Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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000 FXUS62 KRAH 311057 AFDRAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 657 AM EDT MON AUG 31 2015 .SYNOPSIS...AN UPPER LEVEL DISTURBANCE WILL MOVE THROUGH THE CAROLINAS BY EARLY AFTERNOON. SEASONABLE CONDITIONS WILL PERSIST THROUGH THE REMAINDER OF THE WORK WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 345 AM MONDAY... DAMPENING MID-LEVEL WAVE OVER THE WESTERN CAROLINAS WILL MOVE SLOWLY NORTHEASTWARD ACROSS THE AREA THROUGH THE LATE MORNING/EARLY AFTERNOON. ASSOCIATED ENHANCED 850-700MB SOUTHERLY FLOW WILL DIRECT A PLUME OF TROPICAL MOISTURE(PWATS OF 2.0-2.25)NORTHWARD INTO EASTERN HALF OF THE CAROLINAS THIS MORNING...THAT WILL EVENTUALLY SHIFT OFFSHORE LATER THIS AFTERNOON. INITIALLY DRIVEN BY SHORTWAVE TROUGH DYNAMICS AND ENHANCED MID/UPPER LEVEL WIND FIELDS...BAND OF SHOWERS CURRENTLY OVER THE WESTERN PIEDMONT WILL PROGRESS STEADILY EASTWARD INTO THE CENTRAL PIEDMONT AND SANDHILLS AND COASTAL PLAIN THROUGH THE MORNING HOURS. BY MIDDAY...BEST FORCING WILL QUICKLY SHIFT ALONG THE COAST AND PERHAPS JUST OFFSHORE...INVOF OF A WEAK INVERTED COASTAL TROUGH AND EXITING TROPICAL PLUME. WHILE RAIN CHANCES SHOULD DROP OFF CONSIDERABLY BY THE EARLY AFTERNOON...TEMPERED DIURNAL HEATING AND RESULTING MODERATE BUOYANCY WITHIN THE LINGERING MOIST ~2.0" PWAT AIRMASS IN PLACE ACROSS CENTRAL/EASTERN NC WILL SUPPORT ISOLATED TO SCATTERED SHOWERS AND STORMS. HIGHS TODAY WILL ULTIMATELY DEPEND ON PRECIP COVERAGE AND HOW THE LOW-LEVEL CLOUD COVER EVOLVES DURING THE MID TO LATE AFTERNOON. HIGHS TODAY COULD RANGE FROM MID TO UPPER 70S TO MID 80S. LOWS TONIGHT IN THE UPPER 60S TO LOWER 70S. && .SHORT TERM /TUESDAY AND TUESDAY NIGHT/... AS OF 345 AM MONDAY... A WEAK/NONDESCRIPT SFC PATTERN WILL EXTEND ACROSS THE AREA ON TUESDAY WITH HEIGHTS ALOFT BUILDING OVER THE SOUTHEAST AS THE SUBTROPICAL RIDGE OVER THE SOUTHWEST ATLANTIC RETROGRADES WESTWARD. OTHER THAN DAYTIME HEATING ATOP A SEASONABLY MOIST AIRMASS... FORCING MECHANISM IS LACKING WITH ISOLATED DIURNAL CONVECTION AT BEST. HIGHS IN THE UPPER 80S TO LOWER 90S. LOWS IN THE UPPER 60S TO LOWER 70S. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... AS OF 310 AM MONDAY... MEDIUM RANGE MODELS ARE IN GENERAL AGREEMENT IN SHOWING A WEAK DISTURBANCE ALOFT TRACKING FROM THE OHIO VALLEY MIDWEEK TO ACROSS CENTRAL NC THURSDAY OR THURSDAY NIGHT. HOWEVER... THE LATEST GFS AND ECMWF CONTINUE TO DISAGREE WRT WHAT HAPPENS TO IT. THE LATEST ECMWF CONTINUES TO SHOW THE S/W SHIFTING TO THE EAST/SOUTHEAST AND OFFSHORE BY THURSDAY AFTERNOON... WITH BRIEF S/W RIDGING BUILDING