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
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KRNK 280557 AFDRNK AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BLACKSBURG VA 157 AM EDT SUN JUN 28 2015 .SYNOPSIS... A COLD FRONT WILL CROSS THE AREA OVERNIGHT. COOLER...AND DRIER HIGH PRESSURE WILL BUILD INTO THE AREA FOR THE REMAINDER OF THE WEEKEND. OUR CHANGE IN WEATHER REGIMES WILL BE SHORT LIVED AS WE RETURN TO A MORE PROGRESSIVE WEATHER PATTERN NEXT WEEK...WITH SHOWERS AND STORMS IN THE FORECAST EVERY DAY FROM TUESDAY ONWARD. && .NEAR TERM /THROUGH TODAY/... AS OF 1030 PM EDT SATURDAY... FROPA! FRONTAL PASSAGE ONGOING. IT PASSED NWS BLACKSBURG AT JUST AFTER 10 PM. SHOULD CROSS THE ROANOKE VALLEY BETWEEN NOW AND MIDNIGHT...THEN EAST OF THE CWA BY SUNRISE SUNDAY. A REFRESHINGLY DRIER AIRMASS WILL OVERTAKE THE REGION...COMPLIMENTED BY A FRESH NORTHWEST WIND. SEVERE THREAT HAS ENDED. ASIDE FROM A FEW LINGERING SHOWERS ASSOCIATED WITH THE FRONT...TREND WILL BE FOR DECREASING PRECIP COVERAGE. STRENGTH OF SURFACE FRONT IS SIMILAR TO WHAT WE TYPICALLY EXPERIENCE DURING THE WINTER WITH GUSTY WINDS PERSISTING FOR ABOUT 24 HOURS AFTER FROPA. GIVEN THE MAGNITUDE OF THE WINDS ALOFT... 850 MB WINDS INCREASING TO BETWEEN 40-50KTS BY DAYBREAK SUNDAY... SHOULD EXPERIENCE SOME RESPECTABLE SURFACE GUSTS...ESPECIALLY ALONG THE RIDGE CRESTS...AND JUST LEE OF THE MOUNTAIN RIDGES. THE HIGHEST ELEVATIONS ARE EXPECTED TO SEE GUSTS UP TO 45 MPH WITH 25 TO 35 MPH MORE COMMON ACROSS THE REMAINDER OF THE AREA NEAR THE BLUE RIDGE. WITH LEAVES ON THE TREES...AND A RELATIVELY WET GROUND COURTESY OF THE SHOWERS THE LAST FEW DAYS...GUSTS OF THESE SPEEDS MAY UPSET A FEW TREES. AS SUCH...A WIND ADVISORY IS IN EFFECT FOR LATE TONIGHT THROUGH SUNDAY AFTERNOON TO STRESS THIS POTENTIAL IMPACT ACROSS THE MOUNTAINS. WINDS ARE EXPECTED TO SUBSIDE SUNDAY EVENING AS HIGH PRESSURE SETTLES OVER THE AREA FOR SUNDAY NIGHT. FOR TEMPERATURES...LOW TEMPERATURES TONIGHT WILL BE SOME FIVE TO TEN DEGREES COOLER THAN READINGS EXPERIENCED EARLY SATURDAY MORNING. LOOK FOR MID TO UPPER 50S ACROSS THE MOUNTAINS TO LOWER 60S ACROSS THE PIEDMONT. ON SUNDAY...HIGH TEMPERATURES WILL RANGE FROM THE MID TO UPPER 70S ACROSS THE MOUNTAINS TO AROUND 80 TO THE LOWER 80S ACROSS THE PIEDMONT. SUNDAY NIGHT WILL BE THE COOLEST NIGHT WE HAVE EXPERIENCED FOR A WHILE...AROUND 50 TO THE MID 50S ARE EXPECTED ACROSS THE MOUNTAINS TO THE MID TO UPPER 50S ACROSS THE PIEDMONT. WHILE NO RECORD LOWS ARE FORECAST SUNDAY...A FEW LOCATIONS WILL GET WITHIN FIVE DEGREES OF THEIR CORRESPONDING RECORDS. REVIEW THE CLIMATE SECTION OF THIS DISCUSSION FOR DETAILS. && .SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/... AS OF 130 PM EDT SATURDAY... BROAD TROUGHING WILL DOMINATE THE EASTERN