Area Forecast Discussion
Issued by NWS Wakefield, VA

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000 FXUS61 KAKQ 030556 AFDAKQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 1256 AM EST TUE MAR 3 2015 .SYNOPSIS... HIGH PRESSURE BUILDS INTO THE MID ATLANTIC STATES TONIGHT THROUGH TUESDAY MORNING. A WARM FRONT LIFTS NORTHEAST ACROSS THE REGION TUESDAY NIGHT...FOLLOWED BY A COLD FRONT SLOWLY CROSSING THE AREA WEDNESDAY AFTERNOON THROUGH WEDNESDAY NIGHT. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... CURRENT ANALYSIS REVEALS ~1033 MB SFC HIGH PRESSURE CENTERED OVER THE ERN GREAT LAKES...RIDGING SOUTH INTO THE MID ATLC REGION. FLOW ALOFT IS FROM THE WNW...WELL OUT AHEAD OF BROAD TROUGHING OVER THE WRN CONUS. SKIES ARE MAINLY CLEAR ACRS N/NE SECTIONS OF THE CWA...WHILE MID/HIGH LEVEL CLOUDINESS IS STREAMING THROUGH THE REMAINDER OF THE CWA. SEEING SOME LOWER CLOUDS/BKN CIGS IN NC AS WELL. FOR THE OVERNIGHT PERIOD...AS UPPER RIDGE OVER THE MID MS VALLEY ADVANCES EAST INTO THE OHIO VALLEY...WILL CONTINUE TO SEE INCREASING CLOUDS INTO THE LOCAL AREA. HAVE ADJUSTED MIN TEMPS UP A FEW DEGREES ACRS THE SOUTH DUE TO MORE CLOUD COVER...WHILE GENLY KEEPING MINS UNTOUCHED FARTHER N/NE WHERE SKIES STAY MOSTLY CLEAR THROUGH MOST OF THE NIGHT. EXPECT MINS TO RANGE FROM THE UPPER 20S/LOWER 30S OVER NE NC/FAR SOUTHERN VA...TO THE LOWER 20S FROM THE NRN NECK TO THE MD ERN SHORE. LATEST 00Z NAM12 SIMULATED REFLECTIVITY SHOWS SOME LIGHT RETURNS ENTERING SW ZONES BY 12Z...BUT THIS WOULD JUST BE VIRGA OVER THE DRY AIRMASS IN PLACE SO NO CHC FOR PRECIP THROUGH 12Z. && .SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY/... CENTER OF SFC HI PRES SLOLY EXITS TO THE E ON TUE...BUT LO LVL CAD RMNS OVR THE FA. CLDNS WILL CONT TO INCRS TUE MRNG LIMITING TEMP RISE. SOME LGT PCPN MAY BREAKOUT...ESP FAR WNW AREAS...DURING THE MIDDAY HRS...THEN BETTER COVERAGE OF PCPN ACRS FA XPCD BY MID/LT AFTN. MDL SOUNDINGS CONT TO HINT AT PTNTL FOR BRIEF PD OF FZRA OVR FAR NNW AREAS AS TEMPS STRUGGLE TO REACH 32F THROUGH EARLY AFTN. CONFIDENCE RMNS LO ATTM...AND WILL HOLD OFF ON ANY WINTER WX ADVISORY. OTRW...P-TYPE TO BE RA OVR THE RGN TUE AFTN/EVE. HI TEMPS TO BE REACHED LT IN THE DAY...RANGING FM THE M/U30S NW-CNTRL LOCATIONS TO L40S SE. WARM FRONT TO LIFT NE THROUGH THE FA TUE NGT. BEST MOISTURE AND UVM ACRS CNTRL/NRN PORTIONS OF FA...THUS THE HIGHEST POPS...W/ WITH CHC POPS LIMITED TO SRN VA/NE NC. BULK OF THE RA LIFTS TO NRN PORTION BY LT AT NGT. LO TEMPS LIKELY ARND 00Z/04 WITH RISING TEMPS THROUGH THE NIGHT. TEMPS BY 12Z/04 WED RISE INTO THE U40S- M50S. FA BECOMES "WARM SECTORED" WED DUE TO SURGE OF A STRONG SSW FLOW. THERE RMN TIMING ISSUES W/ THE APPROACHING CDFNT FM THE NNW...AS 12Z/02 NAM ABOUT 12HRS SLOWER THAN THE 12Z/02 GFS. AGAIN...THE 12Z/02 ECMWF SEEMS LIKE A GOOD COMPROMISE. WILL HAVE HIGHEST POPS (40-60%) BY AFTN ACRS NRN TIER OF FA...W/ SLGT CHC TO CHC (20-40%) TO THE S. FOR NOW...LEAVING OUT ANY MENTION OF T ACRS SRN VA/NE NC...SINCE IT APRS MOST OF