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 091007 AFDRNK AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BLACKSBURG VA 507 AM EST TUE FEB 9 2016 .SYNOPSIS... A STRONG CYCLONE IN THE UPPER LEVELS OF THE ATMOSPHERE IS CENTERED OVER THE OHIO VALLEY. THIS FEATURE WILL REMAIN NEARLY STATIONARY THROUGH WEDNESDAY BEFORE SLOWLY MOVING EAST. WEAK UPPER LEVEL IMPULSES WILL MOVE ACROSS THE MOUNTAINS THROUGH WEDNESDAY NIGHT RESULTING IN PERSISTENT SNOW SHOWER AND FLURRY ACTIVITY. TEMPERATURES WILL REMAIN BELOW NORMAL FOR THE REMAINDER OF THE WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 500 AM EST TUESDAY... COLD UPPER LEVEL LOW IS CENTERED OVER OHIO WITH WIDESPREAD SNOW SHOWER ACTIVITY OCCURRING FROM THE GREAT LAKES TO THE SOUTHERN APPALACHIANS. THIS UPPER LOW IS PROGGED TO REMAIN NEARLY STATIONARY OVER THE NEXT 24 HOURS RESULTING IN A PERSISTENT STREAM OF MOISTURE INTO THE WESTERN SIDE OF THE APPALACHIAN MOUNTAINS. THIS WILL PROVIDE THE WEST SIDE OF THE MOUNTAINS WITH PERIODS OF MODERATE ACCUMULATING SNOW. AS THE AIR PASSES OVER THE MOUNTAINS...THE AIR WILL DRY OUT...RESULTING IN A MORE SCATTERED NATURE TO THE SNOW SHOWERS WITH LITTLE OR NO ACCUMULATION EAST OF THE BLUE RIDGE. MODELS CONTINUE TO FAVOR THE HEAVIEST SNOW ACCUMULATIONS ALONG THE WEST FACING SLOPES OF THE WEST VIRGINIA HIGHLANDS WITH MULTIDAY SNOW TOTALS UPWARDS OF 8 TO 12 INCHES IN WESTERN GREENBRIER COUNTY. LESSER BUT RESPECTABLE AMOUNTS WILL BE OBSERVED FARTHER SOUTHWEST THROUGH SUMMERS AND MERCER WEST VIRGINIA...TAZEWELL...SMYTH...AND WESTERN GRAYSON VIRGINIA...AND INTO ASHE AND WATAUGA COUNTIES IN NORTH CAROLINA. EAST OF THESE COUNTIES...AMOUNTS WILL TAPER TO JUST AN INCH OR TWO...WITH ONLY TRACE AMOUNTS EAST OF THE BLUE RIDGE. WILL NOT MAKE ANY CHANGES TO THE CURRENT WARNING AND ADVISORY CONFIGURATION...MAINTAINING A WINTER STORM WARNING FROM WESTERN GREENBRIER COUNTY TO NEAR FLAT TOP WEST VIRGINIA...AND WINTER WEATHER ADVISORIES FROM THE VA/WV BORDER SOUTHWEST THROUGH THE WESTERN NEW RIVER VALLEY AND INTO THE MOUNTAINS OF NORTHWEST NORTH CAROLINA. TEMPERATURES TODAY WILL STRUGGLE TO CLIMB ABOVE 32 IN THE MOUNTAINS AND MAY ONLY MAKE IT 5 DEGREES OR SO ABOVE FREEZING FOR AREAS EAST OF THE BLUE RIDGE. AFTER TODAY...TEMPERATURES WILL TREND LOWER WITH LOWS TONIGHT HEADED FOR THE TEENS IN THE MOUNTAINS TO THE LOWER 20S IN THE PIEDMONT. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 400 AM EST TUESDAY... BROAD UPPER TROUGH WILL SLOWLY MOVE EAST ALONG THE EAST COAST WEDNESDAY INTO THURSDAY NIGHT. THERE REMAINS DIFFERENCES IN THE STRENGTH OF THE UPPER TROUGH...AND IN THE SPEED AND LOCATION OF SHORTWAVES EMBEDDED IN THE LARGE UPPER TROF. THE NAM AND ECMWF ARE DEEPER WITH THE UPPER TROUGH COMPARED TO THE GFS. THIS TRANSLATES TO A FURTHER SOUTH PLACEMENT AND TRACK OF THE ROBUST SHORTWAVE WEDNESDAY WHICH ROTATES EAST AROUND UPPER TROUGH WEDNESDAY NIGHT INTO THURSDAY. SNOW SHOWERS AND SNOW FLURRIES CONTINUE WEDNESDAY INTO WEDNESDAY NIGHT WITH THE NORTHWEST FLOW AND COLD ADVECTION. THE BEST CHANCES FOR SNOW WILL OCCUR IN THE MOUNTAINS AND WESTERN SLOPES. HIGH TEMPERATURES WEDNESDAY WILL RANGE FROM THE LOWER TEENS IN THE NORTHWEST MOUNTAINS TO THE MID 30S IN THE PIEDMONT. 850 MB TEMPERATURES WILL DROP TO -18 TO -20 BY 12Z/7AM THURSDAY. THIS WILL MAKE SNOW SHOWERS IN THE WESTERN MOUNTAINS QUITE EFFICIENT WITH SNOW TO LIQUID RATIOS OF 25:1 POSSIBLE WEDNESDAY NIGHT. IN GENERAL...ADDITIONAL SNOW ACCUMULATIONS WEDNESDAY AND WEDNESDAY NIGHT WILL VARY FROM A COATING TO NEAR 3 INCHES ALONG THE WESTERN FACING SLOPES ESPECIALLY IN GREENBRIER COUNTY OF SOUTHEAST WEST VIRGINIA. LOW TEMPERATURES WEDNESDAY NIGHT WILL RANGE FROM AROUND ZERO IN THE NORTHWEST MOUNTAINS TO NEAR 20 DEGREES IN THE PIEDMONT. THE COMBINATION OF WIND AND TEMPERATURES WILL MAKE WIND CHILLS AS COLD AS 5 BELOW TO 20 BELOW ZERO WEDNESDAY NIGHT INTO THURSDAY MORNING IN THE MOUNTAINS. THERE IS ENOUGH DRY AIR AND DOWNSLOPING ON THURSDAY TO CREATE SOME CLEARING EAST OF THE BLUE RIDGE. WHILE IN THE WEST...ISOLATED TO SCATTERED SNOW SHOWERS WILL CONTINUE ESPECIALLY IN THE NORTHWEST. AROUND AN INCH OR SO SNOW ACCUMULATION MAY BE POSSIBLE WITH A HEAVIER SNOW SHOWER THURSDAY. HIGH TEMPERATURES ON THURSDAY WILL BE IN THE TEENS IN THE MOUNTAINS TO THE LOWER 30S IN THE PIEDMONT. ON THURSDAY NIGHT...THE UPPER TROUGH AXIS PULLS NORTHEAST AND MOST OF SNOW SHOWERS AND SNOW FLURRIES SHOULD TAPER OFF. LOW TEMPERATURES THURSDAY NIGHT WILL RANGE FROM THE SINGLE DIGITS TO THE TEENS. WIND CHILLS MAY STILL BE NEAR WIND CHILL LEVELS FOR THE NORTHWEST MOUNTAINS THURSDAY NIGHT INTO FRIDAY MORNING. && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 250 PM EST MONDAY... EASTERN UPPER TROF GETS RE-ENFORCED FRIDAY NIGHT AND SATURDAY...THEN TROF AXIS MOVES OF THE COAST ON SUNDAY. BOTH THE ECMWF AND GFS BRING A CLIPPER ACROSS THE CENTRAL UNITED STATES MONDAY THEN INTO THE MID ATLANTIC REGION BY TUESDAY. WPC SUGGESTED THE TRACK OFF THE ECMWF MAY BE TOO FAR SOUTH. SOME 850 MB WARM AIR ADVECTION AND LOW LEVEL CONVERGENCE ALONG THE LEADING EDGE OF THE NEXT SURGE OF ARCTIC AIR. BEST LIFT LOOKS TO BE ON FRIDAY WITH SOME UPPER DIFFLUENCE. SNOW SHOULD BE MORE WIDESPREAD THAN JUST UPSLOPE. THEN GUSTY WINDS AND VERY LOW WIND CHILL VALUES ON FRIDAY NIGHT THROUGH SATURDAY NIGHT WITH NORTHWEST 850 MB WINDS APPROACHING 50 KNOTS. WIND CHILLS WILL AGAIN BE IN ADVISORY CRITERIA...BETWEEN -5 TO -19 IN THE MOUNTAINS ON SATURDAY NIGHT. A ROUGHLY 1045 MB