Area Forecast Discussion
Issued by NWS Blacksburg, VA

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KRNK 190640 AFDRNK AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BLACKSBURG VA 240 AM EDT SAT APR 19 2014 .SYNOPSIS... AN AREA OF LOW PRESSURE MOVING THROUGH THE SOUTHEASTERN UNITED STATES WILL PUSH SOME PRECIPITATION INTO NORTHWEST NORTH CAROLINA...AND INTO VIRGINIA UP TO ROUTE 460...TONIGHT AND TOMORROW. HIGH PRESSURE WILL THEN BUILD ALONG THE EASTERN SEABOARD AND BRING FAIR WEATHER TO THE REGION INTO THE FIRST PART OF NEXT WEEK. HOWEVER...A COLD FRONT WILL MOVE THROUGH ON TUESDAY WITH SHOWERS AND THUNDERSTORMS...FOLLOWED BY BREEZY CONDITIONS AND DRY WEATHER FOR MIDWEEK. && .NEAR TERM /THROUGH TODAY/...
-- Changed Discussion --
AS OF 240 AM EDT SATURDAY... INCREASED POPS ACROSS AREAS SOUTH OF THE BLUE RIDGE TO LIKELY TO CATEGORICAL TO BETTER MATCH UP WITH CURRENT RADAR TRENDS. MOST LOCATIONS FROM DAN TO TNB WILL RECEIVE A FEW HUNDREDTHS DURING THE NEXT FEW HOURS...SO 100 POPS WERE IN ORDER AT THIS POINT. ONLY MINOR CHANGES TO T/TD. SKY COVER INCREASED TO 100 PERCENT ALL AREAS THROUGH 18Z. AS OF 947 PM EDT FRIDAY... INCREASED POPS ACROSS NORTH CAROLINA THIS EVENING INTO SATURDAY MORNING TO MATCH UP BETTER WITH LATEST RADAR TRENDS. ALSO ADJUSTED TEMPERATURES FOR TONIGHT INTO SATURDAY. AS OF 806 PM EDT FRIDAY... THE CHALLENGE IN THE FORECAST TONIGHT IS THE NORTHERN EDGE OF CLOUDS/RAINFALL ASSOCIATED WITH THE VERTICALLY STACKED COASTAL LOW THAT MOVES EAST ACROSS NORTHERN FLORIDA TONIGHT AND OFF THE SOUTHEAST COAST SATURDAY. LOOKS LIKE THE RICHER MOISTURE ARRIVES OVERNIGHT WITH A DEVELOPING UPSLOPE FLOW INTO THE NORTHWEST NORTH CAROLINA MOUNTAINS LATE. OVERALL LEANED TOWARDS A SLIGHTLY SLOWER SOLUTION TONIGHT GIVEN DRY ADVECTION FROM HIGH PRESSURE TO THE NORTH AND GRADUAL DEVELOPMENT OF DEEP CONVECTION ALONG THE COAST EARLY SATURDAY. KEPT THE ENSEMBLE BLEND FOR POPS SIMILAR TO LATEST WPC WITH MOISTURE HOLDING SOUTH OF HIGHWAY 460. MODELS REMAIN IN THEIR RESPECTIVE CAMPS WITH NAM STILL KEEPING MOST OF RAIN SOUTH...WHILE THE GFS HAS A DEFORMATION BAND ACROSS SRN VA/NW NC BY SATURDAY MORNING. LATEST RUN OF RNK WRFARW WAS DRIER AND FURTHER SOUTH WITH RAIN AND QPF FOR TONIGHT. IT APPEARS THAT BETTER LIFT AND COLUMN SATURATION DEVELOPS AFTER MIDNIGHT NORTHWEST NORTH CAROLINA INTO SOUTHERN VIRGINIA EARLY SATURDAY WHERE LIKELY POTENTIAL FOR LIGHT