Area Forecast Discussion
Issued by NWS Blacksburg, VA

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000 FXUS61 KRNK 030509 AFDRNK AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BLACKSBURG VA 109 AM EDT THU SEP 3 2015 .SYNOPSIS...
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HIGH PRESSURE ACROSS THE AREA WILL KEEP A HOT AND HUMID AIRMASS IN PLACE THROUGH THE END OF THE WEEK. A BACKDOOR COLD FRONT WILL CROSS THE REGION LATE FRIDAY NIGHT INTO SATURDAY...AND BRING AN INCREASED COVERAGE OF PRECIPITATION IN ADVANCE OF IT LATE FRIDAY INTO FRIDAY NIGHT. DRIER AND COOLER AIR WILL WORK ITS WAY INTO THE AREA FOR THE LATTER HALF OF THE WEEKEND INTO THE START OF NEXT WEEK.
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&& .NEAR TERM /THROUGH TODAY/... AS OF 950 PM EDT WEDNESDAY... KEEPING A FEW SHOWERS IN THE FORECAST TIL MIDNIGHT FROM HALIFAX TO YADKIN...BUT HAVE IT DRY OVERNIGHT. UPPER VORT NOW CENTERED OVER THE SHENANDOAH VALLEY ALLOWING MORE LIFT AHEAD OF IT INTO ERN VA/NC. THERE ARE SOME SHOWERS ACROSS OHIO WHICH MODELS TRY TO TRACK SE TOWARD SE WV TOWARD MORNING...BUT FADE IT OUT BEFORE THEN. STILL EXPECT FOG TO FORM OVERNIGHT IN THE RIVER VALLEYS. PREVIOUS VALID DISCUSSION... ON THURSDAY...PATCHY MORNING FOG WILL DISSIPATE BY 10AM AT MOST LOCATIONS. ANOTHER UPPER LEVEL DISTURBANCE WILL APPROACH FROM THE WEST DURING THE AFTERNOON HOURS. THIS ONE LOOKS TO HAVE A TRACK A LITTLE FARTHER SOUTH THAN THE SYSTEM OF TODAY. THIS WILL HAVE THE IMPACT OF BRING SCATTERED COVERAGE TO NORTHWESTERN PARTS OF THE AREA BY THE AFTERNOON...WITH ISOLATED COVERAGE EXPECTED EAST TO AT LEAST THE CREST OF THE BLUE RIDGE. ISOLATED COVERAGE ACROSS THE PIEDMONT WILL OCCUR LATER IN THE AFTERNOON. TEMPERATURES WILL CONTINUE WITH READINGS ABOVE NORMAL. HIGHS IN THE MOUNTAIN WILL RANGE FROM THE LOW TO MID 80S WITH UPPER 80S TO LOWER 90S ACROSS THE FOOTHILLS AND PIEDMONT. && .SHORT TERM /TONIGHT THROUGH SATURDAY/... AS OF 315 PM EDT WEDNESDAY... 500 MB HEIGHTS CONTINUE TO RISE OVER THE NORTHEAST UNITED STATES THROUGH FRIDAY NIGHT. BUT AT THIS SAME TIME THE SHORT WAVE COMING OUT OF MINNESOTA TRACKS OVER THE GREAT LAKES WILL CONTRIBUTE TO AN ELONGATED REGION OVER LOWER HEIGHTS FROM THE GREAT LAKES TO THE CAROLINAS...BETWEEN TWO PARTS OF THE UPPER RIDGE BY FRIDAY. FRIDAY WILL STILL HAVE MAXIMUM TEMPERATURES ABOVE NORMAL BUT BY SATURDAY MORNING NORTHEAST WINDS BRINGS IN AN AIR MASS WITH 850 MB TEMPERATURES AROUND +14. THESE COOLER TEMPERATURES COMBINED WITH UPSLOPE CLOUDS ON EASTERN SLOPES WILL KEEP MAXIMUM TEMPERATURES AT OR JUST BELOW NORMAL ON SATURDAY. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... AS OF 100 PM EDT WEDNESDAY... A BULK OF THE UPPER RIDGE REMAINS OVER THE SOUTHERN PLAINS WHILE ANOTHER PIECE MOVES ACROSS THE NORTHEAST UNITED STATES. SUNDAY AND MONDAY MODELS STILL SHOWED RELATIVELY LOWER HEIGHT OVER THE SOUTHEAST UNITED STATES. DURING THE WEEK THE UPPER RIDGE FLATTENS AND BY WEDNESDAY...A DEEP TROF HAS PROGRESSED INTO THE CENTRAL UNITED STATES. DRY AIRMASS REMAINS OVER THE AREA SATURDAY NIGHT AND SUNDAY. MODELS BEGIN TO BRING LOW LEVEL MOISTURE BACK INTO THE REGION ON TUESDAY NIGHT AND WEDNESDAY. BY TUESDAY...AT THE SURFACE...THE PARENT HIGH MOVES FAR ENOUGH OFFSHORE THAT THE PART OF THE HIGH OVER THE CENTRAL APPALACHIANS WILL BE VERY WEAK. CHANGE IN UPPER PATTERN WILL SET UP DEEPER SOUTHWEST FLOW OVER THE REGION ON WEDNESDAY AHEAD OF THE APPROACHING UPPER TROF. BETTER COVERAGE OF PRE-FRONTAL SHOWERS AND THUNDERSTORMS WILL NOT BE UNTIL WEDNESDAY. WILL HAVE A MAINLY DRY FORECAST FOR SATURDAY NIGHT THROUGH TUESDAY IN ALL BUT THE FAR SOUTHWEST COUNTIES OF THE FORECAST AREA. TEMPERATURES WILL BE CLOSE TO NORMAL ON SATURDAY AND SUNDAY BUT WILL THEN GRADUALLY WARM THROUGH WEDNESDAY. && .AVIATION /06Z THURSDAY THROUGH MONDAY/...
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AS OF 1258 AM EDT THURSDAY... EARLIER SHOWERS HAVE PUSHED TO THE SOUTH TONIGHT LEAVING MAINLY VFR CONDITIONS UNDER CLEAR SKIES IN PLACE. THIS WILL LEAD TO ANOTHER ROUND OF FOG/STRATUS ESPECIALLY IN THE VALLEYS WITH KLWB LIKELY TO FALL INTO LIFR...WITH A PERIOD OF IFR/MVFR POSSIBLE AT KBCB AND KLYH. ELSEWHERE EXPECTING FOG TO REMAIN SPOTTY WITH ONLY LIMITED MVFR COVERAGE BY DAYBREAK. THURSDAY...VFR CONDITIONS TO RETURN AGAIN BY MID MORNING...FOLLOWED BY INCREASING CU AND CB BUILD UPS ESPECIALLY OVER THE MOUNTAINS. HOWEVER...IN THE AFTERNOON...SHOWERS AND STORMS WILL AGAIN FIRE UP OVER MOUNTAINS AS OLD OUTFLOW AND PERHAPS A WEAK WAVE ALOFT ENHANCE LIFT A BIT. APPEARS KBLF/KLWB MORE IN LINE FOR SHOWERS OR STORMS...BUT STILL ONLY SCATTERED COVERAGE. THUS WILL INCLUDE A VCTS MENTION...AFTER 18Z/2PM WITH VCSH AT KBCB. OTHERWISE CIGS WILL MAINLY BE VFR 4-6KFT. EXTENDED AVIATION DISCUSSION... WILL SEE A WEAK FLOW PATTERN WITH AN UPPER TROUGH EXTENDING FROM EAST-WEST OVER OUR AREA FRIDAY INTO SUNDAY. THIS ALONG WITH HIGH PRESSURE TO THE NORTHEAST WILL CAUSE THE LOW LEVEL FLOW TO TURN MORE EASTERLY IN TIME. AS OF NOW...THE TERMINALS WILL BE VFR DURING THE DAY...WITH POSSIBLE MVFR OR WORSE WITH FOG AT NIGHT INTO FRIDAY NIGHT. THE EASTERLY FLOW EXPECTED BY SATURDAY WILL BRING LOWER CLOUDS IN AND POTENTIAL FOR MVFR CIGS AT LEAST FOR THE MOUNTAINS...AND LOW END VFR ROA/LYH/DAN. WITH THIS UPPER TROUGH THERE WILL BE DAILY THREAT OF SHOWERS...SO SUB VFR IN THESE IS POSSIBLE. BY SUNDAY-MONDAY THE WEAK TROUGH ALOFT MOVES OVER THE SOUTHEAST COAST WHILE UPPER RIDGING ELONGATES OVER THE MID ATLANTIC. WE WILL SEE SOME DRYING TAKE PLACE SO VFR SHOULD OCCUR SUNDAY-MONDAY WITH THE STILL A THREAT OF FOG AT NIGHT AT KBCB/KLWB.
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&& .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...DS/JH NEAR TERM...DS/WP SHORT TERM...AMS LONG TERM...AMS AVIATION...JH/WP

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