Area Forecast Discussion
Issued by NWS Wakefield, VA

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000 FXUS61 KAKQ 251822 AFDAKQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 122 PM EST SUN JAN 25 2015 .SYNOPSIS... HIGH PRESSURE WILL SLIDE ACROSS THE GULF COAST STATES AND OFF THE SOUTHEAST COAST TODAY. MEANWHILE...LOW PRESSURE WILL DROP SOUTHEAST FROM THE MIDWEST INTO THE LOWER OHIO VALLEY. THAT LOW WILL CROSS THE AREA LATE TONIGHT INTO MONDAY MORNING...THEN RAPIDLY INTENSIFY OFF THE MID ATLANTIC AND NEW ENGLAND COASTS MONDAY AFTERNOON INTO TUESDAY NIGHT. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... LATE MORNING ANALYSIS DEPICTS CLIPPER SYSTEM NOW OVER SOUTHERN IL...WITH HIGH PRESSURE OVER THE GULF OF MEXICO. SKIES AVG MOSTLY SUNNY OVER MOST OF THE CWA...WITH A SMALL AREA OF MOSTLY CLOUDY SKIES (CIGS AROUND 15 K FT) OVER THE FAR WRN/NW ZONES. ADJUSTED CLOUDS AND TEMPS SLIGHTLY...BUT OVERALL NOT MUCH CHANGE TO PREVIOUS THINKING. RAISED HIGHS A DEGREE OR TWO FOR CENTRAL AND SE VA WHERE SKIES WILL AVG MAINLY SUNNY. HIGHS INTO THE MID TO PERHAPS UPPER 50S IN A FEW SPOTS. HIGHS IN THE UPPER 40S TO LOWER 50S ACRS THE NORTH UNDER PARTLY SUNNY SKIES. && .SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/... HAVE RAISED A WINTER STORM WATCH FOR THE MD ERN SHORE MON NIGHT INTO TUE... CONTINUING TO EVALUATE 12Z MODELS COMING IN...HAVE NOTED 12Z GFS HAS A SPURIOUS LOOKING BULLSEYE OF QPF OVER PORTIONS OF THE CWA WEST OF THE BAY MON NIGHT/EARLY TUE. THE 06Z GFS HAD THIS AS WELL (ALTHOUGH A BIT FARTHER TO THE SOUTH). GENLY WE ARE FAVORING A BLEND OF THE 12Z NAM/09Z SREF/00Z ECMWF OVER THE GFS AS THIS AREA OF QPF DOES NOT NOT MAKE SENSE GIVEN THE POSITION OF THE OFFSHORE SYSTEM. WILL BE CONSIDERING A POTENTIAL WINTER STORM WATCH FOR A FEW OTHER ZONES OVER NE PORTIONS OF THE CWA THAT ARE NOT IN THE CURRENT WATCH (MAINLY THE NRN NECK/MIDDLE PENINSULA/VA ERN SHORE) BUT WOULD LIKE TO SEE THE 12Z ECMWF BEFORE DOING SO). PREV DISC... ACTIVE PATTERN IN THE SHORT TERM...GENERAL PATTERN IS AGREED UPON BY THE LATEST 00Z SUITE OF MODELS...BUT WITH DIFFERENCES IN PLACEMENT OF THE EVENTUAL TRACK OF THE SFC LO (AND ITS STRENGTH) OFF THE MID ATLC AND NEW ENGLAND CSTS LATE MON THRU TUE...LEADING TO SUBSTANTIAL DIFFERENCES IN SENSIBLE WX...MAINLY POTENTIAL SNOW AMOUNTS FOR THE REGION MON EVENG THRU TUE. 00Z ECMWF/GFS MODELS ARE THE MOST AGGRESSIVE AT DEVELOPING A CUTOFF UPPER LOW IN THE VICINITY OF THE DELMARVA MON NIGHT/TUE...WHILE THE NAM IS WEAKER WITH THIS FEATURE. MAIN THEME FOR TNGT INTO MON AFTN IS A SLOWER ARRIVAL OF PCPN AND COLD AIR...THUS MOST OF THE CWA WILL SEE RAIN THROUGH MOST OF THE DAY MON...RATHER THAN SNOW. HAVE ADJUSTED POPS AND WX GRIDS SLGTLY TO REFLECT THIS CHANGE. WILL CARRY HIGH CHC TO LIKELY POPS (HIGHER NRN AND WRN COUNTIES) AFTR MIDNGT TNGT THROUGH MON MORNG. LOWS TNGT RANGING FM THE MID 30S N...TO THE UPR 30S/NEAR 40 S. CONFIDENCE IN THE MON NGT TO TUE PERIOD REMAINS BELOW AVG GIVEN THE MAJOR MODEL DISCREPANCIES. AT THIS TIME...GOING WITH A BLEND OF THE 00Z ECMWF/GFS THRU TUE...WHICH IS CLOSE TO WPC FCSTS. THESE MODEL SOLUTIONS WOULD RESULT IN