Area Forecast Discussion
Issued by NWS Blacksburg, VA

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000 FXUS61 KRNK 202333 AFDRNK AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BLACKSBURG VA 733 PM EDT MON OCT 20 2014 .SYNOPSIS... A COLD FRONT WILL APPROACH THE REGION OVERNIGHT...AND CROSS THE AREA ON TUESDAY. FLOW BEHIND THE FRONT WILL REMAIN GUSTY FROM THE NORTHWEST THROUGH THURSDAY BETWEEN THE DEPARTING PARENT LOW PRESSURE SYSTEM...AND A BUILDING RIDGE ACROSS THE CENTRAL UNITED STATES. THIS RIDGE OF HIGH PRESSURE WILL GRADUALLY BUILD OUR DIRECTION...PROVIDING FOR MODERATING TEMPERATURES AND DRY CONDITIONS HEADING INTO THE WEEKEND. && .NEAR TERM /THROUGH TUESDAY/... AS OF 245 PM EDT MONDAY... AN UPPER TROUGH AND ASSOCIATED COLD FRONT WERE MOVING EASTWARD THROUGH THE GREAT LAKES INTO THE MISSOURI VALLEY. AHEAD OF IT...SOUTHWEST FLOW AHEAD OF THE FRONT WAS ADVECTING BANDS OF SHOWERS TOWARD THE REGION. THE FIRST WAS ARRIVING CURRENTLY ACROSS THE WESTERN PORTION OF THE AREA. THIS FEATURE IS EXPECTED TO ITS PROGRESS INTO THE AREA THE REMAINDER OF THE AFTERNOON...AND WASH OUT AFTER IT CROSSES THE CREST OF THE BLUE RIDGE THIS EVENING. THE SECOND BAND WAS CURRENTLY EXTENDING FROM OHIO INTO INDIANA. IT TOO WILL REACH THE AREA LATER THIS EVENING...AND ALSO WASH OUT EAST OF THE BLUE RIDGE AROUND OR A LITTLE AFTER MIDNIGHT. LOW TEMPERATURES OVERNIGHT WILL BE NOTABLY MORE MILD COMPARED TO READINGS OF THIS MORNING THANKS TO INCREASING DEW POINTS. ANTICIPATE A MIX OF MID TO UPPER 40S ACROSS THE AREA. TUESDAY MORNING AROUND DAYBREAK...THE AXIS OF THE UPPER TROUGH AND ASSOCIATED COLD FRONT WILL MOVE THROUGH THE AREA. ANTICIPATE A RESURGENCE OF UPSLOPE SHOWERS IN THE WEST...WITH A BIT MORE COVERAGE EAST OF THE BLUE RIDGE BY MIDDAY. A REINFORCING PIECE OF ENERGY WILL BUILD INTO THE AREA IN THE WAKE OF THE COLD FRONT. THIS FEATURE IS ANTICIPATED TO ENHANCE THE UPSLOPE COVERAGE. COVERAGE WILL BE LIMITED OR LACKING ACROSS THE AREA NEAR SOUTHSIDE VIRGINIA AND NEIGHBORING NORTH CENTRAL NORTH CAROLINA THANKS TO DOWNSLOPE COMPRESSIONAL WARMING IN THIS REGION. HIGHS TOMORROW WILL RANGE FROM THE UPPER 50S TO AROUND 60 ACROSS THE MOUNTAINS...WITH MID 60S TO LOWER 70S ACROSS THE PIEDMONT. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/... AS OF 200 PM EDT MONDAY... FOCUS FOR MID WEEK WILL BE CLOSED LOW WHICH PARKS ITSELF OVER THE NORTHERN MID ATLANTIC AND SOUTHERN NEW ENGLAND. THIS FEATURE WILL RESULT IN A MULTIDAY COOL PERIOD WITH BLUSTERY NORTHWEST WINDS AND CONSIDERABLE CLOUDINESS. WITH THE LOW CENTERED TO OUR NORTH...THE CLOUDIER CONDITIONS WILL FAVOR THE VIRGINIAS WITH DRIER AIR RESULTING IN MORE SUN THAN CLOUDS ACROSS THE CAROLINAS. SOME LIGHT PRECIPITATION IS POSSIBLE ACROSS THE VIRGINIAS...MAINLY IN THE FORM OF SCATTERED INSTABILITY SHOWERS DURING THE DAY...AND UPSLOPE SHOWERS ACROSS THE MOUNTAINS AT NIGHT. WITH THE EXCEPTION OF THE VA/WV HIGHLANDS...QPF LOOKS PRETTY SCANT. THE VA/NC HIGHLANDS MAY RECEIVE UPWARDS OF A QUARTER INCH OF PRECIP TUESDAY NIGHT INTO WEDNESDAY...BUT THE REMAINDER OF THE CWA SHOULD SEE LESS THAN A TENTH OF AN INCH AND POSSIBLY NOTHING AT ALL. TEMPERATURES WILL BE QUITE COOL THROUGH THE PERIOD WITH ABUNDANT CLOUD COVER AND 850MB TEMPS HOVERING IN THE LOW SINGLE DIGIT CENTIGRADE RANGE. THERE IS A POCKET OF NEAR 0C 850MB TEMPS ON THE BACK SIDE OF THE UPPER LOW THAT SETTLES DOWN OVER THE WESTERN PART OF THE CWA...SO CAN`T RULE OUT A MIX OF -SN/RA AT ELEVATIONS ABOVE 3500 FEET...BUT NO ACCUMULATION CONCERNS ATTM DUE TO GROUND TEMPERATURES BEING ABOVE FREEZING. WE MAY NEED TO ENTERTAIN