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 041702 AFDRNK AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BLACKSBURG VA 1202 PM EST THU FEB 4 2016 .SYNOPSIS...
-- Changed Discussion --
HIGH PRESSURE WILL GRADUALLY BUILD INTO THE CENTRAL APPALACHIANS FROM THE WEST THIS AFTERNOON...PASSING OVERHEAD FRIDAY INTO SATURDAY. AN UPPER LEVEL DISTURBANCE WILL CROSS THE REGION FROM THE WEST LATE TONIGHT BRINGING INCREASING NORTHWEST WINDS AND PERHAPS A PERIOD OF LIGHT SNOW OR SNOW SHOWERS. ANOTHER LOW PRESSURE SYSTEM WILL SKIRT THE SOUTHEAST COAST SUNDAY FOLLOWED BY A CLIPPER AREA OF LOW PRESSURE FOR EARLY NEXT WEEK.
-- End Changed Discussion --
&& .NEAR TERM /THROUGH TONIGHT/... AS OF 930 AM EST THURSDAY... SURFACE COLD FRONT HAS FINALLY SLIPPED JUST EAST OF THE CWA THIS MORNING WHILE THE ACTUAL 85H FRONT IS NOW CROSSING THE BLUE RIDGE. THIS SHOULD ALLOW FOR INCREASING NORTH/NW FLOW FLOW THIS AFTERNOON WITH DRIER AIR GRADUALLY WORKING INTO THE MOUNTAINS EXCLUDING THE UPSLOPE AREAS WHERE LOW CLOUDS LIKELY TO LINGER. HOWEVER OVERALL DRY SINCE MOISTURE IS QUITE SHALLOW WITH DEEPER MOISTURE NOW TO THE EAST. ACROSS THE EAST MAIN CONCERN IS WITH A WEAK WAVE ALONG THE FRONT THAT WILL LIKELY HOLD A STRIPE OF DEEPER MOISTURE IN PLACE AHEAD OF ANOTHER WEAK IMPULSE THAT WILL SLIDE UP THE BOUNDARY LATER IN THE DAY. THIS MAY RESULT IN SOME LIGHT RAIN BEING PULLED BACK INLAND ACROSS THE SE LATE BUT MORE SO OVERNIGHT AS A STRONGER UPSTREAM TROUGH SWINGS THROUGH TOWARD MORNING. THIS SUPPORTS KEEPING SOME LOW POPS IN THE EAST LATER TODAY WITH SOME SUNNY BREAKS CENTRAL AND SW SECTIONS. GIVEN THE GRADUAL BLEEDING IN NATURE OF THE COLD AIR AND SLOWNESS TO REACH THE EAST...LOWERED HIGHS FAR WEST WHILE STAYING IN THE LOW/MID 50S EAST PER TEMPS ALREADY NEAR 50. AS OF 701 AM EST THURSDAY... RAIN THIS MORNING IS FURTHER EAST OVER CENTRAL AND EASTERN NC. MODELS ARE FAVORING SHIFTING SOME OF THIS WWD LATER THIS MORNING...BUT UNTIL THEN KEEPING IT DRY OVER OUR AREA. MAY SEE SOME SUNSHINE IN THE BLUE RIDGE AND ADJACENT AREAS...HUGGING THE FINE LINE BETWEEN THE DEEPER MOISTURE IN THE PIEDMONT AND THE LOW LVL UPSLOPE OVER THE HIGHER TERRAIN IN THE WEST. THEREFORE...LOWERED SKY COVER SOME IN THE NEW RIVER VALLEY/ROANOKE AND EAST TO THE FOOTHILLS FOR THE MORNING. PREVIOUS EARLY MORNING DISCUSSION... THE COLD FRONT IS SLOWLY MOVING ACROSS THE REGION THIS MORNING AND IS CURRENTLY ALONG THE BLUE RIDGE. THIS FRONT WILL MOVE AND STALL OVER THE COASTAL PIEDMONT BY THIS AFTERNOON. MEANWHILE...AN UPPER LEVEL TROUGH WILL TRACK ACROSS THE MISSISSIPPI VALLEY...GENERATING A SURFACE REFLECTION ALONG THE SOUTHEAST COAST. THIS REFLECTION WILL TRACK NORTH ALONG THE STALLED FRONT AS THE UPPER LEVEL TROUGH APPROACHES THE OHIO AND TENNESSEE VALLEYS. MOISTURE IS EXPECTED TO BUCKLE BACK ACROSS THE PIEDMONT