONS WERE PINGING SATURDAY/SATURDAY NIGHT AS A POTENTIAL PERIOD OF RATHER STRONG NORTHWEST WINDS. HOWEVER...WILL PROLLY NEED TO TAKE A WAIT-AND-SEE APPROACH TO HOW MUCH OF THE REGION WARMS TO ABOVE FREEZING THURSDAY AND FRIDAY FOR THE POTENTIAL TO PLACE A GOOD CRUST ON TOP OF REGION-WIDE SNOW COVER...AND THEREFORE JUST HOW MUCH OF THE REGION COULD SEE SIGNIFICANT BLOWING SNOW PROBLEMS THAT DAY. FOR NOW...JUST ADDED SOME AREAS OF BLOWING SNOW MENTION INTO THE WEATHER GRIDS FOR SATURDAY. && .AVIATION... 18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS PRECIPITATION HAS ENDED AT THE KMBG AND KPIR TAF SITES THIS MORNING AS THE BAND OF PRECIPITATION CONTINUES TO TRACK EAST INTO NORTHEAST SOUTH DAKOTA AND WEST CENTRAL MINNESOTA. MVFR CIGS ARE STILL EXPECTED FOR THE NEXT FEW HOURS AT KPIR AND KMBG HOWEVER. RECENT REPORTS INDICATE PTYPE HAS TURNED ALL TO SNOW...AND EXPECTING PRECIP TO REMAIN SNOW AS THE BAND PUSHES EAST OF THE AREA. MVFR TO IFR CIGS AND VSBYS AT KATY AND KABR WILL GRADUALLY IMPROVE. WINDS AT KABR AND KATY WILL ALSO SWITCH FROM THE SOUTHWEST AROUND TO THE NORTHWEST. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...WINTER WEATHER ADVISORY UNTIL 6 PM CST /5 PM MST/ THIS EVENING FOR BROWN-BUFFALO-CAMPBELL-CLARK-CODINGTON-CORSON-DAY-DEUEL- DEWEY-EDMUNDS-FAULK-GRANT-HAMLIN-HAND-HUGHES-HYDE-JONES- LYMAN-MARSHALL-MCPHERSON-POTTER-ROBERTS-SPINK-STANLEY-SULLY- WALWORTH. MN...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR BIG STONE-TRAVERSE. && $$ UPDATE...MOHR SHORT TERM...FOWLE LONG TERM...DORN AVIATION...SERR WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1055 AM CST TUE DEC 24 2013 .UPDATE... HAD SEVERAL REPORTS OF FREEZING RAIN/SLEET ACROSS THE WEST THIS MORNING WITH SNOW MOVING EAST. THE BAND OF ECHOES IS NOT THAT WIDE THIS MORNING AS IT WAS MOVING EAST. THE HRRR MODEL SHOWED THIS BAND WELL. THUS...IT LOOKS LIKE THE PRECIPITATION WILL END EARLY THIS AFTERNOON AND MAY CANCEL ADVISORY EARLY OUT WEST. THE EAST MAY YET HAVE BETTER DEVELOPMENT THIS AFTERNOON WITH THE SNOWFALL. THE LATEST NAM AND GFS SHOW MORE DEVELOPMENT AND QPF THROUGH 00Z THIS EVENING ACROSS THE EASTERN CWA. && .PREVIOUS DISCUSSION... .SHORT TERM...TODAY AND TONIGHT PRIMARY FORECAST CHALLENGES ARE P-TYPE AND SNOW AMOUNTS THROUGH THIS EVENING. FORECASTER CONFIDENCE: LOW TO MEDIUM VERY CHALLENGING FORECAST SHAPING UP OVER THE AREA...WITH PLENTY OF ISSUES. 