MOISTURE CONFINED TO W/ AND BEHIND THE FNT. HI TEMPS FM THE U50S/L60S N TO L70S IN FAR SE VA/NE NC. JUST ONE YEAR AGO...MARCH 2ND-3RD...WENT FM 60S TO L70S (THE 2ND) TO A FEW INCHES OF SN (ON THE 3RD). THIS MAY OCCUR AGN THIS WK (WED-THU). FCST CHALLENGES CONT WED NGT THROUGH THU AS CDFNT SETTLES SSE THROUGH THE FA...AND ANOTHER AREA OF ARCTIC SFC HI PRES BUILDS TWD THE MS/OH VLYS. WILL LEAN TWD THE FASTER ARRIVAL OF COLDER SFC AIR FM THE NNW (GFS/ECMWF) BY LT WED NGT AND CONTG ON THU. THE MDLS EACH HINT AT WK SFC LO PRES TRACKING THROUGH NC AS S/W ALOFT (IN FAST SWLY FLO) IS SHEARED AS IT MOVES EWD INTO THE RGN. ALL THIS LEADS TO A TRANSITION (WRT P-TYPE) LT WED/THU. RA...BECOMES MIXED W/ IP-CHANGING TO SN/IP THEN ENDING AS SN FM NNW TO SE ACRS THE FA (LASTLY ACRS NE NC BY MID OR LT AFTN THU). TIMING THOSE TRANSITIONS AT THIS POINT VERY DIFFICULT...THOUGH CURRENTLY EXPECT A LEAST LGT SN ACCUMS FOR AREAS N OF THE NC/VA BORDER BEFORE THE DAY ENDS THU (T-2 INCHES S...1-4 INCHES N (HIGHEST PTNTTLY FM RIC-SBY)). ALONG W/ THE TRANSITION TO WINTRY PCPN...GUSTY NNE WNDS WILL BE PUSHING COLDER AIR INTO THE RGN. LO TEMPS WED NGT FM ARND 30F N TO THE L40S FAR S. TEMPS THU STEADY OR FALLING. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... COLD TO BEGIN THE EXTENDED IN WAKE OF THURS COLD FRONT...BUT MODERATING TEMPS THRU THE WEEKEND WILL BRING TEMPS BACK TO NEAR NORMAL EARLY NEXT WEEK. SHORTWAVE PUSHES OFFSHORE THURS NIGHT WITH THE NRN PORTION OF THE FRONT PUSHING WELL OFFSHORE. SRN PORTION PUSHES SWD OVER THE GULF STATES/NRN GULF...STALLING IN WLY FLOW ALOFT. ENDED CHANCE POPS NEAR THE COAST AT MIDNIGHT...WITH DRYING/CLEARING CONDITIONS THEREAFTER. 1030+MB ARCTIC HIGH PRESSURE BUILDS OVER THE REGION FRI...RESULTING IN ANOTHER COLD DAY WITH HIGHS AROUND 20 DEGS BELOW NORMAL. H85 TEMPS BOTTOM OUT AROUND -12C (-2 STD DEV)...WITH THICKNESSES YIELDING TEMPS IN THE LOW-MID 30S. SFC HIGH PUSHES OFFSHORE FRI NIGHT WITH LIGHT RETURN FLOW HELPING MODERATE LOW LEVEL THICKNESSES. TEMPS FORECAST IN THE MID-UPPER TEENS FRI NIGHT UNDER MOSTLY CLEAR SKIES. THEREAFTER...MEDIUM RANGE GUIDANCE BEGINS TO DIVERGE THANKS TO DEVELOPING SPLIT FLOW OVER THE WRN CONUS. THE UPPER PATTERN WILL AGAIN BE CHARACTERIZED BY CYCLONIC FLOW (TROUGHING) OVER THE ERN CONUS AND RIDGING (RETURN TO A +PNA) OVER THE WRN CONUS. MODELS STRUGGLING WITH A NUMBER OF CANADIAN IMPULSES SET TO IMPACT THE NE STATES...BUT ALSO SRN STREAM ENERGY OVER THE BAJA THIS WEEKEND. ECMWF RATHER ROBUST WITH THIS ENERGY...TRANSLATING ACROSS NRN MEXICO AND THE SRN PLAINS SAT NIGHT-SUN...POSSIBLY PHASING WITH NRN STREAM ENERGY OVER THE MIDWEST. THIS SOLUTION WOULD LIFT THE STALLED FRONTAL BOUNDARY OVER THE GULF NWD LATE IN THE WEEKEND...BRINGING RAIN TO THE REGION EARLY NEXT WEEK. THE GFS SHEARS THE ENERGY...KEEPING IT WELL SOUTH OF THE REGION...KEEPING THE LOCAL AREA DRY. HAVE TRENDED FORECAST TOWARD A WPC/ENSEMBLE APPROACH WHICH KEEPS THE SRN STREAM WAVE FLAT AND THE LOCAL AREA DRY THROUGH THE WEEKEND..WITH MODERATING TEMPS. HIGHS SAT FORECAST IN THE UPPER 40S-LOW 50S INLAND AND LOW-MID 40S NEAR THE COAST. HIGHS SUN IN THE MID 50S INLAND AND MID-UPPER 40S NEAR THE COAST. