Area Forecast Discussion
Issued by NWS Blacksburg, VA

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000 FXUS61 KRNK 271136 AFDRNK AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BLACKSBURG VA 636 AM EST THU NOV 27 2014 .SYNOPSIS... A FAST MOVING AREA OF LOW PRESSURE WILL PASS JUST SOUTH OF THE REGION THIS MORNING AND OFFSHORE LATER THIS AFTERNOON. COLD HIGH PRESSURE BUILDS IN BEHIND THIS SYSTEM BRINGING COLDER AIR AND GUSTY WINDS OVERNIGHT INTO FRIDAY. THE HIGH WILL SLIDE OFFSHORE THIS WEEKEND RESULTING IN WARMER...AND DRIER WEATHER INTO SUNDAY BEFORE ANOTHER COLD FRONT ARRIVES WITH THE NEXT CHANCE OF SHOWERS BY EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 230 AM EST THURSDAY... STRONG SHORTWAVE ROUNDING THE BASE OF THE 5H TROUGH WILL FINALLY SERVE AS THE CABOOSE TO THE ONGOING WINTRY WEATHER TODAY AS IT PASSES ACROSS THE NC RIDGES THIS MORNING AND TO THE SE OF THE REGION THIS AFTERNOON. THIS FEATURE WILL AGAIN TEND TO ENHANCE MOISTURE CONVERGENCE OVER THE CWA THIS MORNING...WITH THE MAIN LIFT BACK OVER THE WEST/SW PORTIONS IN THE COLDER AIR ALOFT EARLY ON BEFORE BETTER SUPPORT SHIFTS OFF TO THE SE WITH A WEAK INDUCED SURFACE WAVE. MODELS CONTINUE TO PAINT MOST OF THE REGION IN A BROAD SWATH OF LIGHT PRECIP THIS MORNING BEFORE TAPERING TO MAINLY THE EAST BY EARLY AFTERNOON BEFORE ENDING. DEGREE OF ORGANIZATION LOOKS IFFY BUT SUSPECT WILL SEE A FEW MORE BANDS OF SNOW WEST THIS MORNING WITH ENHANCEMENT ALONG THE WESTERN SLOPES AS THE FLOW TURNS MORE UPSLOPISH BEHIND THE PASSING VORT AXIS. THEREFORE WILL BE LEAVING THE GOING ADVISORY IN PLACE WITH ANOTHER INCH OR TWO POSSIBLE MAINLY SW PORTIONS...AND ONLY SPOTTY ADDED TOTALS HEADING OUT TOWARD THE BLUE RIDGE WHERE MAY INIT AS RAIN BEFORE DAYBREAK. SHOULD ALSO SEE PATCHY/BANDS OF RAIN EAST BUT PERHAPS MIXED WITH SNOW AT TIMES WHERE PRECIP COMES DOWN A BIT HARDER. PRECIP MAY ALSO END AS A BRIEF PERIOD OF SNOW PIEDMONT LATE MORNING AS THE COLD POCKET ALOFT PASSES. HOWEVER QPF LOOKING RATHER LIGHT WITH A TENTH OR LESS MOST SPOTS TODAY EXCEPT UP TO A QUARTER INCH OUT EAST AND ACROSS THE SW RIDGES. EXPECT A BREAK IN POPS THIS AFTERNOON WITH SOME SUN POSSIBLE AS DOWNSLOPE KICKS IN AND BEFORE BETTER UPSLOPE DEVELOPS WEST THIS EVENING. KEPT HIGH TEMPS CLOSER TO THE COLDER MAV MOS ALTHOUGH MAY BE EVEN COLDER SE PENDING DEGREE OF CLOUDS/PRECIP COVERAGE THIS MORNING. COLD HIGH PRESSURE SLOWLY BUILDS IN BEHIND THE PASSING CLIPPER TYPE WAVE TONIGHT WITH LEFTOVER MOISTURE LEADING TO ADDED UPSLOPE -SHSN ESPCLY THROUGH MIDNIGHT. SOME ADDED ACCUMULATIONS POSSIBLE BUT THINKING