00Z UPPER AIR ANALYSIS AND WATER VAPOR ANALYSIS INDICATED A VERY POTENT UPPER SHORTWAVE/PV ANOMALY SLIDING E/SEWD ACROSS THE NRN ROCKIES. VERY IMPRESSIVE H5 HEIGHT FALLS ON THE ORDER OF 150 METERS NOTED OVER THE PAC NW. IN CONJUNCTION...VERY STRONG LOW LEVEL WAA SIGNAL NOTED ON REGIONAL RAOBS...WITH A SIGNIFICANT INCREASE IN PWATS. AT THE SFC...MSAS ANALYSIS AT 10Z SHOWED A DEEPENING SFC LOW OVER MT/WY WITH A STRONG SLY SFC FLOW OVER THE CWA. INITIAL CONCERN IS WIND CHILL VALUES. WITH ABOVE MENTIONED WAA PATTERN...TEMPS HAVE BEEN STEADILY RISING OVERNIGHT WITH READINGS IN THE CWA NOW IN THE SINGLE DIGITS ABOVE AND BELOW ZERO. STILL FLIRTING WITH WIND CHILL ADV CRITERIA /ESP IN THE FAR EAST/...BUT BELIEVE WE WILL BE ABLE TO CANCEL AS SCHEDULED AROUND 12Z /6AM CST/. ATTENTION THEN TURNS TO THE P-TYPE AND SNOW AMOUNTS WITH THE NEXT UPPER DISTURBANCE. RADAR ECHOES ARE ALREADY EXPANDING ACROSS PORTIONS OF MT AND WRN SD AS OF 10Z AND THIS LINE OF PCPN IS MOVING EWD. FORECAST SOUNDINGS INDICATE A WELL DEFINED WARM LAYER TO IMPACT AT LEAST THE WRN CWA...SO EXPECTING AN WINTRY MIX OF FREEZING RAIN...SLEET...AND SNOW THROUGH MID-MORNING. ICE ACCUMS STILL EXPECTED TO BE LIGHT...GENERALLY LESS THAN A TENTH OF AN INCH. HIGHEST ICE AMOUNTS ARE CURRENTLY FORECAST ALONG AND WEST OF THE MISSOURI RIVER NEAR KPIR. WILL BE INTERESTING TO SEE HOW LONG ANY ICING CAN PERSIST...AS THE MODELS DO INDICATE QUITE A BIT OF DRY AIR WHICH MAY ACT TO WET BULB THE COLUMN BELOW FREEZING RELATIVELY QUICKLY. FURTHER EAST...EXPECTING SNOW TO BE THE DOMINANT PTYPE AS THE WARM NOSE FOLDS S/SE. BIG QUESTIONS STILL REMAIN ON STRENGTH AND LONGEVITY OF FORCING. 00Z GFS WAS THE MOST BULLISH WITH QPF IN OUR AREA...WITH 00Z NAM/GEM SHOWING BEST FORCING/SATURATION OVER ND. DURING THIS FORECAST CYCLE...USED A MODEL BLEND OF GFS/ECMWF WHICH APPEARED MOST REASONABLE. IT SHOULD BE NOTED THAT A NUMBER OF THE HI-RES MODELS REMAIN VERY PROGRESSIVE WITH THE MOVEMENT OF THIS FRONTAL BAND. THIS WOULD SUGGEST A RATHER SHORT LIVED...BUT INTENSE BURST OF SNOWFALL. ALL IN ALL...HAVE SNOW AMOUNTS IN THE EAST RANGING FROM AROUND 4 INCHES IN OUR MN COUNTIES TO AROUND 2 INCHES WEST OF ABERDEEN. ONCE THE EVOLUTION OF THIS SYSTEM BECOMES CLEARER...THE AXIS OF HEAVIEST QPF MAY NEED TO BE ADJUSTED. WINTER WX ADVISORY WILL RUN TO 00Z WED. TEMPERATURES TODAY WILL BE MUCH MILDER...WITH READINGS GENERALLY IN THE TEENS TO LOW 30S. COULD SEE SOME LINGERING SNOW IN THE FAR EAST THIS EVENING...BEFORE YET ANOTHER SHORTWAVE DROPS SWD LATE TONIGHT. WILL SEE ANOTHER CHANCE FOR LIGHT SNOW WITH THIS LOBE OF ENERGY...AND SOME POTENTIAL FOR WINDS IN THE WAKE OF THE SYSTEM. .LONG TERM...WEDNESDAY THROUGH MONDAY TRACKING S/W ENERGY OVER ALBERTA/SASKATCHEWAN EMBEDDED WITHIN THE LONGWAVE TROF...SAID S/W ENERGY SHOULD BE SWEEPING SEWD THROUGH THE FAR NORTHEASTERN CWA ON WEDNESDAY...POTENTIALLY DRAGGING SOME LIGHT SNOW UP OVER THE PRAIRIE COTEAU. LOW LEVEL CAA ON WEDNESDAY AND SOME