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... SCT-BKN HIGH CLOUDS SHOULD CONTINUE TO PASS OVER THE REGION OVERNIGHT...WITH A LIGHT NNE WIND DUE TO 1030MB HIGH PRESSURE OVER PA. ONE EXCEPTION WILL BE ECG...WHICH WILL HAVE A PERIOD OF 5KFT CIGS OVER THE NEXT FEW HOURS. HIGH PRESSURE MOVES OFFSHORE TODAY...FOLLOWED BY A WARM FRONT TONIGHT. A PERIOD OF -RA IS EXPECTED TO DEVELOP LATER THIS AFTERNOON...PRIMARILY AFTER 21Z. CIGS LOWER TO 4-5KFT THROUGH THE DAY ALONG WITH A LIGHT ESE WIND. THERE IS AN INCREASING POTENTIAL FOR IFR CIGS TONIGHT...ESPECIALLY AFTER 06Z AS THE WARM FRONT LIFTS THROUGH THE REGION. CONDITIONS SHOULD IMPROVE FOR A BRIEF PERIOD LATER WEDNESDAY MORNING. HOWEVER...A COLD FRONT IS EXPECTED TO DROP THROUGH THE REGION DURING THE AFTERNOON FOLLOWED BY DETERIORATING FLIGHT CONDITIONS. THE CHC OF RA INCREASES LATER WEDNESDAY AFTERNOON...WITH RA OVERSPREADING THE ENTIRE REGION WEDNESDAY EVENING. A TRANSITION TO A MIX AND EVENTUALLY SN SHOULD BEGIN AT SBY AFTER 06Z...WITH THE TRANSITION OCCURRING AT RIC CLOSER TO 12Z. FARTHER SE...THE CHANGE SHOULD OCCUR LATER IN THE DAY. ADDITIONALLY...A GUSTY NORTHERLY WIND WILL DEVELOP ALONG THE COAST THURSDAY. HIGH PRESSURE SETTLES OVER THE AREA FRIDAY AND SATURDAY. && .MARINE... WEAK/SECONDARY COLD FRONT HAS DROPPED SOUTH OF THE WATER THIS AFTERNOON. WINDS HAVE BECOME NLY...BUT WEAK LOW-LEVEL CAA HAS RESULTED IN SPEEDS GENERALLY AOB 15 KT IN THE BAY/RIVER/SOUND AND AOB 20 KT COASTAL WATERS. THIS AS WINDS A FEW THOUSAND FT ALOFT RANGE FROM 30-35KT. SEAS GENERALLY 2-3 FT AND WAVES 1-2 FT. HAVE DROPPED SCA HEADLINES ALL WATER EXPECT FOR THE COASTAL WATERS SOUTH OF THE VA/NC BORDER AS BETTER FETCH WILL RESULT IN 4-5 FT SEAS TONIGHT. HEADLINES RUN THRU LATE TONIGHT. ~1030+MB SFC HIGH PRESSURE BUILDS OVER THE WATER TONIGHT...SLIDING OFFSHORE TUES. FLOW BECOMES SELY BEHIND THE DEPARTING HIGH AOB 15 KT. WARM FRONT PROGGED TO LIFT OVER THE WATER LATE TUES NIGHT AS A COLD FRONT SLOWLY APPROACHES FROM THE WEST. HIGH PRESSURE CENTERS OFF THE SOUTHEAST COAST. SWLY FLOW INCREASES LATE TUES NIGHT...BUT SO DOES WAA OVER VERY COLD WATER. MARGINAL SCA CONDITIONS ARE POSSIBLE...BUT MAYBE ONLY A FEW GUSTS TO 20 KT LATE TUES NIGHT-EARLY WEDS MORNING IN THE BAY. SEAS BUILD TO AROUND 5 FT 20 NM OUT LATE TUES THRU WEDS...BEFORE SUBSIDING WEDS NIGHT AOB 4 FT. FRONT IS SLOW TO CROSS THE WATER WEDS-WEDS NIGHT. CAA SURGES INTO THE REGION LATE WEDS NIGHT...CONTINUING THRU THURS NIGHT. SCA CONDITIONS ARE EXPECTED WITH A NLY WIND. SEAS BUILD TO 4-7 FT (HIGHEST IN THE SRN WATERS) THURS...SUBSIDING FRI MORNING. HIGH PRESSURE RETURNS FRI INTO EARLY NEXT WEEKEND. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...NONE. && $$ SYNOPSIS...ALB/MPR NEAR TERM...ALB/LKB SHORT TERM...ALB/MPR LONG TERM...SAM AVIATION...AJZ MARINE...SAM

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