Area Forecast Discussion
Issued by NWS Blacksburg, VA

Current Version | Previous Version | Text Only | 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 260533 AFDRNK AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BLACKSBURG VA 133 AM EDT TUE APR 26 2016 .SYNOPSIS... HIGH PRESSURE WILL DRIFT FURTHER OFFSHORE TONIGHT...WHILE A COLD FRONT MOVES SOUTHWARD TO THE MID ATLANTIC ON TUESDAY. THIS FRONT SHOULD STALL OVERHEAD DURING WEDNESDAY...BEFORE A STRONGER COLD FRONT ARRIVES FROM THE PLAINS BY THURSDAY. && .NEAR TERM /THROUGH TODAY/... AS OF 940 PM EDT MONDAY... MINOR TWEAKS WERE MADE TO THE TEMPERATURES AND DEWPOINTS BASED ON THE LATEST OBSERVATIONS. OVERALL...IT REMAINS A MILD NIGHT WITH LOWS RANGING FROM THE LOWER 50S TO THE LOWER 60S. A COLD FRONT REMAINS TO THE NORTH...BUT A WAVE ALONG THIS FRONT SHOULD PUSH A WEAK TROUGH OVER THE MOUNTAINS ON TUESDAY MORNING...BEFORE STALLING IT OVER THE PIEDMONT BY THE AFTERNOON. THIS SITUATION SHOULD INCREASE THE CHANCES FOR A FEW SHOWERS AND THUNDERSTORMS LATER IN THE DAY. HIGHS FOR TUESDAY SHOULD VARY FROM THE LOWER 70S IN THE HIGHER ELEVATIONS TO THE MID 80S IN THE PIEDMONT. && .SHORT TERM /TONIGHT THROUGH THURSDAY/... AS OF 245 PM EDT MONDAY... UNSETTLED WEATHER IS EXPECTED DURING THIS PORTION OF THE FORECAST. AT THE SURFACE...A COLD FRONT PUSHES SOUTH INTO OUR FORECAST AREA BY WEDNESDAY MORNING IN RESPONSE TO A DEEPENING UPPER TROF IN NEW ENGLAND AND SOUTHEAST CANADA. WITH THE MEDIUM RANGE MODELS INDICATING A WEAK UPPER LEVEL WAVE PASSING THROUGH...KEPT POPS IN PLACE THROUGH THE NIGHT AND LEANED TOWARD THE WARMER SIDE OF GUIDANCE WITH ANTICIPATED CLOUD COVER. FOR WEDNESDAY...THIS SFC FRONT WILL STALL SOMEWHERE ACROSS OR JUST SOUTH OF THE FORECAST AREA. THE 00Z ECMWF...AND TO A LESSER EXTENT...THE 12Z NAM AND 09Z SREF MODELS MORE AGRESSIVE WITH DEVELOPING THE WEDGE COMPARED TO THE GFS. SREF 2M TEMP PLUMES SHOW LOW CONFIDENCE FOR TEMPS ON WEDNESDAY WITH A WIDE RANGE OF POSSIBILITIES. LEANED TOWARD THE MAJORITY OF MODELS AND KNOCKED TEMPS DOWN A FEW DEGREES IN THE EAST...WHICH MAY NOT BE COLD ENOUGH...AND KEPT CHANCES FOR THUNDER ACROSS THE SOUTHERN HALF OF THE FORECAST AREA. PRECIPITATION MAY BE FAIRLY WIDESPREAD ON WEDNESDAY AS LOW LEVEL CONVERGENCE INCREASES ALONG THE SFC BOUNDARY...AHEAD OF A DEVELOPING SFC WAVE...AND UPPER LEVEL DIVERGENCE INCREASES THROUGH THE DAY IN ADVANCE OF THE CENTRAL PLAINS UPPER LOW. STILL NO FLOODING CONCERNS ANTICIPATED WITH RAINFALL RATES NOT EXPECTED TO BE EXCESSIVE AND DRY ANTECEDENT CONDITIONS. SHOWERS...ALONG WITH THUNDERSTORMS OUTSIDE THE WEDGE...WILL AGAIN BE FOUND WEDNESDAY AND ESPECIALLY THURSDAY AS MODELS GENERATE GOOD LIFT IN ADVANCE OF AN UPPER LEVEL SHORTWAVE TRACKING THROUGH THE GREAT LAKES INTO THE OHIO VALLEY...ALONG WITH PWATS 2-3 STANDARD DEVIATIONS ABOVE NORMAL. THE NAM MODEL APPEARS TO BE THE OUTLIER WITH ITS MUCH FASTER SOLUTION. HIGH TEMPERATURE FORECAST AGAIN WILL BE TRICKY DEPENDING IF/WHEN THE LOW LEVEL WEDGE ERODES. UNDERCUT FORECAST HIGHS THURSDAY BY SEVERAL DEGREES IN VA PIEDMONT AND SOUTHERN SHENANDOAH VALLEY. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... AS OF 245 PM EDT MONDAY... WEAK UPPER RIDGING DEVELOPING LATE FRIDAY THROUGH SATURDAY WILL KEEP PRECIP CHANCES CONFINED TO ISOLATED/WIDELY SCATTERED IN COVERAGE. AT THE SFC...12Z ECMWF KEEPS WEDGE IN PLACE THROUGH SATURDAY. WHILE TEMPS WERE BROUGHT DOWN A COUPLE OF DEGREES DURING THIS TIME...THESE FORECAST VALUES STILL MAY BE TOO WARM. HOWEVER...BETTER CHANCES FOR MORE WIDESPREAD PRECIPITATION ARRIVE LATER SUNDAY INTO MONDAY...DEPENDING ON THE ARRIVAL OF AN OPENING UPPER LOW MOVING THROUGH THE OHIO VALLEY. AS IT TYPICAL FOR THE LONG RANGE MODELS...THERE IS DISAGREEMENT IN THE TIMING AND TRACK OF THIS SYSTEM...BUT INDIVIDUAL GEFS ENSEMBLE MEMBERS SUGGEST THE BEST CHANCES FOR PRECIPITATION WILL BE LATE SUNDAY INTO EARLY MONDAY...AND THIS IS THE TIME PERIOD WHERE THE POPS ARE HIGHEST. TEMPS ARE EXPECTED TO BE BELOW NORMAL EARLY WITH THE WEDGE IN PLACE TO NEAR NORMAL LATER IN THE LONG TERM PERIOD. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/...
-- Changed Discussion --
AS OF 130 AM EDT TUESDAY... A COLD FRONT EXTENDED FROM RHODE ISLAND TO MICHIGAN TO MISSOURI EARLY THIS MORNING. THIS FRONT WILL MOVE SOUTH INTO THE MID ATLANTIC REGION TODAY. WITH THE BOUNDARY IN THE AREA AND MOISTURE ON THE INCREASE...SCATTERED SHOWERS AND THUNDERSTORM WITH MVFR CEILINGS AND VISIBILITIES ARE EXPECTED THIS AFTERNOON...MAINLY ACROSS THE MOUNTAINS. BY THE LATE MORNING SURFACE WIND GUSTS WILL BE IN THE 15 TO 20 KT RANGE. MODELS BRING THE BEST CHANCE OF SHOWERS AND THUNDERSTORMS INTO THE AREA AFTER 3PM IN KLWB AND NOT UNTIL 5PM AT KDAN. MEDIUM CONFIDENCE ON THE TIMING OF THE PRECIPITATION. EXTENDED AVIATION DISCUSSION... THIS FRONT WILL REMAIN STALLED OVERHEAD TUESDAY NIGHT AND WEDNESDAY...BEFORE A STRONGER COLD FRONT ENTERS FROM THE WEST TO PUSH THE WEAKER FRONT OFFSHORE. DURING THIS TIME...SCATTERED SHOWERS WITH A FEW AFTERNOON THUNDERSTORMS APPEAR LIKELY. THE GREATEST CHANCE OF RAIN AND MVFR/IFR CONDITIONS WILL ACCOMPANY THE STRONGER COLD FRONT ON THURSDAY. SOME CLEARING SHOULD TAKE PLACE DURING FRIDAY...ALTHOUGH A FEW MOUNTAIN SHOWERS AND MVFR CLOUDS ARE POSSIBLE.
-- End Changed Discussion --
&& .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...PW NEAR TERM...PW/RCS SHORT TERM...PH LONG TERM...PH AVIATION...AMS/DS

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