Area Forecast Discussion
Issued by NWS Blacksburg, VA

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000 FXUS61 KRNK 242334 AFDRNK AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BLACKSBURG VA 734 PM EDT FRI APR 24 2015 .SYNOPSIS... HIGH PRESSURE SHIFTS EAST OFF THE COAST TONIGHT AS LOW PRESSURE TRACKS FROM THE CENTRAL PLAINS TONIGHT...PASSING ACROSS OUR AREA SATURDAY NIGHT. THIS SYSTEM WILL LINGER INTO SUNDAY. HIGH PRESSURE WILL ARRIVE EARLY NEXT WEEK...FOLLOWED A SOUTHERN STREAM STORM SYSTEM WHICH MAY BRING WET WEATHER MIDWEEK. && .NEAR TERM /THROUGH SATURDAY/... AS OF 700 PM EDT FRIDAY... MADE ONLY MINOR ADJUSTMENTS TO EXISTING GRIDS...FORECAST APPEARS TO BE ON TRACK. PREVIOUS VALID DISCUSSION... AS OF 245 PM EDT FRIDAY... LOWS TONIGHT FROM THE MID 30S OVER THE MTN VALLEYS IN THE NORTH TO LOWER 40S SOUTH. NOT EXPECTING ANY FROST/FREEZE AS CLOUDS WILL MOVE IN AND DRY AIRMASS AT FIRST WILL NOT ALLOW ANY FROST TO FORM...AND OVERNIGHT AS THE CLOUDS ARRIVE...TEMPERATURES STEADY OUT OR COULD RISE A DEGREE OR TWO. MODELS ARE CONSISTENT BRINGING MAINLY LIGHT RAIN TO THE MOUNTAINS BY 12Z SATURDAY THE QUICKLY SHIFTING BETTER LIFT ALONG/AHEAD OF A WARM FRONT THROUGH OUR AREA BY MIDDAY SATURDAY. GOOD SW FLOW AHEAD OF THE SFC LOW OVER MISSOURI INTO THE LOWER OHIO VALLEY SATURDAY WILL KEEP RAIN GOING OFF AND ON MOST OF THE DAY. QUESTION IN THE AFTERNOON IS IN SITU WEDGE WITH DEPARTING HIGH AND INSTABILITY/WEDGE FRONT OVER THE SW CWA. SPC HAS OUR FAR SW VA/NW NC/SE WV IN MARGINAL TO SLIGHT RISK FOR SVR STORMS. THE ENERGY IS THERE...BUT THINK THE OVERRUNNING RAIN AHEAD OF THIS WILL ACT TO HOLD ANY SVR THREAT OFF. THUNDERSTORM CHANCES ARE POSSIBLE FROM BKW-BLF-MKJ-TNB AND POINTS SW BY LATE AFTERNOON. WITH WEDGE IN PLACE UNDERCUT MOS IN THE TYPICAL CAD AREAS BY 5-8 DEGREES FROM MOS. THE 00Z ECMWF MOS WAS CLOSEST TO SHOWING THIS. WITH RAIN AND WEDGE TEMPERATURES SHOULD ONLY MANAGE THE LOWER TO MID 50S FROM SE WV...SOUTHEAST TO THE BLUE RIDGE OF NC AND POINTS EAST...WHILE THE MTNS OF FAR SW VA AND ALONG THE TN/NC LINE COULD SEE LOWER 60S. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/... AS OF 330 PM EDT FRIDAY... WE WILL START OFF THE PERIOD SATURDAY NIGHT WITH A WARM FRONT DRAPED ACROSS THE REGION EXTENDING FROM A LOW PRESSURE AREA OVER THE MID MISSISSIPPI VALLEY WITH WAVES RIPPLING ALONG IT. THIS WILL BRING A GOOD DOSE OF RAINFALL TO THE REGION ALONG WITH SOME EMBEDDED THUNDER ESPECIALLY WEST AND SOUTH. BELIEVE ANY SIGNIFICANT CONVECTION THAT INITIATES TO OUR WEST WILL WEAKEN SUBSTANTIALLY AS IT ENCOUNTERS COOLER AND MUCH LESS FAVORABLE CONDITIONS OVER OUR AREA. THE LOW WILL CROSS OUR AREA SUNDAY MORNING AND LEAVE US WITH JUST SOME LINGERING SHOWERS WINDING DOWN DURING THE AFTERNOON. QPF TOTALS FROM SATURDAY AND EARLY SUNDAY WILL BE SIGNIFICANT WITH MANY LOCATIONS AROUND AN OE INCH...BUT LATEST ENSEMBLE RIVER GUIDANCE DOES NOT INDICATE ANY LOCATIONS EXCEEDING FLOOD STAGE. GIVEN THE WET ANTECEDENT