-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KILM 172349
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
749 PM EDT THU APR 17 2014

.SYNOPSIS...
HIGH PRESSURE WILL LINGER ACROSS THE CAROLINAS TODAY THROUGH
FRIDAY. RAIN CHANCES WILL INCREASE DURING THE WEEKEND AS A LOW
PRESSURE SYSTEM MOVES FROM THE GULF OF MEXICO AND INTO THE
ATLANTIC OCEAN. A WEAK PRESSURE PATTERN WILL SETTLE OVER THE
CAROLINAS FOR MUCH OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
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AS OF 715 PM THURSDAY...LATEST SAT IMAGERY TRENDS INDICATE A
MOSTLY CLEAR SKY TO START OUT AND CONTINUE INTO THIS EVENING. FOR
LATER THIS EVENING AND OVERNIGHT...THIN TO OPAQUE CIRRUS WILL MOVE
IN FROM THE SW. AT THE SAME TIME...STRATOCU JUST OFFSHORE...WILL
BEGIN TO SHOW A WESTERLY COMPONENT IN ITS MOVEMENT TOWARDS LAND AND
EVENTUALLY MOVE ONSHORE DURING THE PRE-DAWN FRIDAY HOURS. WILL
INDICATE INCREASING CLOUDS OR BECOMING MOSTLY CLOUDY FOR THE
OVERNIGHT PERIOD. HAVE HELD OFF THE RAIN CHANCES UNTIL DAYLIGHT
FRIDAY.

TEMPS WILL DROP AFTER SUNSET...HOWEVER WINDS WILL STAY SOMEWHAT
ACTIVE AROUND 5 MPH...EXCEPT UP TO 10 MPH COASTAL AREAS...AND THUS
PREVENT TEMPS FROM DROPPING TOO QUICKLY. IN ADDITION...CLOUDS
INCREASING OVERNIGHT WILL PREVENT A FURTHER DROP IN THE LOW TEMPS
TONIGHT.

PREVIOUS DISCUSSION..............................................
AS OF 3:00 PM THURSDAY...HIGH PRESSURE WEDGED ACROSS THE INTERIOR
CAROLINAS HAS WEAKENED SLIGHTLY THROUGH THE DAY...AND THIS TREND
WILL CONTINUE OVERNIGHT. THE 850-500 MB LAYER WILL REMAIN QUITE
DRY THROUGH THE OVERNIGHT PERIOD...HOWEVER UPPER-LEVEL MOISTURE
WILL BE ON THE INCREASE AHEAD OF A MID-LEVEL TROUGH SWEEPING
ACROSS THE PLAINS. DEWPOINTS HAVE SURGED INTO THE LOW-MID 40S AS
OF 18Z. THIS IS A FASTER RECOVERY OVER THE NORTHWESTERN TIER THAN
WAS PROGGED BY MOS...SO HAVE MADE SOME SLIGHT UPWARD ADJUSTMENTS
TO MIN TEMPS IN THAT AREA. GENERALLY A RANGE OF 43-49 EXPECTED
ACROSS THE CWA TONIGHT.
-- End Changed Discussion --

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
AS OF 3:00 PM THURSDAY...AN UPPER TROUGH WITH AN EMBEDDED AND
GRADUALLY DEEPENING LOW CENTER WILL MOVE EAST ACROSS THE GULF COAST
STATES THROUGH THE SHORT TERM. THIS FEATURE WILL DRIVE A
DEVELOPING SURFACE LOW AND ITS ASSOCIATED FRONTAL SYSTEM FROM THE
GULF OF MEXICO ACROSS FLORIDA ON FRIDAY AND ULTIMATELY INTO THE
OPEN WATERS OF THE ATLANTIC ON SATURDAY. GUIDANCE STILL DIFFERS ON
PLACEMENT AND DEVELOPMENT OF THIS SYSTEM SO ALTHOUGH I HAVE GONE
WITH A BLEND OF GUIDANCE HAVE LEANED TOWARDS THE GFS/ECMWF
SOLUTIONS...WHICH SEEMED MORE SIMILAR. WHICH MODELS ULTIMATELY
VERIFY MAKES A SIGNIFICANT DIFFERENCE AS FAR AS POPS AND QPF
GOES...WITH THE NAM BEING SIGNIFICANTLY THE DRYER SOLUTION. AS I
HAVE FAVORED THE GFS/ECMWF SOLUTIONS...I AM NOW EXPECTING A
SIGNIFICANT RAIN EVENT...WITH QPF EVENT TOTALS IN THE 1.0 TO 1.5
INCH RANGE. HEAVIEST RAIN WILL BE CENTERED AROUND FRIDAY NIGHT.