QPF. MODIFIED TEMPERATURES AND DEWPOINTS FOR TONIGHT INTO SATURDAY. MORE CHANGES LATER TONIGHT. AS OF 230 PM EDT FRIDAY... MAIN CONCERN CONTINUES WITH NORTHWARD PROGRESSION OF CLOUDS/RAINFALL OVER THE NEXT 24 HOURS ASSOCIATED WITH THE VERTICALLY STACKED COASTAL LOW THAT WILL DRIFT EAST ACROSS NRN FLORIDA TONIGHT AND OFF THE SE COAST SATURDAY. THIS SYSTEM WILL PUSH DEEPER MOISTURE NORTH OVERNIGHT WITH A DEVELOPING UPSLOPE COMPONENT INTO THE NW NC MOUNTAINS LATE. HOWEVER MODELS REMAIN IN SIMILAR CAMPS AS BEFORE WITH THE NAM KEEPING MOST PRECIP TO THE SOUTH...WHILE THE GFS HAS A DEFORMATION BAND ACROSS SRN VA/NW NC BY MORNING...LEAVING THE CANADIAN AND NEW EC BASICALLY IN BETWEEN WITH MOST RAINFALL ACROSS THE SOUTH/EAST BY EARLY SAT. LATEST CONSENSUS INCLUDING WPC OUTPUT SUGGESTS A SLOWER SOLUTION IN ORDER TONIGHT GIVEN DRY ADVECTION FROM HIGH PRESSURE TO THE NORTH AND GRADUAL DEVELOPMENT OF DEEP CONVECTION ALONG THE COAST EARLY SAT. THUS HAVE CUT BACK ON POPS ENTERING THE SOUTH THIS EVENING WITH BETTER LIFT AND COLUMN SATURATION AFTER MIDNIGHT NW NC INTO SOUTHERN VA EARLY SAT WHERE MAINTAINED LOW LIKELYS FOR LIMITED QPF. NORTHWARD EXTENT ALSO IFFY AS APPEARS THE BLUE RIDGE TO SERVE AS A BACKBOARD WITH MID LEVEL DRY HOLDING ANY PRECIP ALONG/SOUTH OF HIGHWAY 460...SO MAINLY CHANCE POPS IN THESE SPOTS. OTRW MAINLY CLOUDY AND DRY ELSW WITH UNIFORM LOWS MOSTLY IN THE UPPER 30S TO MID 40S. GUIDANCE SHOWS THE DEFORMATION AXIS STRETCHING OUT ALONG OR SOUTH OF THE VA/NC BORDER SAT UNDER CONFLUENCE ALOFT AND SOUTH OF HIGH PRESSURE BUILDING IN FROM THE NORTH. AGAIN LOOKS LIKE MOST -RA/DZ ALONG AND SOUTH OF THE BORDER BUT A TIGHT GRADIENT LIKELY FROM LOW CLOUDS/PRECIP SOUTH TO HIGH/MID CLOUDS AND LITTLE -RA NORTH AND WEST. ENSEMBLES SHOW PRECIP PIVOTING ACROSS THE EAST THROUGH MUCH OF SATURDAY BUT SEEMS OVERDONE WITH THE LOW LEVEL FLOW MORE NE THAN EAST WHICH SOMETIMES ACTS TO LIMIT PRECIP INTO AN ENHANCED WEDGE. THEREFORE MAINTAINED CONTINUITY WITH LINGERING LIKELY POPS FAR SOUTH/SE DURING THE MORNING AND CHANCES UP TO 460...THEN DRYING FROM NW TO SE SAT AFTERNOON WITH MOST RAINFALL EXITING LATE. HIGH TEMPS VERY TRICKY WITH LARGE MOS SPREADS ATTM PENDING DEGREE OF CLOUDS AND RAIN WHICH COULD KEEP SOME SPOTS IN THE 40S TO AROUND 50 IF PRECIP IS MORE WIDESPREAD. OTRW STAYING CLOSER TO THE COOLER MAV MOS SOUTH/EAST BUT SLIGHTLY WARMER NORTH WHERE SOME SUN POSSIBLE.