THIS AFTERNOON AND EVENING WITH A CHANCE OF LIGHT RAIN EAST OF HWY 29. THIS REFLECTION WILL INCREASE CLOUDS OVER THE AREA...WHICH WILL KEEP WINDS SPEEDS LOWER. WITH LESS WESTERLY WINDS...UPSLOPE RAIN AND SNOW SHOWERS WILL BE LIMITED. THEREFORE WE HAVE REDUCED POPS AND ACCUMULATIONS ALONG WESTERN SLOPES TODAY AND TONIGHT. ALSO WITH THE FRONT STALLING FARTHER INLAND THAN PREVIOUSLY FORECASTED...TEMPERATURES WILL RUN SLIGHTLY WARM THAN NORMAL WITH 40S WEST TO LOWER AND MID 50S EAST. AS THIS REFLECTION MOVES OFF THE EAST COAST TONIGHT...TEMPERATURES WILL DROP INTO THE 20S ACROSS THE MOUNTAINS AND LOWERS 30S ACROSS THE PIEDMONT. && .SHORT TERM /FRIDAY THROUGH SUNDAY/... AS OF 328 AM EST THURSDAY... MODELS SEEM IN GENERAL AGREEMENT THAT WE WILL STAY SEASONABLY COLD AND DRY THIS PERIOD WITH HIGH PRESSURE IN CONTROL. WILL HAVE TO WATCH THE SRN STREAM SYSTEM MOVING FROM THE GULF CAST STATES SAT NIGHT OFF THE SOUTHEAST COAST SUNDAY EVENING. MODELS HAVE CONTINUED TO TREND IN THIS DIRECTION BUT WILL BEAR WATCHING FOR SUNDAY AS MAY SEE SOME LIGHT SNOW SNEAK NWD TOWARD SOUTHSIDE VA INTO NW NC PIEDMONT...BUT EXPECT BULK OF DEEPER MOISTURE TO STAY ON THE COAST. && .LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/... AS OF 330 AM EST THURSDAY... ONLY CHANGE THIS PERIOD WAS TO GO WITH PTYPE CHANGE TO MORE SNOW INSTEAD OF RAIN MONDAY-TUESDAY...AS MODELS SHOW 8H TEMPS WELL BELOW ZERO AND THICKNESSES SUPPORTING MOSTLY SNOW. WILL KEEP SOME RAIN SHOWERS FOR TEMPS ABOVE 42F...BUT THE MODELS HAVE BEEN TRENDING VERY COLD FOR EARLY-MID WEEK WITH -10 TO -16C AIR PUSHING INTO THE MTNS BY MIDWEEK. PREVIOUS DISCUSSION FROM WEDNESDAY AFTERNOON... PROGRESSIVE FLOW WILL ALLOW A VIGOROUS UPPER TROF TO MOVE OVER THE EASTERN US AND DEVELOP A STRONG COASTAL LOW OFF THE SOUTHEAST COAST. ALL GUIDANCE CURRENTLY KEEPS THE PRECIPITATION SHIELD ASSOCIATED WITH THIS LOW TO THE EAST OF THE REGION WITH JUST SOME SPRINKLES POSSIBLE FOR THE FAR SOUTHEASTERN PORTIONS OF SOUTHSIDE LATE ON SUNDAY. BY MONDAY A MUCH DEEPER TROF WILL MOVE INTO THE EASTERN US AND SET UP A SIGNIFICANTLY COLDER PATTERN...WHILE A COMPLEX SURFACE PATTERN DEVELOPS AS LOW PRESSURE APPROACHES FROM THE GREAT PLAINS...FOLLOWED BY A TRANSFER OF ENERGY TO A DEVELOPING LOW OFF THE MIDDLE ATLANTIC COAST. THE COMBINATION OF THE COLDER AIR AND DEVELOPING SURFACE FEATURES LOOKS LIKE IT MAY BRING SOME LIGHT SNOW/SNOW SHOWERS TO THE AREA MAINLY WEST OF THE BLUE RIDGE. THE PATTERN DOES NOT FAVOR DEVELOPMENT OF A STRONG STORM SYSTEM TO AFFECT THE REGION SO WIDESPREAD WINTER WEATHER ISSUES ARE NOT LIKELY. BY THE MIDDLE OF NEXT WEEK WHEN THE COLDER AIR ARRIVES...HIGH TEMPERATURES WEST OF THE BLUE RIDGE WILL GENERALLY BE IN THE MIDDLE 20S WITH READINGS IN THE MIDDLE 30S EAST OF THE RIDGE. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/...
