Area Forecast Discussion
Issued by NWS Blacksburg, VA

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000 FXUS61 KRNK 131745 AFDRNK AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BLACKSBURG VA 145 PM EDT SUN APR 13 2014 .SYNOPSIS... LOW PRESSURE OVER THE CENTRAL UNITED STATES WILL MOVE EAST TODAY THROUGH MONDAY. THIS SYSTEM WILL PUSH A STRONG COLD FRONT THROUGH THE REGION ON TUESDAY. HIGH PRESSURE WILL BE OVER THE AREA WEDNESDAY AND THURSDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1220 PM EDT SUNDAY... FORECAST APPEARS ON TRACK ALTHOUGH TEMPS ARE RUNNING WARMER IN THE EAST AS LYH HAS ALREADY JUMPED TO 79 DEGREES. HAVE ADDED A FEW MORE DEGREES ACROSS THE AREA WITH HIGHS IN TH LOWER TO MID 80S EAST AND PORTIONS OF THE WIDER VALLEYS IN THE WEST...WITH MID 70S ALONG THE BLUE RIDGE AND HIGHER RIDGES OF THE NW CWA. ASIDE FROM CIRRUS...SHOULD BE PLENTY OF SUNSHINE THIS AFTERNOON. PREVIOUS VALID DISCUSSION... FORECAST AREA STAYS IN MILD AIR MASS TODAY AND TONIGHT WITH GRADUALLY INCREASING MOISTURE. SOUTHWEST FLOW DEEPENS BY LATE TONIGHT. WIND GUSTS IN THE 20 TO 30 MPH RANGE THIS AFTERNOON. MAXIMUM TEMPERATURES STILL LOOK CLOSE TO RECORD VALUES IN THE MOUNTAINS. MODELS BRING CLOUDS ON OVERNIGHT...INCLUDING A LOW LAYER OF CLOUDS AGAINST THE SOUTHERN BLUE RIDGE. HAVE TRIMMED BACK THE PROBABILITY OF MEASURABLE RAIN BUT HAVE KEPT IN PATCHY DRIZZLE. && .SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/... AS OF 400 AM EDT SUNDAY... WILL START MONDAY OFF WITH AREAS OF DRIZZLE AND LIGHT SHOWER ACTIVITY...MAINLY ALONG THE BLUE RIDGE...THANKS TO STRONG SOUTHERLY FLOW DRAWING GULF MOISTURE AHEAD OF AN APPROACHING COLD FRONT. SHOWER ACTIVITY WILL THEN SPREAD ACROSS MUCH OF THE FORECAST REGION DURING THE DAY AS WEAK UPPER LEVEL DISTURBANCES PASS ACROSS FROM THE SOUTHWEST. BELIEVE THESE SHOWERS WILL BE SPOTTY...ON AND OFF ACTIVITY WHERE MOST LOCATIONS RECEIVE AT LEAST A LITTLE BIT OF RAINFALL...BUT ONLY OCCASIONALLY THROUGHOUT THE DAY. INCREASED CLOUD COVER WILL KEEP AFTERNOON TEMPERATURES COOLER THAN THOSE OF SUNDAY...WITH HIGHS RANGING FROM THE MID 60S TO THE LOW 70S ACROSS THE MOUNTAINS...WITH HIGHS REACHING INTO THE MID 70S ACROSS THE SOUTHSIDE WHERE SHOWER ACTIVITY WILL HOLD OFF UNTIL LATE AFTERNOON. THE WARM MOIST SOUTHWESTERLY FLOW WILL ALSO KEEP MONDAY NIGHT LOWS VERY MUCH ON THE MILD SIDE...RANGING FROM THE LOW 50S WEST TO THE LOW 60S EAST. THE COLD FRONT WILL BEGIN TO ENTER OUR SOUTHEAST WEST VIRGINIA AND MOUNTAIN EMPIRE COUNTIES SHORTLY AFTER 8 AM TUESDAY MORNING... SUPPORTED ALOFT BY A STRONG UPPER LEVEL TROUGH. THERE WILL BE A COUPLE OF CONCERNS AS THE FRONT PUSHES ACROSS OUR AREA. THE FIRST WILL BE THE POTENTIAL FOR GUSTY WINDS WITH THE CONVECTION ALONG THE FRONT...AS WELL AS THE GRADIENT WINDS BEHIND THE FRONT. SEVERAL MODELS ARE IN GOOD AGREEMENT OF A 55+KT LOW LEVEL JET DEVELOPING AHEAD OF THE FRONT...AND WHILE THUNDERSTORM ACTIVITY WILL REMAIN LIMITED...EXPECT THAT THE STRONGER SHOWERS WILL BE CAPABLE OF DRAWING THESE WINDS ALOFT DOWN TO THE SURFACE. IN ADDITION...HIGH PRESSURE BUILDING IN BEHIND THE FRONT WILL DO SO ON A ~10MB PRESSURE GRADIENT...WHICH WILL RESULT IN A PERIOD OF GUSTY NORTHWEST WINDS FOR TUESDAY AFTERNOON INTO EARLY WEDNESDAY. ANOTHER CONCERN WILL BE THE POTENTIAL FOR HEAVY RAIN ALONG THE FRONT. FOR THE ENTIRE EVENT...WILL BE LOOKING FOR AROUND AN INCH OF RAIN FOR MOST OF THE FORECAST REGION...WITH 1.5 TO 2 INCHES ALONG THE BLUE RIDGE AND OTHER