Area Forecast Discussion
Issued by NWS Wilmington, NC

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000
FXUS62 KILM 130557
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
157 AM EDT SAT SEP 13 2014

.SYNOPSIS...
A COLD FRONT WILL BRING UNSETTLED WEATHER THROUGH THE WEEKEND. THE
FRONT WILL WEAKEN ON MONDAY BUT MOISTURE WILL LINGER FOR A
SCATTERING OF SHOWERS ON MONDAY. ANOTHER COLD FRONT SHOULD AFFECT
THE REGION ON WEDNESDAY.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 10:30 PM FRIDAY...ALTHOUGH MOST OF THE FORECAST AREA THIS
EVENING SAW STRATIFORM RAIN OF GRADUALLY DIMINISHING EXTENT...THE
CAPE FEAR REGION AND WILMINGTON IN PARTICULAR EXPERIENCED A HEAVY
RAIN EVENT COMPLETE WITH LOCALIZED FLOODING. IT APPEARS THAT A
SERIES OF UNFORTUNATELY PLACED BOUNDARY COLLISIONS AND A JUICY
AIR-MASS WERE RESPONSIBLE. LIGHT TO MODERATE RAIN IS STILL
BLANKETING NEW HANOVER COUNTY AND A FLOOD WARNING IS OUT FOR THAT
AREA. GIVEN P/W VALUES IN EXCESS OF 2 INCHES SHOWER ACTIVITY AREA-
WIDE CONTINUES TO BE A POSSIBILITY...ESPECIALLY GIVEN THE
PROXIMITY OF THE COLD FRONT...WHICH SEEMS TO NOW EXTEND ACROSS THE
NORTHERN HALF OF THE FORECAST AREA WITH A FRONTAL WAVE NOW PLACED
OVER THE CAPE FEAR REGION. THIS ALSO NO DOUBT ENHANCED OUR RECENT
BOUT OF HEAVY RAIN.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...ANOTHER FAIRLY UNSETTLED AFTERNOON IN STORE FOR
THE REGION SATURDAY AS COLD FRONT ENTERS THE COASTAL PLAIN IN THE
PRESENCE OF FAIRLY DEEP TROPICAL MOISTURE. THE MOST WIDESPREAD
COVERAGE WILL BE OVER NWRN ZONES WHICH WILL BE MOST PROXIMAL TO THE
BOUNDARY...PERHAPS RADAR COVERAGE NOT UNLIKE THAT OF THIS AFTERNOON.
WITH A MORE CLOUDY START COMPARED TO TODAY AFTERNOON TEMPERATURES
WILL NOT GROW AS HOT AND TEND TO BE QUITE SEASONABLE. PRECIPITABLE
WATER REMAINS ABOVE 2 INCHES WHILE STORM MOTION REMAINS BELOW 5KT SO
CHANCE FOR HEAVY DOWNPOURS REMAINS INTACT. RAIN CHANCES WILL HAVE A
HARD TIME DIPPING MUCH LOWER THAN LOW END CHANCE RANGE SATURDAY
NIGHT AS THE FRONT MOVES ATOP OF THE FORECAST AREA...ALTHOUGH THE
LOSS OF DAYTIME HEATING SHOULD DIMINISH THEIR INTENSITY AND THE
HEAVY RAIN THREAT. WE WIND UP ON THE OTHER SIDE OF THE FRONT ON
SUNDAY AS IT REMAINS NEARLY STALLED TO OUR SOUTH AND EAST. RAIN
CHANCES WILL BE SHIFTED SOUTH AND EAST ACCORDINGLY AND THE HEAVY
RAIN THREAT WILL BE RELATIVELY MITIGATED. SUNDAY AFTERNOON MAY OFFER
UP A RANGE OF HIGH TEMPERATURES FROM NORTH TO SOUTH FROM THE UPPER
70S TO THE MID 80S.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 3 PM FRIDAY...WEAKENING FRONT STALLED IN THE AREA AT THE START
OF THE PERIOD AND DEEP TROPICAL MOISTURE ENSURE THE FIRST HALF OF
NEXT WEEK REMAIN UNSETTLED. PRECIPITABLE WATER VALUES AROUND 2
INCHES MON AND TUE IN A MODERATELY UNSTABLE AIRMASS SHOULD LEAD TO
SHOWER AND THUNDERSTORM DEVELOPMENT. PLAN TO CARRY CHC POP WITH A
DIURNAL DISTRIBUTION. THE LACK OF FORCING ALOFT SHOULD LEAD TO A
DECREASE IN COVERAGE/ACTIVITY OVERNIGHT BUT DO NOT THINK STORMS WILL
COMPLETELY DISSIPATE. STORM MOTIONS WILL REMAIN 10 KT OR LESS WHICH
WILL MAINTAIN FLOODING POTENTIAL.

