Area Forecast Discussion
Issued by NWS Blacksburg, VA

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000 FXUS61 KRNK 291738 AFDRNK AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BLACKSBURG VA 138 PM 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 1250 PM EDT MONDAY... FOR THE EARLY AFTERNOON FORECAST UPDATE...THE FOLLOWING ADJUSTMENTS WILL BE MADE. A SLIGHTLY MORE RAPID INCREASE IN CLOUD COVER WILL BE FORECAST IN THE WEST BASED UPON THE LATEST SATELLITE IMAGERY AND EXPECTED TRENDS THIS AFTERNOON. HIGH TEMPERATURES HAVE RECEIVED ONLY MINOR ADJUSTMENTS WITH A DEGREE OR TWO ADDED AT A FEW LOCATIONS. PRECIPITATION TRENDS STILL LOOK ON TRACK WITH THE FIRST ISOLATED CELLS ACROSS THE FAR WESTERN PARTS OF THE AREA AFTER ROUGHLY 5PM. HOWEVER...THE FORECAST WILL ALLOW FOR ABOUT AN HOUR OF THE CONVECTION BEING ONLY SHOWERS BEFORE THE CHANCE OF THUNDERSTORMS. NO OTHER SIGNIFICANT CHANGES. AS OF 945 AM EDT MONDAY... THE MORNING FORECAST UPDATE WILL REFLECT NO MAJOR CHANGES TO THE ONGOING FORECAST. MINOR ADJUSTMENTS WERE MADE TO THE HOURLY TEMPERATURE...DEW POINT AND SKY COVER OVER THE NEXT FEW HOURS TO REFLECT THE LATEST OBSERVATIONS AND EXPECTED TRENDS INTO THE EARLY AFTERNOON. ISOLATED SHOWERS AND STORMS ARE STILL FORECAST FOR THE FAR WESTERN PARTS OF THE AREA LATE THIS AFTERNOON INTO THE EARLY EVENING. 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 /18Z MONDAY THROUGH SATURDAY/...
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AS OF 130 PM EDT MONDAY... THE WESTERN EXTENT OF AN AREA OF HIGH PRESSURE WILL KEEP VFR CONDITIONS ACROSS THE REGION THE REMAINDER OF THIS AFTERNOON. A WARM FRONT WILL HEAD NORTHEAST THROUGH TN/KY/WV/OH THIS EVENING. A FEW SHOWERS OR THUNDERSTORMS MAY ACCOMPANY THE FRONT...WITH ANY PRECIPITATION LIMITED TO AREAS ALONG AND WEST OF THE BLUE RIDGE...WITH THE BULK OF THE ACTIVITY ACROSS SOUTHEAST WEST VIRGINIA. STILL...THE MAJORITY OF THE REGION WILL BE PRECIPITATION FREE. SOME MVFR CIGS MAY FILL IN BEHIND THE FRONT TONIGHT IN THE WEST...ALONG WITH SOME POCKETS OF MVFR LIGHT FOG. KLWB MAY DROP EVEN LOWER WITH ITS TYPICALLY FOGGY NEARBY RIVER VALLEY HAVING AN INFLUENCE. ANY SUB-VFR CONDITIONS SHOULD IMPROVE TO VFR BY 14-15Z/10-11AM ON MONDAY. EXTENDED AVIATION DISCUSSION... THE REGION WILL BE IN A GENERAL NORTHWEST FLOW PATTERN THROUGH SATURDAY. WHILE ISOLATED TO SCATTERED SHOWERS AND STORMS CANNOT BE RULE OUT ANY OF THESE DAYS...THE BEST POTENTIAL WILL BE TUESDAY INTO WEDNESAY...AND THEN AGAIN THURSDAY INTO FRIDAY...FOLLOWED BY A THIRD POTENTIAL INCREASE IN COVERAGE ON SATURDAY AS SEPARATE SHORTWAVE TROUGHS PROGRESS INTO AND TROUGH THE AREA WITHIN THE NORTHWEST FLOW. VFR CONDITIONS ARE EXPECTED FOR MOST OF THE AREA MUCH OF THE TIME. THE EXCEPTIONS WILL COME AS TEMPORARY DECREASES WITHIN ANY HEAVIER RAIN SHOWERS OR THUNDERSTORMS...AND THEN LATE AT NIGHT AND EARLY MORNING IN THE FORM OF RIVER OR MOUNTAIN VALLEY FOG...ESPECIALLY IN AREAS THAT RECEIVED PRECIPITATION THE DAY BEFORE.
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&& .EQUIPMENT... AS OF 130 PM EDT MONDAY... THE NOAA WEATHER RADIO IN HINTON WV...BROADCASTING ON A FREQUENCY OF 162.425 MHZ...IS BROADCASTING AGAIN AT FULL CAPACITY. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS/DS SHORT TERM...KK LONG TERM...RAB AVIATION...DS EQUIPMENT...DS

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