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000
FXUS62 KRAH 131747
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
147 PM EDT MON MAY 13 2013

.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE REGION FROM THE WEST THROUGH
TUESDAY. AS THE HIGH MOVES OFFSHORE ON WEDNESDAY...A WARM AND
INCREASINGLY MOIST SOUTHERLY FLOW WILL DEVELOP ACROSS THE CAROLINAS.

&&

.NEAR TERM /THROUGH TUESDAY NIGHT/...
AS OF 145 PM MONDAY...

THROUGH TONIGHT:
AN AMPLIFYING UPPER LEVEL TROUGH DIGGING TOWARD THE MID-ATLANTIC
COAST THIS AFTERNOON WILL PROGRESS OFFSHORE TONIGHT. POTENT
SHORTWAVE ENERGY DIGGING SOUTHWARD THROUGH THE UPPER GREAT LAKES AT
15Z WILL CONTINUE TO DIG S/SSE ALONG THE WESTERN PERIPHERY OF THE
AMPLIFYING UPPER LEVEL TROUGH BETWEEN 21-03Z...RESULTING IN STRONG
DPVA ACROSS CENTRAL/EASTERN VA AND FAR NORTHEAST NC. GIVEN THAT THE
BEST FORCING WILL REMAIN IN CENTRAL/EASTERN VA AND THAT AN
ABNORMALLY DRY AIRMASS (PWAT 50 PERCENT OF NORMAL) IS IN PLACE ALONG
WITH DEEP WESTERLY FLOW THROUGHOUT THE COLUMN...ANTICIPATE LITTLE TO
NO CHANCE FOR LIGHT RAIN OR SPRINKLES IN CENTRAL NC. WILL CONTINUE
TO MAINTAIN A DRY FCST...WITH PARTLY CLOUDY SKIES THROUGH MID
AFTERNOON...BECOMING MOSTLY CLOUDY IN THE NORTHERN PIEDMONT AND NE
COASTAL PLAIN LATE THIS AFTERNOON AND EVENING IN ADVANCE OF THE
APPROACHING SHORTWAVE ENERGY. EXPECT A CLEARING TREND AFTER MIDNIGHT
AS STRONG MID-LEVEL SUBSIDENCE ENSUES IN THE WAKE OF THE
AFOREMENTIONED SHORTWAVE ENERGY. BASED ON THE DRY ADIABATIC METHOD
MIXING UP TO ~800 MB...EXPECT HIGHS RANGING FROM THE MID 60S (NORTH)
TO UPPER 60S AND LOWER 70S SOUTH. WITH CALM WINDS AND A COOL/DRY
AIRMASS IN PLACE...EXPECT BELOW NORMAL LOWS THAT WILL DEPEND
PRIMARILY ON CLOUD COVER...RANGING FROM THE UPPER 30S/40F IN RURAL
AND LOW-LYING AREAS WEST OF HWY 1 TO LOWER 40S ELSEWHERE.

TUESDAY/TUESDAY NIGHT:
THE SYNOPTIC PATTERN OVER THE CAROLINAS WILL BE CHARACTERIZED BY
RISING HEIGHTS AND NW FLOW ALOFT AS AN UPPER LEVEL TROUGH PROGRESSES
FURTHER OFFSHORE THE MID-ATLANTIC AND AN AMPLIFYING UPSTREAM RIDGE
BUILDS EAST TOWARD THE SOUTHERN APPALACHIANS. THOUGH SOME MID-LEVEL
MOISTURE AND/OR OROGRAPHIC CIRRUS COULD DEVELOP TUE INTO TUE NIGHT
IN ASSOCIATION WITH SMALL AMPLITUDE DISTURBANCES IN NW FLOW ALOFT...
DRY/STABLE CONDITIONS WILL PRECLUDE THE POSSIBILITY OF PRECIP AND
WILL MAINTAIN A DRY FORECAST. EXPECT HIGHS ON TUE TO BE SEVERAL
DEGREES WARMER THAN TODAY IN ASSOC/W RISING THICKNESSES...RANGING
FROM 69-74F...WARMEST IN THE SANDHILLS AND SOUTHWEST PIEDMONT.
ACCORDINGLY...LOWS TUE NIGHT WILL BE AT LEAST SEVERAL DEGREES WARMER
(49-54F) AND PRIMARILY DEPENDENT ON THE OPACITY/COVERAGE OF CLOUD
COVER THAT DEVELOPS/MOVES INTO THE AREA IN NW FLOW ALOFT. -VINCENT

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 145 PM MONDAY...

