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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KILM 190323
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
1123 PM EDT FRI APR 18 2014

.SYNOPSIS...
RAIN CHANCES WILL INCREASE TODAY AND TONIGHT AS A LOW PRESSURE
SYSTEM OVER THE NORTHERN GULF OF MEXICO MOVES ACROSS FLORIDA AND
THEN OFF THE SOUTHEAST UNITED STATES COAST. RAIN WILL PERSIST INTO
THE WEEKEND AS THIS SYSTEM DRIFTS NORTHEAST. A HIGH PRESSURE
PATTERN WILL THEN REASSERT ITSELF BRIEFLY BEFORE A COLD FRONT
MOVES THROUGH LATE ON TUESDAY. DRY HIGH PRESSURE RETURNS FOR THE
END OF THE WEEK.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
-- Changed Discussion --
AS OF 1100 PM FRIDAY...KLTX AS WELL AS MOSAIC RADAR TRENDS ILLUSTRATE
THE RAIN COMPLETELY BLANKETING THE ILM CWA. WIDESPREAD STRATIFORM
LIGHT TO MODERATE RAIN IS NOW FALLING ACROSS THE FA...WITH POCKETS
OF HEAVIER RAIN ACROSS WILLIAMSBURG AND HORRY COUNTIES. THE SFC
COASTAL TROF LIES NE-SW JUST OFFSHORE AND PARALLEL TO THE ILM
COASTAL CWA. THE HEAVIER RAIN ACROSS THE MENTIONED ILM CWA IS
ASSOCIATED WITH CONVECTION THAT WAS SOUTH OF THE COASTAL TROF THAT
PUSHED NORTHWARD ACROSS THIS TROF AND THEN ONSHORE WHERE
INSTABILITY LACKED TO SUSTAIN THE CONVECTION. AS A RESULT...THIS
CONVECTIVE PCPN TRANSITIONED INTO STRATIFORM MODERATE TO POCKETS
OF HEAVY RAIN. WITH ALL THIS SAID...LOOKING AT CATEGORICAL POPS
FOR THE REMAINDER OF THE OVERNIGHT AND INTO THE 1ST HALF OF
SATURDAY.

HIGH TIDE LEVELS TO REMAIN BELOW MINOR COASTAL FLOOD ADVISORY
CRITERIA OVERNIGHT...WITH THE PEAK OCCURRING AROUND MIDNIGHT.
VIA CURRENT RADAR TRENDS AND THE LATEST HRRR OUTPUT...THE ONSHORE
MOVEMENT OF MODERATE TO HEAVY PCPN CURRENTLY BEING EXPERIENCED BY
CHS...WILL TRANSLATE NORTHWARD OVERNIGHT INTO THE ILM CWA. IT IS
PROGGED TO LOSE SOME OF ITS PUNCH AS IT REACHES THE ILM CWA DURING
THIS LATE EVENING THROUGH THE SAT PRE-DAWN HOURS. AS A RESULT...
HAVE REFRAINED FROM ISSUING A COASTAL FLOOD ADVISORY AT THIS TIME
FOR DOWNTOWN ILM AND PORTIONS OF CAPE FEAR SOUTH OF SNOWS CUT
RIDGE. WILL CONTINUE TO MONITOR FOR INCREASING RAINFALL COINCIDING
WITH THE HIGH ASTRONOMICAL TIDES. HOWEVER...LIKE PREVIOUSLY SAID
...LOOKS LIKE THE HEAVIER PCPN TO ARRIVE MUCH LATER THEN THE HIGH
TIDE OCCURRENCE LATE THIS EVENING.

MIN TEMPS TONIGHT LOOK AOK...WITH VERY LITTLE MASSAGING NEEDED TO
THE DOWNSIDE. VIA VARIOUS MODEL TIME HEIGHT DISPLAYS ACROSS THE
FA...A NE-ENE 30 TO 40 KT WIND WILL PERSIST JUST OFF THE DECK
OVERNIGHT THRU SATURDAY. SOME OF THESE WINDS MAY GET CARRIED TO
THE SFC AS WIND GUSTS OR BY FURTHER INCREASING SUSTAINED VALUES.
AS A RESULT...HAVE TWEAKED WINDS UPWARDS ACROSS THE CWA ESPECIALLY
CLOSER TO THE COAST WHERE WINDS ARE PRIMARILY ONSHORE. WITH THE
COASTAL TROF REMAINING OFFSHORE...OVERNIGHT TEMPS WILL HOLD IN THE
50S CLOSER TO THE COAST AND IN THE 40S THE FURTHER INLAND.

