779 FXUS61 KAKQ 120845 AFDAKQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 445 AM EDT FRI APR 12 2013 .SYNOPSIS... A COLD FRONT WILL PUSH ACROSS THE AREA TODAY INTO THIS EVENING. HIGH PRESSURE BUILDS INTO AND ACROSS THE REGION TONIGHT THROUGH SUNDAY AFTERNOON. && .NEAR TERM /THROUGH TONIGHT/... EARLY THIS MORNG...LO PRES WAS OVR CNTRL OH WITH A COLD FRONT EXTENDING SWRD THRU ERN KY AND DOWN INTO WRN GA. A WARM FRONT STRETCHED FM THE LO ESE ACRS NRN W.VA AND VA AND INTO THE LWR MD ERN SHR. AREA OF SHOWERS AND TSTMS WELL IN ADVANCE OF THE COLD FRONT WAS EXTENDING FM WRN PA DOWN THRU W.VA...WRN VA AND NC AND INTO ERN SC. THIS PCPN WAS ASSOC WITH AREA OF DECENT SHRTWV ENERGY (PVA) AND STRONG LIFT...AND WAS MOVING EWRD. THIS AREA OF PCPN SHOULD PUSH ACRS OUR CWA BETWEEN 10Z-18Z...WITH QPF AMTS RANGING FM ARND .25 INCH OVR EXTRM SE VA AND NE NC...TO ARND .80 INCH OVR NW PIEDMONT COUNTIES. ANY TSTMS COULD PRODUCE LOCALLY HEAVY RAIN AND WIND GUSTS TO NEAR 40 MPH DURING THIS TIME PERIOD. A SMALLER AREA/LINE OF SCTD SHOWERS AND TSTMS WILL THEN RE- DEVELOP OVR THE PIEDMONT OF VA/NC LATER THIS AFTN RIGHT IN ADVANCE OF THE ACTUAL COLD FRONT...THEN PUSH EWRD AND OFF THE CST DURING THIS EVENG. THESE SHOWERS AND TSTMS WILL RE-DEVELOP DUE TO INCREASED INSTABILITY (LI'S -2/-3 AND CAPE 1000-1200 J/KG) AND ADDITIONAL LIFT FM FRNTL BNDRY MOVNG EWRD. A FEW OF THESE STORMS COULD PRODUCE ISLTD WIND DAMAGE...ESPLY ACRS EXTRM SE VA AND NE NC...WHERE THERE IS A SLGT RISK FOR SEVERE WX. PCPN AND THE COLD FRONT WILL MOVE OFF THE CST AND OUT TO SEA LATER THIS EVENG AND OVRNGT. MAX TEMPS WILL RANGE FM THE LWR 70S TO LWR 80S TODAY. SKY WILL BECOME CLR OR MSTLY CLR TNGT WITH MIN TEMPS RANGING FM THE UPR 40S TO MID 50S. && .SHORT TERM /SATURDAY THROUGH SUNDAY/... HI PRES WILL BLD INTO AND ACRS THE REGION SAT THRU SUN AFTN. THIS WILL RESULT IN PLEASANT...MORE SEASONABLE TEMPS ACRS THE AREA. SNY OR MSTLY SNY ON SAT WITH HIGHS RANGING FM THE MID 60S TO LWR 70S. MSTLY CLR SAT NGT WITH LOWS RANGING THRU THE 40S. MSTLY SNY OR PRTLY SNY ON SUN WITH MAX TEMPS RANGING FM THE MID 60S TO MID 70S. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... THE MEDIUM RANGE PERIOD BEGINS SUN NIGHT WITH THE PERSISTENCE OF AN ACTIVE NORTHERN STREAM WITH A DEEP UPPER LEVEL TROUGH PUSHING ENE OFF THE CANADIAN MARITIMES WITH ANOTHER DEEP TROUGH UPSTREAM OVER THE NORTHERN PLAINS. WELL TO THE SOUTH...SOME OF THE MODELS HAD BEEN HINTING AT A WEAK SOUTHERN STREAM DISTURBANCE MOVING FROM THE GULF COAST TO THE CAROLINAS MON INTO TUE...AND NOW THEY ALL GENLY AGREE ON THIS SCENARIO. HAVE ADJUSTED HIGHS MON DOWN SEVERAL DEGREES OVER THE SOUTHERN ZONES...ESPECIALLY NEAR THE COAST DUE TO MORE CLOUDS AND COOL ONSHORE E/SE FLOW (HIGHS IN UPPER 60S TO LWR 70S). HAVE ALSO ADDED SOME 20% CHANCES FOR SHRA IN THESE AREAS ALTHOUGH BULK OF DEEP MOISTURE LOOKS TO STAY SOUTH OF THE LOCAL AREA. PARTLY TO MOSTLY CLOUDY ELSEWHERE W/ HIGHS IN THE 70S. BY TUE...THE TROUGHING SHOULD BE PUSHING OFF THE SE COAST...WITH UPPER RIDGING GRADUALLY BUILDING BACK NORTH THROUGH THE REMAINDER OF THE PERIOD. THE GFS IS A BIT OF AN OUTLIER BY WED...ALLOWING