OVER THE AREA BEFORE A WEAK MID LEVEL LOW LIFTS NORTHEASTWARD OUT OF THE NORTHWEST GULF OF MEXICO AND INTO THE CAROLINAS BY FRIDAY NIGHT AND LINGERING THROUGH THE END OF THE FORECAST PERIOD. MEANWHILE... THE LATEST GFS IS SLOWER MOVING THE INITIAL S/W DISTURBANCE THROUGH THE AREA ON THURSDAY... LINGERING INTO FRIDAY MORNING. THE S/W IS THEN EXPECTED TO CLOSE OFF INTO A MID LEVEL LOW AND CONTINUE TO SLOWLY SINK SOUTHWARD AS A STRONG 595 DECAMETER HIGH BEGINS TO BUILD SOUTHWARD TOWARDS CENTRAL NC. GIVEN THIS PATTERN... THE LOW IN THE NORTHWESTERN GULF OF MEXICO ACTUALLY SINKS FURTHER SOUTH AND NOT IN THE DIRECTION OF CENTRAL. AT THE SURFACE... WE SHOULD SEE SOME TYPE OF WEAK SURFACE TROUGH TRACK ACROSS THE AREA WITH THE INITIAL S/W DISTURBANCE... WITH SURFACE HIGH PRESSURE BUILDING/EXTENDING INTO CENTRAL NC FROM THE NORTH/NORTHEAST DURING THE WEEKEND. THUS... AT THIS TIME... WILL KEEP POPS GENERALLY LOW... SLIGHT CHANCE TO LOW END CHANCE DURING THE MEDIUM RANGE... GIVEN THE UNCERTAINTY IN WHAT WILL GENERALLY BE MEAN RIDING OVER THE EASTERN HALF OF THE COUNTRY DURING THIS TIME (WITH THE EMBEDDED DISTURBANCES/WEAK CLOSED LOWS). HIGH TEMPS WILL GENERALLY BE NEAR TO SLIGHTLY ABOVE NORMAL FOR THE MID TO LATE WEEK TIME FRAME... THEN NEAR NORMAL TO POSSIBLY SLIGHT BELOW NORMAL FOR THE WEEKEND. LOW TEMPS ARE EXPECTED TO BE NEAR TO SLIGHTLY ABOVE NORMAL DURING THE PERIOD. && .AVIATION /12Z MONDAY THROUGH FRIDAY/...
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AS OF 657 AM MONDAY... DAMPENING MID-LEVEL OVER THE WESTERN CAROLINAS WILL MOVE NORTHEASTWARD ACROSS THE AREA THIS MORNING AND OFF THE MID-ATLANTIC COAST BY THE AFTERNOON. ASSOCIATED PLUME OF TROPICAL MOISTURE OVER THE AREA WILL EVENTUALLY SHIFT OFFSHORE BY THE AFTERNOON. EXPECT WIDESPREAD RAIN TO MOVE STEADILY WEST TO EAST WITH ASSOCIATED IFR TO MVFR CEILINGS/VISIBILITIES. AS THE SYSTEM LIFTS AWAY FROM THE AREA AND THE TROPICAL MOISTURE PLUME SHIFTS OFFSHORE...CONDITIONS SHOULD IMPROVE TO VFR FROM WEST TO EAST DURING THE EARLY TO MID AFTERNOON. DAYTIME HEATING COULD ALLOW FOR ISOLATED TO SCATTERED SHOWERS DURING THE AFTERNOON...ALTHOUGH CONFIDENCE IS TOO LOW TO INCLUDE AT THIS TIME. EASTERN TERMINALS COULD SEE WIDESPREAD STRATUS/FOG MONDAY NIGHT/TUESDAY MORNING WITH VFR CONDITIONS RETURNING ON TUESDAY. OUTSIDE OF ISOLATED TO WIDELY SCATTERED DIURNAL CONVECTION...EXPECT PREDOMINATELY VFR CONDITIONS TUESDAY NIGHT THROUGH FRIDAY.
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&& .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...CBL NEAR TERM...CBL SHORT TERM...CBL LONG TERM...77 AVIATION...CBL

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