Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS62 KRAH 062343 AFDRAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 743 PM EDT MON JUL 6 2015 .SYNOPSIS... AN UPPER TROUGH ACROSS THE SOUTHERN APPALACHIANS WILL LIFT AWAY FROM THE REGION ON TUESDAY. A RIDGE OF HIGH PRESSURE WILL THEN DEVELOP OVER THE SOUTHEAST AND STRENGTHEN THROUGH THE REMAINDER OF THE WORK WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 315 PM MONDAY... VISIBLE AND WATER VAPOR SATELLITE IMAGERY SHOW MULTIPLE VORTEXES ACROSS THE SOUTHERN APPALACHIANS. THE LARGER CIRCULATION ASSOCIATED WITH THE UPPER LEVEL TROUGH AXIS IS EARLY SEEN ON REGIONAL WV IMAGERY. IT WAS LOCATED ACROSS EASTERN TN AND WESTERN NC AND WAS TRIGGERING CONVECTION ACROSS WV AND SOUTHWESTERN VA. ANOTHER VORTEX...THIS ONE LOCATED IN SOUTHERN VA...WAS MORE SHALLOW AND CAN BE IDENTIFIED IN THE VISIBLE SATELLITE IMAGERY. ONLY ISOLATED CONVECTION HAS DEVELOPED SO FAR TODAY...MAINLY IN A NORTHEAST- SOUTHWEST AXIS WHERE ENHANCED CUMULUS CLOUDS ARE INVIGORATED. LATEST MESOANALYSIS SHOWS A WEAKLY UNSTABLE ENVIRONMENT WITH POOR MID LEVEL LAPSE RATES HINDERING UPDRAFTS. IN ADDITION...WEAK... UNIDIRECTIONAL LOW AND MID FLOW SHOULD KEEP STORM UNORGANIZED. LOCALIZED FORCING FOR ASCENT WILL BE DRIVEN BY SPOKES OF VORTICITY EMANATING FROM THE UPPER LOW AND IN SOUTHWEST-NORTHEAST CONVERGENCE ZONES RESULTING FROM DIFFERENTIAL HEATING FROM MORNING STRATUS IN THE EASTERN PIEDMONT AS WELL THE INLAND PENETRATING SEA BREEZE. ANOTHER AREA OF CONVERGENCE WILL BE LOCATED ALONG A WEAK SURFACE TROUGH IN THE WESTERN PIEDMONT. THE CONVECTION WILL HAVE A STORM MOTION TO THE NORTHEAST WITH THE LARGER CONVECTIVE LINES GRADUALLY SHIFTING EASTWARD. MOST OF THE CONVECTION THIS EVENING SHOULD DIMINISH WITH SUNSET BUT GIVEN THE PROXIMITY OF THE THE UPPER TROUGH...WOULD NOT BE SURPRISED TO SEE A SHOWER OR STORM LINGER INTO THE OVERNIGHT. BUT A GENERAL DRYING OF THE ATMOSPHERE SHOULD LIMIT COVERAGE OVERNIGHT AND BRING CONVECTIVE ACTIVITY TO AN END BY MID EVENING. LOWS WILL RANGE IN THE UPPER 60S TO LOWER 70S. -BLAES && .SHORT TERM /TUESDAY AND TUESDAY NIGHT/... AS OF 335 PM MONDAY... EXPECT A PERIOD OF EARLY MORNING STRATUS TO START THE DAY WITH CLOUDS LIFTING AND INTERVALS OF SUNSHINE ARRIVING TOWARD MID TO LATE MORNING. CONVECTIVE COVERAGE ON TUESDAY SHOULD AGAIN BE LIMITED AS THE UPPER TROUGH LIFTS NORTH SOMEWHAT AND THE AIR MASS DRIES OUT WITH PW VALUES DROPPING 0.25 TO 0.50 INCHES FROM MONDAY AFTERNOON TO TUESDAY AFTERNOON. A WEAK SURFACE TROUGH ORIENTED SOUTHWEST ACROSS THE