SUBSIDENCE PROMOTING STEEP LOW LEVEL LAPSE RATES/BETTER MIXING ENVIRONMENT AND A BETTER POTENTIAL FOR HAZARDOUS BLOWING SNOW CONCERNS COMING LESS THAN 24 HOURS AFTER AN EXPECTED LIGHT SNOW EVENT. MAY NEED TO CONSIDER A WINT WX ADV FOR BLOWING SNOW. OTHERWISE...STILL MONITORING NORTHWEST FLOW THROUGHOUT THE REMAINDER OF THE FORECAST. STILL LOOKS LIKE THE CAA WEDNESDAY/WEDNESDAY NIGHT WILL BE QUICKLY REPLACED BY WARMER PACIFIC-MODIFIED AIRMASS FROM THURSDAY THROUGH SATURDAY MORNING BEFORE THE NEXT NW FLOW SYSTEM PUSHES THE POLAR FRONT BACK SOUTHWARD ACROSS THE REGION DURING THE DAY SATURDAY...WITH ANOTHER MULTIPLE-DAY PERIOD OF ARCTIC COLD AIR AROUND HEADING INTO NEXT WEEK. THE 00Z GFS/ECMWF SOLUTIONS WERE PINGING SATURDAY/SATURDAY NIGHT AS A POTENTIAL PERIOD OF RATHER STRONG NORTHWEST WINDS. HOWEVER...WILL PROLLY NEED TO TAKE A WAIT-AND-SEE APPROACH TO HOW MUCH OF THE REGION WARMS TO ABOVE FREEZING THURSDAY AND FRIDAY FOR THE POTENTIAL TO PLACE A GOOD CRUST ON TOP OF REGION-WIDE SNOW COVER...AND THEREFORE JUST HOW MUCH OF THE REGION COULD SEE SIGNIFICANT BLOWING SNOW PROBLEMS THAT DAY. FOR NOW...JUST ADDED SOME AREAS OF BLOWING SNOW MENTION INTO THE WEATHER GRIDS FOR SATURDAY. && .AVIATION... 12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS VFR CONDITIONS ARE BEGINNING TO DETERIORATE ACROSS THE REGION. SO FAR...KMBG HAS DROPPED TO AN IFR CIG CONDITION WHILE KABR...KATY AND KPIR HAVE SEEN AN INCREASE IN MID/HIGH CLOUDINESS OVER THE PAST 6 TO 12 HOURS. REGIONAL RADAR DISPLAYS SHOW PRECIPITATION APPROACHING THE KMBG AND KPIR TERMINALS RIGHT NOW...AND LOW LEVEL TEMPERATURE PROGS ARE ALL STILL VERY SUPPORTIVE OF MIXED PRECIP AND FREEZING PRECIP THIS MORNING FOR A FEW HOURS AT BOTH TERMINALS. AS SUCH...FREEZING RAIN AND ICE PELLETS/SLEET HAVE BEEN INCORPORATED INTO THE KPIR AND KMBG TAFS FOR A COUPLE HOURS THIS MORNING. FURTHER EAST...THE KABR AND KATY TERMINALS WILL SEE SUB-VFR CIG/VIS CONDITIONS IN SNOW SETTING UP AT OR AFTER 15Z THIS MORNING...PERSISTING WELL INTO THE AFTERNOON AND PERHAPS EARLY EVENING HOURS. CONDITIONS SHOULD BEGIN IMPROVING AT ALL FOUR TERMINALS FROM NORTHWEST TO SOUTHEAST FROM LATE THIS AFTERNOON THROUGH LATE THIS EVENING. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...WINTER WEATHER ADVISORY UNTIL 6 PM CST /5 PM MST/ THIS EVENING FOR BROWN-BUFFALO-CAMPBELL-CLARK-CODINGTON-CORSON-DAY-DEUEL- DEWEY-EDMUNDS-FAULK-GRANT-HAMLIN-HAND-HUGHES-HYDE-JONES- LYMAN-MARSHALL-MCPHERSON-POTTER-ROBERTS-SPINK-STANLEY-SULLY- WALWORTH. MN...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR BIG STONE-TRAVERSE. && $$ UPDATE...MOHR SHORT TERM...FOWLE LONG TERM...DORN AVIATION...DORN WEATHER.GOV/ABERDEEN