MID LEVEL RIDGE WILL BUILD OVER THE CAROLINAS ON WEDNESDAY PROVIDING
FAIR WEATHER AND SIGNIFICANT WARMING. LOW LEVEL THICKNESS VALUES
WILL CONTINUE TO RISE ABOUT ANOTHER 50M...PEAKING JUST ABOVE 1400M
BY LATE IN THE DAY. EXPECT HIGHS IN THE MID 80S WED. EXPECT
INCREASING MID AND HIGH CLOUDS OVER OUR REGION WED NIGHT AHEAD OF A
SOUTHERN STREAM S/W TROUGH OVER THE SOUTHERN PLAINS MOVING EAST.
WARMER WITH LOWS IN THE LOWER 60S.

THE AFOREMENTIONED S/W TROUGH WILL MOVE EAST TO THE TN VALLEY ON
THURSDAY. FORECAST SOUNDINGS FOR OUR AREA SHOW INCREASING PWAT AND
SUBTLE MID LEVEL COOLING WITH THE APPROACH OF THE TROUGH. WILL
INCREASE POPS SOME FOR THURSDAY AFTERNOON INTO THE EVENING...HOWEVER
BEST CHANCE FOR RAIN STILL APPEARS TO BE ACROSS OUR NORTHERN AND
WESTERN-MOST ZONES. WITH LITTLE CHANGE IN AIRMASS AND THICKNESS
VALUES...HIGHS SHOULD ONCE AGAIN TOP OUT IN THE MID 80S. -NP

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 145 PM MONDAY...

THIS PERIOD CAN BE CHARACTERIZED AS UNSETTLED...BUT CERTAINLY NOT A
WASHOUT...AS A BROAD TROUGH IS PROGGED TO REMAIN ACROSS THE
SOUTHEAST WITH A SERIES OF WEAKER EMBEDDED TROUGHS PASSING THROUGH
THE LARGER SCALE PATTERN. WHILE THE LATEST GFS SUGGESTS THAT THE
BEST CHANCE FOR RAIN DURING THIS PERIOD WOULD BE ON SUNDAY...THE
ECMWF IS MORE UNIFORM THROUGH THIS PERIOD AND SUGGESTS SIMILAR RAIN
CHANCE EACH DAY. AS SUCH...FOR NOW WILL CONTINUE CARRY CHANCE POPS
RIGHT THROUGH THE PERIOD. MULTILAYER WIND FIELDS AND RESULTING SHEAR
SUGGEST THUNDERSTORMS DURING THIS TIME WOULD BE MORE PULSE IN NATURE
AND NOT WELL-ORGANIZED...THUS AT THIS POINT SEVERE THUNDERSTORM
POTENTIAL LOOKS LOW.  REGARDING TEMPS...GIVEN LITTLE AIRMASS
CHANGE...TEMPS WILL BE AFFECTED MORE BY CLOUDS AND PRESENCE OF ANY
PRECIP...SO WILL FOLLOW PERSISTENCE DURING THIS TIME WITH HIGHS IN
THE MID 80S AND LOWS IN THE LOWER TO MID 60S.

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 145 PM MONDAY...

24-HR TAF PERIOD:
VFR CONDITIONS WILL RULE THROUGH THE TAF PERIOD AS A STRENGTHENING
UPPER LEVEL RIDGE BUILDS EAST TOWARD THE CAROLINAS. ANY CEILINGS
WILL REMAIN AT OR ABOVE 7000 FT. LIGHT AND VARIABLE WINDS WILL
PREVAIL DURING THE TAF PERIOD IN MOST LOCATIONS...ASIDE FROM A SHORT
PERIOD OF 10-15 KT N/NE WINDS AT THE FAY TERMINAL UNTIL ~22Z THIS
AFTERNOON.

LOOKING AHEAD:
VFR CONDITIONS WILL RULE THROUGH WEDNESDAY AS AN UPPER LEVEL RIDGE
BUILDS OVER THE EASTERN US. VFR CONDITIONS ARE EXPECTED TO PREVAIL
THROUGH THE END OF THE WEEK...WITH AN INCREASING POTENTIAL FOR ISOLD
TO SCT DIURNAL CONVECTION LATE FRIDAY INTO THE WEEKEND. -VINCENT

&&

.CLIMATE /RECORD LOWS FOR MAY 13 AND 14/...

RALEIGH... 40 DEGREES RECORDED MAY 13, 1960
           43 DEGREES RECORDED MAY 14, 1997

GREENSBORO... 38 DEGREES RECORDED MAY 13, 1989
              40 DEGREES RECORDED MAY 14, 1941

&&

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

&&

$$

SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...NP
LONG TERM...NP
AVIATION...VINCENT
CLIMATE...BADGETT