Area Forecast Discussion
Issued by NWS Blacksburg, VA

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000 FXUS61 KRNK 010547 AFDRNK AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BLACKSBURG VA 147 AM EDT WED OCT 1 2014 .SYNOPSIS... A WEAK COOL FRONT WILL DROP SOUTHEAST INTO THE AREA OVERNIGHT AND INTO NORTH CAROLINA BEFORE STALLING ON WEDNESDAY. HIGH PRESSURE TO THE NORTH WILL AGAIN WEDGE SOUTH ALONG THE EASTERN SLOPES OF THE APPALACHIANS LATER WEDNESDAY INTO THURSDAY. A STRONG COLD FRONT ARRIVES LATER FRIDAY FOLLOWED BY MUCH COOLER AIR FOR THE WEEKEND. && .NEAR TERM /THROUGH TODAY/... AS OF 1100 PM EDT TUESDAY... UPDATE TO ADD ISOLATED SHOWERS ACROSS THE FAR NORTH WITH PERHAPS A SHOWER OR TWO MAKING IT ACROSS INTO THE HIGHLANDS/SHENANDOAH VALLEY UNDER THE PASSING UPPER SYSTEM TO THE NORTH. ALSO BOOSTED LOW CLOUDS IN THE EAST PER LATEST IR PICS AS EXPECT MORE TO FILL IN UNDER THE RESIDUAL COOL POOL EAST OF THE BLUE RIDGE OVERNIGHT. OTRW CALLING IT PARTLY TO MOSTLY CLOUDY FAR NORTH AND EAST WITH MOSTLY CLEAR SKIES FARTHER SOUTH GIVEN DRY AIR ALOFT ABOVE THE INVERSION. WILL AGAIN SEE AREAS OF DENSE FOG ESPCLY WESTERN VALLEYS PER LOW END STABILITY VALUES AND ACROSS THE EAST WHERE LOW LEVEL MOISTURE REMAINS. HOWEVER APPEARS DRYING FROM EARLIER TODAY WILL LIMIT COVERAGE SOMEWHAT SO NOT EXPECTING A NEED FOR AN ADVISORY OVERNIGHT. ADJUSTED TEMPS DOWN SOME OVER THE WEST WHERE ALREADY CLOSE TO FORECAST LOWS...AND ACROSS THE SOUTH GIVEN BETTER RADIATIONAL COOLING THAN ACROSS THE NORTH WHERE MORE CLOUDS LIKELY. AN AREA OF LOW PRESSURE SOUTH OF THE GREAT LAKES WILL DROP SOUTHWARD INTO THE MID ATLANTIC WEDNESDAY MORNING...BRINGING A COLD FRONT TO THE INTERSTATE 64 CORRIDOR BY SUNRISE...WITH THE FRONT CONTINUING TO DRIFT SOUTH THROUGH THE DAY. BEST INSTABILITY... WHICH OVERALL IS VERY MODEST...WILL BE LOCATED IN THE VICINITY OF THE LOW...AND WILL SUPPORT SPOTTY SHOWER ACTIVITY FROM THE ALLEGHANY HIGHLANDS INTO THE PIEDMONT. EVEN WITH THE FRONT SINKING ACROSS THE AREA...TRULY COOLER AIR WILL REMAIN TO THE NORTH. EXPECT AFTERNOON HIGHS TO RANGE FROM THE LOW TO MID 70S ALONG THE INTERSTATE 64 CORRIDOR AND THE NORTH CAROLINA MOUNTAINS...TO THE LOW 80S ACROSS THE NORTH CAROLINA PIEDMONT. && .SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/... AS OF 257 PM EDT TUESDAY... A CLOSED LOW WILL MOVE OFF THE NORTHEAST COAST WEDNESDAY AFTERNOON. NORTHERLY FLOW ON THE BACK SIDE OF THIS LOW WILL HELP PUSH A WEAK COOL FRONTAL