Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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000 FXUS62 KRAH 010651 AFDRAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 250 AM EDT MON JUN 1 2015 .SYNOPSIS...STRONG HIGH PRESSURE WILL REMAIN OVER THE WESTERN ATLANTIC THROUGH MIDWEEK. THE FLOW AROUND THIS HIGH WILL BRING DEEP MOISTURE ACROSS OUR REGION AS A FRONT APPROACHES FROM THE NORTHWEST. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1015 PM SUNDAY... WE WILL MAINTAIN A CHANCE PROBABILITY OF SHOWERS AND THUNDERSTORMS OVER THE WESTERN PIEDMONT THROUGH AROUND 200 AM... THEN DROP BACK TO MENTION OF AN ISOLATED SHOWER POSSIBLE OVERNIGHT. THE CURRENT SCATTERED SHOWER AND ISOLATED THUNDERSTORMS WERE OUTFLOW DRIVEN AND CONFINED TO THE WESTERN PIEDMONT... MOVING NE AT 40 MPH. SEVERAL WEAK OUTFLOW BOUNDARIES CONTINUE TO FOCUS NEW DEVELOPMENT IN THE NARROW BAND OF INSTABILITY LOCATED OVER THE WESTERN PIEDMONT. THE SEA BREEZE BOUNDARY ALONG WITH HIGHER DEW POINTS WILL ADVANCE INTO THE WESTERN PIEDMONT LATE EVENING. THUS... AN UPTICK IN SCATTERED CONVECTION MAY OCCUR. THE MID/UPPER RIDGE AXIS CONTINUED TO EXTEND NW FROM THE WESTERN ATLANTIC OVER CENTRAL NC THIS EVENING. EASTERN AREAS UNDER THE RIDGE SHOULD CONTINUE TO HAVE NEARLY NIL POP OVERNIGHT. CONVECTIVE ACTIVITY SHOULD BECOME MUCH MORE ROBUST AND WIDESPREAD IN THE WESTERN PIEDMONT MONDAY AS THE THE MOISTURE INCREASES ALONG WITH INCREASING CAPE. FORECAST SOUNDINGS AND SREF PROBABILITIES INDICATE A FAIRLY GOOD CHANCE OF SOME FOG/LOW STRATUS IN THE TRIAD OVERNIGHT TONIGHT AND INTO MONDAY MORNING. THE FORECAST IS LESS CERTAIN FOR POINTS EAST BUT THERE REMAINS AN OUTSIDE CHANCE OF SOME BRIEF REDUCTIONS IN CEILING AND VISIBILITY NEAR DAYBREAK. STRATUS COULD LAST PAST DAYBREAK MONDAY MORNING IN THE TRIAD. LOWS TONIGHT IN THE UPPER 60S TO AROUND 70. && .SHORT TERM /MONDAY AND TUESDAY NIGHT/... AS OF 307 PM SUNDAY... A PATTERN CHANGE WILL FINALLY BE IN THE MAKING ON MONDAY AS AN UPPER LEVEL LONG WAVE TROUGH DIGS INTO THE MISSISSIPPI VALLEY. THIS WILL PUSH THE SURFACE FRONTAL ZONE EASTWARD ON MONDAY AND INCREASING THE CHANCES FOR PRECIPITATION ACROSS THE ENTIRE CWA...BUT STILL MORE FOCUSED IN THE WESTERN HALF. MODELS VARY ON HOW GOOD CONDITIONS WILL BE WITH THE NAM A BULLISH OUTLIER AT THIS TIME SHOWING 1800 J/KG OF INSTABILITY OVER THE WESTERN PIEDMONT BUT STILL HAS BULK SHEAR VALUES OF ONLY ABOUT 10 KTS. THE GFS BACKS THIS DOWN TO ABOUT 1000 J/KG AND 10 KTS WHICH IS PROBABLY CLOSER TO REALITY. REGARDLESS THERE WILL BE PLENTY OF LOW LEVEL MOISTURE TO WORK WITH AS FORECAST SOUNDINGS SHOW SATURATION TO UP ABOVE 700 MB. LAPSE RATES WILL BE BEST IN THIS SATURATED LAYER AS WELL. WITH INVERTED V SIGNATURES PRESENT ON THE SOUNDING AND SOME DRY AIR AT THE