Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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000 FXUS62 KRAH 301755 AFDRAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 154 PM EDT SUN AUG 30 2015 .SYNOPSIS...WEAK SURFACE HIGH PRESSURE WILL REMAIN OVER THE AREA THROUGH EARLY WEEK. IN THE MEANTIME...AN UPPER LEVEL DISTURBANCE WILL TRACK NORTH FROM THE NORTHERN GULF OF MEXICO AND WILL CROSS THE WESTERN CAROLINAS LATE TONIGHT AND MONDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1018 AM SUNDAY... WEAK HIGH PRESSURE REMAINS ACROSS THE AREA THIS MORNING. THE MAIN PLAYER IN OUR WEATHER LATER TODAY AND TOMORROW... AN UPPER LEVEL LOW PRESSURE SYSTEM... CAN BE CLEARLY SEEN ON WATER VAPOR LIFTING NORTHWARD INTO THE PANHANDLE OF FL. AHEAD OF THIS SYSTEM... HIGH CLOUDS ARE STREAMING IN TO THE AREA FROM THE SOUTHWEST. GSO SOUNDING INDICATES GRADUAL MOISTENING OF THE COLUMN FROM 00Z LAST NIGHT... AND THIS TREND SHOULD CONTINUE THROUGH THE DAY AS FLOW BECOMES MORE SOUTHERLY THIS AFTERNOON... LEADING TO PWS OVER 1.5 INCHES IN THE NW AND NEAR 2 INCHES SE. HIGHS IN THE MID 80S... TO UPPER 80S IN THE NW WHERE A FEW MORE HOURS OF SUNSHINE ARE LIKELY BEFORE CLOUDS COMPLETELY OVERTAKE THE REGION. THE UPPER LOW WILL CONTINUE TO MOVE NORTHWARD ALONG THE APPALACHIANS...WEAKENING INTO AN OPEN WAVE. WITH THE MAIN MID/UPPER LEVEL FORCING NOT REACHING THE AREA UNTIL AFTER 00Z... BULK OF THE SHOWER ACTIVITY WILL HOLD OFF UNTIL LATE IN THE EVENING/OVERNIGHT....THOUGH COULD SEE SOME WIDELY SCATTERED ACTIVITY NEARING THE SC/NC BORDER AFTER 18Z. LOWS IN THE MID TO UPPER 60S. && .SHORT TERM /MONDAY AND MONDAY NIGHT/... AS OF 330 AM SUNDAY... SCATTERED SHOWERS SHOULD BE ONGOING ACROSS CENTRAL NC MONDAY MORNING AND SHOULD CONTINUE INTO THE AFTERNOON AND EVENING AS DAMPENED MID- LEVEL WAVE SHIFTS OFFSHORE BY THE AFTERNOON. WHILE UPPER FORCING LOOKS TO BE WANING/EXITING THE AREA BY EARLY AFTERNOON...TEMPERED DIURNAL HEATING WITHIN THE LINGERING MOIST ~2.0" PWAT AIRMASS IN PLACE ACROSS EASTERN NC MAY RESULT IN AN INCREASE IN COVERAGE MONDAY AFTERNOON ALONG WITH SOME THUNDER AS WEAK TO MODERATE BUOYANCY DEVELOPS(MUCAPE OF 700-1500 J/KG). WILL KEEP POPS IN THE CHANCE RANGES...HIGHEST IN THE EAST. RAIN CHANCES ARE EXPECTED TO DIMINISH FROM WEST TO EAST MONDAY EVENING AS BOTH UPPER FORCING AND MOIST PLUME SHIFT OFFSHORE. HIGHS WILL ULTIMATELY DEPEND ON PRECIP COVERAGE...RANGING FROM LOWER 80S IN WETTER MODEL SOLUTIONS TO MID/UPPER 80S WHERE SHOWERS ARE SCARCE. LOWS MONDAY NIGHT IN THE UPPER 60S TO LOWER 70S. && .LONG TERM /TUESDAY THROUGH SATURDAY/... AS OF 400 AM SUNDAY... THE MODELS REMAIN IN RELATIVELY GOOD AGREEMENT REGARDING THE RE- DEVELOPMENT/DISCONTINUOUS