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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KRAH 240700
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
300 AM EDT FRI MAY 24 2013

.SYNOPSIS...
A COLD FRONT WILL CROSS OUR REGION THIS MORNING...FOLLOWED BY
CANADIAN HIGH PRESSURE TODAY THROUGH THE WEEKEND.

&&

.NEAR TERM /TODAY/...
-- Changed Discussion --
AS OF 230 AM FRIDAY...

AN UPPER LOW WILL AMPLIFY SOUTHEASTWARD FROM THE GREAT LAKES TO THE
MIDDLE ATLANTIC REGION TODAY. DESPITE STRONG HEIGHT FALLS AND
DYNAMIC FORCING FOR ASCENT CENTERED OVER VA AND NORTHERN NC IN
ASSOCIATION WITH THIS FEATURE...STRONG LOW LEVEL CAA WILL MOSTLY
OFFSET THIS FORCING...PER DEEP LAYER Q-VECTOR DIAGNOSTICS OVER
CENTRAL NC. AS SUCH...LINGERING MID LEVEL CLOUDINESS THIS MORNING
WILL YIELD TO INCREASINGLY SUBSIDENT AND CLEARING CONDITIONS
THROUGHOUT THE DAY...WITH JUST A SLIGHT CHANCE OF A SHOWER OVER THE
NORTHERN COASTAL THROUGH AROUND 18Z...IN CLOSEST PROXIMITY TO THE
AFOREMENTIONED STRONGEST HEIGHT FALLS ALOFT OVER VA. IT WILL ALSO
BECOME QUITE BREEZY LATE MORNING-MIDDAY ONWARD...AS COOLER AND MUCH
DRIER AIR ASSOCIATED WITH AN INCOMING CANADIAN SURFACE HIGH
OVERSPREADS OUR REGION. DRY ADIABATIC MIXING TO AROUND 6 THOUSAND FT
AND ADDED DOWNSLOPE WARMING SUGGESTS HIGHS IN THE LOWER 70S NW
PIEDMONT TO UPPER 70S SANDHILLS AND SOUTHERN COASTAL PLAIN.
-- End Changed Discussion --

&&

.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
-- Changed Discussion --
AS OF 300 AM FRIDAY...

HEIGHT RISES IN DRY NORTHWESTERLY DEEP LAYER FLOW WILL DEVELOP
TONIGHT...THEN CONTINUE ON THE EASTERN PERIPHERY OF CANADIAN HIGH
PRESSURE THROUGH THE WEEKEND. PROJECTED LOW LEVEL
THICKNESSES...ACCOUNTING FOR CLEAR BUT CAA MIXING OVERNIGHT...
SUPPORT NEAR RECORD LOWS MOSTLY IN THE LOWER TO MIDDLE 40S...WITH
SOME UPPER 30S POSSIBLE IN SHELTERED (CALM) OUTLYING AREAS.

CLEAR/SUNNY CONDITIONS WILL PERSIST THROUGH SAT EVENING...BEFORE
YIELDING TO INCREASING MID-HIGH CLOUDS IN NW FLOW ALOFT OVERNIGHT.
HIGHS...WITH CONTINUED LOW HUMIDITY...IN THE LOWER TO MIDDLE 70S.
LOWS GENERAL 45 TO 50 DEGREES...WARMEST TRIAD WHERE MID-HIGH CLOUDS
WILL ARRIVE SOONEST (LATE SAT EVENING).
-- End Changed Discussion --

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
-- Changed Discussion --
AS OF 300 PM THURSDAY...

SUNDAY AND SUNDAY NIGHT...

MODEST WARM UP EXPECTED SUNDAY AS THICKNESSES RECOVER INTO THE
1370S/LOW 1380S. EXPECT AFTERNOON TEMPS IN THE MID-UPPER 70S UNDER
PARTLY-MOSTLY SUNNY SKIES. SUNDAY NIGHT SHOULD BE A LITTLE MILDER AS
AIR MASS CONTINUES TO MODIFY. MOS GUIDANCE APPEARS TOO WARM BY A
CATEGORY. FAVOR MIN TEMPS NEAR 50 COOLER SPOTS TO LOW-MID 50S
ELSEWHERE.

