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 270540 AFDRNK AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BLACKSBURG VA 140 AM EDT WED AUG 27 2014 .SYNOPSIS... HIGH PRESSURE WILL REMAIN IN CONTROL OF THE WEATHER PATTERN THROUGH WEDNESDAY. A WEAK COLD FRONT WILL ENTER FROM THE NORTH WEDNESDAY NIGHT AND STALL ACROSS OUR AREA THROUGH THURSDAY AND FRIDAY...PROVIDING THE FOCUS FOR OCCASIONAL SHOWERS AND THUNDERSTORMS. THE FRONT WILL LIFT NORTH AGAIN ON SATURDAY AS A WARM FRONT. && .NEAR TERM /THROUGH TODAY/... AS OF 930 PM EDT TUESDAY... TWEAKED NEAR TERM TEMP/DEWPT/SKY GRIDS TO REFLECT CURRENT OBS. ALL OTHER FORECAST DETAILS REMAIN ON TRACK FROM PREVIOUS DISCUSSION. AS OF 330 PM EDT TUESDAY... HIGH PRESSURE ACROSS SOUTHERN PENNSYLVANIA THROUGH NORTHERN VIRGINIA IS THE DOMINANT WEATHER FEATURE IN THE LOW LEVELS... WHILE THE AXIS OF AN UPPER LEVEL RIDGE IS SITUATED EAST TO WEST FROM THE MID ATLANTIC THROUGH THE CENTRAL MISSISSIPPI VALLEY. SATELLITE IMAGERY INDICATES SOME THIN HIGH CLOUDS SPILLING OVER THE RIDGE ACROSS THE APPALACHIANS...OTHERWISE SUBSIDENCE ASSOCIATED WITH THE RIDGE HAS BEEN DOING A GOOD JOB OF LIMITING DEVELOPMENT OF THE LOWER CLOUDS TO ONLY A FEW AREAS ACROSS THE PIEDMONT. FOR TONIGHT...CLEAR SKIES AND LIGHT WINDS WILL RESULT IN ANOTHER NIGHT OF STRONG RADIATIONAL COOLING. WHEN FACTORING IN MOIST SOILS FROM RECENT RAINFALL...CONDITIONS ARE IDEAL FOR ANOTHER ROUND OF PATCHY FOG TO DEVELOP AFTER MIDNIGHT...ESPECIALLY IN THE RIVER VALLEYS ACROSS THE MOUNTAINS. WITH THE UPPER RIDGE IN PLACE HOWEVER...EXPECT SLIGHTLY WARMER OVERNIGHT LOWS COMPARED TO THE PREVIOUS COUPLE NIGHTS...WITH UPPER 50S TO AROUND 60 ACROSS THE PIEDMONT...WHILE THE MOUNTAINS WILL FALL INTO THE LOW/MID 50S MOST AREAS...POSSIBLY INTO THE UPPER 40S IN A FEW OF THE DEEPER VALLEYS. 850 MB TEMPERATURES WILL BE A DEGREE OR TWO WARMER ON WEDNESDAY... DESPITE THE AXIS OF UPPER LEVEL RIDGING MOVING SOUTH OF AREA. WILL ALSO SEE WINDS SHIFT MORE NORTHWESTERLY IN RESPONSE TO HURRICANE CRISTOBAL PASSING NORTHWARD WELL OFF THE ATLANTIC COAST. WHILE WINDS WILL REMAIN LIGHT AND CRISTOBAL WILL HAVE NO FURTHER AFFECT ON OUR WEATHER...THE NORTHWESTERLY DOWNSLOPE FLOW WILL RESULT IN SLIGHTLY BETTER HEATING AND...WHEN COMBINED WITH THE HIGHER 850 MB TEMPERATURES...SHOULD LIFT HIGHS SOME 3 TO 5 DEGREES WARMER OVER THOSE OBSERVED TODAY. WILL START THE DAY WITH MOSTLY CLEAR SKIES...HOWEVER EXPECT CLOUDS TO INCREASE DURING EARLY EVENING AS A COLD FRONT APPROACHES FROM THE NORTH. && .SHORT TERM /TONIGHT THROUGH FRIDAY/... AS OF 320 PM EDT TUESDAY... WILL BE SANDWICHED BETWEEN CRISTOBAL WELL EAST OF HATTERAS AND SFC HIGH RIDGING FROM THE GREAT LAKES INTO THE SRN APPALACHIANS WED NIGHT...WITH A WEAK BACKDOOR FRONT TRACKING ACROSS THE NRN CWA. MAINLY LOOKING AT DRY WX WED NIGHT...COULD SEE A FEW SHOWERS TOWARD WRN GREENBRIER...BUT AIRMASS APPEARS TOO DRY WITH HARDLY ANY UPPER SUPPORT. CRISTOBAL HEADS FURTHER AWAY THURSDAY WHILE SFC HIGH BUILDS EWD TO THE ERN GREAT LAKES...SOUTH TOWARD THE CENTRAL APPALACHIANS WITH WEAK FRONT ACROSS THE NRN CWA. UPPER HEIGHTS START BUILDING DURING THIS PERIOD INTO THE LONG TERM. FRONTAL LIFT IS WEAK...BUT AS THE LOW LVL FLOW TURNS MORE EAST THU-FRI APPEARS ENOUGH SFC CONVERGENCE ACROSS THE AREA TO ALLOW FOR A FEW SHOWERS AND STORMS TO FORM. NOTHING WIDESPREAD AT THIS POINT AS STRENGTHENING UPPER RIDGE MAY CAP THINGS SOME. AFTER COOL LOW TEMPS EARLY THIS WEEK...TEMPS START TO MODERATE BACK TO AUGUST VALUES AS LOWS RANGE FROM AROUND 60 MTNS WED-THU NIGHT TO MID 60S EAST...WHILE HIGHS REACH THE LOWER 80S WEST TO MID TO UPPER 80S EAST. