Area Forecast Discussion
Issued by NWS Blacksburg, VA

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000 FXUS61 KRNK 231840 AFDRNK AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BLACKSBURG VA 240 PM EDT MON MAR 23 2015 .SYNOPSIS... HIGH PRESSURE WILL BUILD SOUTH INTO THE REGION TODAY AND REMAIN WEDGED ALONG THE EASTERN SLOPES OF THE APPALACHIANS TONIGHT INTO TUESDAY. A WEAK DISTURBANCE WILL ALSO PASS NORTH OF THE AREA LATE TONIGHT INTO TUESDAY AHEAD OF A WARM FRONT THAT WILL APPROACH FROM THE SOUTHWEST BY TUESDAY NIGHT. THIS FRONT WILL LIFT NORTHEAST ACROSS THE REGION TUESDAY NIGHT INTO WEDNESDAY AHEAD OF A STRONG COLD FRONT THAT WILL AFFECT THE REGION BY THURSDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1145 AM EDT MONDAY... BUMPED UP THE HIGH TEMPS THIS AFTERNOON 3-5 DEGREES AT MOST LOCATIONS...ESPECIALLY ACROSS SOUTHSIDE WHERE CURRENT TEMPS WERE ALREADY WITHIN A DEGREE OR TWO OF FORECASTED HIGHS. CLOUDS ARE BEGINNING TO ERODE EAST OF THE BLUE RIDGE...EXPECT MOSTLY SUNNY SKIES ACROSS MOST OF THE REGION BY MID AFTERNOON. AS OF 930 AM EDT MONDAY... ONLY SIGNIFICANT CHANGE TO THE NEAR TERM IS SKY COVER WAS BACKED WAY OFF WEST OF THE BLUE RIDGE. VIS SAT AND SURFACE OBS CONFIRM THAT IT IS ALREADY CLEAR FROM BLACKSBURG WEST TO BLUEFIELD. AT THIS POINT HAVE NOT ADJUSTED TEMPS...BUT MAY HAVE TO ADJUST UPWARD SLIGHTLY ACROSS THE WEST WITH THE NEXT UPDATE. AS OF 233 AM EDT MONDAY... DEEPER MOISTURE REMAINS SOUTH OF THE REGION EARLY THIS MORNING WITH LOW PRESSURE TRACKING ACROSS THE SE STATES KEEPING MOST RAINFALL DOWN OVER THE CAROLINAS. EXPECT THIS TREND TO PREVAIL DURING THE MORNING WITH ONLY SPOTTY -RA POSSIBLE ACROSS THE SOUTHERN TIER COUNTIES WITH SOME SPRINKLES NORTH INTO SOUTHERN VA FOR A WHILE LONGER. OTHERWISE WEDGE SLOWER TO DEVELOP WITH QUITE A GRADIENT SEEN IN DEWPOINTS ACROSS THE NORTHERN CWA WITH RANGE FROM 30S ALONG THE I-64 CORRIDOR TO SINGLE DIGITS AND TEENS TO THE NORTH/WEST. MODELS SUGGEST SOME OF THIS VERY DRY AIR WILL GET ADVECTED SOUTH THIS AFTERNOON AS THE WAVE TO THE SE GETS BOOTED OUT BY A MID LEVEL IMPULSE TO THE NW...ALLOWING HIGH PRESSURE TO WEDGE SOUTH ALONG THE EASTERN SLOPES. THIS ALONG WITH INCREASING SUBSIDENCE MAY BE ABLE TO SCOUR OUT A LOT OF THE RESIDUAL CLOUD COVER THIS AFTERNOON GIVEN A DRIER WEDGE THAN EARLIER EXPECTED. THIS SUPPORTED BY MOST GUIDANCE INCLUDING HI-RES SOLUTIONS SO TWEAKED CLOUDS DOWN ALLOWING FOR PERIODS OF MORE SUN ESPCLY WESTERN/NORTHERN SECTIONS WITH PERHAPS SOME LOW CLOUDS LINGERING BLUE RIDGE INTO NW NC LONGER. HIGH TEMPS AGAIN IFFY GIVEN ARRIVAL OF BETTER LOW