SURFACE...SOME WET MICROBURST ACTIVITY IS NOT OUT OF THE QUESTION. FURTHERMORE DECENT CAPE IN THE HAIL GROWTH ZONE AND A FAIRLY LOW FREEZING LEVEL AT 11000 FEET OR SO COULD ALSO PRODUCE SOME SMALL HAIL. AS A RESULT THE STORM PREDICTION CENTER HAS PUT THE CWA IN A MARGINAL RISK FOR SEVERE WEATHER ON DAY 2. CHANCES DECREASE SIGNIFICANTLY EAST OF US 1 WHERE WE CAN PROBABLY EXPECT MORE OF A DAY LIKE TODAY WITH SOME LINGERING SHOWERS OR THUNDERSTORMS BUT OVERALL NOT A VERY IMPACTFUL DAY. WITH OBVIOUSLY MORE CLOUD COVER IN THE WEST...EXPECT THE HIGHEST TEMPERATURES MONDAY AFTERNOON IN THE EAST WITH UPPER 80S TO LOW 90S EXPECTED. MID TO UPPER 80S IN THE NORTHWEST PIEDMONT. WITH THE FRONTAL ZONE LINGERING JUST EAST OF THE CWA...THE CHANCE FOR SHOWERS AND STORMS WILL CONTINUE THROUGH MONDAY NIGHT WITH THE USUAL DIURNAL LIMITATIONS AND NOT MUCH FORCING ALOFT TO HELP IT OUT BUT SOME WEAKER SHOWERS ARE DEFINITELY A POSSIBILITY. LOWS MONDAY NIGHT MAINLY IN THE MID TO UPPER 60S. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/...
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AS OF 250 AM MONDAY... WEDNESDAY THROUGH FRIDAY NIGHT: SURFACE HIGH PRESSURE IS EXPECTED TO EXTEND SOUTHWARD AND INTO PORTIONS OF CENTRAL NC ON WEDNESDAY WITH A SURFACE FRONT STALLING/BISECTING THE AREA... BEFORE WEAKENING AND DISSIPATING LATE THIS WEEK. MEANWHILE... A WEAK MID LEVEL LOW... EXPECTED TO BE LOCATED NEAR THE TN VALLEY REGION WEDNEDAY MORNING... SHOULD SLOWLY SHIFT EASTWARD AND BEGIN TO OPEN UP INTO WEAK MID LEVEL TROUGH AND EVENTUALLY MOVE OVER CENTRAL NC BY FRIDAY. THIS SHOULD LEAD TO A RATHER UNSETTLED PERIOD FROM MID TO LATE WEEK... WITH GOOD DIURNAL CHANCES FOR SHOWERS AND STORMS. HOWEVER... OVERALL DEEP SHEAR WILL REMAIN WEAK... WITH SURFACE INSTABILITY WEAK TO MODEST AT BEST. THUS... EXPECT SCATTERED TO NUMEROUS SHOWERS AND STORMS EACH DAY INTO THE EVENING... WITH A CONTINUED LOW CHANCE TO SLIGHT CHANCE DURING THE OVERNIGHT/EARLY MORNING HOURS. WHILE A FEW STRONG TO MAYBE AN ISOLATED SEVERE STORM WILL BE POSSIBLE EACH DAY (GIVEN WEAK DEEP SHEAR AND NOT GREAT INSTABILITY... BEST INSTABILITY ACROSS THE SOUTHEASTERN HALF)... THE MAIN THREAT WILL BE FROM LOCALIZED FLOODING (ESPECIALLY IN URBAN AREAS AND LOCATIONS THAT HAPPEN TO RECEIVE SEVERAL ROUNDS OF HEAVY PRECIP)... WITH PW`S EXPECTED TO BE ABOVE NORMAL. HIGH TEMPS WEDNESDAY AND THURSDAY WILL BE RATHER TRICKY AND DEPEND ON THE PLACEMENT OF THE FRONT AND HOW FAST IT WASHES OUT AS THE SURFACE HIGH TO THE NORTH BEGINS TO MOVE OFFSHORE ON THURSDAY. GIVEN THE POTENTIAL FOR A BRIEF WARM SEASON CAD... HIGH TEMPS ON WEDNESDAY MAY RANGE FROM THE 60S/LOWER 70S NORTHWEST TO THE LOWER TO MID 80S SOUTHEAST. HIGHS AGAIN ON THURSDAY WILL RESEMBLE THIS PATTERN... BUT WITH THE RANGE OF