PIEDMONT COULD HELP TO INITIATE WIDELY SCATTED CONVECTION. GIVEN WEAK FLOW AND GENERALLY WEAK INSTABILITY...SEVERE WEATHER THREAT APPEARS MINIMAL. WILL INCLUDE SLIGHT CHANCE POPS MAINLY ACROSS THE EAST FOR TUESDAY AFTERNOON AND EVENING. THICKNESS VALUES INCREASE A BIT AS HEIGHTS RISE SLIGHTLY. THIS WILL SUPPORT HIGHS IN THE 89 TO 94 RANGE. -BLAES && .LONG TERM /WEDNESDAY THROUGH MONDAY/... AS OF 150 PM MONDAY... GRADUAL WESTWARD REGRESSION OF SUBTROPICAL RIDGING WILL LIFT THE WESTERLIES AND PERSISTENT FRONTAL ZONE NORTH OF THE AREA IN THE MIDWEEK. THE FRONTAL ZONE MAKES A SOUTHERLY JOG ON FRIDAY AS THE RIDGE BEGINS TO AMPLIFY INTO THE CENTRAL CONUS...WITH ENSUING NORTHWEST FLOW AND A GRADUAL UPTICK IN HEIGHTS OVER THE EAST COAST THROUGH THE WEEKEND. THE RIDING WILL LIMIT CONVECTION THROUGH FRIDAY...WITH SLIGHT CHANCES...PRIMARILY DIURNALLY DRIVEN...ACROSS THE NORTHERN TIER DUE TO PROXIMITY WITH THE ACTIVE WESTERLIES ZONE ACROSS THE OHIO VALLEY. HIGHS WILL RANGE FROM 90 ACROSS THE NORTH TO 95 IN THE SOUTH AFTER MORNING LOWS IN THE LOWER 70S. OVER THE WEEKEND...DEEP NORTHWEST STEERING FLOW WILL INCREASE THE CHANCE THAT UPSTREAM MESOSCALE DISTURBANCES WANDER IN TO INITIATE CONVECTION ACROSS THE AREA. WILL THUS MAINTAIN CHANCE (30-40) POPS...SHADED TOWARDS MAX HEATING EACH DAY...ON SATURDAY THROUGH MONDAY. HIGHS WILL BE A COUPLE OF DEGREES WARMER...MOSTLY IN THE MID 90S...WITH POTENTIAL FOR SOME UPPER 90S ACROSS THE SOUTHERN TIER. && .AVIATION /00Z TUESDAY THROUGH FRIDAY/...
-- Changed Discussion --
AS OF 740 PM MONDAY... 24 HOUR TAF PERIOD: VFR CONDITIONS AT MOST LOCATION WITH SHOWERS IN THE VICINITY OF KINT AND KFAY BUT THESE SHOULD NOT BE AROUND FOR LONG AS CONDITIONS ARE MUCH MORE STABLE THEN THEY HAVE BEEN IN A WHILE. OVERNIGHT TONIGHT MODELS INDICATE THE CHANCE FOR SOME LOW STRATUS ONCE AGAIN FORMING AFTER 9Z AND MOST LIKELY DISSIPATING JUST AFTER SUNRISE. OVERALL IMPACTS WILL BE MINIMAL. MODELS SHOWING MUCH LESS CONVECTIVE COVERAGE ON TUESDAY WHICH MEANS THAT ASIDE FROM ANY OVERNIGHT RESTRICTIONS...CONDITIONS SHOULD REMAIN VFR THROUGH THE END OF THE TAF PERIOD. LONG TERM: A LITTLE BIT OF A BREAK IN THE ACTIVE PATTERN WE HAVE BEEN UNDER LATELY AS HIGH PRESSURE BUILDS OVER THE AREA. ASIDE FROM DIURNAL CONVECTION...NOT TOO MUCH TO HINDER AVIATION CONDITIONS IN THE LONG TERM.
-- End Changed Discussion --
&& ..RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...BLAES NEAR TERM...BLAES SHORT TERM...BLAES LONG TERM...MLM AVIATION..ELLIS

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.