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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KILM 272302
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
700 PM EDT SUN JUL 27 2014

.SYNOPSIS...
OPPRESSIVE HEAT AND HUMIDITY WILL CONTINUE THROUGH MONDAY. A
STRONG COLD FRONT WILL CROSS THE AREA MONDAY NIGHT...BRINGING A
GOOD CHANCE FOR THUNDERSTORMS...SOME OF WHICH MAY BE SEVERE. MUCH
DRIER AND UNSEASONABLY COOL AIR WILL OVERSPREAD THE CAROLINAS
BEGINNING TUESDAY...AND PERSISTING INTO THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 3 PM SUNDAY...MCV FEATURE WHICH TRACKED EAST ACROSS SE NC
EARLIER TODAY LAID OUT A WRINKLE IN THE FABRIC OF HOURLY TEMPS AND
MAXIMUM TEMPERATURES THEMSELVES THIS AFTERNOON...JEOPARDIZING
VERIFICATION OF THE HEAT ADVISORY. MANY DEEP INTERIOR LOCATIONS
ARE REBOUNDING WITH THE HEAT SWITCH FLIPPED TO THE "ON" POSITION
UNDER FULL SUN AND SUBSIDENCE IN WAKE OF THE DECAYING/DEPARTING
WAVE ALOFT...BUT IT APPEARS MANY LOCALS WILL CLEARLY FALL SHORT
OF 105 DEG MAXIMUM APPARENT TEMPERATURE DUE TO CLOUDS AND SHOWERS
EARLIER TODAY INLAND WHICH DIMINISHED BEFORE REACHING THE COAST.

LINGERING WARMTH AND MARITIME HUMIDITY WILL MAKE FOR BALMY NIGHT
TIME CONDITIONS AND AM EXPECTING MANY LOCATIONS ALONG AND NEAR THE
SEA/ICW TO REMAIN ABOVE 80 DEGREES EVEN INTO DAYBREAK MONDAY...AND
MINIMUMS HAVE BEEN PAINTED TO REFLECT THIS EXCEPTIONALLY MILD AIR
IN THE NEAR TERM PERIOD. DRY AND WARM AIR ALOFT WILL PUT A LID ON
RAIN CHANCES THROUGH EARLY MONDAY. A FEW SHOWERS ARE EXPECTED
OFFSHORE BUT LOOKS LIKE THEY WILL REMAIN WELL ENOUGH OUT TO SEA TO
AVOID IMPACTING CAPE FEAR INTO DAYBREAK MONDAY.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...A STRONG COLD FRONT WILL SWEEP ACROSS THE
FORECAST AREA LATE MONDAY...BRINGING AN INCREASING THREAT OF STRONG
TO SEVERE THUNDERSTORMS MONDAY AFTERNOON INTO THE EVENING HOURS.
UNSEASONABLY COOLER AND DRIER AIR WILL SPILL SOUTHWARD INTO THE
CAROLINAS ON TUESDAY FOLLOWING FROPA.

MONDAY LOOKS LIKE ANOTHER HOT AND HUMID DAY WITH DEEP WESTERLY FLOW
ALOFT AND STRENGTHENING SOUTHWEST WINDS AT THE SURFACE. 850 MB TEMPS
REMAIN IN THE 20C RANGE...GIVING ANOTHER DAY WITH FORECAST HIGHS IN
THE MID/UPPER 90S. WITH DEWPOINTS IN THE LOW TO MID 70S...HEAT INDEX
VALUES WILL ONCE AGAIN CLIMB ABOVE TRIPLE DIGITS ACROSS THE AREA. A
HEAT ADVISORY HAS BEEN ISSUED ACROSS OUR SOUTHERN ZONES...FROM
FLORENCE TO MARION TO HORRY COUNTY AND SOUTHWARD...WITH HEAT INDEX
VALUES FORECAST TO EXCEED 105F. ELSEWHERE...EXPECT HEAT INDICES IN
THE 100-104F RANGE.