RETROGRESSION OF A POSITIVELY-TILTED TROUGH FROM THE LOWER GREAT LAKES TO THE TX GULF COAST...THE NORTHERN PORTION OF WHICH IS FORECAST TO CROSS THE CENTRAL APPALACHIANS WED AND VA/NC WED NIGHT. THE SOUTHERN PORTION OF THE TROUGH --FORECAST TO BECOME A CLOSED ALONG THE WESTERN GULF COAST-- WILL DRIFT SLOWLY EAST AND ULTIMATELY MAY GET TRAPPED BENEATH AN AMPLIFYING CENTRAL CONUS RIDGE. IT REMAINS UNCLEAR...HOWEVER...IF THE CLOSED LOW WILL INDEED GET TRAPPED BENEATH IN REX BLOCK FASHION OR INSTEAD BECOME INCORPORATED INTO A SEPARATE CLOSED LOW FORECAST TO EVOLVE OFF THE MIDDLE ATLANTIC COAST - A PROCESS STARTED BY THE AFOREMENTIONED NORTHERN PORTION OF THE TROUGH FORECAST TO CROSS NC WED NIGHT. BEFOREHAND...A LOW-MID LEVEL SHEAR/TROUGH AXIS WILL BE LEFT BEHIND THE SHORTWAVE TROUGH FORECAST TO APPROACH AND CROSS NC IN SW FLOW ALOFT DURING THE NEAR TERM; AND THIS FEATURE WILL BISECT CENTRAL NC FROM NE TO SW AND SERVE AS A FOCUS FOR DIURNAL CONVECTION THROUGH WED...SOME OF WHICH WILL BE AUGMENTED BY THE AFOREMENTIONED SHORTWAVE TROUGH FORECAST TO EMERGE EAST OF THE APPALACHIANS LATE WED-WED NIGHT. WHILE THE REMNANTS OF ERIKA MAY REGENERATE OVER THE FAR NE GOM OR FL PANHANDLE...NOT NECESSARILY AS A TROPICAL ENTITY OWING TO THE PROXIMITY OF THE GOM UPPER LOW AND ASSOCIATED SYNOPTIC/BAROCLINIC EFFECTS...ANY ASSOCIATED AFFECTS WILL STILL LIKELY BE SUPPRESSED MOSTLY SOUTH AND/OR WEST OF CENTRAL NC BY THE FLOW PATTERN OUTLINED ABOVE. AS SUCH...AFTER AROUND OR SLIGHTLY ABOVE CLIMO PROBABILITIES OF DIURNAL PRECIPITATION TUE-WED...THE REMAINDER OF THE FORECAST PERIOD WILL BE CHARACTERIZED BY AOB CLIMO POP...AS RELATIVELY DRY NW FLOW ALOFT SETS UP ACROSS THE CENTRAL APPALACHIANS. PROJECTED AFTERNOON LOW LEVEL THICKNESS VALUES AROUND 1420 METERS THROUGH THE FORECAST PERIOD SHOULD SUPPORT HIGHS GENERALLY IN THE UPPER 80S. NEAR CLIMO LOWS MOSTLY 65-70. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/...
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AS OF 150 PM SUNDAY... VFR CONDITIONS... WITH INCREASING HIGH AND THEN MID CLOUDS... WILL CONTINUE THROUGH THE EVENING HOURS. AN UPPER LEVEL DISTURBANCE WILL BRING A PERIOD OF SHOWERS OVER THE NEXT 24 HOURS... WITH THE HIGHEST POTENTIAL FOR SUB-VFR CONDITIONS AT KRDU... KRWI... AND KFAY WHERE THE DEEPEST MOISTURE WILL RESIDE. CONDITIONS WILL REMAIN GENERALLY VFR THROUGH THE WEEK... WITH PRIMARILY DIURNAL SHOWERS AND THUNDERSTORMS EXPECTED THROUGH THE UPCOMING WEEK.
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&& .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DJF NEAR TERM...30 SHORT TERM...CBL LONG TERM...26 AVIATION...30

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