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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KRAH 200200
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
1000 PM EDT SUN MAY 19 2013

.SYNOPSIS...
A MID LEVEL TROUGH WILL SLOWLY MOVE FROM THE CENTRAL APPALACHIANS
THIS EVENING TO THE NC AND VA COASTS TUESDAY.

&&

.NEAR TERM /THROUGH MONDAY NIGHT/...
-- Changed Discussion --
AS OF 1000 PM SUNDAY...

THROUGH TONIGHT: THE SHORTWAVE LOW EMBEDDED IN THE RIDGE OVER THE
APPALACHIANS...HELPING TO DRIVE THE SHOWERS AND STORMS THIS
EVENING...WILL CONTINUE TO DAMPEN AND SLOWLY DRIFT TO THE ENE. THE
00Z UPPER AIR ANALYSIS SHOWS THE WAVE OVER WESTERN NC AT 850 MB
THROUGH 500 MB...BUT DOES NOT SHOW UP AT 250 MB. AT THE SURFACE...
CENTRAL NC IS SANDWICHED BETWEEN AN OFFSHORE HIGH AND A STRONG LOW
PRESSURE SYSTEM IN THE MIDWEST. HIGH-RES CONVECTION ALLOWING MODELS
INDICATE THE SHOWERS AND STORMS DISSIPATING SOME OVERNIGHT BEFORE
REDEVELOPING ACROSS THE EASTERN HALF OF THE AREA MONDAY MORNING.
SOME LINGERING SHOWERS WILL CONTINUE TO DRIFT NORTH OVER THE NEXT
FEW HOURS...ALTHOUGH INTENSITY AND COVERAGE SHOULD DECREASE WITH
TIME. WITH THE 00Z SOUNDING AT KGSO YIELDING A PWAT VALUE OF 1.6
INCHES WITH A DEEP MOIST LAYER AND WEAK INSTABILITY...ADDITIONAL
SHOWERS CANNOT BE COMPLETELY RULED OUT...THUS HAVE KEPT RAIN CHANCES
IN ACROSS THE AREA OVERNIGHT. GIVEN THE CURRENT COOLING THIS
EVENING...HAVE DECREASED LOWS A DEGREE OR TWO ACROSS THE AREA...
MAINLY IN THE MID 60S. -KC

MONDAY AND MONDAY NIGHT:
MUCH OF THE SAME ON MONDAY WITH A GRADUAL SHIFT OF THE DEEP MOISTURE
AND BEST CONVECTIVE COVERAGE ACROSS THE EASTERN HALF OF THE STATE.
EXTENSIVE CLOUD COVER AND EARLY START OF CONVECTION WILL CURB
SIGNIFICANT DESTABILIZATION...BUT LIKE TODAY EXPECT A DIURNAL
FLAREUP WITH A CONTINUED THREAT OF TRAINING STORM AND ASSOCIATED
MINOR FLOODING INTO THE AFTERNOON AND EVENING. HIGHS WILL AGAIN BE
DEPENDENT ON CLOUDS AND RADAR COVERAGE. HIGHS IN THE UPPER 70S TO
LOWER 80S. MORE LOW STRATUS AND FOG WILL BE LIKELY MONDAY NIGHT
AFTER THE SHOWERS DISSIPATE. LOWS IN THE MID TO UPPER 60S. -CBL
-- End Changed Discussion --

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 245 PM SUNDAY...

THE MID/UPPER LEVEL WAVE (CAUSING ALL OF THE RAIN TODAY AND MONDAY)
WILL STILL BE LINGERING ACROSS THE EASTERN PORTIONS OF THE FORECAST
AREA ON TUESDAY...BEFORE FINALLY SHIFTING OFFSHORE TUESDAY NIGHT.
THEREFORE...SHOWER AND THUNDERSTORM CHANCES WILL REMAIN ELEVATED...
ALTHOUGH COVERAGE SHOULD BE LESS THAN PREVIOUS DAYS. THE HIGHEST
POPS ARE EXPECTED ACROSS THE EAST...AS THE WESTERN PORTIONS OF THE
FORECAST AREA MAY HAVE CONVECTIVE ACTIVITY MORE SUPPRESSED DUE TO
INCREASING SUBSIDENCE OF THE BACKSIDE OF TROUGH AXIS. HIGHS SHOULD
BE IN THE MID/UPPER 80S...WITH OVERNIGHT LOWS GENERALLY IN THE MID
60S.