TEMPS NOT AS GREAT GIVEN THE DISSIPATING CAD BOUNDARY. THUS... EXPECT HIGHS RANGING FROM THE MID TO UPPER 70S NW TO THE LOWER TO MID 80S ELSEWHERE. HIGHS ON FRIDAY ARE EXPECTED TO BE IN THE LOWER TO MID 80S. GIVEN THE EXPECTED CLOUD COVER AND MOISTURE LOW TEMPS SHOULD BE NEAR TO SLIGHTLY ABOVE NORMAL IN THE MID TO UPPER 60S. SATURDAY THROUGH SUNDAY: UNSETTLED FORECAST CONTINUES INTO NEXT WEEKEND. WITH THE PASSAGE OF A NORTHERN STREAM DISTURBANCE TO THE NORTH OF THE AREA ON FRIDAY NIGHT INTO SATURDAY... ANOTHER TRAILING OR BACKDOOR COLD FRONT MAY AGAIN SINK SOUTHWARD INTO CENTRAL NC. THIS COMBINED WITH A CONTINUED WEAK MID LEVEL TROUGH REMAINING ACROSS THE REGION SHOULD RESULT IN AT LEAST CHANCES FOR AFTERNOON AND EVENING SHOWERS AND STORMS. STILL A LITTLE TO EARLY TO TELL HOW FAR SOUTH THIS POSSIBLE FRONT WILL MAKE IT. THUS... WILL CONTINUE TO STICK CLOSE TO WPC FOR TEMPS...WITH HIGH TEMPS NEAR TO SLIGHTLY BELOW NORMAL FOR EARLY JUNE AND LOWS NEAR NORMAL.
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&& .AVIATION /06Z MONDAY THROUGH FRIDAY/... AS OF 1240 AM MONDAY... ISOLATED SHOWERS AND THUNDERSTORMS OCCURRING IN VICINITY OF THE TRIAD TERMINALS WILL CONTINUE TO GRADUALLY DIMINISH THROUGH 08Z. EXPECT MVFR CEILINGS AND VISIBILITY IN THE VICINITY OF THE HEAVIER SHOWERS AND STORMS. OTHERWISE OVERNIGHT VFR CONDITIONS WILL TEMPORARILY DETERIORATE TO MVFR/IFR CEILINGS NEAR DAYBREAK DUE TO A MOIST LOW LEVEL AIR MASS. THE BULK OF THIS LOW STRATUS LAYER IS EXPECTED TO OCCUR ALONG AND WEST OF HIGHWAY 1...AFFECTING THE TRIAD TERMINALS AND POSSIBLY KRDU. EXPECT A RETURN TO VFR CONDITIONS AREAWIDE BY 14-15Z. THE HEATING OF THE MOIST AND SLIGHTLY UNSTABLE AIR MASS WILL LEAD TO THE DEVELOPMENT OF SCATTERED SHOWERS AND THUNDERSTORMS THIS AFTERNOON...MAINLY ACROSS THE PIEDMONT. EXPECT MVFR CONDITIONS IN VICINITY OF THE CONVECTION ALONG WITH WIND GUSTS 30-35KTS WITH THE STRONGEST CONVECTION. THE THREAT FOR SCATTERED SHOWERS AND ATTENDANT MVFR CONDITIONS MAY PERSIST WELL INTO TONIGHT...ESPECIALLY IN VICINITY OF KRDU AND THE TRIAD TERMINALS. AN UNSETTLED WEATHER PATTERN IS EXPECTED ACROSS CENTRAL NC TUESDAY THROUGH WEDNESDAY WITH PERIODS OF SHOWERS AND STORMS...PLUS EXTENDED PERIODS OF MVFR CEILINGS HIGHLY PROBABLE. IN VICINITY OF THE HEAVIER SHOWERS...IFR CEILINGS AND VISIBILITY WILL BE POSSIBLE. AVIATION CONDITIONS ARE EXPECTED TO SLOWLY IMPROVE BY THE END OF THE WEEK THOUGH PERIODS OF MVFR CEILINGS/VISIBILITY ARE HIGHLY LIKELY EACH MORNING ALONG WITH A THREAT FOR SCATTERED CONVECTION THURSDAY AFTERNOON AND AGAIN FRIDAY AFTERNOON. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...PWB/ELLIS NEAR TERM...PWB/ELLIS SHORT TERM...ELLIS LONG TERM...BSD AVIATION...WSS

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