Area Forecast Discussion
Issued by NWS Wilmington, NC

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000
FXUS62 KILM 020321
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
1121 PM EDT WED OCT 1 2014

.SYNOPSIS...
HIGH PRESSURE RIDGING SOUTH ACROSS THE AREA WILL MOVE OFFSHORE
THURSDAY NIGHT. A STRONG COLD FRONT WILL MOVE ACROSS THE AREA
SATURDAY MORNING. DRY AND COOL HIGH PRESSURE WILL FOLLOW FOR THE
WEEKEND AND PERSIST INTO EARLY NEXT WEEK. A WARMING TREND IS
EXPECTED FOR THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
AS OF 1045 PM WEDNESDAY...OVERNIGHT MIN TEMPS ATTM ARE STAYING
ABOVE THE MIN TEMP CURVE FROM EARLIER THIS EVENING. WITH CURRENT
SFC DEWPOINTS IN THE LOW TO MID 60S...WILL GO AHEAD AND TWEAK
TONIGHTS MINS UPWARDS BY 1 TO 3 DEGREES FROM CURRENT VALUES.
LATEST NAMBUFR SOUNDINGS INDICATE AVBL MOISTURE IN THE LOWER
LEVELS...SFC TO 900MB. SFC BASED INVERSION SHOULD GET STRONGER AS
THE NIGHT PROGRESSES...ESPECIALLY INLAND ONCE THOSE DEBRIS
LOW/MID CLOUDS FROM EARLIER CONVECTION DISSIPATES. WILL CONTINUE
TO HIT THE FOG HARD ACROSS THE ILM CWA...JUST DELAYED BY A COUPLE
HOURS FROM EARLIER THINKING. THUS...WILL GO WIDESPREAD AND DENSE
AN HOUR OR 2 BEFORE DAYBREAK.

PREVIOUS DISCUSSION...............................................
AS OF 730 PM WEDNESDAY...AN ISOLATED SHOWER VICINITY OF CLIO AND
MINTURN CONTINUES TO MAKE ITS PROGRESS TOWARD THE SOUTHEAST. THE
SEA BREEZE BOUNDARY CONTINUES TO MAKE PROGRESS INLAND...AND COULD
MEET UP WITH THIS SHOWER WITHIN 1 TO 2 HRS BEFORE THIS BOUNDARY
WEAKENS AND DISSIPATES. WILL HAVE TO UPDATE POPS TO ACCOMODATE.
AREAS TO WIDESPREAD FOG CONTINUES TO BE THE MAIN FORECAST PROBLEM
OVERNIGHT. THE THREAT EXISTS FOR THIS FOG TO BECOME THICK AND
WIDESPREAD ENOUGH TO REDUCE HORIZONTAL AND VERTICAL VSBYS TO DENSE
CRITERIA...ONE QUARTER OF A MILE OR LESS. CURRENT MIN TEMP
FORECAST LOOKS AOK...WITH VERY LITTLE TWEAKING IF ANY APPLIED.

PREVIOUS DISCUSSION....................................
AS OF 300 PM WEDNESDAY...CLEAR SKIES AND LIGHT WINDS EXPECTED
THROUGH THE PERIOD. IN FACT WITH LOSS OF DAYTIME HEATING MUCH OF THE
OVERNIGHT WILL FEATURE CALM WINDS ESPECIALLY AWAY FROM THE COAST.
TEMPERATURE GUIDANCE IS FAIRLY TIGHTLY CLUSTERED TO WITHIN A DEGREE
OR TWO OF 60 AREA-WIDE. THE MAIN FORECAST ISSUE APPEARS RELATED TO
THE DEVELOPMENT OF FOG THAT MAY BE LOCALLY DENSE. THE AFOREMENTIONED
FACTORS CERTAINLY FAVOR FOG DEVELOPMENT. DEWPOINTS APPEAR ABOUT THE
SAME AS LAST NIGHT BUT THE AFTERNOON TURNED OUT A TAD MILDER THAN
YESTERDAY. WITH GOOD RADIATIONAL COOLING EXPECTED THAT SHOULD NOT
MATTER MUCH AND FOG CONTINUES TO BE CARRIED FOR ALL ZONES WITH
LOCALLY DENSE WORDING ADDED. EVENING OR OVERNIGHT SHIFT MAY HAVE A
BETTER IDEA WHAT PLACES IF ANY MAY SEE WIDESPREAD ENOUGH DENSE FOG
FOR AN ADVISORY.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...SURFACE RIDGE OF HIGH PRESSURE WILL
REMAIN IN PLACE THURSDAY AND THEN MOVE OFFSHORE THURSDAY NIGHT.
BUILDING RIDGE ALOFT WILL BE MOST AMPLIFIED THURSDAY AND THURSDAY
NIGHT...MOVING OFFSHORE DURING FRIDAY. A STRONG COLD FRONT WILL
MOVE WEST TO EAST ACROSS THE AREA LATE FRIDAY NIGHT AND SATURDAY
MORNING.

