Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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000 FXUS62 KRAH 271934 AFDRAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 335 PM 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. A COLD FRONT WILL PUSH SOUTH OF THE REGION FRIDAY NIGHT... THEN LIFT BACK NORTHWARD AS A WARM FRONT SUNDAY. && .NEAR TERM /TODAY AND TONIGHT/... AS OF 330 PM WEDNESDAY... THE FRONTAL ZONE...JUST NORTH OF RICHMOND VA...IS FORECAST TO SAG SLOWLY SOUTHWARD TO NEAR THE NC/VA BORDER THIS EVENING. WEAK S/W DISTURBANCES CRESTING THE FLAT RIDGE ALOFT HAS BEEN FEEDING UPSTREAM CONVECTION OVER EAST KY AND SW VA... WITHIN THE WARM SECTOR SOUTH OF THE FRONT. THESE STORMS ALONG WITH ANY REMNANT CONVECTIVE OUTFLOW BOUNDARIES WILL BRING THE HIGHEST CHANCE OF POPS TO THE NORTHERN PIEDMONT/COASTAL PLAIN THIS AFTERNOON AND EVENING. DEEP LAYER SHEAR 20-30KTS...STRONGEST INVOF THE FRONT...WILL BE SUFFICIENT TO SUPPORT ISOLATED HAIL AND/OR DAMAGING WIND GUSTS. GIVEN THE POTENTIAL FOR SOME WEAK SHORTWAVE DISTURBANCES TO EJECT EASTWARD DOWNSTREAM OF THE NEGATIVELY-TILTED SHORTWAVE TROUGH LIFTING SLOWLY NORTHWARD ACROSS THE CENTRAL PLAINS...A CHANCE OF SHOWERS AND AND THUNDERSTORMS WILL BE POSSIBLE ANYWHERE OVERNIGHT. LOWS WEDNESDAY NIGHT RANGING FROM NEAR 60 NORTH TO MID 60S SOUTH. && .SHORT TERM /THURSDAY AND THURSDAY NIGHT/... AS OF 330 PM WEDNESDAY... UPPER LOW OVER THE MID-UPPER MS VALLEY AT THE START OF THE PERIOD WILL CONTINUE TO SHEAR AND WEAKEN AS IT MOVES EWD INTO THE MEAN RIDGE POSITION ACROSS THE OH VALLEY/LOWER GREAT LAKES REGION ON THURSDAY. ASSOCIATED WEAK SURFACE WAVE AND SFC COLD FRONT WILL MOVE INTO THE REGION LATE THURSDAY/THURSDAY EVENING...WHERE IT WILL INTERSECT THE STALLED FRONT IN PLACE ACROSS CENTRAL NC. SEVERAL CONVECTIVE OUTFLOW BOUNDARIES FROM TONIGHTS STORMS ARE LIKELY TO EXIST TO START THE DAY...WITH SCATTERED/PARTIAL BREAKS IN THE LOW TO MID-LEVEL CLOUD COVER ALSO LIKELY TO SET UP A THERMAL MOISTURE BOUNDARY(TMB)ACROSS THE AREA. SO FOR THE SECOND CONSECUTIVE DAY...EXPECT MESOSCALE FEATURES TO PLAY A LARGE ROLE IN CONVECTIVE EVOLUTION ACROSS CENTRAL NC. NEVERTHELESS DAYTIME HEATING WITHIN THE WARM SECTOR...SOUTH OF THE STALLED FRONT WILL RESULT IN MODERATE DESTABILIZATION OF 1000- 2000J/KG MLCAPE. WESTERLY H5 FLOW STRENGTHENS A BIT...WHICH WILL IMPROVE BULK SHEAR VALUES TO 30 TO 35KTS...FAVORABLE FOR MULTICELLS WITH ONE OR TWO SEVERE CLUSTERS POSSIBLE. MAIN THREAT WILL DAMAGING THUNDERSTORM WIND GUSTS AND LARGE HAIL. AS THE FRONT MOVES INTO THE AREA FROM THE WEST LATE EVENING/OVERNIGHT...THE STORMS SHOULD BEGIN TO PUSH EAST AND OUT OF THE AREA. HIGHS IN THE UPPER 70S NORTH TO MID 80S SOUTH. LOWS THURSDAY NIGHT IN THE UPPER 50S/NEAR 60 NORTH TO