Area Forecast Discussion
Issued by NWS Blacksburg, VA

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
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
-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KRNK 161953 AFDRNK AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BLACKSBURG VA 353 PM EDT TUE SEP 16 2014 .SYNOPSIS... WEAK UPPER LEVEL DISTURBANCES PASSING ALONG A COLD FRONT TO OUR SOUTH WILL TRIGGER A FEW SHOWERS...AND POSSIBLY A THUNDERSTORM... THROUGH THIS EVENING BEFORE A COOL WEDGE OF HIGH PRESSURE SETTLES IN FROM THE NORTH EARLY WEDNESDAY. THE HIGH WILL STRENGTHEN TO THE NORTH OF THE REGION THROUGH THE REST OF THE WEEK...KEEPING RATHER COOL BUT OVERALL DRY WEATHER IN PLACE. && .NEAR TERM /THROUGH WEDNESDAY/... AS OF 345 PM EDT TUESDAY... SURFACE OBSERVATIONS INDICATE THAT THE COLD FRONT HAS EXITED OUR AREA TO THE SOUTH THIS AFTERNOON...AND IS CURRENTLY SITUATED ACROSS NORTHERN NORTH CAROLINA...RESULTING IN A WESTERLY TO NORTHWESTERLY WIND FLOW AS HIGH PRESSURE BUILDS IN FROM THE MIDWEST. CLOUD COVER...WHILE LACKING ACROSS PORTIONS OF THE PIEDMONT...WAS SLOW TO BREAK UP TODAY ACROSS THE MOUNTAINS...WHICH HAS RESULTED IN SHARP TEMPERATURE GRADIENT FROM WEST TO EAST...WITH LOW/MID 60S OBSERVED IN SOUTHEAST WEST VIRGINIA...WHILE AREAS ACROSS THE SOUTHSIDE HAVE REACHED THE 80 DEGREE MARK. THE STRONGER HEATING IN THE EAST IS HELPING SUPPORT A FEW SHOWERS THIS AFTERNOON COMING OFF THE MOUNTAINS...ONE OR TWO OF WHICH MAY INTENSIFY INTO WEAK THUNDERSTORMS BEFORE THE DAY IS DONE. THIS ACTIVITY IS EXPECTED TO LINGER INTO THE OVERNIGHT HOURS AS WEAK UPPER LEVEL DISTURBANCES RIDE ALONG THE FRONT JUST SOUTH OF OUR AREA. LOOKING INTO THE EVENING...HIGH PRESSURE WILL PUSH RAPIDLY EAST ACROSS THE SOUTHERN GREAT LAKES. AS THE HIGH REACHES NEW ENGLAND... IT WILL THEN BUILD SOUTHWARD ACROSS THE MID ATLANTIC TO WEDGE AGAINST THE EASTERN FACE OF THE APPALACHIANS. AS SUCH...EXPECT WINDS TO GRADUALLY SHIFT FROM NORTHWESTERLY THIS EVENING TO NORTHEASTERLY DURING THE PREDAWN HOURS OF WEDNESDAY. THE NORTHEASTERLY WIND FLOW WILL DRAW COOL MOIST AIR FROM THE ATLANTIC UP THE BLUE RIDGE MOUNTAINS...WHERE IT WILL DEVELOP INTO A MIXTURE OF FOG...DRIZZLE AND LOW CLOUDS IN THE HIGHER TERRAIN BEFORE SUNRISE. AND WITH WINDS HOLDING OUT OF THE EAST THROUGH THE REMAINDER OF THE DAY...WE CAN EXPECT PATCHES OF FOG AND DRIZZLE TO LINGER ACROSS THE MOUNTAINS WELL INTO THE AFTERNOON BEFORE WE SEE GRADUAL IMPROVEMENT. COOL MARINE COMING AROUND THE HIGH PRESSURE WEDGE...COMBINED WITH THE WIDESPREAD CLOUD COVER...WILL KEEP AFTERNOON TEMPERATURES VERY MUCH ON THE COOL SIDE. WENT A LITTLE ON THE AGGRESSIVE SIDE IN UNDERCUTTING MODEL GUIDANCE BASED ON THE PROLONGED POTENTIAL FOR DRIZZLE AND LIGHT RAIN LASTING INTO THE AFTERNOON. WILL BE LOOKING FOR HIGHS RANGING FROM THE LOW/MID 60S ACROSS THE MOUNTAINS...TO THE UPPER 60S/LOW 70S ACROSS THE PIEDMONT. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/... AS OF 300 PM EDT TUESDAY... WINDS BECOMING NORTHWEST THROUGH THURSDAY NIGHT WITH ONE SHORTWAVE CROSSING THE FORECAST AREA OUT OF THE TENNESSEE VALLEY ON WEDNESDAY NIGHT FOLLOWED QUICKLY BY A WAVE IN THE NORTHERN STREAM. MODELS ALSO DEPICTING A DECENT JET STREAK AND COOLER 500 MB TEMPERATURES WITH THE TENNESSEE VALLEY SHORT WAVE WEDNESDAY NIGHT. NOT VERY IMPRESSIVE HOWEVER WITH THE LIFT OR DEPTH OF THE MOISTURE ON BUFKIT. HIGH PRESSURE AT THE SURFACE WILL BUILD IN THURSDAY NIGHT AND FRIDAY. BUFKIT SHOWED ENOUGH OF A SHALLOW LAYER OF MOISTURE AND SOUTHEAST UPSLOPE WINDS BY FRIDAY MORNING ALONG THE SOUTHERN BLUE RIDGE THAT STRATUS IS EXPECTED. OCCURRENCE OF DRIZZLE AND FOG IS ALSO POSSIBLE LATE THURSDAY NIGHT IN TO FRIDAY MORNING. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AS OF 300 PM EDT TUESDAY... AFTER A BRIEF RETURN OF SOME FLAT UPPER RIDGING ON FRIDAY NIGHT...AN AMPLIFIED EASTERN UNITED STATES TROF DIGS SATURDAY NIGHT THROUGH TUESDAY...WITH THE ECMWF EVEN HAVING A CUT OFF LOW OVER VIRGINIA BY LATE TUESDAY. LARGE SURFACE HIGH COVERS THE EAST THOUGH SATURDAY NIGHT. BACK IN SOUTHWEST FLOW AND WEAK WARM AIR ADVECTION SATURDAY NIGHT THROUGH SUNDAY...THEN MODELS STILL BRING NEXT FRONT THROUGH MONDAY. THE SOUTHWEST WINDS ON SATURDAY AND SUNDAY MAY ALSO LIMIT THE AMOUNT OF LOW LEVEL MOISTURE IN THE REGION. WILL BE WATCHING FOR DEVELOPMENT OF LOW PRESSURE ALONG THE SOUTHEAST COAST SATURDAY AND SUNDAY WHICH MAY PUSH DEEPER MOISTURE BACK INTO THE EASTERN COUNTY WARNING AREA. FOR NOW MODELS HOLD THE HIGHER MOISTURE EAST OF THE FORECAST AREA. CONTINUE TO SEE THE POTENTIAL FOR TEMPERATURES TUESDAY MORNING TO BE BELOW NORMAL. ALSO BEHIND THE COLD FRONT AS UPSLOPE CLOUD COVER WILL DEVELOP OVER THE MOUNTAINS TUESDAY AND TUESDAY NIGHT. && .AVIATION /20Z TUESDAY THROUGH SUNDAY/... AS OF 215 PM EDT TUESDAY... SURFACE OBSERVATIONS INDICATE THAT THE COLD FRONT HAS JUST EXITED THE FORECAST REGION THIS AFTERNOON...CURRENTLY MOVING ACROSS NORTHERN NORTH CAROLINA. CEILINGS FOR THE PIEDMONT HAVE IMPROVED TO VFR...WHILE THE MOUNTAINS ARE OBSERVING CEILINGS RANGING FROM VFR TO LOW MVFR INTERMIXED. RADAR IS ALSO INDICATING A FEW SHOWERS DEVELOPING ACROSS THE MOUNTAINS NEAR THE VIRGINIA NORTH CAROLINA BORDER...ALTHOUGH MUCH OF THIS ACTIVITY IS DIMINISHING IN THE DOWNSLOPE WIND FLOW ONCE REACHING THE BLUE RIDGE. ADDITIONAL SHOWER DEVELOPMENT...POSSIBLY WITH AN ISOLATED THUNDERSTORM...IS EXPECTED THIS EVENING EAST OF THE MOUNTAINS AS AN UPPER LEVEL DISTURBANCE PASSES OVERHEAD...BUT THIS ACTIVITY WILL REMAIN SPOTTY. HIGH PRESSURE WILL PASS EAST ACROSS THE SOUTHERN GREAT LAKES THIS EVENING AND TONIGHT...REACHING NEW ENGLAND WHERE IT WILL THEN BUILD SOUTHWARD INTO THE MID ATLANTIC...WEDGING AGAINST THE EASTERN FACE OF THE APPALACHIANS. THE PROGRESSION OF THE HIGH WILL BRING WINDS FROM NORTHWESTERLY THIS EVENING TO NORTHEASTERLY SHORTLY BEFORE DAWN ON WEDNESDAY...WHERE IT WILL THEN DRAW MARINE AIR FROM THE ATLANTIC UP THE BLUE RIDGE. CEILINGS WILL THICKEN AND LOWER TO IFR FOR MOST OF THE AREA OVERNIGHT...WITH PATCHY FOG AND DRIZZLE DEVELOPING ACROSS THE MOUNTAINS THAT WILL LIMIT VISIBILITIES TO MVFR/IFR AS WELL. BECAUSE WIND DIRECTION WILL REMAIN IDEAL FOR UPSLOPE THROUGH THE AFTERNOON...LOW MVFR/IFR CONDITIONS ARE EXPECTED FOR MUCH OF THE AREA THROUGH THE END OF THE 16/18Z TAF PERIOD. EXTENDED AVIATION DISCUSSION... BROAD UPPER TROUGH REMAINS IN PLACE ACROSS THE EASTERN STATES FOR THE REMAINDER OF THE WEEK ALLOWING A LARGE AREA OF HIGH PRESSURE TO REMAIN WEDGED ACROSS THE MID ATLANTIC THROUGH THE WEEKEND. THIS SHOULD PUSH THE PESKY DEEP MOISTURE FURTHER SOUTH AWAY FROM THE REGION. HOWEVER BIGGER CONCERN WILL BE WITH TRAPPED RESIDUAL LOW LEVEL MOISTURE THAT MAY KEEP SOUTHERN/WESTERN LOCATIONS STUCK IN PERIODS OF MVFR CIGS INTO FRIDAY AS THE LOW LEVEL EAST/SE FLOW TAKES SHAPE. HIGH PRESSURE MAY BE STRONG ENOUGH TO PUSH THE LOW LEVEL MOISTURE TO THE SOUTHWEST SATURDAY AND WITH HEATING/MIXING COULD SEE THINGS RETURN TO OVERALL VFR FOR EARLY IN THE WEEKEND...BUT NOT UNTIL SATURDAY AFTERNOON AT THIS POINT. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...NF NEAR TERM...NF SHORT TERM...AMS LONG TERM...AMS AVIATION...JH/NF

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