RISING HEIGHTS AND SUNSHINE WILL BRING THE WARMEST TEMPS OF THE
WEEK THURSDAY AFTERNOON...LOWER TO MID 80S. A SEABREEZE WILL KEEP
HIGHS AT THE BEACHES AROUND 80. LONGER NIGHTS AND A RATHER DRY
COLUMN SHOULD ALLOW LOWS TO DROP TO THE LOWER TO MID 60S THURSDAY
NIGHT.

FRIDAY LOOKS TO BE DRY MOST OF THE DAY AS THE MODELS CONTINUE TO
SLOW THE EASTWARD PROGRESSION OF DEEP UPSTREAM TROUGH.
THEREFORE...WILL SLOW THE TIMING OF SHOWERS AND THUNDERSTORMS.
SHOWERS AND THUNDERSTORMS MAY REACH THE WESTERNMOST AREAS LATE
FRIDAY AFTERNOON. STRONG FRONTAL LIFT DOES COMBINE WITH A
MOISTENING COLUMN AND SOME UPPER LEVEL SUPPORT...GIVING ENOUGH
CONFIDENCE TO WARRANT A LIKELIHOOD OF SHOWERS AND THUNDERSTORMS
FRIDAY NIGHT THROUGHOUT THE FORECAST AREA.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 300 PM WEDNESDAY...MID LEVEL TROUGH SETS UP OVER THE EAST
COAST SAT...REMAINING IN PLACE THROUGH THE END OF THE PERIOD. THIS
TROUGH WILL KEEP TEMPERATURES BELOW CLIMO FOR THE WEEKEND...BUT
LACK OF DEEP MOISTURE KEEPS THE REGION DRY. BRUNT OF THE COLD
ADVECTION OCCURS SAT INTO SUN WITH TEMPS HOLDING STEADY OR FALLING
THROUGH SAT AFTERNOON. BOUNDARY LAYER MIXING MAY HELP TEMPER LOWS
A BIT SUN MORNING BUT STRENGTH OF COLD AIR WILL STILL LEAD TO LOWS
ON THE ORDER OF 10 DEGREES BELOW CLIMO. UPPER 40S WILL BE POSSIBLE
IN MANY AREAS. AIR MASS WILL MODIFY SOME ON SUN BUT RADIATIONAL
COOLING WILL COME INTO PLAY SUN NIGHT. COOLING WILL NOT BE
MAXIMIZED AS THE RIDGE AXIS SHIFTS OFFSHORE BEFORE DAYBREAK BUT
LOWS MON MORNING WILL STILL END UP SIMILAR TO SUN MORNING. RETURN
FLOW SETS UP MON THROUGH WED...BRIEFLY BROKEN BY PASSAGE OF
FRONTAL REMAINS ON TUE. FRONT IS WASHED OUT BY THE TIME IT REACHES
THE AREA...HAVING LITTLE IN THE WAY OF MOISTURE WITH IT AND ITS
PASSAGE WILL BE DRY. TEMPERATURES WILL RUN BELOW CLIMO INTO MON
BEFORE CLIMBING SLIGHTLY ABOVE CLIMO LATE IN THE PERIOD.

&&

.AVIATION /03Z THURSDAY THROUGH MONDAY/...
AS OF 00Z...VFR PREVAILS ACROSS THE FORECAST AREA THIS EVENING AS
HIGH PRESSURE SETTLES OVER THE REGION. A COUPLE STRAY SHOWERS HAVE
DEVELOPED W-NW OF KLBT THIS EVENING...BUT THESE WILL BE SHORT-
LIVED WITH THE LOSS OF DAYTIME HEATING. THE ONLY IMPACT TO KLBT
WILL BE A BRIEF PERIOD OF INCREASING MID LEVEL CLOUDINESS.
OTHERWISE...CLEAR AND CALM CONDITIONS TONIGHT FAVOR THE
DEVELOPMENT OF AT LEAST PATCHY AREAS OF MVFR/IFR FOG EARLY THU.
EXPECT MVFR VSBYS TO DEVELOP AFTER 06Z...BEGINNING WITH THE INLAND
TERMINALS FOLLOWED BY THE COASTAL SITES. HAVE INCLUDED TEMPO IFR
VSBYS FOR KFLO/KLBT IN THE 09-12Z WINDOW...THOUGH VSBYS COULD
BOUNCE AROUND BETWEEN MVFR/IFR LEVELS BEFORE THIS TIME. HAVE KEPT
THE COASTAL TERMINALS MVFR ATTM...BUT SOME TEMPO IFR COULD BE
ADDED WITH THE NEXT ISSUANCE. ONCE THE FOG DISSIPATES AFTER
12Z...THU WILL BE VFR WITH LIGHT/VRBL WINDS BECOMING SOUTH IN THE
AFTERNOON.

