Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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000 FXUS62 KRAH 300651 AFDRAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 250 AM EDT WED JUL 30 2014 .SYNOPSIS...WEAK HIGH PRESSURE WILL BUILD INTO THE AREA TODAY AND TONIGHT...THEN WEAKEN ON THURSDAY. DEEP MOISTURE WILL GRADUALLY RETURN TO THE REGION THURSDAY NIGHT FRIDAY AS AN UPPER LEVEL TROUGH APPROACHES FROM THE WEST... AND AN ATTENDANT COASTAL FRONT MOVES INLAND INTO THE CAROLINAS. && .NEAR TERM /THROUGH TONIGHT/... AS OF 250 AM WEDNESDAY... THE ANOMALOUSLY DEEP TROUGH WILL PERSIST OVER THE REGION TODAY. MEANWHILE AT THE SURFACE...WEAK SURFACE HIGH PRESSURE WILL BUILD INTO THE AREA FROM THE WEST. GIVEN ALL THE DRY AIR DEPICTED IN BOTH WATER VAPOR IMAGERY AND AREA RAOBS...SURPRISED TO SEE THE SMALL AREA OF SHOWERS NEAR THE NC/VA BORDER PERSIST WELL INTO THE OVERNIGHT HOURS. FCST SOUNDINGS INDICATE THIS SHALLOW MID-LEVEL SATURATION WILL PERSIST THROUGHOUT THE DAY...WITH CONTINUED WEAK MID/UPPER FORCING VIA DCVA AND A ZONE OF ENHANCED OF UPPER LEVEL DIVERGENCE AS SHORTWAVE ENERGY AND A 80- 85KT UPPER JETSTREAK ROTATE ACROSS THE AREA THROUGH THE BASE OF THE TROUGH. WHEN COMBINED WITH DAYTIME HEATING...WOULD EXPECT THIS WILL BE ENOUGH TO SUPPORT ISOLATED SHOWERS THIS AFTERNOON. HIGHS AGAIN IN THE LOWER TO MID 80S. LOWS TONIGHT IN THE THE LOWER TO MID 60S. && && .SHORT TERM /THURSDAY AND THURSDAY NIGHT/... AS OF 250 AM WEDNESDAY... SHORTWAVE ENERGY DIVING DOWN THE BACK-SIDE OF THE HIGHLY AMPLITUDE LONG WAVE TROUGH WILL CAUSE THE TROUGH AXIS CENTERED OVER THE REGION THURSDAY MORNING TO RETROGRADE TO THE MS RIVER THROUGH THE COURSE OF THE DAY ON THURSDAY. STALLED COASTAL TROUGH/FRONT OVER THE WESTERN ATLANTIC WILL FOLLOW SUITE...WITH SELY MOISTURE RETURN FLOW LEADING TO AN INCREASE IN CLOUDS THURSDAY AFTERNOON WITH OVERRUNNING PRECIP DEVELOPING THURSDAY NIGHT/PREDAWN HOURS FRIDAY NIGHT AS THE COASTAL TROUGH MOVES INLAND. HAVE INTRODUCED SLIGHT TO SMALL CHANCE POPS AFTER MIDNIGHT THURSDAY NIGHT. HIGHS THURSDAY 82-87. LOWS THURSDAY NIGHT IN THE MID TO UPPER 60S. && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 250 AM WEDNESDAY... MODELS CONTINUE TO CONVERGE TOWARDS A WETTER SOLUTION FOR THE LONG TERM...ALTHOUGH THE EXACT DETAILS OF WHERE/WHEN THE BEST CHANCES OF PRECIP WILL OCCUR ARE STILL RATHER UNCERTAIN. THE HIGHLY AMPLIFIED RIDGE OVER THE ATLANTIC WILL SHIFT WESTWARD...NUDGING THE HIGHLY UPPER LEVEL TROUGH BACK TOWARDS THE MS RIVER VALLEY. THE LINGERING FRONT/INVERTED TROUGH WILL WILL ALSO MOVE CLOSER TO THE COAST...AND LIKELY INLAND BY THE LATTER HALF OF THE WEEKEND...BEFORE WASHING OUT NEXT WEEK. IN ADDITION... MOISTURE WILL GRADUALLY INCREASE (PWATS RISING BACK OVER 1.5 INCHES BY FRIDAY...THEN APPROACHING 2 INCHES BY SATURDAY/SUNDAY) AS FLOW ALOFT BECOMES MORE SOUTHWESTERLY WITH THE UPPER TROUGH NOW TO OUR WEST. BESIDES SCATTERED SHOWERS AND THUNDERSTORMS RESULTING FROM THE INCREASING MOISTURE AND LINGERING INVERTED TROUGH...ENHANCED PRECIP CHANCES WILL BE DEPENDENT ON PASSING DISTURBANCES ALOFT...WHICH ARE HARD TO PINPOINT WITH ANY CERTAINTY THIS FAR OUT. HOWEVER...AT THIS TIME...ONE LOOKS TO APPROACH THE REGION ON FRIDAY AND THEN ANOTHER ONE IS PROGGED TO PASS NORTH OF THE AREA ON SUNDAY...SO WILL SHOW SLIGHTLY HIGHER POPS (RELATIVE TO THE REST OF THE LONG TERM) DURING THIS TIME FRAME. HIGH TEMPS WILL STILL BE IN THE LOW/MID 80S (WARMEST EARLY NEXT WEEK)...WITH OVERNIGHT LOWS IN THE LOW/MID 60S EARLY IN THE PERIOD AND MID/UPPER 60S BY LATE WEEKEND/EARLY NEXT WEEK. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... AS OF 100 AM WEDNESDAY... 24-HR TAF PERIOD: UPPER DISTURBANCES ROTATING THROUGH THE BASE OF THE DEEP UPPER LEVEL TROUGH IN PLACE OVER THE REGION WILL RESULT IN ISOLATED SHOWERS ACROSS THE AREA. OTHERWISE...DRY AIR IN THE LOW-LEVELS WILL SUPPORT VFR CONDITIONS THROUGH THE TAF PERIOD. LOOKING AHEAD: EXPECT AN INCREASING POTENTIAL FOR ADVERSE AVIATION CONDITIONS ASSOCIATED WITH LOW CEILINGS AND SCATTERED TO WIDESPREAD CONVECTION FRIDAY NIGHT THROUGH THE WEEKEND AS A COASTAL FRONT RETROGRADES INLAND INTO CENTRAL PORTIONS OF THE STATE...IN ADVANCE OF AN UPPER LEVEL TROUGH APPROACHING FROM THE WEST. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...VINCENT NEAR TERM...CBL SHORT TERM...CBL LONG TERM...KRD AVIATION...CBL/VINCENT

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