MOST OF THE CWA SEEING A GOOD CHC FOR AT LEAST LIGHT SNOW ACCUMULATIONS MON NGT INTO TUE MORNG...WITH THE MOST UNCERTAINTY OVER THE ERN 1/3 OF THE CWA WHERE SIGNIFICANT SNOW ACCUMULATIONS WILL BE POSSIBLE...ESPLY OVR THE LWR MD AND VA ERN SHR. WILL CARRY LIKELY POPS NE/E TO HI CHC ELSEWHERE MON AFTN THROUGH MON NGT INTO TUE MORNG. HIGHS ON MON WERE RAISED A BIT INTO THE UPR 40S TO LWR 50S ACRS THE SE...WITH UPR 30S TO MID 40S OVR THE NRN HALF OF THE REGION. TEMPS WILL LIKELY FALL LATER IN THE AFTN INTO THE EVENG...WITH PCPN TYPE BECOMING MAINLY SNOW FM NW TO SE LATE MON AFTN THRU MON EVENG. LOWS MON NGT RANGING FM THE MID 20S EXTRM NW TO THE MID 30S EXTRM SE. HIGHS ON TUE IN THE 30S TO NEAR 40. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... LOW PRESSURE DEEPENS AND LIFTS AWAY FROM THE MID-ATLANTIC COAST TUES NIGHT AS THE DEEP/ANOMALOUS NRN STREAM TROUGH REMAINS OVER THE LOCAL AREA. THE TROUGH AXIS PROGGED TO PUSH OFFSHORE WEDS RESULTING IN NWLY FLOW ALOFT. DISTURBANCES IN THE NWLY FLOW ALOFT WILL TRAVERSE THE LOCAL AREA WEDS...BUT HIGH PRESSURE BUILDING IN AT THE SFC AND DRYING CONDITIONS ALOFT WILL KEEP THE FORECAST DRY. CAA WILL RESULT IN H85 TEMPS FALLING TO AROUND -6 TO -10C DURING THE DAY...YIELDING TEMPS IN THE MID-UPPER 30S. COLDER TEMPS OVER THE ERN SHORE...WITH HIGHS IN THE LOW 30S. UPPER/SFC HIGH PRESSURE BUILDS OVER THE REGION WEDS NIGHT AS THE NEXT SHORTWAVE AND ASSOCIATED SFC LOW APPROACH FROM THE WEST ON THURS. SFC LOW AND TRAILING COLD FRONT CROSS THE REGION THURS NIGHT-FRI MORNING. WHILE THE STRONGEST HEIGHT FALLS ARE EXPECTED TO CROSS THE REGION...BEST MOISTURE PROGGED TO BE ACROSS THE NE. WILL CARRY CHANCE POPS GENERALLY NORTH AND EAST OF RICHMOND THURS NIGHT AND SLIGHT CHANCE SOUTH AND WEST. THERMAL PROFILES...LOW TEMPS AND AIR MASS SUPPORT PREDOMINATELY RAIN ATTM...BUT RAIN/SNOW MIX IS POSSIBLE OVER THE NE ZONES. DRYING FRI AS HIGH PRESSURE BUILDS INTO THE REGION. THEREAFTER...MODELS COMPETING ON WHICH STREAM WINS THRU THE WEEKEND. GFS FAVORS A SRN STREAM SYSTEM WITH THE ECMWF FAVORING A NRN STREAM SYSTEM. TEMPS GENERALLY NEAR NORMAL THURS-FRI...DROPPING INTO THE UPPER 30S-LOW 40S SAT. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... VFR CONDITIONS PREVAIL THROUGH AT LEAST 26/1000Z TONIGHT...WITH CIGS AROUND 3 KFT AGL THEREAFTER AS PRECIPITATION ASSOCIATED WITH A CLIPPER SYSTEM MOVES INTO THE REGION FROM THE WEST. PRECIP BEGINS AS ALL RAIN AND RAINFALL RATES ARE EXPECTED TO INCREASE DURING MON AFTN...ESPECIALLY AT KRIC AND KSBY...WHICH WILL DRIVE CIGS/VIS DOWN INTO IFR/MVFR RANGES AT ALL AIR TERMINALS. RAIN IS EXPECTED TO QUICKLY TRANSITION TO SNOW...DURING EARLY MON EVENING NW AND LATE EVENING/OVERNIGHT MON NIGHT SE...THUS CAUSING OVERALL FLIGHT CONDITIONS TO DETERIORATE FARTHER. THE BIGGEST IMPACTS WILL TAKE PLACE OVER THE NRN NECK...MD/VA EASTERN SHORE...AND KSBY WHERE 1-4 INCHES OF ACCUMULATING SNOW IS ANTICIPATED TO OCCUR MON NIGHT INTO TUE MORNING BEFORE TAPERING OFF TUE AFTN. BREEZY NE WINDS EARLY MON TURN TO THE N BY MON EVENING. NW WINDS BECOME GUSTY...ESPECIALLY ALONG THE COAST...OVERNIGHT MON NIGHT AS COLD AIR ADVECTION BEGINS