PREVIOUS DISCUSSION...........................................
AS OF 3:00 PM FRIDAY...A CUTOFF LOW WILL DRIFT ACROSS THE GULF
COAST STATES THROUGH THE OVERNIGHT HOURS. THE ASSOCIATED SURFACE
LOW WILL SLOWLY MOVE FROM THE NORTHERN GULF OF MEXICO...ACROSS
NORTHERN FLORIDA TO REACH THE GEORGIA COAST BY 12Z SATURDAY. LOW-
LEVEL CONVERGENCE IN THE VICINITY OF THE SURFACE LOW AND ALONG THE
WARM FRONTAL BOUNDARY JUST OFFSHORE WILL COUPLE WITH MID AND
UPPER-LEVEL DIFFLUENCE AHEAD OF THE CUTOFF LOW TO ENHANCE LIFT
ACROSS THE REGION THROUGH TONIGHT. THE WIDESPREAD RAINFALL
CURRENTLY SURGING FROM THE NORTHERN GULF ACROSS MUCH OF GEORGIA
WILL PROGRESS NORTHEAST AND OVERSPREAD THE CWA THIS EVENING. THE
SURFACE TROUGH/FRONTAL BOUNDARY IS EXPECTED TO REMAIN OFFSHORE
OVERNIGHT WHICH WILL RESULT IN CONTINUED NORTHEAST SURFACE WINDS
FOR THE ILM CWA. MOS GUIDANCE IS IN VERY GOOD AGREEMENT WITH MIN
TEMPS TONIGHT. WITH A MIXED BOUNDARY LAYER...EXPECT LOWS TO RANGE
FROM AROUND 50 INLAND TO NEAR 55 ALONG THE COAST.
-- End Changed Discussion --

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 3:00 PM FRIDAY...PERIOD WILL LIKELY BEGIN WITH AN ONGOING
WIDESPREAD RAINFALL EVENT ASSOCIATED WITH A LOW PRESSURE CENTER
AND ITS ASSOCIATED FRONTAL SYSTEM OVER THE DEEP SOUTH. SATURDAY
MORNING WILL FIND THE LOW MOVING OFFSHORE NORTHERN FLORIDA AND
INTO THE ATLANTIC WITH A WARM FRONT LINED UP JUST OFFSHORE THE
SOUTHEAST US COAST. THE LOW WILL DRIFT NORTHEAST THROUGH THE SHORT
TERM WITH LITTLE CHANGE IN INTENSITY AS IT WILL BE NEARLY
VERTICALLY STACKED WITH ITS ASSOCIATED UPPER LOW. HAVE AGAIN
LEANED ON THE GFS/ECMWF SOLUTIONS AS THEY SEEMED IN BETTER
AGREEMENT THAN THE NAM WHICH GOES FOR AN OVERALL DRYER FORECAST.
DID NOT LIKE HOW THE NAM WEAKENS AND THEN TRIES TO WASH OUT THE
SYSTEM EARLY. PREVIOUS EXPERIENCE SHOWS THAT THESE TYPES OF
SYSTEMS HANG IN LONGER THAN GUIDANCE WOULD INDICATE.

GIVEN THE ABOVE AND BASED ON MOVEMENT OF SYSTEM WILL START OFF
SATURDAY WITH WIDESPREAD MODERATE STRATIFORM RAIN AND GRADUALLY
TAPERING OFF PRECIPITATION THEREAFTER. CHANCE POPS AND EXTENSIVE
CLOUD COVER WILL EXTEND INTO SUNDAY...WITH CLEARING SKIES SUNDAY
NIGHT AND NO MENTIONABLE POPS AFTER MIDNIGHT.

A COOL NORTHEAST FLOW AND EXTENSIVE CLOUD COVER WILL SUPPRESS
DAYTIME TEMPERATURES...WITH HIGHS RANGING FROM THE UPPER 50S TO
LOWER 60S ON SATURDAY...AND UPPER 60S ON SUNDAY. OVERNIGHT
TEMPERATURES WILL BE ON THE MILD SIDE...MAINLY UPPER 40S TO LOWER
50S BOTH NIGHTS.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 3:00 PM FRIDAY...COOL AND UNSETTLED TO BEGIN THE
PERIOD...BUT WARMER AND MORE TYPICAL MID-SPRING WEATHER EXPECTED
TO FOLLOW FOR THE MIDDLE AND END OF THE UPCOMING WEEK.

