Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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000 FXUS62 KRAH 270700 AFDRAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 259 AM EDT WED APR 27 2016 .SYNOPSIS... A WEAKENING FRONTAL ZONE WILL APPROACH THE AREA FROM THE NORTHEAST TODAY...THEN STALL OVER OR NEAR THE AREA THROUGH LATE WEEK. && .NEAR TERM /TODAY AND TONIGHT/... AS OF 245 AM WEDNESDAY... THE FRONTAL ZONE APPROACHING FROM THE NORTH APPEARS TO BE LOCATED WELL NORTH OF THE REGION THIS MORNING...IN VICINITY OF THE MASON- DIXON LINE AT 06Z. THIS FEATURE IS EXPECTED TO SAG SOUTHWESTWARD FROM THE DELMARVA TOWARD NORTHEAST NC THIS EVENING...THOUGH LATEST SUGGESTS THE FRONT MAY STALL BEFORE REACHING NC...IN VICINITY OF NORFOLK VA. MEANWHILE...RESIDUAL OUTFLOW FROM CONVECTION THAT DEVELOPED OVER CENTRAL VA YESTERDAY EVENING LINGERS ACROSS PORTIONS OF WESTERN AND SOUTHWESTERN VA. A PRE-FRONTAL SFC TROUGH OVER CENTRAL NC SHOULD SERVE AS A SUFFICIENT FOCUS FOR SCT CONVECTIVE DEVELOPMENT DURING THE DAY...THOUGH MUCH UNCERTAINTY PERSISTS WITH REGARD TO INITIATION TIMING/COVERAGE/MAGNITUDE DUE TO THE COMPLICATED MESOSCALE ENVIRONMENT IN PLACE...NOT TO MENTION CLOUD COVER /DIFFERENTIAL HEATING/ AND THE TIMING/MAGNITUDE OF ANY SMALL AMPLITUDE WAVES EMBEDDED WITHIN A SHORTWAVE RIDGE ALOFT PROGRESSING OVER THE SOUTHERN APPALACHIANS. EXPECT HIGHS IN THE MID 80S...EXCEPT UPPER 70S TO LOWER 80S IN THE FAR NE COASTAL PLAIN IN CLOSEST VICINITY TO THE COOLER AIRMASS SAGGING SOUTHWARD FROM THE DELMARVA. NOCTURNAL DESTABILIZATION ATTENDANT LOW-LEVEL MOISTURE POOLING BENEATH RELATIVELY STEEP MID-LEVEL LAPSE RATES ALOFT MAY PROVIDE SUFFICIENT ENERGY FOR ADDITIONAL CONVECTIVE DEVELOPMENT LATE THIS EVENING AND OVERNIGHT...ESP WITH A LOW-LEVEL TROUGH STALLED OVER PORTIONS OF THE REGION AND INCREASED POTENTIAL FOR SMALL AMPLITUDE WAVES EMBEDDED WITHIN THE SHORTWAVE RIDGE PROGRESSING OVER THE REGION. AN ISOLD POTENTIAL FOR SEVERE WEATHER WILL EXIST THIS AFT/EVE GIVEN MDT DIURNAL DESTABILIZATION PROGGED AND DEEP LAYER SHEAR POTENTIALLY SUPPORTIVE OF SUPERCELLULAR ORGANIZATION. NEVERTHELESS...WITH SUCH A COMPLICATED PATTERN IN PLACE...IT IS DIFFICULT TO SAY MUCH MORE ABOUT THE SEVERE POTENTIAL...OTHER THAN THAT PREVIOUS EXPERIENCE IN SIMILAR PATTERNS WOULD SUGGEST AN ISOLD/LOW-END SVR THREAT. EXPECT LOWS WED NIGHT IN THE MID 60S SOUTH TO LOWER 60S NORTH...PERHAPS UPPER 50S IN THE FAR NE COASTAL PLAIN. -VINCENT && .SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
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AS OF 259 AM WEDNESDAY... A CONVECTIVELY ACTIVE DAY IS EXPECTED THURSDAY. POTENTIALLY GOOD NEWS FOR FOR THE CURRENT DRY CONDITIONS;HOWEVER, A MARGINAL RISK OF SEVERE THUNDERSTORMS MAY COME WITH THE RAINFALL. A WEAKENING MID/UPPER LEVEL TROUGH WILL APPROACH DURING THE DAY... THEN PASS ACROSS THE MID-ATLANTIC THURSDAY NIGHT. SEVERAL CONVECTIVE OUTFLOW BOUNDARY SHOULD EXIST TO START THE DAY... ANY OF WHICH MAY FOCUS CONVECTIVE DEVELOPMENT DURING THE AFTERNOON. THE COLD FRONT NOT APPROACH UNTIL FRIDAY MORNING. AREAS OF SHOWERS AND A FEW THUNDERSTORMS MAY STILL BE ONGOING IN THE WESTERN AND NORTHERN AREAS DURING THE MORNING. THIS WILL CREATE SOME UNCERTAINTY IN THE PLACEMENT OF WHERE THE BEST INSTABILITY WILL GENERATE DURING THE DAY. IT APPEARS THE SOUTHERN... CENTRAL AND EASTERN ZONES WILL BE THE MOST FAVORED FOR STRONG TO MARGINALLY SEVERE STORMS DURING THE AFTERNOON INTO THE EVENING. THIS IS THE REGION WHERE MOST MODELS DEVELOP 1500 TO 2000 J/KG MLCAPE. THE MAIN THREAT SHOULD BE FROM WIND... WITH LARGE HAIL A SECONDARY THREAT. EXPECT CONSIDERABLE EARLY MORNING CLOUDS AND SHOWERY CONDITIONS IN THE NW WILL MIX OUT TO SOME SUNSHINE WITH 1000-1500 CAPES POSSIBLE THERE DURING THE LATE AFTERNOON. THE STRONGEST STORMS MAY FORM ALONG THE EDGE OF THE FADING MORNING CLOUD COVER AND SHOWER REGION... BUT THE PLACEMENT IS PROBLEMATIC. THEREFORE... WE WILL CONTINUE TO GENERALLY BROADBRUSH 50-60 POP AND QPF OF AROUND 0.50 THROUGHOUT CENTRAL NC. HIGHS SHOULD REACH THE MID TO UPPER 80S IN THE SOUTH AND EAST... WITH UPPER 70S TO LOWER 80S IN THE NW. RESIDUAL CLUSTERS OF SHOWERS AND THUNDERSTORMS WILL GRADUALLY DIMINISH TOWARD AND AFTER MIDNIGHT THURSDAY NIGHT WITH LOWS IN THE LOWER TO MID 60S.
