-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KILM 280816
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
416 AM EDT MON JUL 28 2014

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

&&

.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
AS OF 330 AM MONDAY...TWO TYPES OF WEATHER PHENOMENA TO DEAL WITH
THIS TIME FRAME THAT COULD RESULT WITH INJURY AND/OR POSSIBLY
BECOME LIFE THREATENING.

THE 1ST DEALS WITH THE 3 H`S...HAZY HOT AND HUMID. VARIOUS MODEL
MOS GUIDANCE TOPS MAX TEMPS TODAY IN THE MID TO POSSIBLY UPPER
90S. WITH THE UPPER 90S OCCURRING ACROSS THE SOUTHERN PORTIONS OF
THE ILM CWA. WITH DEWPOINTS PROGGED IN THE LOW TO MID 70S...HEAT
INDEX VALUES ARE SLATED TO CLIMB INTO THE 100S...WITH MID 100S
ACROSS MUCH OF THE SC PORTION OF THE ILM CWA INCLUDING THE
IMMEDIATE COAST...AND LOW 100S ACROSS THE REMAINDER OF THE ILM
CWA. WHERE HEAT INDEX THRESHOLDS OF 105 AND GREATER ARE MET...A
HEAT ADVISORY WILL BE ISSUED FOR THOSE LOCATIONS. FOR TODAYS
OCCURRENCE...IT INCLUDES THE MAJORITY OF THE ILM SC COUNTIES.

THE 2ND DEALS WITH THE INCREASED POTENTIAL FOR ISOLATED STRONG TO
SEVERE THUNDERSTORMS...FROM THE MID-DAY HOURS TO MID-EVENING. NAM
AND GFS BUFR SOUNDINGS AS WELL AS VARIOUS MODEL TIME HEIGHT
DISPLAYS...ALL INDICATE THAT MOISTURE WILL INCREASE IN THE LOW TO
MID LEVELS WITH SOUNDING DATA POINTING TO PWS TEMPORARILY REACHING
UP TO 2+ INCHES FROM MIDDAY THRU THIS AFTERNOON. ENOUGH AVAILABLE
MOISTURE HAS BEEN IN QUESTION FOR CONVECTION TODAY DUE TO WINDS
ALOFT PROGGED TO BE W TO WNW...A SCOURING EFFECT COMING OFF THE
MOUNTAINS. MODEL SOUNDINGS INDICATE VARIOUS SVR PARAMETERS MAY BE
MET WITH DAMAGING HAIL AND WIND GUSTS THE PRIMARY CONCERNS. THE
HWO WILL HIGHLIGHT THIS POSSIBILITY. FOR LATE THIS EVENING AND
OVERNIGHT...LOOK FOR DRASTICALLY IMPROVING CONDITIONS ACROSS THE
FA. THE COLD FRONT WILL HAVE PUSHED OFF THE CAROLINA COASTS
FOLLOWED BY THE ADVECTION OF COOLER AND DRIER AIR...RESULTING IN
LOWER RHS. LOOKING AT LOWS DROPPING INTO THE 60S ACROSS THE
MAJORITY OF THE FA BY DAYBREAK TUESDAY.
-- End Changed Discussion --

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 AM MONDAY...COLD FRONT WILL BE OFF THE COAST BY THE START OF
THE PERIOD WITH A MARKEDLY DIFFERENT AIR MASS BUILDING OVER THE
REGION. FLAT MID LEVEL TROUGH WILL REMAIN JUST WEST OF THE AREA
DURING THE PERIOD. LOW LEVEL NORTHERLY FLOW AND MID LEVEL
WEST-NORTHWEST FLOW WILL USHER IN MUCH DRIER AIR. PRECIPITABLE WATER
VALUES DROP TO AROUND 1 INCH TUE/WED WITH DEWPOINTS IN THE UPPER 50S
TO LOWER 60S EACH DAY. PRECIP CHANCES WILL BE CLOSE TO ZERO EACH
DAY. ALTHOUGH GRADIENT WILL BE VERY WEAK THERE WILL NOT BE MUCH IF
ANY SEA BREEZE GIVEN WATER TEMPS WITHIN A FEW DEGREES OF HIGHS...MID
80S. TUE SHOULD BE THE WARMER DAY...MAINLY DUE TO A WARMER START.
LOWS WILL DROP INTO THE MID TO UPPER 60S EACH NIGHT. THERE WILL BE
POTENTIAL FOR RADIATIONAL COOLING WITH LIGHT WINDS...CLEAR
SKIES...AND DRY AIR ALOFT. TYPICAL COLD SPOTS COULD DROP INTO THE
LOWER 60S.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 3 AM MONDAY...MID LEVEL TROUGH HANGING OVER THE EASTERN CONUS
FOR MUCH OF THE PERIOD WILL KEEP COLD FRONT STALLED OFF THE
SOUTHEAST COAST INTO THE WEEKEND. ALTHOUGH DEEP MOISTURE IS LACKING
THERE COULD BE A FEW SHORTWAVES ROTATING AROUND THE BASE OF THE
TROUGH THU INTO FRI...EACH PROVIDING A BRIEF INCREASE IN MID LEVEL
MOISTURE. THESE COULD SPAWN SOME ISOLATED AFTERNOON/EVENING
SHOWERS...IF TIMING IS FAVORABLE. COVERAGE WOULD BE FAIRLY LIMITED
SO AT MOST PLAN TO CARRY A SILENT POP.

