Area Forecast Discussion
Issued by NWS Blacksburg, VA

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000 FXUS61 KRNK 291125 AFDRNK AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BLACKSBURG VA 725 AM EDT MON JUN 29 2015 .SYNOPSIS... HIGH PRESSURE OVER THE REGION WILL MOVE EAST TODAY. LOW PRESSURE OVER ILLINOIS WILL TRACK ACROSS THE OHIO VALLEY TODAY AND INTO THE EASTERN GREAT LAKES ON TUESDAY. A COLD FRONT WILL BECOME STALLED FROM THE TENNESSEE VALLEY ACROSS THE MID ATLANTIC REGION THURSDAY THROUGH SATURDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 300 AM EDT MONDAY... SURFACE LOW OVER ILLINOIS MOVES ACROSS THE OHIO VALLEY AND INTO THE EASTERN GREAT LAKES BY TUESDAY MORNING. ONCE HIGH PRESSURE OVER THE REGION MOVES EAST THIS MORNING AND MIXING BEGINS...WINDS WILL BACK TO THE SOUTH-SOUTHEAST IN RESPONSE TO THIS LOW. MODELS KEEP DRY AIR MASS AND STABLE AIR OVER THE FORECAST AREA FOR MUCH OF THE DAY. BY 00Z/8PM...BETTER INSTABILITY AND HIGHER CAPES ARE FORECAST TO BE MOVING INTO THE FAR WESTERN COUNTY WARNING AREA. MOISTURE INCREASES TOO AFTER 00Z. FOR NOW WILL KEEP HIGHEST PROBABILITY OF PRECIPITATION IN THE WESTERN COUNTY WARNING AREA. STARTING OUT WITH PLENTY OF SUNSHINE THIS MORNING BUT EXPECTING HIGH CLOUDS TO SPREAD INTO THE AREA ONCE PRECIPITATION ASSOCIATED WITH THE ILLINOIS LOW GETS CLOSER AND RE-FIRES TO THE WEST THIS AFTERNOON. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 320 AM EDT MONDAY... THE BROAD UPPER TROUGH WILL SLOWLY MOVE EAST AND FLATTENS TOWARD THE END OF THE WEEK. SEVERAL SHORTWAVES WILL ROTATE THROUGH THE TROUGH DURING THE PERIOD. THE WEATHER PATTERN REMAINS QUITE UNSETTLED WITH THE POTENTIAL FOR UPSTREAM MESOSCALE CONVECTIVE COMPLEXES OR THE RESULTANT OUTFLOW BOUNDARIES AND/OR LEFT OVER CONVECTION TO TRANSLATE ACROSS OUR REGION THROUGH THE PERIOD. INITIALLY DECREASED POPS TUESDAY MORNING...THEN INCREASED TUESDAY AFTERNOON INTO TUESDAY NIGHT. A SHORTWAVE IS PROGGED TO ROTATE THROUGH TUESDAY AFTERNOON AS THE UPPER TROUGH BEGINS TO DEEPEN AND SHIFT EVER SO SLIGHTLY EAST. SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TUESDAY AFTERNOON IN TUESDAY EVENING. INSTABILITY IS QUITE NOTABLE...HEALTHY LAPSE RATES AND PWATS. THETA-E RIDGE IS EVIDENT ACROSS THE WESTERN PART OF THE CWA DURING PEAK HEATING WHEN THE SHORTWAVE ARRIVES...ALONG WITH MODEST LOW-LEVEL SHEAR FOR LATE JUNE. SPC HAS OUTLOOKED THE COUNTY WARNING AREA FOR A MARGINAL SEVERE RISK IN SWODY2. THE PRIMARY THREATS ARE FOR GUSTY WINDS AND HAIL. HIGH TEMPERATURES TUESDAY WILL RANGE FROM THE LOWER 70S IN THE NORTHWEST MOUNTAINS TO NEAR 90 DEGREES INT THE PIEDMONT. DECREASED POPS TUESDAY EVENING INTO TUESDAY NIGHT. LOW TEMPERATURES TUESDAY NIGHT WILL VARY FROM THE UPPER 50S IN THE MOUNTAINS TO THE UPPER 60S IN THE PIEDMONT. THE CONVECTIVE POTENTIAL ON WEDNESDAY IS MORE OF A CHALLENGE IN THE WAKE OF THE TUESDAY SHORTWAVE. MODELS DEPICT THE POTENTIAL OF A MCS TRACKING FROM THE WESTERN TN VALLEY EAST-SOUTHEAST TOWARD THE SOUTHERN APPALACHIANS. WILL KEEP THE HIGHEST POPS IN THE WEST AS SUPPORTED BY ECMWF AND GFS. HIGH TEMPERATURES WILL CLIMB INTO THE LOWER 70S IN THE MOUNTAINS TO AROUND 90 DEGREES IN THE PIEDMONT. HARD TO DETERMINE HOW FAR EAST TO GO WITH POPS WEDNESDAY NIGHT...WITH ANOTHER SHORTWAVE AND FRONTAL BOUNDARY LIFTING NORTH. LOWS