MONDAY THROUGH THURSDAY...

12Z GFS TRENDING TOWARD THE 00Z ECMWF. THE
ECMWF HELD ONTO THE L/W TROUGH ALONG THE EASTERN SEABOARD RESULTING
IN A SLOWER WARMING TREND WHERE AS THE GFS WITH ITS BUILDING
MID-UPPER HEIGHTS ADVERTISES A QUICKER/MORE NOTABLE WARM-UP. THE
ECMWF SOLUTION OF A LINGERING TROUGH NEAR OR OFFSHORE OF THE NEW
ENGLAND COAST AND AN AMPLIFYING RIDGE OVER THE MS RIVER VALLEY WILL
MAINTAIN A NW FLOW ALOFT OVER CENTRAL NC. THE ECMWF HINTS AT
POSSIBLE DISTURBANCES ASSOCIATED WITH MCS ACTIVITY THAT MAY OCCUR IN
THE UPPER MID WEST/GREAT LAKES TUESDAY-THURSDAY CROSSING OUR REGION.
IF THIS WERE TO OCCUR...COULD SEE A PERIOD OF UNSETTLED WEATHER
ANYTIME BETWEEN WEDNESDAY-THURSDAY. IF GFS WERE TO VERIFY WITH THE
RIDGE BUILDING CLOSER TO HOME...MCS ACTIVITY WILL BE SHUNTED MORE TO
OUR NORTH. FOR NOW...WILL KEEP POPS NO HIGHER THAN 20 PERCENT
TUESDAY INTO THURSDAY. LOW LEVEL THICKNESSES RETURN TO NEAR OR
SLIGHTLY ABOVE NORMAL VALUES TUESDAY ONWARD. WILL HAVE AFTERNOON
TEMPS NEAR 80-LOWER 80S TUESDAY...AND LOW-MID 80S
WEDNESDAY/THURSDAY. AGAIN...IF GFS VERIFIES...WED/THU COULD SEE
TEMPS IN THE UPPER 80S TO NEAR 90.
-- End Changed Discussion --

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 210 AM FRIDAY...

JUST A LITTLE LIGHT AND INSIGNIFICANT RAIN REMAINS FROM EARLIER
SHOWERS AND STORMS...AND THIS TOO SHOULD FURTHER DIMINISH DURING THE
NEXT COUPLE OF HOURS IN THE VICINITY OF KFAY/KRDU/KGSO. OTHERWISE...
AREAS OF STRATUS AND FOG ARE LIKELY TO AFFECT KFAY...KRWI...AND
PERHAPS AS FAR WEST AS KRDU THROUGH DAYBREAK...AS LOW LEVEL MOISTURE
WILL REMAIN HIGH AND WINDS LIGHT AHEAD OF A DIFFUSE COLD FRONT
APPROACHING FROM THE WEST. SOME LINGERING 7-9 THOUSAND FT CLOUD
COVER AND A FEW SHOWERS THROUGH MIDDAY AT EASTERN TERMINALS CAN ALSO
BE EXPECTED...WITH OTHERWISE CLEARING CONDITIONS AND A BREEZY AND
GUSTY NORTHWESTERLY WIND DEVELOPING BY AROUND 15Z. WINDS WILL
DIMINISH AROUND SUNSET.

OUTLOOK: A STRETCH OF PROLONGED VFR CONDITIONS IN CANADIAN HIGH
PRESSURE WILL PERSIST THROUGH AT LEAST MEMORIAL DAY...WITH THE NEXT
CHANCE OF SUB-VFR CONDITIONS IN FOG TUE MORNING.

&&

.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...MWS
NEAR TERM...MWS
SHORT TERM...MWS
LONG TERM...WSS
AVIATION...MWS
CLIMATE...RAH