LEVEL COOLING AROUND DAYBREAK AND THEN DEGREE OF CLOUD COVER AS SOME HEATING OF DRIER AIR TAKES SHAPE. GIVEN A WARMER START AND LATEST MOS TRENDS...BUMPED UP HIGHS A GOOD CAT OR TWO WITH POTENTIAL TO SEE THE FAR WEST AROUND BLF JUMP WELL ABOVE GUIDANCE PER DOWNSLOPE. OTRW RUNNING WITH MOSTLY 50S WITH COOLEST EAST UNDER THE WEDGE AXIS AND WARMER WEST OF THE BLUE RIDGE. WEDGE WILL PERSIST OVERNIGHT AS MID LEVEL ENERGY ROUNDING THE RESIDUAL 5H GREAT LAKES TROUGH PIVOTS BY TO THE NORTH AROUND MIDNIGHT BEFORE EXITING LATE. SWATH OF DEEPER MOISTURE LOOKS TO PERHAPS CLIP THE FAR NW WITH THE WETTER GFS SHOWING A BIT MORE DIGGING AND LIFT WHILE MOST OTHER SOLUTIONS REMAIN DRIER WITH PRECIP FARTHER NORTH. SINCE APPEARS SOME LIGHT QPF COULD OCCUR OVER SE WVA...NORTH OF BLF AND ACROSS BATH CTY INTO THE SOUTHERN SHENANDOAH VALLEY...LEFT IN SOME CHANCE POPS FOR -RA THAT COULD END AS FLURRIES OR A PERIOD OF -SN ACROSS THE HIGHER ELEVATIONS LATE. OTRW KEEPING ELSEWHERE DRY WITH JUST SOME INCREASE IN CLOUDS ESPCLY BLUE RIDGE AFTER MIDNIGHT GIVEN WEAK SE FLOW. LOWS SHOULD BE COLDER OVERNIGHT...MAINLY 30S...ESPCLY NORTH/EAST WITH THE WEDGE IN PLACE WHILE SPOTS ALONG/WEST OF I-77 POSSIBLY STAY IN THE 40S ON THE PERIPHERY OF THE WEDGE. && .SHORT TERM /TUESDAY THROUGH THURSDAY/... AS OF 330 AM EDT MONDAY... OUR WEATHER THROUGH MIDWEEK WILL BE RATHER STAGNANT AS LOW AMPLITUDE UPPER FLOW WILL NOT BE CONDUCIVE TO BIG CHANGES. BY TUESDAY ANOTHER WEDGE SCENARIO WILL BE IN PLACE AS SURFACE HIGH PRESSURE OVER THE NORTHEAST CONTINUES TO BUILD DOWN THE EASTERN SEABOARD. THIS WILL COMBINE WITH MOISTURE AND ISENTROPIC LIFT ASSOCIATED WITH WAVES OF LOW PRESSURE MOVING THROUGH THE OHIO VALLEY TO KEEP AN INCREASING CHANCE OF PRECIPITATION IN OUR FORECAST THROUGH MIDWEEK. TEMPERATURES WILL REMAIN A BIT BELOW NORMAL UNTIL THE WEDGE STARTS TO LOSE ITS INFLUENCE OVER OUR WEATHER ON WEDNESDAY. WARMER AIR WILL THEN SURGE INTO THE REGION AS A DIGGING TROF AMPLIFIES THE UPPER FLOW AND PUSHES A STRONG COLD FRONT THROUGH THE REGION LATE ON THURSDAY. && .LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/... AS OF 1245 PM EDT SUNDAY... UPPER PATTERN TRANSITIONS TO A DEEP LONG WAVE TROF AS WE HEAD INTO THE WEEKEND. SURFACE HIGH PRESSURE THAT BUILDS IN BEHIND THE FRONT WILL CROSS THE OHIO AND TENNESSEE VALLEYS ON SATURDAY NIGHT...THEN WILL BE OVER THE SOUTHEAST UNITED STATES ON SUNDAY. THIS WILL ALSO LEAD IN THE STRONGEST PUSH OF COLD AIR THIS WEEK...FOR FRIDAY NIGHT AND SATURDAY. ECMWF HAS 850MB TEMPERATURES DROPPING TO TO THE -6 TO -10 RANGE FOR SATURDAY AND SUNDAY. WITH THAT MUCH COLD AIR AVAILABLE...STILL MONITORING THE POTENTIAL FOR WINTER WEATHER...POSSIBLY FRIDAY NIGHT INTO SATURDAY MORNING. WILL KEEP SATURDAY NIGHT AND SUNDAY DRY FOR NOW AS NEXT LOW PRESSURE SYSTEM TRACKS ACROSS THE GREAT LAKES. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... AS OF 200 PM EDT MONDAY... SATELLITE IMAGERY INDICATES MOSTLY CLEAR SKIES AND VFR CONDITIONS THIS AFTERNOON...WITH A FEW CU DEVELOPING ACROSS THE RIDGES OVER THE NC HIGHLANDS. HIGH PRESSURE IS CENTERED OVER THE DELMARVA...MAINTAINING A DRY EASTERLY WIND FLOW ACROSS THE FORECAST REGION. TO THE NORTHWEST... KEEPING AN EYE ON AN UPPER LEVEL DISTURBANCE PASSING ACROSS THE SOUTHERN GREAT LAKES...WHICH IS TRIGGERING LIGHT SNOW ACROSS IL/IN/OH...WHILE THE LEADING EDGE OF ASSOCIATED CLOUD COVER IS BEGINNING TO PASS ACROSS THE OHIO RIVER INTO WV. MOSTLY CLEAR SKIES WILL PERSIST THROUGH SUNSET...WITH A FEW CU HOLDING ALONG THE RIDGES...HOWEVER MID CLOUDS WILL INCREASE THEREAFTER AS THE UPPER LEVEL DISTURBANCE PASSES EAST. EXPECT TO SEE LIGHT RAIN SHOWERS...POSSIBLY MIXED WITH SNOW ACROSS THE HIGHER RIDGES...ENTER IN THE VICINITY OF KLWB/KHSP...AND SPREAD ACROSS THE AREA NORTH OF HIGHWAY 460 OVERNIGHT. THIS SYSTEM WILL ADD MOISTURE TO THE ATMOSPHERE...WHICH WILL HELP REINTRODUCE MVFR CEILINGS FOR MOST AIRPORTS...ALTHOUGH MAINLY LOW END VFR IS EXPECTED FOR NORTHERN NC. PERSISTENT WEDGING PATTERN WILL MAINTAIN EAST TO SOUTHEASTERLY WIND FLOW ON TUESDAY...CAUSING LOW CEILINGS TO BE SLOW TO ERODE. HIGH PRESSURE WEDGE WILL GRADUALLY ERODE ON WEDNESDAY AS HIGH PRESSURE SHIFTS OFFSHORE...WHILE A DEEP LOW PRESSURE SYSTEM PASSES FROM THE CENTRAL PLAINS TO THE WESTERN GREAT LAKES. BELIEVE THE INFLUENCE OF THE WEDGE WILL STILL BE IN PLAY ACROSS THE AREA...AND CANNOT RULE OUT SPOTTY MVFR CONDITIONS DURING THE MORNING...WITH WINDS SHIFTING MORE SOUTHERLY DURING THE AFTERNOON AND EVENING. A WARM FRONT SHOULD FINALLY LIFT NORTHEAST ACROSS THE REGION WEDNESDAY NIGHT...RESULTING IN DEEPENING SOUTH TO SOUTHWEST FLOW...ALLOWING FOR IMPROVEMENT TO VFR AHEAD OF ANOTHER COLD FRONT TO THE WEST ON THURSDAY. THIS FRONT IS EXPECTED TO MOVE INTO OUR AREA DURING THE EVENING...WITH SHOWERS AND THE POTENTIAL FOR A FEW THUNDERSTORMS. DO SEE SOME POTENTIAL FOR FRONTAL SLOWDOWN AHEAD OF ANOTHER DISTURBANCE APPROACHING FROM THE WEST FRIDAY... RESULTING IN LINGERING SHOWERS AND SUB VFR CEILINGS IN THE MOUNTAINS. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...JH/NF NEAR TERM...CF/JH SHORT TERM...MBS LONG TERM...AMS/MBS AVIATION...JH/NF

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