WONT NEED MORE HEADLINES WITH AN INCH OR SO ALONG THE WESTERN SLOPES AND FLURRIES OUT TO THE BLUE RIDGE EARLY THIS EVENING. OTRW GRADUAL CLEARING OUTSIDE THE UPSLOPE AREAS AS MOISTURE BECOMES SHALLOW AND MIXES OUT IN BETTER DOWNSLOPING OUT EAST. HOWEVER DECENT PRESSURE GRADIENT WITH THE OFFSHORE WAVE DEEPENING AND STEADY 85H COLD ADVECTION...TO MAKE WINDS QUITE GUSTY AND POSSIBLY JUST BELOW ADVISORY LEVELS ACROSS THE HIGHER RIDGES IN NW NC. OTRW QUITE COLD AGAIN WITH LOWS IN THE MIDDLE OF MOS GUIDANCE GIVEN MIXING OFFSET OF COLD ADVECTION...EXCEPT IN SPOTS OVER THE WEST WHERE SOME SNOW COVER WILL RESIDE AND LIKELY HELP PUSH LOWS INTO THE TEENS. && .SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/... AS OF 300 AM EST THURSDAY... HIGH PRESSURE WILL BUILD ACROSS THE AREA ON FRIDAY...CAUSING RESIDUAL UPSLOPE SNOW SHOWERS ACROSS THE WESTERN RIDGES TO COME TO AN END BY LUNCHTIME. ALTHOUGH A COLD UPPER LEVEL TROUGH WILL HAVE SHIFTED OVER THE ATLANTIC BY SUNRISE...HIGH CLOUDS MOVING IN DURING THE AFTERNOON WILL LIMIT HEATING...AND EXPECT AFTERNOON HIGHS TO RANGE FROM THE LOW/MID 30S ACROSS SOUTHEAST WEST VIRGINIA TO THE LOW 40S ACROSS THE SOUTHSIDE. HIGH PRESSURE WILL SHIFT TOWARD THE COAST FRIDAY NIGHT...BRINGING A RETURN OF SOUTHERLY FLOW TO OUR AREA. LOWS WILL BE ON CHILLY SIDE...GENERALLY FALLING INTO THE MID TO UPPER 20S...WITH A FEW UPPER TEENS IN THE DEEPER MOUNTAIN VALLEYS. SOUTHWESTERLY FLOW WILL LEAD TO A WARM UP THROUGH THE WEEKEND...WITH A WARM FRONT PASSING ACROSS OUR AREA SATURDAY NIGHT. MAY SEE A FEW SHOWERS DEVELOP ACROSS SOUTHEAST WEST VIRGINIA AND THE MOUNTAIN EMPIRE ON SUNDAY AS GULF MOISTURE FLOWS NORTHWARD AHEAD OF A COLD FRONT MOVING EAST ACROSS THE PLAINS. EXPECT SATURDAY AFTERNOON HIGHS TO BE IN THE UPPER 40S/LOW 50S...WITH SUNDAY AFTERNOON HIGHS SOME 10 DEGREES WARMER. THE COLD FRONT IS EXPECTED TO APPROACH THE APPALACHIAN CHAIN LATE SUNDAY NIGHT...BRINGING RAIN SHOWERS TO THE WESTERN RIDGES. && .LONG TERM /MONDAY THROUGH WEDNESDAY/... AS OF 330 PM EST WEDNESDAY... MONDAY INTO MONDAY NIGHT...A BACK DOOR FRONT WILL TRY AND PUSH SOUTH OF THE AREA. WITH A STRONG AND BROAD RIDGE ACROSS THE SOUTH... EXPECTING LATER MODEL RUNS TO DELAY THE FRONTAL PASSAGE UNTIL SOMETIME TUESDAY. SINCE THE ECM/GFS HAS THIS FRONT ENTERING THE AREA MONDAY AND MONDAY NIGHT...WILL HAVE SLIGHT/CHANCE POPS FOR RAIN SHOWERS OVER THE AREA. ALSO HAVE SLIGHT/CHANCE POPS TUESDAY FOR A POSSIBLE FRONTAL PASSAGE OR FOR THE FRONT STALLING IN THE REGION. EITHER WAY AND/OR EITHER DAY...TEMPERATURES AND THICKNESSES ARE WARM TO KEEP ANY PRECIPITATION