CONDITIONS AND EXPECTED EMBEDDED THUNDER THIS SITUATION WILL BE MONITORED CLOSELY AND FLOOD WATCHES MAY BE NEEDED IF LATER GUIDANCE COMES IN WETTER. HIGH PRESSURE WILL RIDGE IN FROM THE WEST FOR MONDAY WITH CONTINUED COOL TEMPERATURES AND SOME UPSLOPE SPRINKLES FAR WEST. && .LONG TERM /TUESDAY THROUGH FRIDAY/... AS OF 330 PM EDT FRIDAY... UPPER PATTERN WANTS TO KEEP REBUILDING AN EASTERN TROF WHICH WILL KEEP US IN COOL CONDITIONS THROUGH MID TO LATE WEEK. LATEST GUIDANCE SEEMS TO BE CONVERGING ON A SOLUTION WHICH WAS SUGGESTED BY AN EARLIER NAEFS RUN WITH SIGNIFICANT SHORT WAVE ENERGY ENTERING THE EASTERN TROF AND DRIVING DEVELOPMENT OF A SURFACE LOW OVER THE SOUTHEAST US. THERE ARE STILL SUBSTANTIAL DISPARITIES BETWEEN THE GUIDANCE BUT OUR CHANCES OF PRECIPITATION ARE LOOKING HIGHER FOR WEDNESDAY INTO THURSDAY. FRIDAY LOOKS BREEZY AND COOL WITH A FEW UPSLOPE RAIN SHOWERS. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
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AS OF 730 PM EDT FRIDAY... CONFIDENCE HIGH FOR VFR CIGS/VSBYS TO CONTINUE ACROSS THE REGION THROUGH AT LEAST 09Z/5AM SATURDAY. CONFIDENCE HIGH FOR CIGS/VSBYS TO TREND TO MVFR CONDITIONS DURING THE DAY SATURDAY AS A BROAD REGION OF RAIN SPREADS NORTHEAST ACROSS THE REGION IN ADVANCE OF AN AREA OF LOW PRESSURE MOVING THROUGH THE MID-MISSISSIPPI VALLEY...AND ITS ASSOCIATED WARM FRONT LIFTING NORTH THROUGH THE TENNESSEE VALLEY. POCKETS OF IFR CIGS ALSO POSSIBLE. ISOLATED THUNDERSTORMS ARE POSSIBLE ALONG AND SOUTHWEST OF A KBLF-KMWK LINE AFTER ROUGHLY 20Z/4PM SATURDAY. WIND FORECAST HAS MODERATE CONFIDENCE GIVEN IT HAS VARIABLE WIND DIRECTION EXPECTED...ESPECIALLY DURING THE DAY SATURDAY. WHILE AREAS EAST OF THE PIEDMONT WILL GENERALLY SEE NORTHEAST WINDS...AREAS ACROSS THE MOUNTAINS WILL EXPERIENCE MORE OF A SE-S ORIENTATION. THE GOOD NEWS IS SPEEDS ARE NOT ANTICIPATED TO BE VERY STRONG. MOST AREAS WILL HAVE SPEEDS UNDER 8 KTS. AS OF 135 PM EDT FRIDAY... EXTENDED AVIATION DISCUSSION... MAY SEE SOME VFR RETURNING SAT NIGHT AS WARM FRONT LIFTS NORTH AND WEDGE BREAKS...BUT EXPECT MORE SCATTERED TO NUMEROUS SHOWERS IN SUNDAY...WITH SUB VFR AT TIMES. FLYING CONDITIONS SHOULD START TO IMPROVE SOME BY MONDAY AS THE LOW PULLS FARTHER OFFSHORE AND WEAK HIGH PRESSURE BUILDS IN FROM THE NORTHWEST. HOWEVER CONTINUED CYCLONIC FLOW LIKELY TO KEEP MORE MVFR CIGS OVER THE MOUNTAINS WITH IMPROVEMENT TO VFR ACROSS THE EAST ON MONDAY. BREEZY CONDITIONS MONDAY-TUESDAY WITH HIGH PRESSURE STARTING TO BUILD IN FROM THE NORTHWEST...SO VFR CONTINUES. BY WEDNESDAY A SOUTHERN STREAM SYSTEM APPEARS TO MAINLY AFFECT THE GULF COAST TO CAROLINAS BUT COULD SEE SEND RAIN OR SUB VFR CIGS INTO THE DAN-BCB-BLF AREA...BUT CONFIDENCE IS LOW.
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&& .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...NF/WP NEAR TERM...PC/WP SHORT TERM...MBS LONG TERM...MBS AVIATION...DS/RAB/WP

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