WEDNESDAY NIGHT WILL GENERALLY BE IN THE 60S. PLACED THE HIGHEST POPS IN THE WEST WEDNESDAY NIGHT AND TAPER OFF AS ONE HEADS EAST. && .LONG TERM /THURSDAY THROUGH SUNDAY/... AS OF 350 PM EDT SUNDAY... THE UNSETTLED PATTERN WILL CONTINUE INTO THE WEEKEND. BROAD TROUGHING WILL REMAIN IN PLACE...GENERALLY CENTERED ACROSS THE GREAT LAKES REGION. HOWEVER...OVERALL HEIGHTS ARE ALSO INCREASING ACROSS THE U.S. WITH UPPER RIDGING STRENGTHENING IN THE WESTERN ATLANTIC AND ACROSS THE CENTRAL/WESTERN U.S. THE MCS POTENTIAL APPEARS TO DECREASE THROUGH THE PERIOD AS THE UPPER FLOW BECOMES MORE WEST-SOUTHWEST INSTEAD OF NORTHWEST AS EARLIER IN THE WEEK. WILL NEED TO WATCH THUNDERSTORM POTENTIAL ESPECIALLY SAT AS A STRONGER UPPER DISTURBANCE ROTATES THROUGH THE OHIO VALLEY. NOTABLE SHEAR/INSTABILITY APPEARS DESTINED TO ACCOMPANY THE SOUTH- SOUTHEAST SIDE OF THIS SYSTEM SATURDAY AFTERNOON. THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK CONDITIONS OVERALL BECOME SLIGHTLY LESS FAVORABLE FOR CONVECTION WITH ACTIVITY LIKELY BECOMING MORE SCATTERED AND MORE DIURNAL IN NATURE WITH DECREASING UPPER SUPPORT AND BUILDING HEIGHTS/GENERAL RIDGING ALOFT. WITH THE INCREASING UPPER HEIGHTS COME INCREASING 850MB/SFC TEMPERATURES AS WELL. NOTHING EXTREME BY ANY MEANS...BUT AT LEAST SLIGHTLY ABOVE NORMAL TEMPERATURES APPEAR LIKELY BY THE END OF THE PERIOD WITH LOWS IN THE 60S MOUNTAINS AND 70S PIEDMONT...WITH HIGHS 80S WEST...CREEPING INTO THE LOWER 90S PIEDMONT. && .AVIATION /12Z MONDAY THROUGH FRIDAY/...
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AS OF 725 AM EDT MONDAY... EXPECTING VFR CONDITIONS THROUGH THE TAF PERIOD. SURFACE ANALYSIS SHOWED HIGH PRESSURE AND A DRY AIR MASS OVER THE MID ATLANTIC REGION EARLY THIS MORNING. NORTHEAST DRAINAGE WIND OF COOL AIR OVER THE RELATIVELY WARMER WATER OF THE GREENBRIER RIVER HAS ADVECTED FOG INTO THE KLWB AIRPORT THIS MORNING. HIGH CONFIDENCE THAT THE FOG WILL DISSIPATE AT CONDITIONS WILL IMPROVE TO VFR VISIBILITIES SHORTLY AFTER 13Z/9AM. LOW PRESSURE OVER ILLINOIS WILL MOVE EAST TODAY. MID AND HIGH CLOUDS IN ADVANCE OF THE SHOWERS AND THUNDERSTORMS ASSOCIATED WITH THIS SYSTEM WILL SPREAD INTO THE REGION THIS AFTERNOON. WINDS WILL BACK TO THE SOUTH AS THIS LOW MOVES INTO THE OHIO VALLEY. SINCE THE LOW STAYS NORTHWEST OF THE FORECAST AREA...LOW CONFIDENCE THAT ANY OF THE PRECIPITATION WITH THIS FEATURE WILL IMPACT LOCAL AIRPORTS. BUT BASED ON TIMING FROM THE MODELS...KLWB AND KBLF HAVE THE MOST LIKELY CHANCE OF SHOWERS AND THUNDERSTORMS AFTER 00Z. EXTENDED AVIATION DISCUSSION... THE CHANCE FOR SHOWERS AND THUNDERSTORMS INCREASE ON TUESDAY AHEAD OF THE NEXT COLD FRONT. THE NEXT COLD FRONT IS FORECASTED TO ARRIVE WEDNESDAY AFTERNOON/NIGHT. ANOTHER DISTURBANCE ENTERING THE OHIO VALLEY WILL BRING SHOWERS AND THUNDERSTORMS TO THE REGION THURSDAY AND FRIDAY.
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&& .EQUIPMENT... AS OF 150 AM EDT SUNDAY... THE NOAA WEATHER RADIO IN HINTON WV...BROADCASTING ON A FREQUENCY OF 162.425 MHZ...IS OFF THE AIR DUE TO A TELCO PROBLEM. THIRD PARTY TECHNICIANS ARE CURRENTLY WORKING ON THE COMMUNICATION ISSUE. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS SHORT TERM...KK LONG TERM...RAB AVIATION...AMS EQUIPMENT...DS

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