Area Forecast Discussion
Issued by NWS Blacksburg, VA

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000 FXUS61 KRNK 290549 AFDRNK AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BLACKSBURG VA 149 AM EDT MON JUN 29 2015 .SYNOPSIS... LOW PRESSURE WAS OVER NEW YORK AND WILL MOVE OFF THE NEW ENGLAND COAST BY MONDAY MORNING. HIGH PRESSURE OVER THE TENNESSEE VALLEY WILL MOVE INTO THE MID ATLANTIC REGION TONIGHT. ANOTHER LOW WILL MOVE OVER THE OHIO VALLEY MONDAY NIGHT...PUSHING A COLD FRONT INTO OUR REGION BY MID WEEK. && .NEAR TERM /THROUGH TODAY/... AS OF 1100 PM EDT SUNDAY... HIGH PRESSURE WILL PASS OVERHEAD OVERNIGHT...WINDS LIGHT WITH PLEASANTLY COOL TEMPERATURES...LOWS DROPPING INTO THE 50S AND DEW POINTS INTO THE UPPER 40S TO LOWER 50S. A WARM FRONT WILL MOVE NORTH OF THE AREA BY EARLY MONDAY EVENING. WITH DRY AIR AND ABUNDANT SUNSHINE MONDAY...AFTERNOON TEMPERATURES SHOULD PEAK IN THE UPPER 70S WEST TO LOW TO MID 80S EAST. THESE TEMPERATURES ARE AROUND 3F OR SO COOLER THAN NORMAL. && .SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/... AS OF 345 PM EDT SUNDAY... A BROAD TROUGH WILL REMAIN ANCHORED ACROSS THE GREAT LAKES THROUGH THE PERIOD WITH SEVERAL NOTABLE IMPULSES OR SHORT WAVES PROGGED TO TRACK THROUGH THE TROUGH. THE FAVORED TRAJECTORY OF THESE DISTURBANCES WILL BE FROM THE NORTHERN PLAINS TOWARD THE SOUTHERN APPALACHIANS THROUGH THE PERIOD. THUS...THE PATTERN REMAINS QUITE UNSETTLED THROUGHOUT THE PERIOD WITH SEVERAL CHANCES FOR UPSTREAM MESOSCALE CONVECTIVE COMPLEXES OR THE RESULTANT OUTFLOW BOUNDARIES AND/OR LEFT OVER CONVECTION TO TRANSLATE ACROSS OUR REGION THROUGH THE PERIOD. THERE APPEAR TO BE FEW IF ANY PERIODS WHERE POPS CAN BE ENTIRELY LEFT BELOW MENTIONABLE 15 PERCENT LEVELS. HOWEVER...EXACT TIMING OF WHEN A MORE SIGNIFICANT MCS WILL REACH THE AREA IS ALSO PROBLEMATIC. THE SAFEST APPROACH AT THIS POINT IS FOR MUCH OF THE PERIOD TO INDICATE CHANCE TO HIGH CHANCE POPS DURING THE AFTERNOONS/EVENINGS...AND LOWER CHANCE POPS OVERNIGHT DURING LESS DIURNALLY FAVORED TIMES. THE FIRST DISTURBANCE OF CONCERN ARRIVES MONDAY AFTERNOON...WITH A WEAK SFC WARM FRONT LIFTING NORTH THROUGH THE CWA. 850MB TEMPS BEING TO RISE FROM THE SINGLE DIGITS EARLY IN THE DAY TO THE 10 TO 15C RANGE BY EVENING. INSTABILITY IS MEAGER...BUT ENOUGH CREEPING IN FROM THE WEST LATE IN THE DAY WITH THE DISTURBANCE TO WARRANT THE MENTION OF TSRA. IN ADDITION...THE MAIN TRACK OF THIS FIRST DISTURBANCE IS THROUGH THE OH VALLEY INTO WESTERN PA. WOULD EXPECT A REMNANT OR DISSIPATING MCS TO REACH THE WESTERN BORDER OF THE CWA LATE MONDAY EVENING/EARLY MONDAY NIGHT IN A NON-SEVERE STATE. MUCH OF THIS MAY NEVER MAKE IT EAST OF THE WESTERN MOST TIER OF COUNTIES. THE NEXT DISTURBANCE TO ROTATE THROUGH THE TROUGH ARRIVES TUESDAY AFTERNOON AS THE UPPER TROUGH BEGINS TO DEEPEN AND SHIFT EVER SO SLIGHTLY EAST. CONDITIONS APPEAR SOMEWHAT MORE FAVORABLE FOR STRONGER AND MORE WIDESPREAD THUNDERSTORMS WITH THIS EVENT. INSTABILITY IS QUITE NOTABLE AND PWATS HAVE RISEN BACK TO 1.50 INCH OR BETTER ACROSS MUCH OF THE CWA. A NOTABLE THETA-E RIDGE IS EVIDENT ACROSS THE WESTERN PART OF THE CWA DURING PEAK HEATING WHEN THE SHORT WAVE ARRIVES...ALONG WITH MODEST LOW-LEVEL SHEAR FOR LATE JUNE. SPC HAS ALREADY OUTLOOKED THE ENTIRE CWA FOR A MARGINAL SEVERE RISK IN THIS TIME FRAME...AND THIS CERTAINLY APPEARS REASONABLE. THE CONVECTIVE POTENTIAL ON WEDNESDAY IS MORE QUESTIONABLE. MOST OF THE MODELS INDICATE A MINIMUM OF INSTABILITY DRIFTING ACROSS THE CWA IN THE WAKE OF THE TUESDAY SHORT WAVE. HOWEVER...AN MCS IS CLEARLY DEPICTED IN THE MODELS TRACKING FROM THE MO/WESTERN TN VALLEY EAST-SOUTHEAST TOWARD THE SOUTHERN APPALACHIANS. THE ECMWF BRINGS THE REMNANTS OF THIS MCS RIGHT OVER THE RNK CWA LATE WED...WHILE THE GFS/NAM/CANADIAN TRACK THIS SLIGHTLY FURTHER SOUTH INTO THE NORTHERN PART OF THE SOUTHEAST STATES...BUT CERTAINLY CLOSE ENOUGH GIVEN ANY SOLUTION TO KEEP HIGH CHANCE POPS IN THE SOUTHWEST PART OF THE CWA. AGAIN...AS NOTED ABOVE...THERE IS NO PERIOD WHERE POPS CAN BE LEFT BELOW MENTIONABLE. WITH 850MB TEMPS INCREASING BACK INTO THE +10C TO +15C RANGE...EXPECT DAYTIME MIN/MAX TEMPS TO SLOWLY CREEP BACK TO MORE NORMAL LEVELS AFTER OUR COOL START TO THE WEEK. HOWEVER...ONLY BRIEF...SMALL POCKETS OF +20C ARE NOTED ACROSS THE FAR SOUTHEAST PART OF THE PIEDMONT...MAINLY FURTHER SOUTH AND EAST INTO CENTRAL/EASTERN NC...SO HAVE REFRAINED FROM MENTIONING ANY 90+ READINGS AT THIS POINT THROUGH THIS PERIOD. && .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 /06Z MONDAY THROUGH FRIDAY/... AS OF 140 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...LEADING TO WIDESPREAD VFR CONDITIONS. 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. && .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...RCS NEAR TERM...PM/RCS SHORT TERM...RAB LONG TERM...RAB AVIATION...AMS EQUIPMENT...DS

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