TSTM CHANCES INCREASE AFTER 18Z AS A NARROW RIBBON OF DEEPER
MOISTURE AHEAD OF THE FRONT MOVES INTO THE EASTERN CAROLINAS.
SURFACE CAPE VALUES OF 2500-3000 J/KG AND 35-40 KT OF 0-6 KM BULK
SHEAR DEPICT AN ENVIRONMENT CAPABLE OF SUPPORTING MULTICELLS WITH
ISOLATED SUPERCELLS POSSIBLE. THE LIMITING FACTORS WOULD BE UPSTREAM
DEBRIS CLOUD COVER SLOWING THE RATE OF SFC HEATING EARLIER IN THE
DAY...AS WELL AS A LACK OF WIDESPREAD DEEP MOISTURE. THE STORM
PREDICTION CENTER HAS MAINTAINED A DAY 2 SLIGHT RISK FOR THE
MAJORITY OF OUR CWA. FORECAST DCAPE VALUES > 1000 J/KG AND HEALTHY
CAPE IN THE HAIL GROWTH ZONE MAKE DAMAGING WINDS AND SEVERE HAIL THE
PRIMARY THREATS. THE BEST WINDOW FOR SCATTERED STRONG TO SEVERE
CONVECTION BASED ON THE TIMING OF THE FRONT LOOKS TO BE BETWEEN
18-00Z. EXPECT TSTMS WILL BECOME ORGANIZED INTO A LINE AS THEY MOVE
ACROSS THE AREA AND OFFSHORE BY MONDAY NIGHT.

THE COLD FRONT WILL PUSH OFFSHORE OVERNIGHT MONDAY...BRINGING COOLER
AND DRIER CONDITIONS FOR TUESDAY. NORTHERLY FLOW WILL PERSIST DURING
THE DAY AS HIGHS WILL ONLY REACH THE MID 80S. OVERNIGHT LOWS WILL
DIP INTO THE MID 60S AWAY FROM THE BEACHES.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 300 PM SUNDAY...COLD FRONT WELL OFFSHORE WILL STALL THROUGH
THE WEEK AS ANOMALOUS 500MB TROUGH BECOMES NEARLY STATIONARY ACROSS
THE EASTERN CONUS. AS THE TROUGH AXIS REMAINS WEST OF THE AREA
THROUGH THE END OF THE WEEK...MID-LEVELS WILL REMAIN DRY AS
EVIDENCED BY PWATS OF 1-1.25 INCHES THROUGH FRIDAY...WHICH COMBINED
WITH NE FLOW KEEPING TEMPS A SOLID 5-8 DEGREES BELOW CLIMO...WILL
LIMIT POP COVERAGE AND EXPECT A DRY WEEK. AS MENTIONED BY PREVIOUS
FORECASTER...WEAK IMPULSES ALOFT ROTATING THROUGH THE BASE OF THE
LONGWAVE TROUGH COULD SPAWN ISOLATED SHOWERS THU/FRI...BUT TIMING
THESE ON D5/D6 IS NEARLY IMPOSSIBLE...AND WITH THE COLUMN REMAINING
DRY WILL OPT TO KEEP FORECAST POP AT SILENT. BY THE WEEKEND...THE
ECMWF AND GFS BEGIN TO DIVERGE IN THEIR SOLUTIONS...BUT THE GENERAL
TREND IS THAT THE RIDGE ACROSS THE ATLANTIC WILL EXPAND
WESTWARD...FORCING THE TROUGH TO RETROGRADE. WHILE THIS WILL BRING A
RETURN TO TEMPS CLOSER TO NORMAL VALUES LATE IN THE
PERIOD...MOISTURE WILL INCREASE AS WELL AND WILL RAMP POP UP TO CHC
FOR THE WKND AS THE STALLED FRONT/COASTAL TROUGH MOVES BACK TOWARDS
THE COAST.