FROST/FREEZE ADVISORIES LATE IN THE WEEK...BUT THIS APPEARS MARGINAL PER LINGERING CLOUDINESS AND AT LEAST SOME MIXING FROM THE WIND. USED A MODEL BLEND OF MAX/MIN TEMPS THROUGHOUT THE PERIOD...MAX TEMPS ABOUT 10 DEGREES BELOW NORMAL THROUGH MUCH OF THE WEEK...AND MIN TEMPS NEAR NORMAL. && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 200 PM EDT MONDAY... THE PRIMARY CLOSED LOW WILL BEGIN TO MOVE AWAY FROM THE REGION FRIDAY. BOTH THE GFS/ECMWF SHOW ONE FINAL SHOT OF COOL AIR WITH THE PASSAGE OF A SHORT WAVE TROUGH ON SATURDAY...BUT AFTER THAT...A BROAD UPPER RIDGE OF HIGH PRESSURE IS PROGGED TO BUILD EAST FROM THE CENTRAL CONUS. THIS RIDGE OF HIGH PRESSURE SHOULD DO A COUPLE OF THINGS...ONE...SHUT DOWN THE COOL INTRUSIONS FROM THE NORTH...AND TWO...CLOSE OF THE GULF OF MEXICO FROM ANY MOISTURE...AT LEAST FOR A FEW DAYS. ALL THINGS CONSIDERED THIS SHOULD YIELD A DRY RELATIVELY MILD START TO THE LAST WEEK OF OCTOBER. TEMPERATURES FRIDAY AND SATURDAY SHOULD FAVOR READINGS CLOSE TO NORMAL...WITH SUNDAY AND MONDAY TRENDING ABOVE NORMAL BY AT LEAST 5 DEGREES...POSSIBLY A LITTLE MORE. && .AVIATION /23Z MONDAY THROUGH SATURDAY/... AS OF 730 PM EDT MONDAY... FIRST UPPER LEVEL WAVE ASSOCIATED WITH DEVELOPING TROUGH OVER THE EASTERN U.S. IS MOVING THROUGH THE REGION THIS EVENING...WITH ZONE OF LIGHT SHOWERS MOVING OUT OF THE MOUNTAINS AND INTO THE PIEDMONT. CIGS REMAIN MID LEVEL VFR AND PRECIP VERY LIGHT NOT TO REDUCE VSBYS INTO MVFR RANGE EITHER...AND THESE WILL CONTINUE TO LIGHTEN AND DISSIPATE AS THEY MOVE INTO PIEDMONT APPROACHING LYH...AND MAY NOT EVEN REACH DAN. BEHIND THIS...MORE WESTERLY FLOW WILL EVENTUALLY BRING MVFR CIGS TO UPSLOPE LOCATIONS INCLUDING BLF AND LWB AFTER 04 UTC TONIGHT...BUT LESS CONFIDENT IN ANY SUB VFR CIGS ELSEWHERE. WITH VERY LIGHT RAIN AT BLF...LWB...AND BCB...CANNOT RULE OUT SOME LIGHT FOG LATE TONIGHT...BUT KEEPING THIS MVFR EXCEPT FOR LWB WHERE LATEST GUIDANCE SUGGESTING ALL THE WAY DOWN TO 1/4 MI. AM GOING WITH TEMPO GROUP LIFR AT LWB BUT NOT ALL THE WAY DOWN TO 1/4. COULD STILL BE BRIEF PERIODS OF LIGHT SHWRS LATE TONIGHT IN THE WESTERN SLOPES WITH SECOND WEAK SHORT WAVE...BUT STRONGEST UPPER WAVE WILL NOT ARRIVE UNTIL AFTER DAYBREAK WITH BETTER CHANCE FOR SHWRS AND LOWERING CIGS TO THE LOW END OF MVFR. CANNOT RULE OUT BRIEF IFR IN SOME SHOWERS AT BLF AND LWB...WITH LOWER CONFIDENCE IN THESE CONDITIONS AT BCB. SHWRS NOT LIKELY TO REACH WEST OF BLUE RIDGE AND IF THEY DO SHOULD STILL BE ASSOCIATED WITH VFR CIGS. OTHERWISE DURING THE DAYLIGHT HOURS TUESDAY EXPECT GUSTY WNW WINDS SLOWLY TURNING MORE NW BY LATE IN THE DAY TUESDAY AND INTO THE EVENING WITH SOME SHOWERS CONTINUING WESTERN SLOPES. EXTENDED AVIATION DISCUSSION... THE UPPER LEVEL TROUGH WILL SLOW DOWN AND DEEPEN THROUGH MID WEEK AND ONLY SLOWLY BEGIN TO SHIFT TOWARD THE NORTHEAST BY THURSDAY. THE MAIN IMPACT WITH BE A PERSISTENT NORTHWEST GUSTY WIND AND SCATTERED RAIN SHOWERS THAT WILL IMPACT PRIMARILY THE PREFERRED UPSLOPE REGION OF SOUTHEAST WEST VIRGINIA INTO WED NIGHT OR EVEN THURS MORNING. MVFR CLOUDS WILL THUS BE COMMON ACROSS THE MOUNTAINS DURING THIS TIME PERIOD...BUT FROM ROA TO LYH TO DAN CONDITIONS ARE LIKELY TO REMAIN VFR THROUGH THIS PERIOD. THE PERSISTENT TROUGH WITH NORTHWEST FLOW AND LOW- LEVEL UPSLOPE CLOUDS IN WEST WILL SLOWLY BE REPLACED BY AN UPPER LEVEL RIDGE BY FRIDAY AND INTO THE WEEKEND...FOR DRY AND WARM CONDITIONS. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...DS NEAR TERM...DS SHORT TERM...PM LONG TERM...PM AVIATION...MBS/SK

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