-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KRAH 250119
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
920 PM EDT FRI MAY 24 2013

.SYNOPSIS...
A CANADIAN HIGH PRESSURE SYSTEM WILL BUILD INTO THE CAROLINAS THROUGH
TONIGHT...THEN LINGER OVERHEAD THROUGH THE HOLIDAY WEEKEND.

&&

.NEAR TERM /TONIGHT/...
-- Changed Discussion --
AS OF 920 PM FRIDAY...

...NEAR-RECORD LOWS TONIGHT...

SUBSIDENCE IN THE WAKE OF THE SHORTWAVE TROUGH PUSHING OFF TO THE
EAST COMBINED WITH CONTINUED LOW-LEVEL DRY COOL AIR ADVECTION
WILL RESULT IN CHILLY CONDITIONS. WIND GUSTS HAVE ALREADY SUBSIDED
AT THE MAJORITY OF THE OBSERVATIONS SITES WITH A LIGHT NORTHWESTERLY
BREEZE EXPECTED FOR THE REMAINDER OF THE NIGHT. STILL EXPECT
NEAR-RECORD LOWS RANGING FROM THE LOWER TO MIDDLE 40S WITH SOME
UPPER 30S POSSIBLE IN SHELTERED LOCATIONS (SEE CLIMATE SECTION BELOW
FOR RECORDS).
-- End Changed Discussion --

&&

.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
AS OF 315 PM FRIDAY...

HIGH PRESSURE WILL BE CENTERED OVER THE SE STATES ON SATURDAY.
HOWEVER WITH THE MID LEVEL RIDGE STILL OVER THE PLAINS...NW FLOW
ALOFT WILL CONTINUE...AND WILL BRING SOME MID AND HIGH CLOUDS ACROSS
OUR AREA STARTING TOMORROW AFTERNOON. NEVERTHELESS...SATURDAY SHOULD
BE A PLEASANT DAY WITH PLENTY OF SUNSHINE AND HIGHS IN THE LOW TO
MID 70S.

LATEST GUIDANCE SUGGESTS THE MID/HIGH CLOUDS WILL CONTINUE OVER OUR
AREA SATURDAY NIGHT...THUS LOOK FOR SLIGHTLY WARMER OVERNIGHT LOWS
BUT STILL COOLER THAN NORMAL...UPPER 40S ACROSS MOST OF CENTRAL NC.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
AS OF 250 PM FRIDAY...

SUNDAY INTO MONDAY...
A DEEP UPPER LEVEL LOW OVER THE NORTHERN MID ATLANTIC-SOUTHERN NEW
ENGLAND COAST EARLY SUNDAY WILL CONTINUE TO MOVE NWD THROUGH EARLY
MONDAY AND BE POSITIONED OVER THE CANADIAN MARITIMES. DUE TO THE
BROAD CIRCULATION ASSOCIATED WITH THIS SYSTEM IN COMBINATION WITH A
BUILDING MID-UPPER LEVEL RIDGE IN THE CENTRAL U.S....A NW FLOW WILL
EXIST ALOFT OVER CENTRAL NC THROUGH THIS PERIOD. WHILE THIS FLOW
WILL MAINTAIN COOL AND DRY CONDITIONS...CONVECTIVE CLOUD DEBRIS FROM
ANY CONVECTION THAT DEVELOPS OVER THE UPPER MIDWEST WILL  SPREAD
SEWD INTO OUR PART OF THE COUNTRY SUNDAY INTO MONDAY. PER LATEST
MODEL HUMIDITY CROSS SECTIONS...THESE CLOUDS MAY BE MORE PROMINENT
ACROSS OUR WEST AND SOUTH SECTIONS VERSUS THE NE.

LOW LEVEL THICKNESSES AVERAGE 10-20M BELOW NORMAL THROUGH THE
PERIOD...SUGGESTIVE OF MAX TEMPS 3-6 DEGREES BELOW NORMAL FOR LATE
MAY. EXPECT MAX TEMPS SUNDAY MID=UPPER 70S...AND 75-80 MONDAY. MIN
TEMPS SUNDAY NIGHT SHOULD BE MORE MILD COMPARED TO PREVIOUS NIGHTS
DUE TO AN UPTICK IN CLOUD COVERAGE AND A MODIFYING AIR MASS. MIN
TEMPS SUNDAY NIGHT LOW-MID 50S.

