Area Forecast Discussion
Issued by NWS Wakefield, VA

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000 FXUS61 KAKQ 151908 AFDAKQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 308 PM EDT TUE APR 15 2014 .SYNOPSIS... A STRONG COLD FRONT WILL CROSS THE AREA TODAY...THEN MOVE OFF THE COAST THIS EVENING. CANADIAN HIGH PRESSURE BUILDS IN FROM THE NORTHWEST TUESDAY NIGHT AND SETTLES OVER THE MID ATLANTIC AND NORTHEAST WEDNESDAY AND THURSDAY. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... THE SEVERE THREAT FOR THIS AFTERNOON AND EVENING HAS DIMINISHED FROM EARLIER FORECASTS. THE SPC SLIGHT RISK HAS BEEN REMOVED. THIS DOES NOT ELIMINATE THE POSSIBILITY OF SEVERE THUNDERSTORMS. SHOWERS AND THUNDERSTORMS ALONG THE COLD FRONT COULD STILL MIX DOWN SOME WIND GUSTS THAT WOULD APPROACH OR EXCEED SEVERE CRITERIA. THE SEVERE POTENTIAL HAS DIMINISHED FOR A FEW REASONS: THE LINE OF SHOWERS AND THUNDERSTORMS THAT MOVED OFFSHORE AROUND NOON RESULTED IN SOME STABILIZING. THUNDERSTORMS OVER GEORGIA IS ROBBING SOME OF THE INFLUX OF MOISTURE TO THE AREA. FINALLY...THE BACKING OF SURFACE WINDS TO SE IS NOT AS IMPRESSIVE AS EARLIER EXPECTED. AT 1 PM EDT...THE COLD FRONT WAS NEAR THE SHENANDOAH VALLEY IN NORTHERN VIRGINIA AND JUST EAST OF LYNCHBURG. A BAND OF HEAVY RAIN AND GUSTY WINDS CAN BE EXPECTED WITH THE FRONTAL PASSAGE. MOST WIND GUSTS SHOULD BE 40 MPH OR LESS BUT ISOLATED SEVERE GUSTS ARE STILL POSSIBLE. HIGH TEMPERATURES TODAY WILL GENERALLY RUN BETWEEN 70 AND 75. TEMPERATURES WILL FALL NOTICEABLY FOLLOWING THE COLD FRONT WITH READINGS IN THE 50S IN THE PIEDMONT COUNTIES AND INTERIOR NORTHERN NECK BY LATE AFTERNOON. STRONG NORTH WINDS ARE FORECAST ALONG THE COAST. WINDS OF 25 TO 35 MPH WITH HIGHER GUSTS ARE EXPECTED THIS EVENING OVER PORTIONS OF HAMPTON ROADS AND CURRITUCK COUNTY NORTH CAROLINA THIS EVENING. THESE WINDS ARE ALSO EXPECTED IN THE VIRGINIA PORTION OF THE LOWER EASTERN SHORE. STRONGEST WINDS WILL BE NEAR THE COAST AND IN AREAS OF HAMPTON ROADS DIRECTLY EXPOSED TO THE CHESAPEAKE BAY. RAIN MOVES OFF THE COAST LATE THIS EVENING. SKIES WILL CLEAR OVERNIGHT FROM WEST TO EAST. . LOW TEMPERATURES TONIGHT DROP TO BETWEEN 28 AND 32 OVER INLAND RURAL AREAS. A FREEZE WARNING IS IN EFFECT FOR MOST OF EASTERN VIRGINIA EXCLUDING SOUTHSIDE HAMPTON ROADS AND THE LOWER VIRGINIA EASTERN SHORE. THE FREEZE WARNING IS IN EFFECT FOR THE MD EASTERN SHORE EXCEPT FOR OCEAN CITY. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY/... COLD WEDNESDAY UNDER SUNNY SKIES. LIKELY WILL BE SOME STREAMERS OVER THE BAY INTO SE VA/NE NC WEDS MORNING. H85 TEMPS WILL FALL TO ~-5C (-2 STD DEV)...TRANSLATING TO DAYTIME TEMPS GENERALLY IN THE LOW 50S...EVEN UNDER THE STRONG APRIL SUN. TEMPS AGAIN MAY FALL TO AROUND FREEZING OVER INLAND COUNTIES WED NIGHT-THURS MORNING. THERE IS A POSSIBILITY FOR LIGHT RAIN NEAR THE NC COAST BY THURS. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