A VERY SLOW MOVING CUTOFF LOW AND ITS ASSOCIATED SURFACE
REFLECTION WILL FINALLY BE PUSHING AWAY FROM THE COAST MONDAY AS A
WEAK RIDGE OF HIGH PRESSURE BUILDS SOUTH AND DEFLECTS IT OFFSHORE.
WHILE LOW LEVEL CLOUDINESS MAY PERSIST THE FIRST PART OF
MONDAY...DRYING OF THE COLUMN WILL OCCUR THROUGH THE DAY AND A LOT
OF SUNSHINE IS EXPECTED MONDAY WITH TEMPS JUST BELOW SEASONABLE
NORMS. THIS WILL BE SHORT LIVED HOWEVER...AS A COLD FRONT WORKS
EAST ON TUESDAY...LIKELY CROSSING THE CWA TUESDAY NIGHT. THIS WILL
BE ACCOMPANIED BY GOOD CHANCES FOR SHOWERS AND ISOLATED TSTMS.
AHEAD OF THIS COLD FRONT TEMPS WILL WARM WELL INTO THE 70S...BUT
SOME CAA BEHIND THE BOUNDARY WILL DRIVE TEMPS TO SEASONABLE OR
JUST BELOW AGAIN WED/THU...EVEN WITH AMPLE LATE-APRIL SUNSHINE.
HIGH PRESSURE DRIFTING OFFSHORE BY THE END OF THE WEEK WILL BEGIN
A NICE WARMING TREND BEGINNING ON FRIDAY.

&&

.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
AS OF 00Z...MVFR CONDITIONS WILL DETERIORATE TO IFR THIS EVENING AS
WIDESPREAD RAIN IMPACTS ALL TERMINALS OVERNIGHT THROUGH SATURDAY.

SURFACE LOW PRESSURE PRESENTLY NEAR THE FLORIDA BIG BEND WILL BE THE
DRIVING FORCE FOR AN EXTENDED PERIOD OF RAINFALL AND POOR FLIGHT
CONDITIONS. CURRENT RADAR IMAGERY SHOWS THE RAIN SHIELD IS ALREADY
SPREADING ACROSS MUCH OF OUR AREA. MVFR CIGS WILL LOWER TO IFR THIS
EVENING AS STEADY RAIN CONTINUES TO FALL...BEGINNING WITH KFLO...
KMYR AND KCRE BY AROUND MIDNIGHT. AS THE RAIN SPREADS EASTWARD...
KILM/KLBT SHOULD DROP TO IFR BY 06Z. EXPECT CONSTANT -RA/RA TONIGHT
WITH TEMPO +RA LOWERING VSBYS TO MVFR/IFR LEVELS. NORTHEAST WINDS
AROUND 10 KTS WILL PERSIST THROUGH THE OVERNIGHT HOURS. RAIN WILL
CONTINUE INTO SATURDAY AS CIGS LIKELY REMAIN BELOW 1KFT FOR MUCH OF
THE PERIOD. COULD SEE SOME IMPROVEMENT TO MVFR BY AFTN...MOST LIKELY
AT KFLO/KLBT IF IT OCCURS. GUSTY NORTHEAST WINDS 15-20 KTS WILL
DEVELOP DURING THE DAY AS THE SURFACE LOW MEANDERS OVER THE
SOUTHEAST AND ITS WARM FRONT REMAINS OFFSHORE.

EXTENDED OUTLOOK...MVFR/IFR CIGS WILL LINGER OVERNIGHT SATURDAY INTO
SUNDAY...LOWEST ALONG THE COAST. BECOMING VFR ON MONDAY. CHANCE OF
SHOWERS ON TUESDAY WITH A COLD FRONT. VFR ON WEDNESDAY.