DEEPER SOUTHWEST FLOW DEVELOPS FRI AND CONTINUES THROUGH THE WEEKEND
AS 5H TROUGH DIGS. GULF MOISTURE ADVECTED INTO THE SOUTHEAST LATE IN
THE WEEK PUSHES PRECIPITABLE WATER VALUES OVER 1.5 INCHES LATER FRI
AND CLOSE TO 2 INCHES BY THE END OF THE PERIOD. INCREASING DEEP
MOISTURE...POSSIBILITY OF SHORTWAVES AND DIURNAL INSTABILITY WILL
ALL CONTRIBUTE TO AN INCREASE IN POP FRI-SUN. THERE ALSO REMAINS THE
SPECTER OF POTENTIAL LOW PRESSURE DEVELOPMENT ALONG THE FRONT
STALLED OFF THE SOUTHEAST COAST. FOR NOW THE MAJOR MEDIUM RANGE
GUIDANCE KEEPS THIS FEATURE QUITE WEAK BUT DEVELOPMENT OF SAID
FEATURE WOULD NOT BE UNPRECEDENTED AND IS SOMETHING TO WATCH.
TEMPERATURES THROUGH THE PERIOD WILL REMAIN BELOW CLIMO WITH HIGHS
IN THE MID TO UPPER 80S AND LOWS IN THE MID TO UPPER 60S.

&&

.AVIATION /08Z MONDAY THROUGH FRIDAY/...
AS OF 06Z...A DYING MCS/MCC WELL UPSTREAM BOOKING ESE COULD REACH
THE INLAND TERMINALS BEFORE DISSIPATING ALTOGETHER. HAVE INCLUDED
VICINITY CONVECTION TO ACCOMODATE. MAINLY MID-UPPER LEVEL
CONVECTIVE DEBRIS CLOUDINESS WILL PUSH ACROSS THE AREA TERMINALS
DURING THIS MORNING...THINNING OUT AFTER DAYBREAK. THE CLOUDINESS
AND SFC WINDS AT 5 TO 10 KT WILL BOTH KEEP ANY FOG FROM DEVELOPING
THIS AM.

FOR DAYTIME INTO EARLY EVENING MONDAY...THE ATMOSPHERE WILL
MOISTEN UP MAINLY THE LOWER LEVELS WITH PROGGED PWS AROUND 2
INCHES...AND FURTHER BECOME UNSTABLE AHEAD OF AN APPROACHING COLD
FRONT. THE FRONT WILL PUSH ACROSS THE TERMINALS FROM NW TO SE FROM
LATE THIS AFTERNOON INLAND...AND OFF THE COAST EARLY THIS EVENING.
TIGHTENED SFC PG AND OVERALL STRONG WINDS ALOFT WILL PREVENT ANY
INLAND PROGRESSION OF THE SEA BREEZE. THUS...LOOKING AT 240-270
DEGREES WINDS AROUND 15 KT WITH GUSTS TO 20 KT. ISOLATED TO
SCATTERED STRONG CONVECTION AHEAD OF THE FRONT REMAINS A
POSSIBILITY...AND HAVE HIGHLIGHTED ITS OCCURRENCE ACROSS THE
TERMINALS. AFTER FROPA...THREAT FOR CONVECTION WILL CEASE AND
WINDS TO VEER TO THE NW AT 10 KT OR LESS.

EXTENDED OUTLOOK...MORNING FOG POSSIBLE THURSDAY AND
FRIDAY...OTHERWISE VFR.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 10:15 PM SUNDAY...NO CHANGES TO THE FORECAST WITH THE LATEST
UPDATE. PREVIOUS DISCUSSION FOLLOWS:

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.

SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 AM MONDAY...BRIEF NORTHERLY SURGE FOLLOWING THE COLD FRONT
WILL BE WANING AS THE PERIOD BEGINS. WINDS MAY BE 10 TO 15 KT TUE
MORNING BUT BY MIDDAY NORTHEAST FLOW SHOULD BE 10 KT OR LESS. WINDS
REMAIN 10 KT OR LESS WED BUT MAY BECOME SLIGHTLY MORE ONSHORE DURING
THE AFTERNOON. SEA BREEZE IS NOT LIKELY TO BE A FACTOR EITHER DAY
GIVEN THE BELOW NORMAL FORECAST HIGHS. HOWEVER...THERE WILL BE
POTENTIAL FOR A WELL DEFINED LAND BREEZE EACH NIGHT AS LOWS OVERLAND
DROP INTO THE 60S. SEAS WILL RUN 2 TO 3 FT THROUGH THE PERIOD...WITH
HIGHEST SEAS EXPECTED DURING THE FIRST HALF OF TUE.

LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 3 AM MONDAY...STALLED FRONT EAST OF THE WATERS AND HIGH
PRESSURE TO THE WEST WILL MAINTAIN LIGHT NORTHEAST TO EAST FLOW OVER
THE WATERS THROUGH THE PERIOD. SPEEDS WILL GENERALLY BE AROUND 10 KT
WITH SEAS RUNNING 2 TO 3 FT.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...HEAT ADVISORY FROM 11 AM THIS MORNING TO 6 PM EDT THIS EVENING
     FOR SCZ032-033-039-053>056.

NC...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...III
NEAR TERM...DCH
SHORT TERM...III
LONG TERM...III
AVIATION...DCH
MARINE...