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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KILM 262239
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
640 PM EDT SAT JUL 26 2014

.SYNOPSIS...
HIGH PRESSURE OFFSHORE WILL RIDGE BACK INTO THE CAROLINAS THROUGH
MONDAY...CREATING VERY HOT AND HUMID CONDITIONS. A HEAT ADVISORY
IS IN EFFECT FOR PORTIONS OF THE AREA SUNDAY...AND MAY BE NEEDED
AGAIN ON MONDAY. AN UNUSUALLY STRONG COLD WILL CROSS ON
MONDAY...BRINGING A GOOD CHANCE FOR THUNDERSTORMS...SOME OF WHICH
MAY BE SEVERE. MUCH COOLER AND DRIER WEATHER WILL DEVELOP
TUESDAY...AND CONTINUE THROUGH THE UPCOMING WEEK.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 330 PM SATURDAY...OUR ATMOSPHERE IS BECOMING PROGRESSIVELY
RESISTANT TO PROSPECTS OF DEEP CONVECTION AS DRY AIR CONTINUES
TO DIG INTO THE LOWER PORTIONS OF THE TROPOSPHERE ON NORTHWEST
WIND TRAJECTORIES. NO SHORTAGE OF LOW-LEVEL VAPOR CONTENT WITH
MUGGY HEAT BOOSTING LOCAL HEAT INDICES TO 100 DEGREES CURRENTLY.
THIS WAS RESULTING IN A VIGOROUS BUT SUPPRESSED CUMULUS FIELD
AND AN OVERALL SWELTERING TONE TO OUTSIDE CONDITIONS INLAND.

SINCE OUR LOCAL ATMOSPHERE IS BECOMING INCREASINGLY UNFAVORABLE
FOR MATERIALIZATION OF SHOWERS/TSTMS...POP VALUES WILL BE LOWERED
BELOW MENTIONABLE THRESH-HOLDS IN MOST AREAS AWAY FROM SEA BREEZE
CONVERGENCE BASED ON RADAR TRENDS PRIOR TO ZFP/CWF DISSEMINATION.

TONIGHT A MILD ONE ANTICIPATED ROUGHLY 3 DEGREES MILDER THAN LAST
NIGHT...PARTIALLY A RESULT OF SW BOUNDARY LAYER WINDS INCREASING
AS THE LOWER ATMOSPHERE DECOUPLES AMIDST A SLIGHTLY TIGHTENING
LOW-LEVEL PRESSURE GRADIENT...AND ALSO BECAUSE OF RELATIVELY HIGH
TD VALUES LIMITING OVERNIGHT TEMPERATURE FALLS. EXPECTING MIDDLE
70S AT DAYBREAK INLAND TO THE UPPER 70S TO NEAR 80 AT THE COAST.
CLOSER TO THE ICW/SEA...SUSTAINED SW WINDS OVERNIGHT WILL LIKELY
KEEP TEMPERATURES LEVELED OFF IN THE LOWER 80S.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
AS OF 330 PM SATURDAY...AN INTERESTING PERIOD ON TAP FOR THE
SHORT-TERM PERIOD AS BOTH EXTREME HEAT/HEAT INDICES AND SPRING-LIKE
SEVERE WEATHER IS ANTICIPATED. WITH HIGH PRESSURE IN PLACE OVER THE
ATLANTIC AND A MID-LEVEL RIDGE...VERY WARM AND HUMID AIR WILL
CONTINUE TO BE USHERED INTO THE AREA. WITH A HEAT ADVISORY NOW IN
PLACE FOR ALL SOUTH CAROLINA INLAND COUNTIES...ALONG WITH
ROBESON...COLUMBUS...AND BRUNSWICK COUNTIES IN NORTH CAROLINA...WILL
ALSO FOCUS ON THE POSSIBILITY OF HEAT ADVISORY FOR MONDAY AS WELL
WITH APPARENT TEMPS BOTH DAYS NEARING/AT/OR JUST ABOVE HEAT ADVISORY
CRITERIA OF 105 DEGREES THANKS TO HIGHS IN THE UPPER 90S AND
DEWPOINTS IN THE LOWER 70S. GIVEN FAIRLY DRY ATMOSPHERE AND
SUBSIDENCE ALOFT...DO NOT ANTICIPATE ANY CONVECTION ON
SUNDAY...THOUGH WILL NOT ENTIRELY RULE OUT AN ISOLATED SHOWER OR
THUNDERSTORM ON THE AFTERNOON SEA BREEZE...BUT CONFIDENCE IS VERY
LOW.