COOL NORTHEAST FLOW WILL KEEP MAXIMUM TEMPERATURES IN THE BELOW
NORMAL RANGE...WITH HIGHS IN THE MID 60S BOTH DAYS. EXTENSIVE
CLOUD COVER WILL HELP KEEP MINIMUM TEMPERATURES ON THE MILD
SIDE...WITH LOWS RANGING FROM THE UPPER 40S TO MID 50S BOTH DAYS.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 3:00 PM THURSDAY...CUTOFF UPPER LOW TRAVERSING FLORIDA ON
SUNDAY. MODELS AT ODDS AS TO HOW FAR NORTH PRECIPITATION IS
SPREADING. HOWEVER EVEN THE MORE SUPPRESSED GUIDANCE IMPLIES THAT
COASTAL LOCATIONS SHOULD HAVE SOME SMALL RAIN CHANCES AND THE FCST
HAS BEEN ADJUSTED ACCORDINGLY. THERE IS A POSSIBILITY HOWEVER THAT
THIS WILL HAVE TO BE TRENDED UPWARDS BOTH WITH RESPECT TO POP
VALUES AND NORTHERN EXTENT. THIS SYSTEM PROGRESSES EASTWARD BY
MONDAY PAVING THE WAY FOR A DRIER AND MORE SEASONABLE AFTERNOON
WITH A WEAK SURFACE PRESSURE PATTERN AND ZONAL MID LEVEL FLOW. BY
TUESDAY THE STILL WEAK BL FLOW TURNS FROM NRLY TO SRLY BOOSTING
TEMPS. AN UPPER LOW AND COLD FRONT APPEAR SLATED FOR TUESDAY NIGHT
OR WEDNESDAY BUT IT SEEMS TOO MOISTURE-DEPRIVED TO YIELD
MEANINGFUL RAIN CHANCES.

&&

.AVIATION /23Z THURSDAY THROUGH TUESDAY/...
AS OF 00Z...WEDGE WILL HANG ON AT LEAST FOR THE NEXT 12-18
HOURS...BUT WILL BREAK DOWN AS LOW PRESSURE APPROACHES FRIDAY
AFTERNOON. LOOK FOR SCATTERED SKIES OVERNIGHT WITH NO FOG EXPECTED
DUE TO THE MOISTURE PROFILES AND THE FACT THAT THE WIND WILL LIKELY
STAY ABOVE 6 KTS. THE NAM IS HINTING AT A VFR STRATOCU CEILING LATER
TONIGHT...BUT NOT BUYING THIS SCENARIO AT THIS TIME.

FRIDAY...INCREASING CLOUDS AS THE SYSTEM APPROACHES. WEATHER WILL
AFFECT THE SOUTHERN TERMINALS FIRST...WITH RAIN EXPECTED TO
OVERSPREAD THE AREA BY 20-21Z...ONE TO THREE HOURS LATER FOR THE
NORTHERN TERMINALS. DECENT ISENTROPIC LIFT SHOULD PRODUCE FAIRLY
STEADY STRATIFORM PRECIP WITH LOWER CEILINGS TOWARD THE END OF THE
FORECAST PERIOD. NORTHEAST WINDS WILL CONTINUE...GUSTY ON FRIDAY.

EXTENDED OUTLOOK...EXPECT AT LEAST PERIODS OF MVFR/IFR CIGS FRIDAY NIGHT
AND SATURDAY AS WELL AS INCREASING RAIN CHANCES. MVFR CIGS COULD
LINGER INTO SUNDAY. VFR ON MONDAY.

&&

.MARINE...
-- Changed Discussion --
NEAR TERM /THROUGH TONIGHT/...
AS OF 730 PM THURSDAY...EXTENDED THE SCA INTO SUNDAY WHICH
BASICALLY MATCHES OUR NEIGHBORING WATERS.