-- Changed Discussion --
AS OF 1145 AM EST THURSDAY... FRONTAL BOUNDARY LINGERING IN THE EAST CONTINUES TO FOCUS DEEP MOISTURE TO THE EAST OF THE REGION ATTM. THIS ALONG WITH DRIER AIR ALOFT PER MORNING SOUNDINGS FILTERING IN EXPECT TO SEE SOME IMPROVEMENT TO VFR MOST SITES INTO THE AFTERNOON EXCLUDING THE UPSLOPE AREAS THAT COULD SEE MVFR LINGER AT KBLF/KLWB THE REST OF THE DAY. SOME POTENTIAL FOR LIGHT RAIN TO PUSH AS FAR WEST AS DANVILLE LATE THIS AFTERNOON AS ANOTHER WAVE OF LOW PRESSURE TRACKS ALONG THE FRONT. HOWEVER...THE CONSENSUS AMONG MODELS IS TO KEEP THIS EAST...SO NOT ADDING RAIN TO KDAN AT THIS POINT FOR THIS AFTERNOON. HOWEVER LATEST MODELS HAVE TRENDED WETTER OVERNIGHT WITH A STRONG UPPER DISTURBANCE CROSSING THE REGION WITH A LITTLE TAP TO RESIDUAL MOISTURE AT THE COAST. APPEARS GUIDANCE MAY BE OVERDONE GIVEN CURRENT DEGREE OF DRY AIR ALOFT BUT SOME POTENTIAL TO SEE LIGHT RAIN AT KDAN/KLYH TRANSITION TO -SN BEFORE ENDING LATE TONIGHT WITH SPOTTY LIGHT SNOW AS WELL AROUND KROA/KBCB. THE MOISTURE IN THE WEST LINGERS THROUGH TONIGHT AND DEEPENS ENOUGH WITH THE PASSING WAVE AND UPSLOPE TO SUPPORT ADDING SOME VFR/MVFR VSBY RESTRICTIONS IN SNOW SHOWERS OVERNIGHT. EXPECT MOISTURE TO DECREASE FROM WEST TO EAST BY FRIDAY DAYBREAK POSSIBLY ALLOWING LOCATIONS FROM THE BLUE RIDGE WEST TO RETURN TO VFR. NW WINDS WILL TURN QUITE STRONG BEHIND THE PASSING WAVE OVERNIGHT WITH GUSTS TO 30-35 KTS POSSIBLE MAINLY AFTER MIDNIGHT ACROSS THE WESTERN RIDGES. ON FRIDAY...HIGH PRESSURE WILL BUILD OVERHEAD TO PROVIDE COLDER AND DRIER CONDITIONS...AND WILL KEEP VFR CONDITIONS AT ALL TAF SITES THROUGH SATURDAY. EXTENDED DISCUSSION... ANOTHER SYSTEM MOVING ACROSS THE SOUTHEAST APPEARS TO STAY JUST SOUTH OF US SUNDAY WITH POSSIBLE LIGHT PRECIP AND MVFR CIGS EDGING TOWARD THE VA/NC BORDER SUNDAY AFTERNOON. AN ARCTIC FRONT/CLIPPER PUSHES IN MONDAY AND WILL BRING SOME SNOW TO PORTIONS OF THE AREA...MAINLY THINKING KBLF/KLWB AND EAST TOWARD KROA/KLYH. SHOULD SEE SOME MVFR TO AT TIMES IFR CIGS/VSBYS IN WV AND POTENTIALLY TO KBCB/KROA/KLYH MONDAY. LINGERING NW FLOW WILL SUPPORT A CONTINUATION OF MVFR CIGS OVER THE MOUNTAINS MONDAY NIGHT INTO TUESDAY WITH PERIODIC SUB-VFR IN SNOW SHOWERS. EXPECT CIGS EAST OF THE MOUNTAINS TO RETURN TO MAINLY VFR BY MONDAY NIGHT INTO TUESDAY.
-- End Changed Discussion --
&& .HYDROLOGY...
-- Changed Discussion --
AS OF 1130 AM EST THURSDAY... MINOR FLOODING CONTINUES ALONG THE LOWER ROANOKE RIVER AROUND RANDOLPH AND ACROSS THE DAN RIVER BASIN MAINLY FROM DANVILLE DOWNSTREAM TO SOUTH BOSTON. THIS FLOODING IS EXPECTED TO PERSIST INTO FRIDAY. SEE THE LATEST WBCFLSRNK PRODUCT FOR ADDED DETAILS.
-- End Changed Discussion --
&& .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...JH/PM/WP NEAR TERM...JH/RCS/WP SHORT TERM...WP LONG TERM...MBS/WP AVIATION...RCS/WP HYDROLOGY...JH/PC/WP

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