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&& .LONG TERM /FRIDAY THROUGH TUESDAY/...
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AS OF 259 AM WEDNESDAY... FRIDAY IS NOW LOOKING DRIER THAN IN PREVIOUS FORECASTS AS THE MODELS HAVE TRENDING THAT WAY. THE COLD FRONT WILL PUSH SOUTH THROUGH THE REGION FRIDAY MORNING. HOWEVER... THERE MAY STILL BE ENOUGH INSTABILITY WITH HEATING AND THE LINGERING COOL POCKET TO OUR NE THAT WOULD SUPPORT A FEW SHOWERS. FOR NOW... WE WILL CARRY JUST SLIGHT CHANCE IN THE AFTERNOON AND EARLY EVENING... AND MAINLY IN THE COASTAL PLAIN. HIGHS FRIDAY WILL BE COOLER WITH PARTLY SUNNY SKIES. EXPECT READINGS IN THE MID 70S NORTH TO MID 80S SOUTH. FRIDAY NIGHT THROUGH SATURDAY NIGHT IS EXPECTED TO BE COOLER AND DRIER WITH THE FRONT TO OUR SOUTH. WEAK SURFACE HIGH WILL BE TO OUR NORTH AND WILL SUPPLY A LIGHT NE FLOW. LOWS WILL BE IN THE 50S WITH MOSTLY CLEAR SKIES FRIDAY NIGHT. HIGHS SATURDAY IN THE 70S WITH PLENTY OF SUN. THEN INCREASING CLOUDS FOR SATURDAY NIGHT WITH LOWS IN THE UPPER 50S TO LOWER 60S. SUNDAY THROUGH TUESDAY... EXPECT A STORM SYSTEM TO LIFT NE FROM THE MID-MISSISSIPPI VALLEY THROUGH THE OHIO VALLEY REGION SUNDAY INTO MONDAY. THE TRAILING COLD FRONT SHOULD PUSH SE INTO CENTRAL NC MONDAY NIGHT AND TUESDAY. ANOTHER WAVE IS POSSIBLE ON THE FRONT TUESDAY. SUNDAY INTO MONDAY IS LOOKING WET WITH SHOWERS AND SCATTERED THUNDERSTORMS. QPF ON THE ORDER OF 0.5 TO 1 INCH EAST... WITH 1-2 INCHES IN THE WEST. ADDITIONAL RAIN WILL BE POSSIBLE INTO TUESDAY. CONFIDENCE IS INCREASING IN THE SIGNIFICANT RAIN EVENT SUNDAY INTO MONDAY. HOWEVER... AS IS TYPICAL WITH CONVECTIVE RAINS... SOME MAY STILL GET LEFT OUT. IT WILL BE COOLER WITH ALL THE CLOUDS AND THE TROUGH IN PLACE.
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&& .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... AS OF 200 AM WEDNESDAY... 24-HOUR TAF PERIOD: VFR CONDITIONS WILL PREVAIL THROUGH THE MORNING...WITH AN INCREASING POTENTIAL FOR SUB-VFR CONDITION ATTENDANT SCATTERED CONVECTION THIS AFT/EVE INTO TONIGHT AT ALL TERMINALS...ESPECIALLY THE INT/GSO/RDU/RWI TERMINALS. LOOKING AHEAD: IN THE PRESENCE OF INCREASING MOISTURE VIA PERSISTENT SOUTHERLY RETURN FLOW...SUB-VFR CONDITIONS ASSOC/W CONVECTION WILL REMAIN POSSIBLE AT ALL TERMINALS THROUGH THU NIGHT. PRE-DAWN FOG/STRATUS WILL BE POSSIBLE EACH MORNING...ESP. IN AREAS AFFECTED BY AFT/EVE CONVECTION. -VINCENT && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...VINCENT NEAR TERM...VINCENT SHORT TERM...BADGETT LONG TERM...BADGETT AVIATION...VINCENT

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