THE COMBINATION OF THE 1040+ MB HIGH CENTERED OVER THE NE STATES
AND DEVELOPING LOW PRESSURE OVER THE NE GULF OF MEXICO...WILL
RESULT IN A TIGHTENED SFC PRESSURE GRADIENT OVERNIGHT THROUGH
FRIDAY AND INTO THE WEEKEND. WIND SPEEDS TO RANGE BETWEEN 15 TO 25
KT OVERNIGHT. THE PROGGED SFC PRESSURE PATTERN WILL YIELD A NE-ENE
WIND DIRECTION. MODELS INDICATE A SFC COASTAL TROF WILL DEVELOP
LATE TONIGHT...JUST OFFSHORE AND ORIENTED NE-SW. THIS MAY ENHANCE
WIND SPEEDS ACROSS THE LOCAL WATERS AS WELL AS BE A FOCUS FOR PCPN
DEVELOPMENT. SIGNIFICANT SEAS TO REMAIN IN THE 4 TO 7 FT RANGE
OVERNIGHT...WITH THE HIGHEST SEAS ACROSS THE AREA WATERS OCCURRING
OFF CAPE FEAR...AND OFF CAPE ROMAIN. AN EASTERLY 2 TO 3 FOOT
GROUND SWELL IN THE 9 TO 10 SECOND PERIOD RANGE WILL REMAIN
ACTIVE. HOWEVER...THE NE WIND DRIVEN WAVES WILL DOMINATE THE SEAS
SPECTRUM WITH AVERAGE PERIODS IN THE 5.5 TO 6.5 SECOND RANGE.

PREVIOUS DISCUSSION..............................................
AS OF 3:00 PM THURSDAY...A RELATIVELY STRONG PRESSURE GRADIENT
WILL PERSIST ACROSS THE COASTAL WATERS THROUGH THE NIGHT BETWEEN A
STATIONARY SURFACE TROUGH WELL OFFSHORE AND A WEDGE OF HIGH
PRESSURE INLAND. THE WEDGE WILL WEAKEN SLIGHTLY
OVERNIGHT...HOWEVER THIS WILL RESULT IN VERY LITTLE CHANGE TO THE
STRENGTH OF THE GRADIENT AS SURFACE PRESSURES FALL OVER THE
NORTHERN GULF OF MEXICO. NORTHEAST WINDS ARE EXPECTED TO REMAIN IN
A 15-20 KT RANGE WITH SOME GUSTS TO 25 KTS...AND THIS WILL KEEP
SEAS OVER THE SMALL CRAFT ADVISORY THRESHOLD THROUGH THE DURATION
OF THE NIGHT.

SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3:00 PM THURSDAY...NORTHEAST FLOW WILL PERSIST THROUGH THE
SHORT TERM AS A FRONTAL SYSTEM EXITS THE GULF OF MEXICO AND MOVES
INTO THE OPEN WATERS OF THE ATLANTIC. WILL EXTEND THE SMALL CRAFT
ADVISORY THROUGH FRIDAY NIGHT AS MODERATE NORTHEASTERLY WINDS WILL
KEEP SEAS IN THE 4 TO 6 FT RANGE. ANTICIPATE THAT WE WILL FURTHER
EXTEND THE SCA INTO SATURDAY AS CONDITIONS ARE EXPECTED TO FURTHER
DETERIORATE WITH A DEEPENING LOW PRESSURE SYSTEM MOVING INTO THE
ATLANTIC.

LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 3:00 PM THURSDAY...SMALL CRAFT ADVISORY LIKELY IN EFFECT FOR
MOST OF THE PERIOD. GRADIENT WILL BE PINCHED BY A SLOW MOVING LOW
WHOSE UPPER LOW IS CUT OFF FROM THE MAIN JET STREAM FLOW. THIS
FEATURE PAIRED WITH A FAIRLY STRONG HIGH OFF NEW ENGLAND COAST
WILL LEAD TO STRONG WINDS THAT MAY EVEN OCCASIONALLY GUST TO GALE
FORCE ON SUNDAY OR SUNDAY NIGHT. ABATING TREND ON MONDAY WILL BE
GRADUAL DUE TO THE SLOW MOVEMENT OF THE SYSTEM. WINDS DROP OFF
MORE SUBSTANTIALLY MONDAY NIGHT AS IT GETS CAUGHT BACK UP IN THE
JET AND ACCELERATES EASTWARD. FLAGS WILL BE ABLE TO BE DROPPED
SOME TIME LATE MONDAY. TUESDAY BRINGS LIGHT WINDS THAT WILL BE
BACKING AND THERE WILL STILL BE A LITTLE BACKSWELL FROM THE SYSTEM
AS IT CONTINUES TO MOVE EAST OUT TO SEA.
-- End Changed Discussion --

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT SUNDAY FOR AMZ250-252-254-
     256.
-- End Changed Discussion --

&&

$$
SYNOPSIS...REK
NEAR TERM...DCH/CRM
SHORT TERM...REK
LONG TERM...MBB
AVIATION...DL