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AN AREA OF SFC LOW PRESSURE IS EXPECTED TO DEVELOP ON A STALLED BOUNDARY OFF THE SOUTHEAST COAST FRI NIGHT. THE LOW SHOULD TRACK NE WELL OFF THE CAROLINA COAST ON SAT. THIS FEATURE MAY BRING A FEW RAIN SHOWERS TO FAR SE VA/NE NC DURING THIS TIMEFRAME. MEANWHILE...AN UPPER LEVEL TROUGH OVER THE UPPER MIDWEST WILL SWING INTO THE ERN GREAT LAKES FRI NIGHT AND SKIRT ACROSS NRN VA ON SAT. A WEAK SFC LOW WILL BE ASSOCIATED WITH THIS FEATURE AND MAY BRING A BRIEF ROUND OF SHOWERS TO FAR NRN PORTIONS OF THE FA (INCLUDING THE MD/VA EASTERN SHORE) SAT AFTN/EARLY EVENING BEFORE MOVING OFFSHORE AND DISSIPATING. THE SFC LOW ASSOCIATED WITH THE GREAT LAKES TROUGH IS EXPECTED TO PHASE WITH THE AFOREMENTIONED COASTAL LOW SAT NIGHT...BUT THIS SHOULD OCCUR OVER NEW ENGLAND AND HAVE VERY LITTLE IMPACT TO THE MID ATLANTIC STATES. SFC HIGH PRESSURE BUILDS INTO THE REGION SUN...THEN SLIDES OFFSHORE BY SUN EVENING AS A RELATIVELY FLAT (WEST TO EAST ORIENTED) FRONTAL BOUNDARY SAGS DOWN INTO THE AREA MON NIGHT INTO TUE. WEAK SHORTWAVE ENERGY AND A SUBSEQUENT SFC LOW TRAVELLING ALONG THIS BOUNDARY MAY BRING ANOTHER SHOT OF PRECIPITATION TO THE AREA ON MON/TUE. GFS PRECIP-GENERATION AND GENERAL MOVEMENT IS A BIT AGGRESSIVE VERSUS THE ECMWF...THEREFORE TRIED TO SPLIT THE DIFFERENCE WITH THE POP FORECAST AND LIMITED COVERAGE TO NO HIGHER THAN 40 PERCENT. TEMPERATURES ARE EXPECTED TO BE STRAIGHT-FORWARD SAT NIGHT THROUGH SUN NIGHT AS HIGH PRESSURE CROSSES THE REGION. EXPECT LOWS NEAR NORMAL BOTH NIGHTS IN THE 40S (LOWER 50S POSSIBLE IMMEDIATE SE VA/NE NC COASTS). HIGHS SAT/SUN RANGE FROM ROUGHLY 65 DEGREES FAR NE TO 70 DEGREES SW. AS THE FLAT FRONTAL BOUNDARY STARTS TO SAG INTO THE MID ATLANTIC STATES MON THROUGH TUE...THE TEMP FORECAST BECOMES TRICKY IN REGARD TO WHERE EXACTLY THE WARM SECTOR DEVELOPS. WITH PRECIP EXPECTED TO APPROACH THE AREA ON MON...INCREASING CIRRUS SHOULD KEEP HIGH TEMPS IN THE UPPER 60S WEST OF I-95 WITH WARMER TEMPS IN THE LOWER 70S EAST OF I-95 (MID-UPPER 60S MD/VA EASTERN SHORE). HIGHS TUE SHOULD BE IN THE LOWER 70S INLAND AND IN THE UPPER 60S NEAR THE IMMEDIATE CHES BAY AND ATLANTIC COASTS. LOW TEMPERATURES AREAWIDE ON MON/TUE NIGHT SHOULD ALSO BE WARM WITH READINGS IN THE 50S (OR ABOUT 10 DEGREES ABOVE NORMAL).