U.S. THROUGH THE PERIOD WITH BELOW NORMAL HEIGHTS AND CONSIDERABLY LOWER 850MB TEMPS THAN WE HAVE SEEN IN RECENT WEEKS. HOWEVER...THERE APPEAR TO BE NUMEROUS EMBEDDED DISTURBANCES WITHIN THE FLOW IN AN ALMOST WINTERLIKE PATTERN THAT SETS UP THROUGH THE PERIOD. OVERALL THE PATTERN IS QUITE UNSETTLED WITH NUMEROUS CHANCES FOR SHOWERS AND THUNDERSTORMS. CLEARLY FEW IF ANY SIGNIFICANT TIME PERIODS DURING THE PERIOD WHERE POPS CAN BE LEFT UNMENTIONABLE. THE FIRST DISTURBANCE OF CONCERN ARRIVES MONDAY AFTERNOON...WITH A WEAK SFC WARM FRONT LIFTING NORTH THROUGH THE CWA. 850MB TEMPS BEING TO RISE FROM THE SINGLE DIGITS EARLY IN THE DAY TO THE 10 TO 15C RANGE BY EVENING. INSTABILITY IS MEAGER...BUT ENOUGH CREEPING IN FROM THE WEST LATE IN THE DAY WITH THE DISTURBANCE TO WARRANT THE MENTION OF TSRA. SEVERE POTENTIAL APPEARS HIGHLY UNLIKELY WITH THIS FIRST SYSTEM AND MOISTURE IS JUST BEGINNING TO RETURN IN EARNEST...SO HEAVY RAIN SHOULD NOT BE A THREAT EITHER AT THAT POINT. MUCH OF THE FOCUS OF THIS FIRST SYSTEM WILL BE WEST OF THE BLUE RIDGE...AND MORE SO ACROSS WV...LIFTING NORTHWARD TOWARD MD/PA BY EVENING. THE NEXT DISTURBANCE TO ROTATE THROUGH THE TROUGH ARRIVES TUESDAY AFTERNOON AS THE UPPER TROUGH BEGINS TO DEEPEN AND SHIFT EVER SO SLIGHTLY EAST. CONDITIONS APPEARS SLIGHTLY MORE FAVORABLE FOR STRONGER AND MORE WIDESPREAD THUNDERSTORMS WITH THIS EVENT. HOWEVER...AT THIS POINT HAVE CAPPED POPS IN THE 50 PERCENT RANGE WEST AND 40 PERCENT RANGE EAST. FOR A CHANGE...TEMPERATURES WILL BE SLIGHTLY BELOW NORMAL AT THE BEGINNING OF THE PERIOD...MODERATING TO NEAR NORMAL READINGS BY THE END OF THE PERIOD. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... AS OF 215 PM EDT SATURDAY... THE BROAD UPPER TROUGH WILL CONTINUE THROUGH THE EXTENDED PERIODS...BUT WILL GRADUALLY RETROGRADE WITH TIME. A QUITE ACTIVE BAROCLINIC ZONE APPEARS DESTINED TO BECOME ESTABLISHED FROM THE NORTHERN PLAINS ACROSS THE TN/OH VALLEY INTO THE SOUTHERN APPALACHIANS AND SOUTHEAST STATES. MODELS VARY SLIGHTLY ON THE EXACT PLACEMENT OF THIS BAROCLINIC ZONE...BUT MOST HAVE IT OVER OR VERY NEAR THE SOUTHERN END OF THE CWA THROUGH MUCH OF THE PERIOD. THE GFS IS THE MOST AGGRESSIVE IN PUSHING IT INTO THE SOUTHEAST STATES. THUS...I PREFER TO TAKE THE MORE CONSERVATIVE APPROACH AND EXPECT THE BOUNDARY TO LINGER MORE ACROSS OUR REGION. THUS...HAVE CONTINUED CHANCE TO HIGH CHANCE POPS THROUGH THE PERIOD FOR MUCH OF THE CWA...WITH THE BEST FOCUS ACROSS THE WESTERN AREAS. THE STRONGEST DISTURBANCE...A SOMEWHAT NEGATIVELY TILTED ONE AT THAT...APPEARS TO ROTATE THROUGH THE REGION FRIDAY AFTERNOON...AT WHICH TIME WOULD BE THE GREATEST THREAT FOR ANY STRONG TO SEVERE STORMS AS WELL AS HEAVY RAINFALL AS PWATS CREEP BACK CLOSE TO 2 INCHES ONCE AGAIN. TEMPERATURES WILL REMAIN NEAR