-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KRAH 231432
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
642 AM EDT THU MAY 23 2013

.SYNOPSIS...
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A COLD FRONT WILL APPROACH THE AREA FROM THE WEST TODAY...LEADING TO
UNSETTLED WEATHER MOST OF THE DAY. AFTER FRONTAL PASSAGE
TONIGHT...THE INTRODUCTION OF CANADIAN HIGH PRESSURE WILL BRING
COOLER AND MORE SETTLED CONDITIONS TO THE REGION THROUGH THE HOLIDAY
WEEKEND.
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&&

.NEAR TERM /THROUGH TONIGHT/...
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AS OF 1030 AM THURSDAY...

EARLIER CONVECTION THAT FORMED ON AN OUTFLOW BOUNDARY OVERNIGHT AND
MOVED ACROSS THE WESTERN HALF OF THE CWA HAS DISSIPATED AT THIS
TIME. THE MAIN FORCING FOR CONVECTION AT THIS HOUR REMAINS ACROSS
THE EAST AND COASTAL PLAIN WHERE THE BEST LOW LEVEL CONVERGENCE AND
MOISTURE TRANSPORT IS AT THIS TIME. THE SURFACE COLD FRONT REMAINS
WELL BACK TO THE WEST AT THIS TIME. FOR THE NEAR TERM...THE FOCUS
FOR CONVECTION WILL BE ON A SHORTWAVE TROUGH MOVING NORTHEAST OUT OF
NORTHERN GA THIS MORNING AS WELL AS WITH SOME LEFT OVER OUTFLOW
BOUNDARIES FROM LAST NIGHTS CONVECTION. SPC MESO-ANALYSIS SHOWS SOME
ML CIN STILL OVER MUCH OF CENTRAL NORTH CAROLINA BUT THIS SHOULD NOT
LAST LONG AS SOME CLEARING OVER THE CENTRAL PART OF THE STATE HAS
LEAD TO MUCH BETTER HEATING SO FAR THIS MORNING. WILL LOOK FOR
SCATTERED CONVECTION TO BEGIN TO BREAK OUT THIS MORNING ALONG THE
AFOREMENTIONED BOUNDARIES AND COVERAGE SHOULD PROGRESSIVELY INCREASE
THROUGHOUT THE DAY. SEVERE POTENTIAL IS STILL LIMITED AS THE BEST
DYNAMICS REMAIN OFF TO THE NORTHEAST. LATER TODAY AS THE FRONT AND
ASSOCIATED UPPER LEVEL TROUGH MOVE CLOSER TO THE AREA BULK SHEAR
SHOULD IMPROVE TO ABOUT 20 KNOTS AND DCAPE WILL INCREASE SHORTLY
BEFORE FRONTAL PASSAGE. IF CONVECTION IS STILL ONGOING LATER THIS
AFTERNOON IN THE NORTHWEST...THIS IS WHERE THE HIGHEST SEVERE WIND
THREAT WILL BE. NOT EXPECTING MUCH IN THE WAY OF HAIL AS CAPE IN THE
HAIL GROWTH ZONE IS VERY LIMITED. RECENT RAINS LAST NIGHT AND IN
DAYS PRIOR WILL MAKE URBAN AND SMALL STREAM FLOODING THE GREATEST
THREAT TODAY BUT THIS SHOULD BE LOCALIZED. OUTSIDE OF CONVECTION
WINDS WILL REMAIN SOUTHERLY AT 5-10 KNOTS WITH SOME GUSTS OF 15-20.
WHILE MUCH OF THE CWA IS VFR AT THIS TIME...MVFR CEILINGS COULD
REMAIN FOR A WHILE ESPECIALLY IN THE WEST WHERE A THICKER CLOUD DECK
EXISTS. TEMPERATURES WILL RISE INTO THE LOW TO MID 80S TODAY.

FRONT WILL CROSS THE AREA TONIGHT AFTER DARK AND MAY NOT EXIT THE
EASTERN PORTION OF THE CWA UNTIL CLOSER TO SUNRISE ON FRIDAY. THIS
WILL LEAVE A GOOD POSSIBILITY FOR FOG AND LOW STRATUS AGAIN
TONIGHT...ESPECIALLY IN THE EAST. IF DEWPOINTS BEGIN TO DROP IN THE
NORTHWEST AFTER FRONTAL PASSAGE THIS MAY NOT BE AN ISSUE. LOWS
TONIGHT WILL BE DEPENDENT ON THE PROGRESSION OF THE FRONT BUT
GENERALLY UPPER 50S TO NEAR 60 IN THE NORTHWEST AND MIDDLE 60S IN
THE SOUTHEAST.
-- End Changed Discussion --

&&

.SHORT TERM /FRIDAY AND FRIDAY NIGHT/...
AS OF 330 AM THURSDAY...