&&

.MARINE...
-- Changed Discussion --
NEAR TERM /THROUGH TONIGHT/...
AS OF  PM FRIDAY...NE-ENE WINDS REMAIN QUITE ACTIVE ACROSS THE
AREA WATERS. A TIGHTENED SFC PG FOR THE REMAINDER OF THE NIGHT AND
CONTINUING INTO SATURDAY...AND THE 40+ KT WINDS JUST OFF THE
DECK...WILL COMBINE TO PRODUCE A NE WIND AT 15-25 KT ACROSS THE
LOCAL WATERS FOR THE REMAINDER OF THE NIGHT AND INTO SATURDAY.
STRONGLY WORDED SCA REMAINS IN PLACE BUT WILL HAVE TO ONCE AGAIN
WATCH FOR FUTURE CONDITIONS THAT MAY REQUIRE GALES. SIGNIFICANT
SEAS WILL HOLD RELATIVELY IN THE 4 TO 7 FOOT RANGE WITH SEAS
APPROACHING 8 TO 9 FT ACROSS THE OUTER WATERS OFF CAPE FEAR...AND
ALSO OFF CAPE ROMAIN. DOMINANT PERIODS WILL RUN 6 TO 7 SECONDS.

PREVIOUS DISCUSSION.................................
AS OF 3:00 PM FRIDAY...SURFACE LOW PRESSURE WILL DRIFT FROM THE
NORTHERN GULF OF MEXICO ACROSS NORTHERN FLORIDA TO THE GEORGIA
COAST BY EARLY SATURDAY. AN ASSOCIATED FRONTAL BOUNDARY WILL
EXTEND NORTHEASTWARD FROM THE LOW CENTER AND WILL APPROACH THE
COASTAL WATERS FROM THE SOUTH OVERNIGHT. AS THE FRONT NEARS THE
WATERS...WINDS WILL VEER TOWARDS THE ENE AND ARE EXPECTED TO
LIGHTEN UP A BIT IN RESPONSE TO A WEAKER GRADIENT. DESPITE THE
POSSIBILITY OF WINDS FALLING BELOW SMALL CRAFT ADVISORY
THRESHOLDS...ROUGH SEAS WILL WARRANT ITS CONTINUATION THROUGHOUT
THE PERIOD.

SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3:00 PM FRIDAY...SMALL CRAFT ADVISORY WILL EXTEND THROUGH
MOST...IF NOT ALL OF THE NEAR TERM AS A STEADY MODERATE
NORTHEASTERLY FLOW WILL CONTINUE THROUGH THE PERIOD. ALTHOUGH
WINDS EARLY IN THE PERIOD ON SATURDAY MORNING WILL BE
MODEST...ONLY IN THE 10 TO 15 KT RANGE...THEY WILL INCREASE TO 20
TO 25 KTS SATURDAY NIGHT AS A LOW PRESSURE SYSTEM MOVES EAST OF
FLORIDA. SEAS WILL BUILD INTO THE 6 TO 10 FT RANGE AS A RESULT.
HAZARDOUS BOATING CONDITIONS WILL LIKELY EXTEND THROUGH THE ENTIRE
WEEKEND.

LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 3:00 PM FRIDAY...SLOW MOVING LOW PRESSURE OFF THE SOUTHEAST
COAST WILL GRADUALLY SHIFT AWAY FROM THE AREA ON MONDAY...LEAVING
NORTHERLY WINDS WHICH WILL EASE FROM 15-20 KTS EARLY TO LESS THAN
10 KTS MONDAY NIGHT. A RIDGE OF HIGH PRESSURE THEN BUILDS DOWN
INTO THE AREA BRIEFLY AHEAD OF A COLD FRONT WHICH WILL CROSS
TUESDAY NIGHT. WINDS RESPOND QUICKLY TO THESE CHANGING
CONDITIONS...BECOMING SW AT 10-20 KTS TUESDAY...AND THEN QUICKLY
VEERING TO THE NW BEHIND THE COLD FRONT TUESDAY NIGHT AT 15-25
KTS. THIS IS WHEN THE HIGHEST SEAS ARE EXPECTED AS WELL...AND SOME
6 FT SEAS ARE POSSIBLE TUESDAY INTO WEDNESDAY WHEN A BRIEF SCA MAY
BE NEEDED. WINDS THEN REMAIN FROM THE NW ON WEDNESDAY...BUT WITH
SLOWLY DECREASING SPEEDS.
-- End Changed Discussion --

&&

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

&&

$$
SYNOPSIS...REK
NEAR TERM...DCH/CRM
SHORT TERM...REK
LONG TERM...JDW
AVIATION...BJR
MARINE...