LARGER RIDGELINES. WHILE THIS WOULD NOT BE CONSIDERED TOO EXCESSIVE FOR OUR AREA...SOME OF THIS RAIN MAY FALL OVER A SHORT PERIOD OF TIME...RESULTING IN LOCALIZED FLOODING ISSUES...SOMETHING THAT WE WILL HAVE TO MONITOR CLOSELY. FINALLY...TEMPERATURES WILL FALL OFF QUICKLY WITH FRONTAL PASSAGE... ON THE ORDER OF 5 TO 8 DEGREES PER HOUR FOR THE FIRST FEW HOURS AFTER PASSAGE...AND WILL APPROACH FREEZING FROM SOUTHEAST WEST VIRGINIA THROUGH THE NORTH CAROLINA MOUNTAINS BY EARLY EVENING. AS SUCH...EXPECT TO SEE RESIDUAL RAIN SHOWERS CHANGE OVER TO SNOW BY SUNSET. CONSIDERING WARM GROUND CONDITIONS...DO NOT EXPECT ANY ACCUMULATIONS OVER AN INCH. SNOW SHOWER ACTIVITY WILL COME TO AN END EARLY WEDNESDAY MORNING. HIGH PRESSURE WILL PASS SOUTH OF THE GREAT LAKES TO NEW ENGLAND ON WEDNESDAY TO WEDGE AGAINST THE EASTERN FACE OF THE APPALACHIANS. THE COOL NORTHEASTERLY WIND FLOW WILL LIMIT WEDNESDAY HIGH TEMPERATURES TO THE UPPER 40S AND LOW/MID 50S UNDER MOSTLY SUNNY SKIES. WEDNESDAY NIGHT LOWS WILL FALL INTO THE UPPER 20S AND LOW 30S. && .LONG TERM /THURSDAY THROUGH SATURDAY/... AS OF 300 PM EDT SATURDAY... EXPECT HIGH PRESSURE TO CONTROL THE WEATHER PATTERN FOR THURSDAY INTO FRIDAY. CHANGE IN AIRMASS WILL BRING COOL DRY CONDITIONS TO THE AREA BY THURSDAY WITH POTENTIAL FOR A COUPLE OF FROSTY MORNINGS. A COLD FRONT WILL APPROACH FROM THE WEST FRIDAY NIGHT INTO SATURDAY. ADDED SOME ISOLATED TO SCATTERED SHOWERS FRIDAY NIGHT INTO SATURDAY. AFTER STARTING COOL ON WEDNESDAY...TEMPERATURES MODERATE TOWARD NEXT WEEKEND AS THE AIRMASS BEGINS TO MODIFY. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/...
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AS OF 135 PM EDT SUNDAY... VFR WITH GUSTY SOUTH TO SOUTHWEST WINDS THIS AFTERNOON...UP TO 20 KNOTS AT TIMES AT MOST SITES. WINDS SUBSIDE THIS EVENING. TONIGHT...MODELS SHOWING LOW LEVEL MOISTURE INCREASE WITH POTENTIAL FOR MVFR CIGS AT MOST SITES ALONG AND EAST OF THE WV/VA BORDER SO HAVE MVFR IN AT BCB/ROA/LYH/DAN. POTENTIAL FOR MVFR VSBYS AND DRIZZLE EXISTS AS WELL ESPECIALLY AT BCB/ROA BUT CONFIDENCE NOT HIGH ENOUGH TO LOWER THIS. CIGS ARE EXPECTED TO RISE ABOVE MVFR BY MID-LATE MORNING MONDAY WITH SOUTH WINDS INCREASING AGAIN...ESPECIALLY IN THE AFTERNOON PLUS INCREASED THREAT FOR SHRA/TSRA. LOOKS WET INTO TUESDAY WITH MOST STAYING BELOW VFR MONDAY EVENING THRU TUESDAY NIGHT. STRONG GUSTY WINDS ARE POSSIBLE BEHIND THE FRONT TUESDAY AFTERNOON AND NIGHT. DRIER AIR WORKS IN BEHIND THE SYSTEM FOR WEDNESDAY ALTHOUGH RESIDUAL MOISTURE AND COLD AIR ALOFT MAY ACT TO KEEP MVFR CIGS OVER THE MOUNTAINS ON TUESDAY NIGHT. VFR THEN EXPECTED THURSDAY WITH HIGH PRESSURE RIDGING IN FROM OFF NEW ENGLAND BETWEEN THE EXITING FRONT OFFSHORE AND THE NEXT COLD FRONT TO THE NW.
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&& .CLIMATE...
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WARM SOUTHWEST FLOW WILL BRING HIGH TEMPERATURES CLOSE TO RECORDS AT OUR MOUNTAIN CLIMATE SITES TODAY APRIL 13. THE ROA/LYH/DAN RECORDS ARE OUT OF REACH...SO WERE NOT INCLUDED IN THIS SECTION. STATION RECORD/YEAR/RECORDS BEGAN FORECAST HIGH APR 13TH BLACKSBURG 80/1977/1952 78 BLUEFIELD 81/1977/1959 80 LEWISBURG 79/1977/1973 78
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&& .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS/JH/WP NEAR TERM...AMS/CF/WP SHORT TERM...NF LONG TERM...KK AVIATION...AMS/JH/WP CLIMATE...WP

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