SURFACE HIGH WILL BUILD INTO THE AREA FRIDAY NIGHT AND SATURDAY. THIS FEATURE WILL BE CENTERED OVER THE MID ATLANTIC REGION MONDAY MORNING. WINDS WILL DIMINISH ENOUGH WITH THE APPROACH OF THIS HIGH...AND WITH THE ASSOCIATED DRY AIR...TO END UPSLOPE SNOW SHOWERS IN THE MOUNTAINS SUNDAY. && .AVIATION /10Z TUESDAY THROUGH SATURDAY/... AS OF 1145 PM EST MONDAY... WILL SEE A PERIOD OF SNOW SHOWERS AFFECT MAINLY BLF AND SOME AT BCB/LWB EARLY WITH IFR/MVFR VSBYS/CIGS. FURTHER EAST CLEARING SKIES AND LIGHT WINDS ALLOWED FOR FOG FORMATION AT LYH/DAN THANKS TO EARLIER RAINFALL. EXPECT THE FOG STAYING AROUND THROUGH 09Z THEN SOME IMPROVEMENT FROM LIFR/IFR TO MVFR. AS WINDS PICK UP AS THE SHORTWAVE MOVES ACROSS AFTER 12Z LOOK FOR VFR VSBYS. OVERALL CIGS FROM ROA EAST SHOULD STAY VFR...POTENTIALLY TOUCH HIGH END MVFR IF A FLURRY OR LIGHT SNOW SHOWER PASSES BUT SEEMS THAT THE TIME PERIOD FOR THIS IS SMALL AND NOT ENOUGH TO WARRANT MENTION IN THE TAF. A DECENT UPPER DISTURBANCE IS GOING TO MOVE OVER SRN WV/SW VA 10-14Z...WHICH WILL BRING AN AREA OF HEAVIER SNOW SHOWERS TOWARD BLF/LWB. THIS WILL BRING CIGS/VSBYS BACK TOWARD IFR MAINLY BLF. ONCE THIS WAVE MOVES BY WINDS WILL BE PICKING UP BUT SNOW SHOWERS/FLURRIES WILL PERSIST THROUGH THE REST OF THE PERIOD FROM BCB TO BLF/LWB...WITH MAINLY MVFR CIGS BLF/LWB AND LOW END VFR AT BCB. EXTENDED DISCUSSION... SUB-VFR SHOULD BECOME MORE CONFINED TO THE MOUNTAINS AND WESTERN SLOPES TUESDAY NIGHT INTO MIDWEEK WITH PROLONGED MVFR/IFR CONDITIONS AT KBLF/KLWB IN SNOW SHOWERS THROUGH AT LEAST WEDNESDAY NIGHT AS ARCTIC AIR ARRIVES. POTENTIAL ALSO FOR PERIODS OF MVFR AT KBCB/KROA AS IMPULSES ROTATE ACROSS THE MOUNTAINS AND BANDS OF SNOW DEVELOP DURING THE OVERNIGHT HOURS. ACCUMULATING SNOW IS LIKELY IN THE MOUNTAINS WEST OF THE BLUE RIDGE. FLURRIES MAY ALSO OCCUR AS FAR EAST AS THE PIEDMONT WHERE INTERVALS OF VFR TO MVFR CIGS COULD ALSO OCCUR. CONDITIONS SHOULD BRIEFLY RETURN TO MAINLY VFR THURSDAY/THURSDAY NIGHT AS WEAK HIGH PRESSURE BUILDS IN AND MOISTURE DECREASES. ANOTHER SYSTEM MOVING ACROSS THE SOUTH MAY BRING SUB VFR CONDITIONS WITH WINTRY PRECIP FRIDAY INTO FRIDAY NIGHT. ANOTHER ARCTIC FRONT CROSSES BY SAT MORNING WITH GUSTY WINDS AND UPSLOPE SNOW SHOWERS WITH SUB VFR IN THE MTNS. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...WINTER WEATHER ADVISORY UNTIL 7 AM EST THURSDAY FOR VAZ007- 009>012-015-019-020. NC...WINTER WEATHER ADVISORY UNTIL 7 AM EST THURSDAY FOR NCZ001-018. WV...WINTER WEATHER ADVISORY UNTIL 7 AM EST THURSDAY FOR WVZ042>044- 507. WINTER STORM WARNING UNTIL 7 AM EST THURSDAY FOR WVZ043-508. && $$ SYNOPSIS...PM NEAR TERM...PM SHORT TERM...KK LONG TERM...AMS AVIATION...RCS/WP

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