FOR A BACK-DOOR COLD FRONT TO PUSH THROUGH PORTIONS OF THE CWA. HAVE FOLLOWED THE CONSENSUS ECMWF/GEM/HPC SOLUTION AND KEPT THE FCST DRY WITH TEMPERATURES WARMING BACK INTO THE UPPER 70S TO LOWER 80S FOR MOST OF THE REGION TUE-WED...A LITTLE COOLER NEAR THE IMMEDIATE COAST AND ERN SHORE. THE UPPER RIDGE GRADUALLY BREAKS DOWN FROM THE WEST LATE IN THE WEEK. WILL CARRY SOME LOW CHC POPS BY THU AFTN...AS MODELS SHOW CHC FOR SOME SHRA WELL OUT AHEAD OF THE FRONT. IN GENERAL THOUGH...HIGHER CHANCES FOR PRECIP W/ THE NEXT FRONT PROBABLY HOLD OFF UNTIL THU NIGHT/FRI. HIGHS MAINLY IN THE MID-UPPER 70S TO LOWER 80S THU. && .AVIATION /08Z FRIDAY THROUGH TUESDAY/... VFR TO MVFR CONDITIONS STILL PREVAIL AT ALL TERMINALS SOUTH OF BACKDOOR COLD FRONT, CURRENTLY DRAPED ACROSS NORTHERN VA AND THE LOWER EASTERN SHORE. STRATUS REMAINS IN PLACE ALONG AND NROTH OF THESE AREAS, AND HV HELD ONTO LOW CIGS THROUGH MID-MORNING, WHEN SHRAS AND STRONGER COLD FRONT APPROACHES FROM THE WEST. SECOND ISSUE FOR REMAINDER OF THE AREA IS WHETHER SHWRS/IS TSTMS OVER WESTERN CAROLINAS MAKE IT TO KRIC. EXPECT CIGS TO DETERIORATE TO MVFR (TEMPO IFR) AS LINE OF SHRAS PUSH IN FROM THE WEST...HV VCSH IN RIC AFTER 6AM, WITH SHRAS IN RIC IN 12-14Z TIMEFRAME, SHIFTING TO THE COAST BETWEEN 14-18Z, WITH CONDITIONS DRYING OUT (BRIEFLY) INLAND (RIC). THERE COULD BE ANOTHER NARROW LINE OF SHWRS/PSBL TSTMS TOWARD 00Z ACROSS COASTAL TERMINALS...BUT THERE IS ENOUGH UNCERTAINTY TO LEAVE OUT ATTM. ONCE FRONT CLEARS AFTER 00Z SAT...VFR CONDITIONS EXPECTED THROUGH THE WEEKEND AS HIGH PRESSURE BUILDS IN FROM THE WEST. && .MARINE... LATEST OBS AND ANALYSIS REFLECT S TO SW FLOW AT ~15-20KT...WITH THE EXCEPTION OF ALONG AND NORTH OF A BACK-DOOR COLD FRONT WHICH IS DRAPED ACROSS NORTHERN VA AND LOWER EASTERN SHORE. CURRENTLY NOTING LIGHTER EASTERLY FLOW ALONG AND NORTH OF THIS BOUNDARY OVER NORTHERN TWO ATLANTIC COASTAL ZONES. GOOD MODEL AGREEMENT REMAINS IN SHUNTING FRONT BACK NORTH THIS MORNING AHEAD OF COLD FRONT APPROACHING FROM THE WEST. TIGHTENING PRESSURE GRADIENT AHEAD OF THIS SYSTEM WILL ALLOW FOR SCA CONDITIONS TO DEVELOP OVER ALL ZONES TODAY...WITH THE HEADLINES RUNNING THROUGH FRIDAY NIGHT (EXCEPT INTO SATURDAY AM FOR COASTAL WATERS AS SEAS WILL BE SLOW TO SUBSIDE). COASTAL SEAS BUILD TO 5-7 FT N AND 4-6 FT S BY THIS AFTN/ERY EVENING, WHILE WAVES IN THE CHES BAY BUILD FROM 2-3 FT TO 3-4 FT BY AFTN. FRONT IS EXPECTED TO BECOME HUNG UP ACRS SE VA/NE NC THIS AFTN/EVENING BEFORE FINALLY GETTING SHUNTED OFFSHORE LATE FRI NIGHT. HIGH PRESSURE BUILDING IN FROM THE NW SAT NIGHT INTO SUN WILL ALLOW SEAS TO SUBSIDE ON SATURDAY, THOUGH WE MAY SEE SOME INCREASE IN WINDS SAT NIGHT BRIEFLY AS THE HIGH BUILDS IN AND SOME WEAK CAA ENSUES (AT THIS TIME IT APPEARS TO BE TOO BRIEF TO ATTAIN SCA CONDITIONS, ALTHOUGH IT MAY BE CLOSE). OTHERWISE...GENLY SUB- SCA CONDITIONS INTO EARLY NEXT WEEK. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR ANZ630>638. SMALL CRAFT ADVISORY UNTIL 6 AM EDT SATURDAY FOR ANZ650-652- 654-656-658. && $$ SYNOPSIS...TMG NEAR TERM...SAM/TMG SHORT TERM...SAM/TMG LONG TERM...LKB AVIATION...MAM MARINE...LKB/MAM