-- End Changed Discussion --
&& .SHORT TERM /TONIGHT THROUGH MONDAY/... AS OF 300 PM EDT FRIDAY... BY SATURDAY NIGHT...THE LOW WHICH AFFECTED US ON SATURDAY SHOULD SINK FAR ENOUGH SEWD TO PULL THE PCPN SHIELD OUT OF OUR AREA. THEN...HIGH PRESSURE RIDGING DOWN THE COAST COMBINED WITH NELY FLOW AROUND THE LOW WILL KEEP A BRISK WIND OVER THE PIEDMONT. NEXT SYSTEM BEGINS TO APPROACH ON MONDAY AND MODELS SPIT OUT SOME LIGHT QPF WITH WEAK DYNAMIC SUPPORT. WILL OPT TO KEEP MONDAY DRY AND LEAVE POPS JUST BELOW THRESHOLD. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... AS OF 200 PM EDT FRIDAY... MAIN WEATHER MAKER THOUGH THE EXTENDED WILL BE CFROPA ON TUESDAY. THE FRONT LOOKS TO HAVE GOOD SUPPORT...AND AREAS EAST OF THE BLUE RIDGE LOOK TO DESTABILIZE A BIT AHEAD OF THE FRONT TUESDAY AFTERNOON. WILL GO WITH LIKELY POPS AND CONFINE CHC THUNDER TO ERN AREAS. NOT SEEING MUCH IN THE DATA TO INDICATE MORE THAN GENERAL THUNDERSTORMS ATTM. BELIEVE THERE WILL BE A CHC FOR SOME UPSLOPE RAIN SHOWERS IN CAA WEST OF THE BLUE RIDGE AND WILL INDICATE THIS FOR WEDNESDAY NIGHT...AND WEDNESDAY LOOKS BREEZY AS HIGH PRESSURE BUILDS IN WITH QUIET WX FOR THURSDAY. && .AVIATION /07Z SATURDAY THROUGH WEDNESDAY/... AS OF 145 AM EDT SATURDAY... UPPER LOW PRESSURE AREA SOUTHEAST U.S. WILL CONTINUE TO CLOSE OFF AND DRIFT VERY SLOWLY EAST ALONG THE GULF COAST TO THE SOUTHEAST ATLANTIC COAST THROUGH THE PERIOD. MARITIME EASTERLY FLOW ON THE NORTH SIDE OF THIS WAS ADVECTING LIGHT RAIN INTO THE REGION...WHICH HAD SPREAD INTO NORTHWEST/NORTH CENTRAL NC AND SOUTHEAST VA...INCLUDING DAN. MUCH OF THIS -RA STILL FALLING OUT OF CIGS AOA100...WITH SEVERAL AWOS/ASOS STATIONS IN THE AREA REPORTING CLR BLO 120 WITH -RA. VERY DRY MID-LEVEL AIR WILL GRADUALLY MOISTEN...BUT CIGS APPEAR DESTINED TO REMAIN MOSTLY VFR THROUGH THE TAF VALID PERIOD...BUT WILL LIKELY LOWER TO LOW END VFR LYH-DAN FOR A PERIOD LATE MORNING/EARLY AFTERNOON...BEFORE THE DEEPER MOISTURE ASSOCIATED WITH THE UPPER LOW SPREADS FURTHER EAST LATE AFTERNOON/EVENING. UNLIKE YESTERDAY MORNING...SFC FLOW NOW NE AS OPPOSED TO SE...WHICH IS HELPING TO TRANSPORT DRIER AIR INTO THE REGION FROM THE NORTHEAST. FEEL THAT LOW CLOUDS WHICH ARRIVED LATE NIGHT/EARLY MORNING YESTERDAY SHOULD NOT OCCUR TODAY...DESPITE PRESENCE OF RAIN. OCCASIONAL MVFR VSBYS ARE ALSO POSSIBLE LYH/DAN...BUT ELSEWHERE DO NOT EXPECT ENOUGH -RA OR -DZ TO WARRANT MENTION OF ANY VSBYS LESS THAN VFR. WINDS WILL BE ON THE INCREASE AS THE DAY PROGRESSES WITH A TIGHTENING OF THE PRESSURE GRADIENT BETWEEN NORTHEASTERN U.S. HIGH PRESSURE AND SOUTHEAST U.S. LOW. EXPECT ENE 10-12KTS WITH GUSTS TO 20KTS ACROSS THE PIEDMONT BY AFTERNOON AND EVENING...DIMINISHING TOWARD THE END OF THE TAF VALID PERIOD. MEDIUM CONFIDENCE IN CIGS AND VSBYS THROUGH THE TAF VALID PERIOD. MEDIUM TO HIGH CONFIDENCE IN WIND DIR/SPD THROUGH THE TAF VALID PERIOD. EXTENDED AVIATION DISCUSSION... THE UPPER LOW SLOWLY EXITS TO THE EAST SUNDAY AND HIGH PRESSURE RETURNS BRINGING A RETURN TO VFR CONDITIONS INTO EARLY NEXT WEEK. THE NEXT COLD FRONT APPROACHES MONDAY NIGHT WITH MORE SHOWERS AND POSSIBLE THUNDERSTORMS INCLUDING PERIODS OF MVFR. FRONT EXITS TUESDAY NIGHT RESULTING IN A RETURN TO VFR WEDNESDAY EXCEPT FOR MVFR CIGS OVER THE FAR WESTERN SITES IN SE WEST VA. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...MBS NEAR TERM...RAB/KK/JH SHORT TERM...MBS LONG TERM...MBS AVIATION...RAB/RCS

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.