TO SLIGHTLY ABOVE NORMAL THROUGH MOST OF THE PERIOD AS 850MB TEMPS GENERALLY REMAIN BELOW +20C COMPARED TO RECENT DAYS. TOWARD THE VERY END OF THE PERIOD THERE ARE SOME INDICATIONS THAT UPPER RIDGING WILL INTENSIFY ACROSS THE WESTERN ATLANTIC AS THE BROAD TROUGH ATTEMPTS TO RETROGRADE WEST. HOWEVER...SUBSTANTIAL CLOUD COVER AND MOISTURE IN OUR REGION SHOULD KEEP MOST AREAS...EXCEPT POSSIBLE THE KDAN AREA...BELOW 90S DEGREES. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... AS OF 150 AM EDT SUNDAY... COLD FRONT AT 05Z/1AM HAD JUST CROSSED THROUGH KLYH. FRONT WILL BE VERY CLOSE TO KDAN AT 06Z/2AM SO HAVE STARTED THE TAF WITH A WEST WIND. 850 MB WINDS ARE PROGGED TO BE IN THE 40 TO 50 KT RANGE SO SURFACE WIND GUSTS WILL RANGE FROM 30 TO 40 KNOTS TODAY...WITH THE HIGHER GUSTS AT THE HIGHER ELEVATIONS. WINDS WILL DIMINISH TONIGHT AS THE LOW LEVEL JET WEAKENS AND SURFACE HIGH PRESSURE BUILDS INTO THE AREA. SATELLITE PICTURES SHOWED UPSLOPE MVFR CLOUD COVER WELL INTO WEST VIRGINIA EARLY THIS MORNING. HAVE SLOWED DOWN THE IMPROVEMENT TO VFR AT KBLF AND KLWB BASED ON THE LATEST LAV GUIDANCE AND STRENGTH OF THE UPSLOPE WINDS TODAY. A SMALL AREA OF LIFR CLOUDS NEAR THE FRONT WILL IMPACT KDAN BUT AS DRIER AIR MASS MOVES IN BEHIND THE FRONT CONDITIONS WILL IMPROVE TO VFR BEFORE 12Z. EXTENDED AVIATION DISCUSSION... EXPECT MAINLY VFR CONDITIONS SUNDAY NIGHT INTO MONDAY AS HIGH PRESSURE SPREADS ACROSS THE FORECAST AREA. NEXT COLD FRONT IS FORECAST TO ARRIVE WITH POTENTIAL FOR SHOWERS MONDAY EVENING/OVERNIGHT. TIMING OF SHOWERS WITH THIS FRONT A BIT UNCERTAIN BUT COULD SEE PERIODS OF MVFR MONDAY NIGHT AND MAINLY ALONG THE WESTERN SLOPES TUESDAY...OTHERWISE VFR ACROSS THE EAST. ANOTHER DISTURBANCE SLIDING IN FROM THE NW MAY BRING THE NEXT ROUND OF SUB-VFR CONDITIONS ESPCLY ACROSS THE MOUNTAINS ON WEDNESDAY INTO THURSDAY. && .CLIMATE... AS OF 300 PM EDT FRIDAY... JUNE 29TH RECORD LOWS BLACKSBURG...42 IN 1974 BLUEFIELD....52 IN 1970 DANVILLE.....54 IN 1968 LEWISBURG....49 IN 1981 LYNCHBURG....51 IN 1970 ROANOKE......44 IN 1919 && .EQUIPMENT... AS OF 150 AM EDT SUNDAY... THE NOAA WEATHER RADIO IN HINTON WV...BROADCASTING ON A FREQUENCY OF 162.425 MHZ...IS OFF THE AIR DUE TO A TELCO PROBLEM. THIRD PARTY TECHNICIANS ARE CURRENTLY WORKING ON THE COMMUNICATION ISSUE. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...WIND ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR VAZ007-009>020- 022>024-034-035. NC...WIND ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR NCZ001-002-018. WV...WIND ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR WVZ042>044-507- 508. && $$ SYNOPSIS...DS NEAR TERM...DS/PM SHORT TERM...RAB LONG TERM...RAB AVIATION...AMS/PM CLIMATE...DS EQUIPMENT...DS

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