A STRONGER COLD FRONT WILL DROP IN FROM THE NORTHWEST MID WEEK. THIS
FRONT HAS A MORE DEFINED TROUGH BEHIND IT WHICH WILL PUSH THE
BOUNDARY SOUTH OF THE AREA BY THE END OF THE WEEK. HOWEVER THERE IS
STILL SOME UNCERTAINTY AS TO HOW FAR SOUTH THIS FRONT MOVES BEFORE
STALLING. ECMWF HAS THE FRONT FARTHER SOUTH...SO DOES WPC...WHILE
THE GFS KEEPS THE FRONT CLOSER TO THE CAROLINAS. BOTH MEDIUM RANGE
SOLUTIONS DEVELOP A WEAK LOW ON THE FRONT AND LIFT IT NORTH...THOUGH
TIMING IS DIFFERENT. ECMWF SOLUTION WOULD PRODUCE SLIGHT CHC TO LOW
CHC OF PRECIP THROUGH THU...MAINLY ALONG THE COAST...WITH DRYING
FRI. GFS IS WETTER WITH HIGH CHC TO LIKELY POP THROUGH THE END OF
THE PERIOD FOR MUCH OF THE FORECAST AREA. PREVIOUS FORECASTS HAVE
BEEN IN LINE WITH THE DRIER ECMWF/WPC SOLUTION AND AT THIS POINT CAN
SEE NO REASON TO MAKE A CHANGE. CONFIDENCE REMAINS LOW SO
SIGNIFICANT CHANGES IN LATER FORECASTS IS STILL A POSSIBILITY.

TEMPERATURE RANGES EARLY IN THE PERIOD WILL BE ON THE NARROW END
WITH CLOUD COVER AND PRECIP KEEPING HIGHS NEAR TO SLIGHTLY BELOW
CLIMO BUT HELPING HOLD LOWS SEVERAL DEGREES ABOVE CLIMO. PASSAGE OF
FRONT MID WEEK WILL BRING BELOW CLIMO TEMPS FOR THE END OF THE WEEK.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 06Z...STRATIFORM LIGHT RAIN NEAR KILM SHOULD DISSIPATE
OVER THE NEXT SEVERAL HOURS...ALTHOUGH THE HRRR MODEL SUGGESTS
ISOLATED CONVECTIVE SHOWERS WILL RE-DEVELOP EARLY THIS MORNING
ACROSS THE AREA. EXPECT THICK MID/UPPER CLOUD COVER THROUGH THE TAF
VALID PERIOD WITH COPIOUS AMOUNTS OF LOW LEVEL MOISTURE. IFR/LIFR
CONDITIONS WILL DEVELOP THIS MORNING KLBT/KILM/FLO WITH HIGHEST
CONFIDENCE AT KLBT/KILM WHICH IS NEAREST A STATIONARY FRONT.
KCRE/KMYR ARE MORE LIKELY TO EXPERIENCE MVFR CONDITIONS THIS
MORNING. ANY IFR IMPROVES TO MVFR FAIRLY QUICKLY AFTER SUNRISE WITH
VFR DEVELOPING MID-LATE MORNING. CLOUD COVER SHOULD INITIALLY
INHIBIT HEATING AND LIFT SO THINK WORSE CASE VCSH COASTAL TERMINALS
IN THE MORNING HOURS. BY AFTERNOON THUNDERSTORM POTENTIAL SHOULD BE
GREATEST AT KLBT. THIS POTENTIAL SHOULD SHIFT SE-E TO KFLO AND THE
THE COASTAL TERMINALS IN THE LATE AFTERNOON/EARLY EVENING.