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&& .AVIATION /19Z TUESDAY THROUGH SUNDAY/... INITIAL BATCH OF SHOWERS AND TSTMS HAS MOVED OFF THE COAST THIS MORNING. THE MAIN FRONT IS STILL WELL TO THE WEST. TIMING LOOKS QUITE GOOD ON THE NAM AND RUC SO WILL FOLLOW THEM CLOSELY. NOTICED MAINLY VFR TO MVFR CONDITIONS AHEAD OF THE FRONT AND WILL MAINTAIN THAT. WITH THE UPPER SYSTEM NOW ROTATING NORTHEAST TOWARD THE AREA CAN SEE MORE SHOWERS AHEAD AND BEHIND THE FRONT DEVELOPING. WILL CONTINUE JUST SCATTERED SHOWERS AHEAD OF THE FRONT. THE RUC MODEL SOUNDINGS AND THE LACK OF INSTABILITY INDICATE IT WILL BE HARD FOR ANY TSTMS TO DEVELOP. SO FOR NOW WILL NOT PUT THEM IN THE TAFS BUT IT IS STILL POSSIBLE FOR SOME TO FORM ALONG THE FRONT AS IT CROSSES THE AREA. BEHIND THE FRONT MODELS SHOW AT LEAST SEVER HOURS OF MODERATE TO HEAVY SHOWERS ESPECIALLY OVER SOUTHEAST VIRGINIA AND NORTHEAST NORTH CAROLINA. WILL GIVE A TEMPO GROUP THERE FOR LOWER CIGS AND VSBY WITH THESE SHOWERS. CURRENTLY WEST OF THE FRONT ONLY MVFR CONDITIONS AND CURRENT GUIDANCE ALSO GOING MVFR. WILL KEEP PREDOMINATE CIGS AND VSBY MVFR. IT WILL BECOME WINDY ESPECIALLY AFTER THE FRONT PASSES WITH NORTHWEST WINDS GUSTING OVER 30 KTS AND COULD BE OVER 35 KTS IN ORF. THESE WINDS WILL SLOWLY DIMINISH LATER TONIGHT BUT REMAIN NORTHWEST 15 TO 20 THROUGH THE MORNING ON WEDNESDAY. SKIES CLEAR LATE TONIGHT AND CONTINUE VFR CONDITIONS THROUGH THURSDAY AS HIGH PRESSURE BUILDS OVER THE AREA. && .MARINE... RAISED GALE WARNINGS FOR ALL MARINE ZONES...REMOVED RAMP-UP SCA`S AS WE ARE WITHIN ~ 12 HRS OF THE ONSET OF GALE CONDITIONS. SOUTHERLY FLOW TODAY WILL INCREASE TO AROUND 20-25 KT WITH GUSTS TO 30 KT...AS PRESSURE FALLS MOVE INTO THE AREA AHEAD OF THE APPROACHING COLD FRONT. HOWEVER...STRONGER WINDS ARE ANTICIPATED BETWEEN ABOUT 20Z AND 00Z AS WINDS SHIFT IN ASSOCIATION WITH THE FRONT (AND MAY BE ENHANCED BY SCATTERED CONVECTION). THIS EVENING...IMPRESSIVE PRESSURE RISES ON THE ORDER OF 12 TO 15 MB IN A 6 HR PERIOD SHOULD BRING GUSTS OF 35-40 KT FOR ALL ZONES. THIS WILL ALSO USHER IN MUCH COLDER AIR THAT WILL ENHANCE MIXING OVER THE WATERS. WAVES WILL BLD TO 4 TO 6 FT OVR THE CHES BAY...AND SEAS WILL BLD TO 5 TO 9 FT ON THE COASTAL WATERS. HI PRES WILL THEN BLD JUST TO THE N BY WED AFTN...WHICH WILL ALLOW THE GRADIENT TO WEAKEN SIGNIFICANTLY. HAVE THE GALES ENDING AT 12Z FOR THE BAY/RIVERS...BUT HOLDING INTO EARLY AFTN FOR THE COAST AND CURRITUCK SOUND. HIGH PRESSURE SLIDES NE ACRS NEW ENGLAND AND INTO THE CANADIAN MARITIMES WED NGT THRU FRI...AS A WEAK COASTAL TROUGH DEVELOPS OFF THE SE COAST. THIS WILL RESULT IN NE WINDS AND ELEVATED SEAS THRU THE END OF THE WEEK. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...FREEZE WARNING FROM 3 AM TO 9 AM EDT WEDNESDAY FOR MDZ021>024. NC...FREEZE WARNING FROM 3 AM TO 9 AM EDT WEDNESDAY FOR NCZ012. VA...FREEZE WARNING FROM 3 AM TO 9 AM EDT WEDNESDAY FOR VAZ048-049- 060>085-087>094. MARINE...GALE WARNING UNTIL 10 AM EDT WEDNESDAY FOR ANZ650-652-654. GALE WARNING UNTIL 1 PM EDT WEDNESDAY FOR ANZ633-656-658. GALE WARNING UNTIL 7 AM EDT WEDNESDAY FOR ANZ630>632-634>638. && $$ SYNOPSIS...LSA NEAR TERM...LSA SHORT TERM...SAM LONG TERM...BMD AVIATION...LKB/JAB MARINE...LKB

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