REGARDING SEVERE WEATHER...WE WILL LOOK CLOSELY AT MONDAY LATE
AFTERNOON/EVENING AS SPC HAS ALREADY HIGHLIGHTED THE AREA IN A
SLIGHT RISK ON DAY 3. A STRONG AND VERY SPRING-LIKE DIGGING
TROUGH/SFC COLD FRONT WILL PROPAGATE INTO THE CAROLINAS LATE SUNDAY AND
THROUGHOUT THE DAY ON MONDAY AS ITS ASSOCIATED DEEPENING LOW
PRESSURE MOVES EASTWARD ACROSS THE GREAT LAKES AND INTO NEW ENGLAND.
WHILE THE AREA IS NOT USUALLY SUSCEPTIBLE TO FRONTAL BOUNDARIES AS
SUCH DURING THE MID-SUMMER MONTHS...THE SETUP IS BECOMING MUCH MORE
INTERESTING ESPECIALLY GIVEN THE 95+ TEMPERATURES ANTICIPATED FOR
MONDAY...WHICH IS MUCH WARMER THAN WHAT WE WOULD SEE IN A TYPICAL
SETUP LIKE THIS FOR APRIL/MAY. WHILE THE LATEST GUIDANCE SUGGESTS A
SLIGHT LACK OF SUPPORT IN THE UPPER LEVELS WITH THE UNFAVORABLE
LOCATION/NATURE OF THE JET...FOCUS TURNS TO THE MID AND LOWER
LEVELS. LATEST GUIDANCE SEEMS TO BE IN PRETTY GOOD AGREEMENT WITH
THE TIMING OF THE FRONT/CONVECTION ACROSS OUR AREA (MONDAY
AFTERNOON/EVENING)...AND HAVE DECIDED TO UTILIZE GFS MORE IN
FORECAST ESPECIALLY IN ANALYZING SEVERE WEATHER PARAMETER VALUES.

PRECIPITABLE WATER VALUES WILL INCREASE THROUGHOUT THE DAY ON
MONDAY...REACHING UP TO 2 INCHES BY 18Z. WHILE TIME-HEIGHT ANALYSIS
SUGGESTS FEW/SCT HIGH CLOUDS SUNDAY NIGHT INTO
MORNING...TEMPERATURES WILL ALREADY BE AROUND 80 DEGREES TO
KICK-START MONDAY MORNING AND THUS AM NOT OVERLY CONCERNED WITH THE
AFTERNOON HIGH TEMPS POTENTIALLY NOT CLIMBING INTO THE MID TO UPPER
90S. PER LATEST 12Z GFS FCST SOUNDINGS...A SLIGHT THERMAL RIDGE IS
PRESENT...BUT AGAIN GIVEN ANTICIPATED HIGH TEMPERATURES FOR THE
DAY...AN ADJUSTED SKEW-T WOULD MAKE THIS OBSOLETE AND PRESENT ITSELF
AS A NEARLY-CLASSIC INVERTED-V SOUNDING...SUPPORTIVE OF SEVERE
WEATHER. LOOKING AT OTHER PARAMETERS...BOTH LOW AND MID-LEVEL LAPSE
RATES ARE FAIRLY STEEP...WITH VALUES OF 6-7 C/KM AND LIFTED INDEX
VALUES ARE SHOWING TO BE ROUGHLY -6 TO -8. THIS WITH CAPE VALUES
INCREASING TO NEAR 2000+ AS 500 MB HEIGHTS CONTINUE TO FALL WILL
CREATE QUITE AN UNSTABLE AIRMASS FOR THE AREA. ALSO...DCAPE VALUES
WILL BE 300+...ESPECIALLY CLOSER TO THE COAST PER LATEST GUIDANCE.
FCST HODOGRAPHS ARE ILLUSTRATING A MORE FAVORABLE SETUP FOR SPEED
SHEAR VERSUS DIRECTIONAL SHEAR...SO WHILE EXPECT A LOW TORNADO
THREAT...COULD BE LOOKING AT THE POSSIBILITY OF DISCRETE
CELLS/SPLITTING SUPERCELLS. LOCATION-WISE...WHILE WILL FOCUS ON THE
FRONTAL BOUNDARY FOR LIFT...EXPECT THE SEA BREEZE TO PLAY A ROLE IN
CONVECTIVE INITIATION AS WELL (LATE AFTERNOON/EARLY EVENING) AS IT
WILL BE PINNED TO THE COAST GIVEN THE DECENT MID LEVEL WESTERLY FLOW
AND THE FRONT ITSELF MOVES CLOSER INTO THE EARLY EVENING.