MONDAY NIGHT THROUGH TUESDAY NIGHT...
THE PATTERN OF AN UPPER LEVEL RIDGE OVER THE MS VALLEY AND AN UPPER
LEVEL LOW OVER THE CANADIAN MARITIMES WILL MAINTAIN THE NW FLOW
ALOFT OVER THE CAROLINAS. MODEL GUIDANCE CONTINUES TO SUGGEST THE
POTENTIAL FOR A CONVECTIVELY INDUCE VORTICITY MAXIMUM TO
APPROACH/CROSS OUR REGION MONDAY NIGHT THROUGH TUESDAY. TIMING STILL
UNCERTAIN AS THIS FEATURE HAS YET TO DEVELOP SO WILL NEED TO MONITOR
CONDITIONS TO OUR NW (MINNESOTA/WISCONSIN) SUNDAY INTO MONDAY FOR
CONVECTIVE DEVELOPMENT. THIS FEATURE IN TANDEM WITH AN INCREASINGLY
MOIST AIR MASS OVER THE CAROLINAS MAY SUPPORT THE
DEVELOPMENT/SUSTAIN ISOLATED-SCATTERED CONVECTION MONDAY NIGHT INTO
TUESDAY. BASED ON EXPECTED MID-UPPER FLOW...OUR NORTHERN COUNTIES
WILL STAND A BETTER CHANCE OF SEEING ANY CONVECTION VERSUS THE
SOUTHERN COUNTIES. FOR NOW WILL CONTINUE TO MENTION SLIGHT CHANCE
POP AND SEE HOW THE SCENARIO EVOLVES MONDAY. EXPECT WARMER TEMPS
TUESDAY AS LOW LEVEL FLOW BECOME MORE SW....SENDING THICKNESSES BACK
TO NEAR OR ABOVE NORMAL VALUES. MAX TEMPS 80-85. MIN TEMPS MONDAY
NIGHT UPPER 50S TO LOWER 60S...AND LOW-MID 60S TUESDAY NIGHT.

WEDNESDAY THROUGH FRIDAY...
MODEL GUIDANCE CONTINUE TO ADVERTISE AN AMPLIFYING MID-UPPER LEVEL
RIDGE OVER THE DEEP SOUTH-GREAT LAKES...DRIFTING EAST INTO THE
SOUTHEAST U.S. THE WARMING ALOFT ASSOCIATED WITH THE RISING HEIGHTS
WILL INDUCE THE FORMATION OF A MID LEVEL INVERSION...WHICH WILL ACT
AS A CAP OR LID ON THE ATMOSPHERE. THIS SHOULD LIMIT CONVECTIVE
DEVELOPMENT. WILL LIMIT SLIGHT CHANCE POPS TO WEDNESDAY WITH POPS
LESS THAN 20 PERCENT THU-FRI. THE WARMING AIR MASS WILL SEND LOW
LEVEL THICKNESSES INTO THE 1415-1420M RANGE...ABOUT 15M ABOVE
NORMAL. POSITION AND STRENGTH OF THE MID-UPPER LEVEL ANTI-CYCLONE
OVER THE SE U.S. SUGGEST MAX TEMPS WELL ABOVE NORMAL....WITH TEMPS
AROUND 90 PROBABLE THU-FRI. WILL ADVERTISE TEMPS IN THE MID-UPPER
80S FOR NOW SINCE WE ARE TALKING DAYS 7/8.

&&

.AVIATION /00Z SATURDAY THROUGH TUESDAY/...
AS OF 745 PM FRIDAY...

SUBSIDENCE IN THE WAKE OF DEPARTING SHORTWAVE TROUGH AND LOW-LEVEL
COOL DRY AIR ADVECTION WILL RESULT IN VFR CONDITIONS TO CONTINUE
THROUGH THE 24 HOUR TAF PERIOD. BREEZY NWLY WINDS WILL DECOUPLE
SHORTLY AFTER 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...
-- Changed Discussion --
MORNING LOW TEMPERATURES ON THE 25TH 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

FAY                           46 / 1967           44 / 1988

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
-- End Changed Discussion --

&&

$$

SYNOPSIS...WSS
NEAR TERM...CBL/NP
SHORT TERM...NP
LONG TERM...WSS
AVIATION...CBL/NP
CLIMATE...RAH