SOME WEAK SHORTWAVE RIDGING WILL START TO BUILD OVER THE AREA BY
WEDNESDAY...WHILE AT THE SURFACE...THE BERMUDA HIGH WILL START TO
RIDGE WESTWARD INTO THE CAROLINAS. ALL OF THIS WILL TRANSLATE TO AN
EVEN FURTHER DECREASE IN PRECIP COVERAGE ON WEDNESDAY. HOWEVER...
SUFFICIENT MOISTURE WILL STILL BE IN PLACE OVER THE REGION...WITH
PWAT VALUES HOVERING NEAR 1.5 INCHES OR SO. THEREFORE...AM STILL
EXPECTING TO SEE WIDELY SCATTERED TO SCATTERED DIURNALLY DRIVEN
CONVECTION. HIGHS ONCE AGAIN SHOULD BE IN THE MID/UPPER 80S...WITH
OVERNIGHT LOWS IN THE MID/UPPER 60S.



.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 245 PM SUNDAY...

SHOWER AND THUNDERSTORM COVERAGE SHOULD BEGIN TO INCREASE ONCE AGAIN
BY THE END OF THE WEEK WITH THE APPROACH OF OUR NEXT MID/UPPER LEVEL
TROUGH AND ASSOCIATED COLD FRONT. THERE IS STILL SOME UNCERTAINTY
(MAINLY DUE TO RUN TO RUN INCONSISTENCIES) WITH THE TIMING OF THE
COLD FRONTAL PASSAGE...BUT OVERALL THE TREND HAS BEEN WITH A QUICKER
PASSAGE. IN FACT...THE MODELS ARE IN GENERAL AGREEMENT WITH BRINGING
THE FRONT THROUGH THE FORECAST AREA EARLY FRIDAY...ALMOST 12-18
HOURS EARLIER THAN WHAT MODELS INDICATED 24 HOURS AGO.
THEREFORE...WILL SHOW POPS HIGHEST POPS CONCENTRATED DURING THE
THURSDAY/EARLY FRIDAY TIME FRAME...THEN DECREASING FROM WEST TO EAST
THROUGHOUT THE DAY ON FRIDAY. AS OF NOW...IT NOW APPEARS THE WEEKEND
WILL BE DRY AS HIGH PRESSURE BUILDS IN BEHIND THE DEPARTING FRONT.
WITH INCREASED PRECIP CHANCES/CLOUDS ON THURSDAY AND FRIDAY...TEMPS
WILL MOSTLY BE IN THE LOW/MID 80S...WITH SLIGHTLY COOLER TEMPS
EXPECTED FOR THE WEEKEND (GENERALLY IN THE 70S).



&&

.AVIATION /00Z MONDAY THROUGH THURSDAY/...
AS OF 820 PM SUNDAY...

A PERSISTENCE FORECAST HAS BEEN FOLLOWED FOR THE 00Z TAF PERIOD...
GIVEN LITTLE EXPECTED CHANGE IN THE OVERALL WEATHER PATTERN
CHARACTERIZED BY THE INTERACTION OF A SLOW-MOVING MID LEVEL WITH
ABUNDANT DEEP MOISTURE AND DIURNALLY-ENHANCED INSTABILITY. AS
SUCH...A REDEVELOPMENT/LOWERING OF CEILINGS THROUGH MVFR TO IFR-LIFR
RANGE (WITH MOSTLY MVFR VISIBILITY RESTRICTIONS) AT TRIAD
TERMINALS...RANGING TO MVFR OR BRIEFLY IFR AT EASTERN TERMINALS
(KRWI/KFAY) WILL BE LIKELY THROUGH MON MORNING. SCATTERED RAIN
SHOWERS SHOULD CONTINUE TO DIMINISH IN COVERAGE AND INTENSITY WITH
NOCTURNAL COOLING OVERNIGHT...THEN BECOME NUMEROUS AGAIN - WITH
HIGHEST COVERAGE EAST OF TRIAD TERMINALS - WITH HEATING ON
MON. -MWS

RAIN CHANCES WILL BEGIN TO DIMINISH BY TUESDAY AND ESPECIALLY INTO
WEDNESDAY WITH ONLY ISOLATED TO WIDELY SCATTERED SHOWERS/STORMS
EXPECTED. OTHERWISE...ASSOCIATED RESTRICTIONS IN MORNING STRATUS AND
FOG WILL CONTINUE THROUGH THURSDAY. -CBL

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SYNOPSIS...MWS
NEAR TERM...KC/CBL
SHORT TERM...KRR
LONG TERM...KRR
AVIATION...MWS/CBL