GIVEN THE LATEST GUIDANCE AND THE ANTICIPATION OF CONVECTIVE
DEVELOPMENT...EXPECT DAMAGING WINDS AND HAIL TO BE THE PRIMARY
THREAT. WOULD NOT ENTIRELY RULE OUT THE POSSIBILITY OF LARGE HAIL
GIVEN THE FAVORABLE AMOUNT OF CAPE IN THE HAIL GROWTH ZONE...BUT
BEING THAT THE EVENT IS STILL A FEW DAYS AWAY...WILL REMIND THAT
THIS IS A POSSIBILITY. ANY DECREASE/INCREASE IN SPEED OF THE SYSTEM
COULD CHANGE THINGS ENTIRELY.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 330 PM SATURDAY...FALL COMES EARLY THIS YEAR...OR SO IT
SEEMS...AS THE END OF JULY AND BEGINNING OF AUGUST FEATURE A PATTERN
RARELY SEEN IN MID-SUMMER. THIS FALL LIKE PATTERN IS DUE TO A VERY
STRONG MID-LEVEL TROUGH...PROGGED TO REACH -4 SD`S FROM
CLIMO...DIVING ACROSS THE EASTERN CONUS AND THEN SITTING IN PLACE
THROUGH THE UPCOMING WEEK. WHILE THIS WILL BRING A PERIOD OF MUCH
DRIER AIR...AS SHOWN BY PWATS AROUND OR BELOW 1 INCH TUE-THU...AND A
THETA-E RIDGE DISPLACED WELL EAST OF THE AREA...TEMPS WILL ALSO
STRUGGLE TO VALUES WELL BELOW NORMAL FOR LATE JULY. 850MB TEMPS DROP
TO AROUND -2 SD`S...AND HIGHS AND LOWS THROUGH THE WEEK WILL BE 5-10
DEGREES BELOW NORMAL. PRECIP CHANCES WILL BE MINIMAL THROUGH
FRIDAY...AND ALTHOUGH ISOLATED SHOWERS WILL BE POSSIBLE LATE
WEEK...WILL KEEP POP SILENT ATTM. BY THE END OF THE PERIOD THE
HIGHLY AMPLIFIED RIDGE ACROSS THE ATLANTIC WILL TRY TO BACK UP
TOWARDS THE COAST...CREATING SLIGHTLY WARMER TEMPS AND HIGHER POP
FOR SATURDAY.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
AS OF 00Z...PRETTY QUIET NIGHT OVERALL WITH PREDOMINATELY VFR
CONDITIONS. WINDS WILL PROBABLY STAY ABOVE 5 KTS ALONG THE
COAST...PRECLUDING ANY FOG. INLAND...BETTER RADIATIONAL COOLING WILL
PROBABLY PRODUCE LIGHT FOG STARTING AROUND 07-08Z...WITH POCKETS OF
IFR FOG POSSIBLE BETWEEN 09-11Z. SUNDAY...SOUTHWESTERLY FLOW WILL
PICK UP WITH THE TIGHTENING GRADIENT IN ADVANCE OF A FRONT THAT WILL
DROP INTO THE REGION ON MONDAY. SOME ISOLATED/SCATTERED CONVECTION
IS EXPECTED ALONG THE SEA BREEZE AND INLAND ALONG THE PIEDMONT
TROUGH.