MID 60S SE. && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 300 PM WEDNESDAY... A BROAD UPPER LEVEL TROUGH WILL COVER THE COUNTRY AT THE BEGINNING OF THE PERIOD. A SERIES OF S/WS IN THE CYCLONIC FLOW WILL CAUSE BOUTS OF UNSETTLED WEATHER TO CENTRAL NC. THE FIRST MINOR S/W WILL CROSS NEAR OR NORTH OF OUR REGION FRIDAY AFTERNOON-EVENING. THE COOL POOL ALOFT ASSOCIATED WITH THIS FEATURE COUPLED WITH AFTERNOON HEATING AND RESIDUAL MOISTURE SHOULD TRIGGER A FEW SHOWERS/ISOLATED T-STORMS...PRIMARILY OVER OUR NE PIEDMONT/NORTHERN COASTAL PLAIN COUNTIES LATE FRIDAY-FRIDAY EVENING. WEAK HIGH PRESSURE WILL EXTEND ACROSS THE REGION SATURDAY BUT QUICKLY SCOOT EAST BY SATURDAY EVENING. THE RETURN FLOW ON THE BACKSIDE OF THE HIGH IN CONJUNCTION WITH AN APPROACHING S/W TRAVERSING THE DEEP SOUTH/TN VALLEY SHOULD ENHANCE LOW LEVEL MOISTURE RETURN...LEADING TO AREAS OF RAIN BREAKING OUT OVER OUR REGION BY SUNDAY. THE SFC PRESSURE PATTERN SUPPORTS THE POTENTIAL FOR A HYBRID/INSITU COLD AIR DAMMING EVENT...SUGGESTING TEMPS WELL BE LOW NORMAL IF THE RAIN DEVELOPS. EARLY NEXT WEEK...MODELS ADVERTISING A PATTERN AMPLIFICATION WITH A WESTERN U.S. RIDGE AND EASTERN US.S TROUGH. DISTURBANCES IN THE AMPLIFYING FLOW WILL CONTINUE TO BRING PERIODS OF UNSETTLED WEATHER THROUGH MID WEEK. TEMPERATURES ON AVERAGE WILL BE A LITTLE SHY OF NORMAL EARLY NEXT WEEK. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... AS OF 136 PM WEDNESDAY... 24-HOUR TAF PERIOD: A COLD FRONT OVER CENTRAL/SOUTHERN VIRGINIA WILL SAG SLOWLY SOUTH TOWARDS THE NC/VA STATE LINE THIS EVENING. WEAK DISTURBANCES ALOFT MOVING ATOP THE LOW-LEVEL FRONTAL ZONE WILL SUPPORT SCATTERED SHOWERS AND STORMS...MAINLY ACROSS THE NORTHERN PIEDMONT AND COASTAL PLAIN THIS AFTERNOON AND EVENING. KINT...KGSO...KRWI...AND KRDU HAVE THE BEST CHANCES OF SEEING SUB-VFR CONDITIONS IN ASSOCIATION WITH THIS CONVECTION...WITH LESSER CHANCES AT KFAY. WITH THE STALLED FRONT NEARBY AND CONTINUED POTENTIAL TO SEE WEAK DISTURBANCES TRACKING THROUGH THE REGION...ISOLATED SHOWERS TO SMALL CHANCE POPS WILL CONTINUE OVERNIGHT...ESPECIALLY ACROSS THE NORTH. CANNOT RULE OUT SOME PRE-DAWN FOG/STRATUS THURSDAY MORNING...ESPECIALLY IN AREAS THAT RECEIVE HEAVY RAINFALL. SHOWERS AND THUNDERSTORMS AND ASSOCIATED RESTRICTIONS SHOULD BE MORE WIDESPREAD THURSDAY AFTERNOON AND EVENING AHEAD OF A COLD FRONT APPROACHING FROM THE WEST. LOOKING AHEAD: DRY CONDITIONS ARE EXPECTED FRIDAY AND SATURDAY ...BEFORE UNSETTLED WEATHER AND POSSIBLE RESTRICTIONS RETURN FROM THE WEST SUNDAY THROUGH MONDAY FROM POTENTIAL CAD. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...VINCENT/BADGETT NEAR TERM...CBL SHORT TERM...CBL LONG TERM...WSS AVIATION...CBL

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