EXTENDED OUTLOOK...A CHANCE OF SHOWERS WITH MAINLY AFTERNOON
THUNDERSTORMS/TEMPO MVFR THROUGH TUESDAY.

&&

.MARINE...
NEAR TERM/THROUGH TONIGHT/...
AS OF 10:30 PM FRIDAY...LIGHT AND VARIABLE WINDS WITH 2 FT SEAS
CONTINUE ACROSS THE WATERS THIS EVENING. FORECAST REMAINS
UNCHANGED. PREVIOUS DISCUSSION FOLLOWS:

OUTSIDE OF TSTMS NO REAL PROBLEMS EXPECTED ON THE WATERS WITH
LIGHT WINDS OVERALL AND SEAS 2 FEET OR LESS...AS A WEAK FRONTAL
BOUNDARY REMAINS IN VICINITY OF THE AREA. MOST STORMS SHOULD STAY
OVER LAND BUT TONIGHT CELLS MAY BEGIN TO FAVOR THE 0-20 NM WATERS.
SEAS AROUND 2 FEET IN A MIX OF SE WAVES 1-1.5 FT EVERY 8-9 SECONDS
AND S WAVES 0.5-1 FT EVERY 3-4 SECONDS. WITHIN TSTMS WINDS AND
SEAS WILL BE LOCALLY AND SIGNIFICANTLY HIGHER.

SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...PREFRONTAL SOUTHWESTERLY FLOW ON SATURDAY SHOULD
REMAIN AT 10 KT PREVENTING SEAS FROM ATTAINING HEIGHTS MORE THAN 2
FT. LATE SATURDAY NIGHT AS THE FRONT DRAWS NEAR THE COAST THERE MAY
BE A GENTLE BACKING OF THE FLOW FOLLOWED BY A MORE PRECIPITOUS VEER
ON SUNDAY ASSOCIATED WITH ACTUAL FROPA. THE FRONT WILL NOT MOVE VERY
FAR TO OUR SOUTH BEFORE STALLING WHICH PRECLUDES MUCH OF A SURGE OF
HIGH PRESSURE AND THUS ANY HIGHER WINDS. THUS THE VEER TO ENE FLOW
APPEARS TO BE THE MAIN EFFECT OF THE FROPA AS WIND SPEEDS AND WAVE
HEIGHTS REMAIN UNCHANGED...ALTHOUGH WAVE PERIODS MAY SHORTEN UP A
BIT.

LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 3 PM FRIDAY...DIMINISHING NORTHERLY SURGE AT THE START OF THE
PERIOD WILL LEAVE LIGHT AND VARIABLE WINDS OVER THE WATERS FOR MUCH
OF MON AND TUE GIVEN PROXIMITY TO THE STALLED FRONT. ANOTHER COLD
FRONT WILL DROP IN FROM THE NORTHWEST DURING THE SECOND HALF OF THE
PERIOD. THIS FRONT IS MORE DEFINED AND SHOULD BE ACCOMPANIED BY A
STRONGER NORTHERLY SURGE LATER WED INTO WED NIGHT. WINDS WILL
APPROACH A SOLID 15 KT WED NIGHT WITH GUSTS AROUND 20 KT POSSIBLE.
SEAS 2 TO 3 FT FOR MUCH OF THE PERIOD WILL BUILD AS HIGH AS 5 FT AS
THE PERIOD ENDS DUE TO THE PROLONGED AND STEADILY INCREASING NATURE
OF THE NORTHERLY SURGE.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...COASTAL FLOOD ADVISORY UNTIL 3 AM EDT EARLY THIS MORNING FOR
     NCZ107.

MARINE...NONE.

&&

$$
SYNOPSIS...MBB
NEAR TERM...MJC/REK
SHORT TERM...MBB
LONG TERM...III
AVIATION...DCH/MRR



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