-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KRAH 170659
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
259 AM EDT THU APR 17 2014

.SYNOPSIS...UNSEASONABLY STRONG...POLAR HIGH PRESSURE WILL BUILD
SOUTH FROM NEW ENGLAND TODAY...THEN LINGER THROUGH FRIDAY.
MEANWHILE...LOW PRESSURE WILL DEVELOP OVER THE NORTHEASTERN GULF OF
MEXICO FRIDAY...THEN MEANDER ALONG THE SOUTHEAST US COAST THROUGH
THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
AS OF 300 AM THURSDAY...

UNSEASONABLY STRONG/1040-1045 MB POLAR HIGH PRESSURE CENTERED OVER
MAINE WILL RIDGE SOUTH AND MAINTAIN CONTINUED COOL...BUT
INCREASINGLY MODIFIED...NORTHEASTERLY FLOW TODAY. A SOUTHERN STREAM
WAVE ALOFT AND ASSOCIATED CIRRUS OVER AL/GA WILL LIFT NORTHEASTWARD
ACROSS CENTRAL NC DURING THE MIDDAY-EARLY AFTERNOON HOURS. BUFR
FORECAST SOUNDINGS HAVE TRENDED LESS AGGRESSIVE WITH THE WESTWARD
EXPANSION OF ATLANTIC MOISTURE BENEATH THE ~4000 FT SUBSIDENCE
INVERSION EVIDENT ON REGIONAL RAOBS FROM WED. HOWEVER...EARLY
MORNING SATELLITE IMAGERY INDICATES A FEW PATCHES OF STRATOCUMULUS
HAVE SPREAD INLAND OVER NE SC AND SE NC THIS MORNING...SO SOME OF
THIS MOISTURE - TRAPPED BENEATH THE INVERSION ABOVE - IS APT TO
AFFECT AT LEAST COASTAL PLAIN COUNTIES FROM MID-MORNING TO EARLY
AFTERNOON. DRY ADIABATIC MIXING THROUGH 900 MB...AND ABOUT A 20-25
METER INCREASE IN FORECAST LOW LEVEL THICKNESSES OVER THOSE OF
WED...SUPPORT HIGHS MAINLY BETWEEN 60 AND 65 DEGREES.

TONIGHT: CHILLY WITH GOOD RADIATIONAL COOLING...PARTICULARLY WITH
MAINLY CLEAR SKIES THROUGH MIDNIGHT...FOLLOWED BY THE ARRIVAL OF
ADDITIONAL CIRRUS DOWNSTREAM OF ANOTHER SOUTHERN STREAM SHORTWAVE
TROUGH OVER NM THIS MORNING. LOWS GENERALLY IN THE MIDDLE TO UPPER
30S. PATCHY FROST WILL CONSEQUENTLY BE POSSIBLE...PARTICULARLY IN
RURAL PIEDMONT LOCATIONS.
-- End Changed Discussion --

&&

.SHORT TERM /FRIDAY /...
-- Changed Discussion --
AS OF 330 PM WEDNESDAY...

SHOULD SEE AT A MINIMUM A MIXTURE OF SUN AND CLOUDS FRIDAY WITH THE
CHARACTER OF THE SKY BECOMING MOSTLY CLOUDY OR OVERCAST BY FRIDAY
AFTERNOON. ISENTROPIC UPGLIDE DOES NOT APPEAR STRONG ENOUGH TO
SUPPORT PRECIP FRIDAY AFTERNOON...ASIDE FROM A STRAY SHOWER ACROSS
THE FAR SE.

AIR MASS WILL CONTINUE TO GRADUALLY MODIFY BUT AFTERNOON TEMPS WILL
REMAIN WELL BELOW NORMAL. MAX TEMPS 60-65.
-- End Changed Discussion --

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
AS OF 3 PM WEDNESDAY...