BOUNDARY SOUTH OF THE AREA WEDNESDAY NIGHT. THIS WEDGE OF HIGH PRESSURE WILL HAVE LIGHT EASTERLY FLOW AND...COMBINED WITH MOISTURE...LOW CLOUDS/FOG/DRIZZLE ARE LIKELY ALONG AND EAST OF THE BLUE RIDGE INTO AT LEAST THURSDAY MORNING. THROUGH THE DAY THURSDAY...AN UPPER LEVEL RIDGE AXIS WILL MOVE OVER THE EAST COAST AND WITH THE HELP OF WESTERLY FLOW...FOG AND STRATUS DECK SHOULD SCOUR BY THE AFTERNOON. ISENTROPIC LIFT MAY REMAIN OVER THE PIEDMONT LONGER WITH LOW CLOUDS LINGERING WELL INTO THE AFTERNOON...POSSIBLY THE EVENING. A COLD FRONT WILL APPROACH THE AREA THURSDAY NIGHT. INCREASED MIXING OVER THE REGION WILL ERODE WHAT IS LEFT OF THE WEDGE THROUGH THE NIGHT AND INTO FRIDAY MORNING. THE COLD FRONT WILL MOVE QUICKLY ACROSS THE EASTERN HALF OF THE USA FRIDAY AND FRIDAY NIGHT. AROUND SUNRISE FRIDAY...THE FRONT IS OVER THE MISSISSIPPI VALLEY. AROUND SUNSET...THE FRONT IS OVER THE OHIO/TENNESSEE VALLEYS MOVING INTO THE APPALACHIAN MOUNTAINS. THIS FRONT WILL BE ALONG THE EASTERN SEA BOARD BY SUNRISE SATURDAY MORNING. MODEL TIMING OF PREFRONTAL SHOWERS REMAINS CONSISTENT... OVER THE MOUNTAINS IN THE MORNING...ENTIRE FORECAST AREA IN THE AFTERNOON...EXITING THE PIEDMONT DURING THE EVENING. INSTABILITIES ARE NOT TOO IMPRESSIVE WITH THIS STRONG FRONT...SOME MAY BE LUCKY TO HEAR A FEW RUMBLES OF THUNDER. RAINFALL AMOUNTS WILL RANGE FROM A QUARTER TO HALF OF AN INCH /0.25-0.50/. BEHIND THE FRONT...A TIGHT PRESSURE GRADIENT WILL BRING BREEZY AND GUSTY CONDITIONS ALONG RIDGE TOPS...WITH STRONGER WINDS MIXING TO THE LOWER LEVELS DURING THE DAY SATURDAY. WEST-NORTHWEST FLOW MAY KEEP CLOUDS OVER THE MOUNTAINS FRIDAY NIGHT WITH SOME PATCHY DRIZZLE ALONG WESTERN SLOPES. DOWNSLOPE FLOW EAST OF THE BLUE RIDGE WILL ERODE CLOUDS AND BE CLEAR BY SUNRISE. WITH EASTERLY FLOW AND A WEAK WEDGE IN THE EAST...UNIFORM TEMPERATURES IN THE 70S ARE EXPECTED THURSDAY. SINCE SHOWERS WILL OVERSPREAD THE MOUNTAINS DURING THE MORNING...HIGH TEMPERATURES MAY REACH 70F. LATER ARRIVAL OF SHOWERS AND CLOUDS ACROSS THE FOOTHILLS AND PIEDMONT COULD HAVE TEMPERATURES PEAKING OUT IN THE UPPER 70S...POSSIBLY LOWER 80S TOWARDS SOUTHSIDE FRIDAY AFTERNOON. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 310 PM EDT TUESDAY... A COLD FRONT WILL BE ALONG THE EAST COAST SATURDAY MORNING WITH DRIER COOLER AIR MOVING IN ON WEST-NORTHWEST FLOW. HIGH PRESSURE ALONG THE GULF AND LOW PRESSURE OVER NEW ENGLAND WILL PLACE A PRESSURE GRADIENT OVER THE AREA SATURDAY. BREEZY AND GUSTY CONDITIONS THROUGH SATURDAY EVENING...THEN HIGH PRESSURE BUILDS NORTH INTO THE REGION. HIGH PRESSURE WILL CONTINUE TO TRACK EAST ALONG THE GULF OVER THE WEEKEND...SHUTTING DOWN ANY MOISTURE RETURNING INTO THE REGION. MODELS ARE MOVING A MID LEVEL DISTURBANCE ACROSS THE OHIO VALLEY MONDAY NIGHT INTO TUESDAY. AS THIS DISTURBANCE APPROACHES THE AREA...IT WILL BE HARD-PRESSED TO PRODUCE WIDESPREAD SHOWERS DUE TO A LACK OF MOISTURE RECOVERY. TEMPERATURES WILL RUN 5F-10F COOLER THAN NORMAL OVER THE WEEKEND. TEMPERATURES BEGIN TO MODERATE TOWARDS NORMAL MONDAY AND TUESDAY. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... AS OF 138 AM EDT WEDNESDAY... TRICKY AVIATION FORECAST...AS GETTING LOW CLOUDS AND FOG STRETCHING FROM ROANOKE EAST TO LYH/DAN PER WEDGE. MODELS NOT HANDLING THIS THAT GOOD...BUT PERSISTENCE GIVEN NIGHTTIME FAVORS NO CHANGE IN THE OVERALL IFR OR LOWER CIGS/VSBYS. ROANOKE WILL BE ON THE WESTERN FRINGE OF THIS SO AT TIMES IT MAY SCATTER OUT...BUT CONFIDENCE IS TO KEEP THEM STUCK IN OVC SUB 1KFT CIGS. WILL HAVE DENSE FOG GOING AT DAN/LYH THOUGH AT TIMES THIS WILL BE AFFECTED BY SOME CLOUDINESS. OVER THE MOUNTAINS IN THE CLEAR TO PARTLY CLOUDY SKIES MAY SEE SOME FOG AT LWB/BCB WITH LOCALLY DENSE AT BCB...AS SOME CIGS AROUND 5-7KFT AROUND LWB SHOULD KEEP FOG LIMITED. FOR LATE THIS MORNING...LEANING TOWARD A SLOWER LIFTING OF THE STRATUS DECK FROM ROA EAST TO LYH/DAN WHILE THE WEST BECOMES VFR AROUND 13-14Z. WILL SEE VFR BKN CIGS RETURN TO THE PIEDMONT BY MIDDAY-EARLY AFTERNOON. A FEW SHOWERS WITH BACK DOOR FRONT MAY SKIRT CLOSE TO LYH BUT NOT ENOUGH TO WARRANT MENTION IN TAFS AT THIS POINT. EXTENDED AVIATION DISCUSSION... VFR CEILINGS AND VISIBILITIES CAN BE EXPECTED FOR THURSDAY... ALTHOUGH LOCALIZED PERIODS OF SUB-VFR ARE LIKELY TO OCCUR FOR THE MOUNTAIN VALLEY AIRPORTS KBCB/KLWB AGAIN THURSDAY MORNING. THE NEXT THREAT FOR SUB VFR CEILINGS AND VISIBILITIES WILL COME WITH A STRONGER FRONTAL PASSAGE ON FRIDAY. THIS FRONT WILL LIKELY BE ASSOCIATED WITH A LINE OF SHOWERS AND FEW THUNDERSTORMS...SWEEPING WEST TO EAST ACROSS THE REGION. NORTHWEST WINDS WILL BE GUSTY BEHIND THE FRONT FRIDAY NIGHT INTO SATURDAY. SATURDAY SHOULD BE VFR ALTHOUGH SOME UPSLOPE MVFR CEILINGS ARE POSSIBLE AT KLWB AND ESPECIALLY KBLF. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...JH NEAR TERM...JH/NF/PM SHORT TERM...RCS LONG TERM...RCS AVIATION...WP

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