A SHARP...REINFORCING UPPER TROUGH AXIS WILL PIVOT ACROSS THE MIDDLE
ATLANTIC STATES FRI...THEN OFFSHORE FRI NIGHT. STRONG LOW LEVEL CAA
WILL LARGELY OFFSET THE ASSOCIATED FORCING WITH THE UPPER
TROUGH...SO ASIDE FROM A LINGERING CHANCE OF A SHOWER OR STORM IN A
RESIDUALLY MOIST REGIME OVER THE COASTAL PLAIN THROUGH 1-2
PM...STRONG SUBSIDENCE AND ASSOCIATED CLEAR AND STABLE CONDITIONS
WILL PREVAIL. NOT AS WARM...WITH HIGHS IN THE 70S...AND MUCH COOLER
WITH LOWS IN THE 40S OVERNIGHT...AS CANADIAN/CONTINENTAL POLAR HIGH
PRESSURE BUILDS SOUTHEASTWARD.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 255 AM THURSDAY...

SATURDAY AND SUNDAY...

A TERRIFIC WEEKEND IS SHAPING UP AS CANADIAN HIGH PRESSURE WILL
BUILD SOUTH OUT OF THE GREAT LAKES INTO THE EASTERN CONUS. THIS WILL
RESULT IN CLEAR SKIES SATURDAY WITH DRY AND COOLER AIR IN PLACE.
UPPER FLOW WILL BE NORTHWEST AND MODEL CROSS SECTIONS SHOW THAT SOME
HIGH CLOUDINESS COULD MILDLY IMPEDE THE SUNSHINE ON SUNDAY. HIGHS
BOTH DAYS WILL BE MOSTLY IN THE MID 70S. MEANWHILE... SUNDAY
MORNINGS LOW TEMPERATURE WILL BE CONSIDERABLY BELOW NORMAL DUE TO
EXCELLENT RADIATIONAL CONDITIONS...IN THE 45 TO 50 DEGREE RANGE.

MONDAY THROUGH WEDNESDAY....

THE SURFACE HIGH PRESSURE MIGRATES OFFSHORE EARLY NEXT WEEK WHICH
WILL RESULT IN A GRADUAL WARMER AND MOISTER TREND INTO MIDWEEK. WE
WILL BE UNDER A BUILDING LOW AMPLITUDE UPPER RIDGE THROUGH THE
PERIOD WHICH WILL TEND TO SUPPRESS CONVECTION...ESPECIALLY WITH NO
EASILY IDENTIFIABLE FORCING OTHER THAN GENERALLY INCREASING
INSTABILITY WITH LEE TROFFING IN NORTHWEST FLOW AND POTENTIAL FOR
SOME INLAND PENETRATION OF SEA BREEZE CONVECTION IN THE EAST. AS
SUCH...WILL NOT MEDDLE WITH ONGOING SLIGHT CHANCE FOR LATE DAY
CONVECTION MONDAY THROUGH WEDNESDAY. TEMPS WILL BE ON THE UPTICK...
FROM 75 TO 80 ON MONDAY RISING TO 80 TO 85 ON WEDNESDAY...WITH MINS
FOLLOWING A SIMILAR TREND...FROM THE MID 50S MONDAY MORNING TO THE
LOWER 60S WEDNESDAY MORNING.


&&

.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS OF 640 AM THURSDAY...

A WEAKENING LINE OF SHOWERS SHOULD CONTINUE TO DISSIPATE DURING THE
NEXT COUPLE OF HOURS...LEAVING GENERALLY DRY CONDITIONS THROUGH
MIDDAY. SUB-VFR CEILINGS AT PRESENT WILL ALSO LIFT AND SCATTER TO
VFR DURING THIS TIME. THEREAFTER...DAYTIME HEATING OF THE MOIST AIR
MASS WILL CAUSE SCATTERED TO NUMEROUS SHOWERS AND STORMS TO DEVELOP
THIS AFTERNOON...AND THESE WILL LIKELY PERSIST IN THE VICINITY OF
CENTRAL NC TERMINALS UNTIL A COLD FRONT SWEEPS ACROSS CENTRAL NC
FROM WEST TO EAST BETWEEN 04-06Z AT TRIAD TERMINALS...TO 09-12Z AT
EASTERN ONES. AREAS OF FOG OR LOW STRATUS IN THE MOIST AIR MASS WILL
ALSO BE POSSIBLE AHEAD OF THE COLD FRONT...MOST LIKELY AT KFAY AND
KRWI BETWEEN 06-12Z.

VFR CONDITIONS WILL OTHERWISE PREVAIL IN CANADIAN HIGH PRESSURE
THROUGH THE HOLIDAY WEEKEND.

&&

.CLIMATE...
MORNING LOW TEMPERATURES ON THE 25TH AND 26TH ARE EXPECTED TO BE
NEAR RECORD MIN TEMPS FOR THE DATE.

RECORD MIN TEMP/YEAR SET      MAY 25TH            MAY 26TH

RDU                           43 / 1967           43 / 1979

GSO                           43 / 1956           42 / 1930


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

&&

$$

SYNOPSIS...ELLIS
NEAR TERM...ELLIS
SHORT TERM...MWS
LONG TERM...MLM
AVIATION...MWS
CLIMATE...RAH