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AS OF 210 PM EDT TUESDAY... AIRMASS CHANGE IN STORE AS 5H RIDGE BUILDS ACROSS THE SOUTHEAST THEN SHIFTS EWD THROUGH NEXT WEEK. THIS IS GOING TO PROVIDE HOTTER TEMPS FOR LABOR DAY WEEKEND WITH INCREASED HUMIDITY. TROUGH WILL BE SITUATED OVER THE MIDWEST SAT...SHIFTING EWD INTO THE GREAT LAKES SUNDAY WHILE SHEARING OUT. FRONTAL BOUNDARY IS GOING TO LAY ACROSS THE OHIO VALLEY. MOISTURE SURGING NWD FROM THE GULF COAST SHOULD START TRACKING CLOSER TO OUR AREA. SAT WILL BE THE DRIEST DAY FOR THE OFFICIAL END TO THE SUMMER SEASON...BUT ISOLATED STORMS ARE POSSIBLE IN THE MTNS. SUNDAY IS GOING TO BE A BIT WETTER AS THE FRONT TRACKS CLOSER BUT STILL IT LOOKS SCATTERED INSTEAD OF WIDESPREAD...BEST COVERAGE OVER THE MTNS. SO FOR THOSE PLANNING OUTDOOR ACTIVITIES BE AWARE FOR BOTH STORMS/LIGHTNING AND HOTTER TEMPS. LABOR DAY ITSELF SHOULD BE STORMY ALTHOUGH FRONT WILL BE NORTH OF US...BUT UPPER SHORTWAVE MAY PASS ACROSS THE CENTRAL APPALACHIANS INDUCING BETTER LIFT WITH INCREASED MOISTURE. THE UPPER HEIGHTS FLATTEN SOMEWHAT AS WELL. HIGHS MONDAY ARE GOING TO STILL BE VERY WARM WITH LOWER 80S MOUNTAINS TO NEAR 90 SOUTHEAST...THOUGH INCREASED HUMIDITY AND SW FLOW WILL HINDER A BIG RISE IN TEMPS. BY TUESDAY...WE ARE STILL SEEING SOMEWHAT FLATTENING OF THE RIDGE NORTH OF US...WITH NEXT UPSTREAM TROUGH MOVING ACROSS THE UPPER MISSISSIPPI VALLEY. LOOKS MORE LIKE DIURNALLY DRIVEN CONVECTION THOUGH 00Z ECMWF SHOWS WEAK IMPULSE MOVING ACROSS THE AREA TUESDAY AFTN. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... AS OF 130 AM EDT WEDNESDAY... AREAS OF MVFR TO LIFR VALLEY FOG WILL DEVELOP EARLY THIS MORNING...ESPECIALLY ALONG THE NEW AND GREENBRIER RIVER. HIGH CONFIDENCE THAT KBCB AND KLWB WILL LOWER TO LIFR VISIBILITIES FROM AROUND 08Z/4AM TO 12Z/8AM. FOG WILL BURN OFF QUICKLY AFTER 13Z AS DAYTIME HEATING AND MIXING DEVELOPS. ELSEWHERE...LITTLE OR NO IMPACT EXPECTED FROM THE RIVER VALLEY FOG WITH VFR CONDITIONS DOMINATING THROUGH THE 24 HOUR TAF PERIOD. EXTENDED DISCUSSION... A COLD FRONT WILL SINK SOUTHWARD FROM THE GREAT LAKES EARLY THURSDAY TO SETTLE ACROSS THE CENTRAL APPALACHIANS. SPOTTY SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE INTO THE WEEKEND AS WEAK DISTURBANCES PASS ALONG THE BOUNDARY. BRIEF PERIODS OF SUB VFR CONDITIONS ARE EXPECTED WITH THE PRECIPITATION. && .EQUIPMENT... AS OF 130 AM EDT WEDNESDAY ... THE VISIBILITY SENSOR AT KDAN...DANVILLE REGIONAL AIRPORT...WAS OUT OF SERVICE. REPAIRS WILL BE MADE LATER THIS MORNING. THE NOAA ALL HAZARDS RADIO...WXL92...ON 162.550 MHZ...WAS OFF THE AIR DUE TO A PHONE LINE OUTAGE. TECHNICIANS WERE WORKING TO RESTORE SERVICE. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...NF NEAR TERM...CF/NF SHORT TERM...WP LONG TERM...WP AVIATION...AMS/PM EQUIPMENT...AMS

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