FALLING AS RAIN. SURFACE HIGH PRESSURE WILL MOVE OVER NEW ENGLAND FOLLOWING THE FRONTAL PASSAGE AND REMAIN IN THE AREA TROUGH THE REMAINDER OF THE WORKWEEK. EVEN THOUGH THIS WEDGE IS STRONG (1035MB)...MODELS REMAINING WARM AND CLOSE TO SEASONAL TEMPERATURES. && .AVIATION /11Z THURSDAY THROUGH MONDAY/... AS OF 605 AM EST THURSDAY... WEAK LOW PRESSURE OVER NW NORTH CAROLINA WILL HEAD EAST PASSING TO THE SOUTH OF THE REGION THIS MORNING. THIS FEATURE SHOULD CONTINUE TO PRODUCE BANDS OF -SN OVER THE MOUNTAINS MAKING FOR MVFR TO IFR CONDITIONS INCLUDING AREAS OF LIFR IN DENSE FOG. MOSTLY -RA CAN BE EXPECTED EAST OF THE BLUE RIDGE WHERE CIGS WILL BE MORE VFR TO OCNL MVFR INTO MID MORNING. ONCE THE LOW PASSES EAST LATE THIS MORNING...HIGH PRESSURE WILL BEGIN TO BUILD INTO THE AREA...WITH WIND SPEEDS FROM THE WEST GUSTING 15KT TO 25KT... TOPPING 30KT AT TIMES. CEILINGS WILL ALSO IMPROVE TO VFR FOR KROA/KLYH/KDAN...HOWEVER THE TRANSITION TO VFR WILL BE MORE GRADUAL FOR KBCB...TAKING UNTIL LATE EVENING. CIGS WILL BE SLOWER TO IMPROVE OVER THE FAR WEST WHERE UPSLOPE FLOW MAY KEEP KBLF AND KLWB MVFR WITH PASSING SNOW SHOWERS OR FLURRIES THROUGH MUCH OF TONIGHT. EXTENDED DISCUSSION... HIGH PRESSURE WILL PASS ACROSS THE REGION FRIDAY...RESULTING IN VFR CONDITIONS AREAWIDE. A COLD FRONT WILL REACH THE REGION ON MONDAY...BRINGING A RETURN OF SUB-VFR CONDITIONS. && .HYDROLOGY... STORM TOTAL PRECIPITATION AMOUNTS RANGED FROM ABOUT 0.50 TO 1.25 INCHES OF LIQUID EQUIVALENT WITH A FEW GAGES PICKING UP IN EXCESS OF 1.50 INCHES MAINLY ACROSS PARTS OF THE NEW RIVER AND UPPER ROANOKE AND DAN RIVER BASINS. THE LESSER AMOUNTS WERE GENERALLY OBSERVED OVER THE WESTERN BASINS INCLUDING THE GREENBRIER AND UPPER JAMES. RADAR PRECIPITATION ESTIMATES EXTREMELY CONTAMINATED BY BRIGHT BAND EFFECTS. RUNOFF CAUSING SMALLER STREAMS TO SHOW SOME NICE RISES BUT ALL WELL WITHIN BANKS. && .EQUIPMENT... AS OF 1030 AM EST WEDNESDAY... VISIBILITY SENSOR AT KLYH...LYNCHBURG AIRPORT...WAS MALFUNCTIONING AGAIN. PARTS HAVE BEEN ORDER BUT THE REPAIR MAY NOT BE UNTIL MONDAY. THE VISIBILITY AT KLYH WILL BE AUGMENTED BY STAFF WHEN THE CONTROL TOWER IS OPEN...OTHERWISE THE VISIBILITY WILL BE MISSING. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR VAZ007-009- 015. NC...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR NCZ001-018. WV...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR WVZ508. && $$ SYNOPSIS...JH/MBS NEAR TERM...JH SHORT TERM...NF LONG TERM...RCS AVIATION...JH/NF/PC HYDROLOGY...PC EQUIPMENT...AMS

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