ALL 3 OF THE EXTENDED OPERATIONAL MODELS...GFS/ECM/CMC...SUGGEST
LOW PRESSURE MAY DEVELOP ALONG THIS BOUNDARY NEXT WEEKEND FURTHER
ENHANCING THE RAINFALL POTENTIAL. WILL NOT SHOW ANYTHING BUT
HIGHER POP IN THE FORECAST FOR D7...BUT IT IS SOMETHING WORTH
WATCHING DURING THE UPCOMING DAYS.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
-- Changed Discussion --
AS OF 00Z...NOT MUCH HAPPENING OVERNIGHT WITH VFR CONDITIONS
EXPECTED. THINK THE WINDS WILL BE IN THE 7-8KT RANGE
OVERNIGHT...WHICH SHOULD KEEP FOG AT BAY...PERHAPS 5-6SM AT THE
INLAND TERMINALS AROUND SUNRISE...WORST CAST. MONDAY...ATMOSPHERE
WILL BECOME QUITE UNSTABLE AHEAD OF A COLD FRONT THAT WILL BE
DROPPING IN DURING THE EVENING. CAPES AHEAD OF THE FRONT WILL APPROACH
3000 J/KG...ALONG WITH WEST SOUTHWEST WINDS GUSTING TO NEAR 20 KTS.
EVEN THOUGH MOISTURE IS LIMITED...EXPECT STRONG CONVECTION TO BREAK
OUT A FEW HOURS AHEAD OF THE FRONT. PRECIPITABLE WATER WILL BE NEAR
TWO INCHES...SO HEAVY DOWNPOURS ARE LIKELY. WINDS WILL SHIFT TO THE
NORTHWEST JUST AFTER THE END OF THE TAF PERIOD.

EXTENDED OUTLOOK...MORNING FOG POSSIBLE THURSDAY AND
FRIDAY...OTHERWISE VFR.
-- End Changed Discussion --

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM SUNDAY...BUMPY MARINE CONDITIONS WILL DEVELOP TONIGHT
AND PERSIST THROUGH MONDAY DUE TO STIFF SW WINDS AHEAD OF AN
APPROACHING AND UNSEASONABLY STRONG COLD FRONT. FOR TONIGHT INTO
SUNRISE MONDAY...SW WINDS OF 15-20 KT AND 3-5 FOOT SEAS WILL
PREVAIL...PROMPTING THE CAUTION STATEMENT. THE SEA SPECTRUM WILL
FEATURE SSW WAVES 2-4 FEET EVERY 4-6 SECONDS...AND SE WAVES 1-1.5
FR EVERY 9 SECONDS. A FEW TSTMS ARE POSSIBLE LATE TONIGHT FAVORED
ACROSS THE OUTER WATERS.

SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...THE PERIOD WILL BEGIN WITH SCEC CONDITIONS AS
SOUTHWEST WINDS STRENGTHEN TO 15-20 KT WITH OCCASIONAL GUSTS UP TO
25 KT AHEAD OF AN APPROACHING COLD FRONT. SEAS WILL BE 3-5 FT...
BECOMING 4-6 FT ACROSS THE FAR OUTER PORTIONS OF AMZ250/252 BY
MONDAY EVENING. MARGINAL SCA CONDITIONS MAY WARRANT A HEADLINE
TOMORROW...BUT CONFIDENCE IS STILL TOO LOW TO RAISE IT TODAY. WINDS
WILL SHIFT OVERNIGHT AS THE COLD FRONT PUSHES OFFSHORE...BECOMING
WEST AROUND 10 KTS AFTER MIDNIGHT AND THEN NORTH AROUND 10 KTS BY
TUESDAY MORNING. SEAS WILL SUBSIDE ON TUESDAY WITH THE LIMITED
NORTHERLY FETCH...BECOMING 2-3 FT BY THE END OF THE PERIOD.

LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 300 PM SUNDAY...PRETTY UNIFORM WIND/WAVE CONDITIONS THROUGH
THE EXTENDED AS COLD FRONT STALLS WELL OFFSHORE AND SURFACE HIGH
PRESSURE RIDGES DOWN THE COAST. THIS LEAVES E/NE WINDS THROUGH THE
PERIOD WITH LITTLE FLUCTUATION...AND SPEEDS WITHIN A FEW KTS OF 10
BOTH DAY AND NIGHT. ALTHOUGH A WEAK SE GROUND SWELL WILL EXIST IN
THE WAVE SPECTRUM...SEAS OF 2-3 FT EACH DAY WILL BE FORMED PRIMARILY
FROM AN EASTERLY 4 SEC WIND CHOP.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR SCZ017-023-024-
     032-033-039-053-055.

     HEAT ADVISORY FROM 11 AM TO 6 PM EDT MONDAY FOR SCZ032-033-039-
     053>056.

NC...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR NCZ087-096-099-
     109.

MARINE...NONE.

&&

$$
SYNOPSIS...JDW
NEAR TERM...MJC
SHORT TERM...BJR
LONG TERM...JDW
AVIATION...43
MARINE...MJC/JDW/BJR