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

NWS RAH Office Area Forecast Discussion