TO TAKE PLACE OVER THE REGION. SNOW SHOWERS SLOWLY TAPER OFF ON TUE...HOWEVER BREEZY NW WINDS WILL PERSIST TUE INTO TUE NIGHT DUE TO A LINGERING AND TIGHTENED PRESSURE GRADIENT AND CONTINUED COLD AIR ADVECTION. ALL PRECIPITATION COMES TO AN END BEFORE MIDNIGHT TUE NIGHT AND HIGH PRESSURE BUILDS INTO THE AREA FROM THE WEST. CLEARING SKIES AND A RETURN TO VFR CONDITIONS IS ANTICIPATED TUE NIGHT THROUGH EARLY THU UNDER THE INFLUENCE OF HIGH PRESSURE. && .MARINE... AS OF 725 AM EST...LATEST WX ANALYSIS FEATURES DEEPENING AREA OF LOW PRESSURE NOW WELL NE OF THE WATERS OVER ATLANTIC CANADA THIS MORNING...AS HIGH PRESSURE BUILDS OVER THE SOUTHEAST COAST. EXPECT IMPROVING CONDITIONS OVER THE WATERS TODAY AS SFC HIGH CONTINUES TO BUILD TO THE SOUTH...EXTENDING NWD OVER THE WATERS. FLOW BECOMES SLY DURING THE AFTERNOON AOB 10KT...AND SEAS WL SUBSIDE TO 2-4FT BY AFTN. GRADUALLY DETERIORATING CONDITIONS EXPECTED LATE TONIGHT THROUGH TUESDAY AS THE NEXT IN A SERIES OF CLIPPER SYSTEMS APPROACHES FROM THE WEST ON MON. THE LOW IS THEN EXPECTED TO STRENGTHEN RAPIDLY AS IT LIFTS NWD ALONG THE COAST. MODELS HAVE COME INTO BETTER AGREEMENT WITH HANDLING THIS SYSTEM, QUICKLY BUILDING WINDS AND SEAS MONDAY NIGHT. STRONG SCA CONDITIONS CONTINUE TO APPEAR CERTAIN FOR ALL WATERS...WITH CONFIDENCE REGARDING LOW END GALE CONDITIONS INCREASING...ESPECIALLY OVER THE NORTHERN AND CENTRAL COASTAL WATERS. THE RESULT WILL BE AN EXTENDED PERIOD OF SCA CONDITIONS OVER THE WATERS. DUE TO ONGOING SCA, WILL WAIT UNTIL CURRENT HAZARDS EXPIRE BEFORE HOISTING NEW FLAGS. BEST CHANCE FOR GALES WILL BE MON NIGHT WITH SCA CONDITIONS PERSISTING THRU TUES NIGHT. DECIDED TO FOREGO GALE WATCH HEADLINE FOR NOW WITH LIKELY TIME PERIOD OF GALES 4 FORECAST PERIODS AWAY. EITHER WAY, WINDS TO START TO DROP OFF WED/WED NGT AS SFC HIGH PRESSURE BUILDS FROM THE OHIO VALLEY, WITH WINDS BECOMING SSW THURSDAY AS HIGH SLIPS OFFSHORE. SEAS WL TAKE AWHILE TO DROP OFF, AND WL LKLY REMAIN ELEVATED AOA 5 FT THRU THE DAY WEDS. NEXT SYSTEM SET TO CROSS THE WATERS THURS NIGHT. SCA CONDITIONS APPEAR POSSIBLE YET AGAIN WITH FRONTAL PASSAGE THU NGT/FRI. && .TIDES/COASTAL FLOODING... LOW PRESSURE FORECAST TO INTENSIFY RAPIDLY OFF THE MID-ATLANTIC COAST MONDAY NIGHT/TUESDAY. THE RESULT WILL BE A PERIOD OF STRONG NLY WINDS OVER THE WATERS. TIDAL ANOMALIES ARE EXPECTED TO REACH 1 TO 1.5 FT...POSSIBLY HIGHER...DURING MONDAY NIGHT AND TUESDAY MORNINGS HIGH TIDE CYCLES. SEVERAL SITES IN THE LOWER BAY WILL REACH HIGHEST ASTRO TIDE WITH WATER LEVELS APPROACHING MINOR FLOODING THRESHOLDS AT SEWELLS POINT MONDAY NIGHT. MINOR FLOODING IS ALSO POSSIBLE AT OCEAN CITY INLET. HIGH TIDES ARE EXPECTED AGAIN TUES...BEFORE ANOMALIES DROP OFF LATE TUES INTO TUES NIGHT AS THE LOW LIFTS AWAY FROM THE REGION. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...WINTER STORM WATCH FROM MONDAY EVENING THROUGH TUESDAY AFTERNOON FOR MDZ021>025. NC...NONE. VA...NONE. MARINE...NONE. && $$ SYNOPSIS...LKB NEAR TERM...LKB/TMG SHORT TERM...LKB/TMG LONG TERM...SAM AVIATION...BMD MARINE...MAM TIDES/COASTAL FLOODING...AKQ

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