EXTENDED OUTLOOK...SHOWERS/TSTMS/TEMPO MVFR POSSIBLE SUNDAY AND
MONDAY. OTHERWISE EXPECT VFR.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 330 PM SATURDAY...MODERATE SW WINDS WILL HOLD OVERNIGHT DUE
TO INTERACTION OF A SURFACE TROUGH OVER THE CENTRAL CAROLINAS AND
HIGH PRESSURE CIRCULATING OFFSHORE...EQUATING TO A STEADY SW 10-15
KT TONIGHT INTO DAYBREAK SUNDAY. SEAS 2-3 FOOT SEAS CAN BE EXPECTED
IN A MIX OF S WAVES OF 1-1.5 FEET EVERY 4-5 SECONDS AND SE WAVES 1
TO 2 FEET EVERY 8-9 SECONDS. ANY SHOWERS OR TSTMS WILL BE FAVORED
FOR LATE TONIGHT INTO EARLY SUNDAY MORNING...BUT ISOLATED AT BEST.

SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 330 PM SATURDAY...SCEC POSSIBLE SUNDAY NIGHT...WITH SMALL
CRAFT ADVISORY ANTICIPATED MONDAY AND MONDAY NIGHT. SOUTH-SOUTHWEST
WINDS WILL INCREASE SUNDAY INTO MONDAY AHEAD OF AN APPROACHING
STRONG COLD FRONT. ON SUNDAY WILL SEE SUSTAINED WINDS 15 TO 20 KTS
INCREASING TO AROUND 20 KTS LATE SUNDAY NIGHT AND INTO MONDAY. SEAS
OF 2 TO 4 FT WILL INCREASE TO 4 TO 6 FT OVERNIGHT SUNDAY INTO
MONDAY. LATE MONDAY NIGHT SEAS WILL BEGIN TO DECREASE TO 2 TO 4 FT
WITH WEST-SOUTHWEST WINDS REMAINING AROUND 15 KTS.

LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 330 PM SATURDAY...COLD FRONT WILL BE OFFSHORE AT THE START OF
THE PERIOD...LEAVING GUSTY NW WINDS OF 10-15 KTS EARLY TUESDAY.
THESE WINDS WILL EASE AND VEER TO THE NE DURING TUESDAY AS RIDGE OF
HIGH PRESSURE BUILDS DOWN THE COAST...LEAVING A RELATIVE WEAK
PRESSURE GRADIENT ACROSS THE AREA. WINDS WILL REMAIN FROM THE NE
THROUGH THE REMAINDER OF THE EXTENDED...INCREASING SLOWLY TO 10-15
KTS BY THURSDAY. SEAS TUESDAY WILL BE 1-3 FT ON THE NW WINDS...BUT
THEN BECOME A MORE STEADY 2-3 FT LATE TUESDAY....WEDNESDAY...AND
INTO THURSDAY WITH A SLOWLY AMPLIFYING NE WIND WAVE DOMINATING THE
WAVE SPECTRUM. SEAS THURSDAY WILL RISE SLIGHTLY HIGHER ON THE
STRONGER WINDS...BECOMING 3-4 FT.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...HEAT ADVISORY FROM NOON TO 7 PM EDT SUNDAY FOR SCZ017-023-024-
     032-033-039-053-055.

NC...HEAT ADVISORY FROM NOON TO 7 PM EDT SUNDAY FOR NCZ087-099-109.

MARINE...NONE.

&&

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