FRIDAY NIGHT THROUGH SUNDAY NIGHT: THE WEEKEND FORECAST CONTINUES TO
HAVE SOME UNCERTAINTY WITH REGARD TO THE EVOLUTION OF A POSSIBLE
CLOSED LOW LINGERING ACROSS THE SOUTHEASTERN U.S/OFFSHORE. WHILE THE
NORTHERN STREAM ENERGY IS PROGRESSIVE AND PUSHES EASTWARD FRIDAY
NIGHT INTO SATURDAY. IN ADVANCE OF THE NORTHERN STREAM TROUGH BOTH
THE 12Z GFS AND ECMWF PULLS MOISTURE NORTHWARD... AND PRODUCED SOME
LIGHT RAIN ACROSS OUR FAR SOUTHEAST/EAST ON FRIDAY NIGHT INTO EARLY
SATURDAY MORNING... WITH THE BULK OF THE PRECIP EXPECTED TO BE TO
OUR EAST AND SOUTH. HOWEVER... MODEL GUIDANCES IS STRUGGLING WITH
WHAT WILL HAPPEN WITH THE LINGERING SOUTHERN STEAM ENERGY THAT
POSSIBLY CLOSES OFF INTO A CLOSED LOW AND LINGERS NEAR FL AND OFF
THE SOUTHEAST U.S. COAST. THE 12Z ECMWF HAS COME A MORE IN THE LINE
WITH THE 12Z GFS IN SHOWING LINGERING MID LEVEL ENERGY SLOWLY
SHIFTING EASTWARD AND FAR ENOUGH AWAY FROM THE COAST TO KEEP US DRY
SATURDAY AFTERNOON THROUGH THE REST OF THE WEEKEND. HOWEVER...
GUIDANCES HAS SHOWN POOR RUN TO RUN CONTINUITY. THUS... CONFIDENCE
IS NOT HIGH THAT LATE SATURDAY INTO SUNDAY THAT WE WILL BE
COMPLETELY DRY AT THIS TIME ACROSS OUR ENTIRE AREA (IF PRECIP
LINGER... LOCATIONS ACROSS THE EAST/SOUTHEAST WOULD SEE THE BEST
CHANCE/MOST). FOR NOW WILL GO WITH A DRY FORECAST AS MENTIONED ABOVE
FROM SATURDAY AFTERNOON ONWARD.

WITH SURFACE HIGH PRESSURE BUILDING INTO THE AREA FROM THE NORTH AND
A COOL EAST TO NORTHEASTERLY LOW LEVEL FLOW EXPECT HIGH TEMPS WILL
REMAIN SLIGHTLY BELOW NORMAL WITH AT LEAST SOME CLOUD COVER (MORE
EAST VS WEST). THUS... WILL GO WITH HIGH TEMPS THIS WEEKEND IN THE
UPPER 60S TO LOWER 70S... WITH LOW TEMPS IN THE 40S TO LOWER 50S.

MONDAY THROUGH WEDNESDAY: NEXT MID LEVEL DISTURBANCE IS EXPECTED TO
CROSS THE REGION ON TUESDAY... ALONG WITH A WEAK SURFACE TROUGH.
HOWEVER... WITH LACK OF ANY SIGNIFICANT MOISTURE RETURN WILL KEEP
POPS LOW AT THIS TIME. TEMPS EARLY TO MID NEXT WEEK ARE EXPECT TO
WARM AGAIN... WITH HIGHS IN THE 70S AND LOWS IN THE 50S.

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 200 AM THURSDAY...

UNSEASONABLY STRONG/POLAR HIGH PRESSURE WILL RIDGE SOUTH FROM NEW
ENGLAND AND RESULT IN CLEAR/VFR CONDITIONS THIS MORNING...WHICH WILL
YIELD TO BOTH INCREASING CIRRUS IN SW FLOW ALOFT FROM THE WEST...AND
A BRIEF PERIOD OF SCT TO PERHAPS EVEN BKN STRATOCUMULUS BETWEEN 2500-
4000 FT MAINLY AT EASTERN TERMINALS BETWEEN MID-MORNING THROUGH
EARLY AFTERNOON. THE SURFACE RIDGE WILL ALSO MAINTAIN A
NORTHEASTERLY SURFACE WIND OVER CENTRAL NC...STRONGEST AND
OCCASIONALLY GUSTY INTO THE UPPER TEENS KTS AT EASTERN TERMINALS...
ALSO FROM MID-MORNING TO EARLY AFTERNOON.

OUTLOOK: A LOW PRESSURE SYSTEM WILL DEVELOP AND LINGER OFFSHORE THE
SOUTHEAST US COAST LATE FRI THROUGH THE WEEKEND...AND THIS SYSTEM
MAY RESULT IN RAIN AND SUB-VFR CONDITIONS AT KFAY/KRWI/KRDU FRI
NIGHT-SAT. FORECAST CONFIDENCE REMAINS BELOW AVERAGE REGARDING THE
TRACK OF THE LOW AND ASSOCIATED IMPACTS OVER CENTRAL NC...HOWEVER.

&&

.CLIMATE...

THE FOLLOWING ARE THE RECORD LOW TEMPERATURES FOR THIS MORNING:

      THU 04/17

       LOW/YEAR
FAY:   31/1953
GSO:   29/1953
RDU:   29/1962

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
FREEZE WARNING FROM MIDNIGHT TONIGHT TO 9 AM EDT THURSDAY FOR
NCZ007>011-021>027-038>041-073>077-083>086.

&&

$$

SYNOPSIS...MWS
NEAR TERM...MWS
SHORT TERM...WSS
LONG TERM...BSD
AVIATION...MWS
CLIMATE...MWS