EXTENDED OUTLOOK...MVFR/IFR VSBYS POSSIBLE EARLY FRI MORNING.
SHOWERS AND A CHANCE OF TSTMS/MVFR LATE FRI/EARLY SAT WITH A COLD
FRONT. OTHERWISE VFR.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1045 PM WEDNESDAY...NO CHANGES NEEDED FROM THE PREVIOUS
UPDATE.

PREVIOUS DISCUSSION..............................................
AS OF 730 PM WEDNESDAY...BROAD SFC RIDGING FROM THE EASTERN GREAT
LAKES HIGH WILL EXTEND DOWN THE EAST COAST OVERNIGHT. SFC PRESSURE
PATTERN WILL BE CONDUCIVE FOR NNE-ENE WINDS AT 10 KT OR LESS. EVEN
10 KT MAY BE PUSHING IT GIVEN THE LACK OF A SFC PG. SIGNIFICANT
SEAS WILL RUN 2 FT OR LESS...AND CONSIST OF A LAZY 1 FOOT ENE
GROUND SWELL EXHIBITING 13 SECOND PERIODS COMBINED WITH LOCALLY
PRODUCED WIND DRIVEN WAVES AT 6 SECOND PERIODS.

PREVIOUS DISCUSSION....................................
AS OF 300 PM WEDNESDAY...THE FRONT THAT HAD BEEN NEARLY STALLED WELL
OFFSHORE FOR A WHILE NOW THAT HAS BEEN BOLSTERING THE NE FLOW WILL
FINALLY PULL AWAY ENOUGH TO NO LONGER BE A LOCAL WIND-MAKER.
SIMILARLY A WEAK RIDGE OF HIGH PRESSURE WILL SETTLE INTO THE
CAROLINAS, ITS PARENT ANTICYCLONE ALL THE WAY UP THE EAST COAST INTO
THE CANADIAN MARITIMES. LOOK FOR A DECREASING N TO NE FLOW LOCALLY,
LIKELY SETTLING TO JUST 10 KT. SEAS WILL ABATE TO JUST 2 FT
AREA-WIDE.

SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...WINDS AND SEAS WILL STILL BE RATHER
BENIGN INTO FRIDAY MORNING AS HIGH PRESSURE MOVES PROGRESSIVELY
OFFSHORE. A LAND BREEZE MOVING OFFSHORE WILL KEEP WINDS OUT OF THE
NORTH THURSDAY MORNING. THE DIRECTION WILL VEER TO THE SE AND S
THURSDAY AFTERNOON AND EVE AND TO THE SW LATE THURSDAY NIGHT. WIND
SPEEDS WILL BE LESS THAN 10 KT AND SEAS LESS THAN 3 FT. AS A
STRONG COLD FRONT APPROACHES THE WATERS FROM THE WEST ON FRIDAY...
WINDS AND SEAS WILL BEGIN TO INCREASE. SW WINDS FRIDAY AFTERNOON
WILL INCREASE TO AROUND 15 KT WITH SEAS BUILDING TO 3 TO 4 FT.
SMALL CRAFT ADVISORY CONDITIONS ARE POSSIBLE FRIDAY NIGHT AS SW
WINDS INCREASE UP TO 20 TO 25 KT AND SEAS BUILD TO 5 TO 7 FT.

LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 300 PM WEDNESDAY...PASSAGE OF COLD FRONT EARLY SAT WILL
RESULT IN 15 TO 20 KT WINDS VEERING FROM SOUTHWEST TO NORTHWEST
DURING SAT. GUSTY WINDS SAT AFTERNOON WILL WANE IN THE EVENING AS
COLD ADVECTION WEAKENS AND GRADIENT RELAXES. OFFSHORE FLOW WILL
CONTINUE INTO SUN BUT WITH SPEEDS 10 TO 15 KT. SURFACE RIDGE AXIS
SHIFTS OFFSHORE LATE SUN WITH WINDS BECOMING LIGHT AND VARIABLE
BEFORE BACKING TO SOUTHWEST 10 TO 15 KT MON INTO MON NIGHT. WIDE
RANGE OF SEAS AT THE START OF THE PERIOD...2 TO 6 FT...WILL NARROW
AS OFFSHORE FLOW DEVELOPS AND SPEEDS DECREASE. SEAS SUN WILL BE 1
TO 3 FT DROPPING TO 2 FT OR LESS FOR MON.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...RJD
NEAR TERM...DCH/MBB
SHORT TERM...RJD
LONG TERM...III
AVIATION...BJR




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