Area Forecast Discussion
Issued by NWS Wilmington, NC

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000
FXUS62 KILM 311938
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
338 PM EDT FRI OCT 31 2014

.SYNOPSIS...
WINDY AND CHILLY FOR SATURDAY WITH SOME SHOWERS. A POWERFUL COLD
FRONT WILL CROSS THE REGION SATURDAY MORNING. LOW PRESSURE WILL
STRENGTHEN OFF THE NORTH CAROLINA COAST ON SATURDAY AND THEN
RAPIDLY INTENSIFY AS IT MOVES TO THE NORTHEAST SATURDAY NIGHT AND
SUNDAY. COLD CANADIAN HIGH PRESSURE WILL KEEP IT CHILLY ON SUNDAY
AS SUNSHINE RETURNS. TEMPERATURES WILL MODERATE BEGINNING MONDAY
AS HIGH PRESSURE MOVES SLOWLY OFFSHORE.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 300 PM FRIDAY...MOTHER NATURE IS TRULY PROVIDING US WITH A
"TREAT" ON THIS HALLOWEEN...WITH A BEAUTIFUL FALL DAY ONGOING
ACROSS THE CWA. BUT RATHER THAN BEING CAST FROM A WITCHES
SPELL...A RIDGE OF HIGH PRESSURE IS RESPONSIBLE FOR THE SUNSHINE
WHILE A COLD FRONT OFFSHORE IS ASSISTING WITH THE COOL
TEMPERATURES. THIS TRANQUIL WEATHER WILL LAST FOR A SHORTER TIME
THAN ME GOING THROUGH A HAUNTED HOUSE HOWEVER...AS A STRONG LOW
PRESSURE BEGINS TO DEVELOP TONIGHT.

THE "TRICK" TO THE FORECAST INVOLVES A RAPIDLY DEEPENING UPPER LOW
CURRENTLY ACROSS THE GREAT LAKES. THIS IMPULSE WILL DIG INTO THE
CAROLINAS LATE TONIGHT...ALL WHILE DEEPENING TO A GHASTLY -4 TO -5
SD`S BELOW NORMAL WITH RESPECT TO 500MB HEIGHTS. THIS STRONG IMPULSE
WILL SPAWN A SURFACE LOW...AND WHILE MOST IMPACTS WILL HOLD OFF
UNTIL SATURDAY...DETERIORATING CONDITIONS WILL BE LURKING...WAITING
FOR THE SURFACE LOW TO MOVE INTO THE STRONG BAROCLINIC ZONE OFFSHORE
BEFORE COMING TO LIFE. GUIDANCE IS ALL UNDER-FORECASTING THE DRY AIR
TONIGHT SO HAVE SLOWED SHOWER DEVELOPMENT UNTIL AFTER MIDNIGHT...BUT
INCREASING CLOUD COVER WILL CLOAK THE FIRST QUARTER MOON IN AN EERIE
VEIL. CANNOT RULE OUT A FEW SHOWERS TONIGHT...MOSTLY WEST OF
I-95...SO BE ALERT FOR THAT POTENTIAL AS WELL AS THE GHOSTS AND
GOBLINS SURE TO BE ROAMING ABOUT.

WINDS WILL EASE TO NEAR CALM AFTER DARK MAKING FOR EASY BROOMSTICK
NAVIGATION...BUT ALSO ALLOW TEMPS TO PLUMMET AFTER DARK...SO THAT
SHIVER YOU FEEL MAY JUST BE FROM TEMPS IN THE 40S AND NOT A PASSING
SPIRIT. MINIMUMS MAY BE REACHED A FEW HOURS BEFORE DAWN HOWEVER AS
SW WINDS DEVELOP LATE AHEAD OF THE NEXT COLD FRONT...ALLOWING TEMPS
TO RISE FROM THE BOTTOM LIKE A ZOMBIE FROM THE GRAVE BEFORE SUNRISE
ON SATURDAY.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 300 PM FRIDAY...WINDY AND CHILLY WEATHER EXPECTED FOR SAT
WITH AT LEAST A LIKELIHOOD OF SHOWERS. A COLD FRONT WILL BE MOVING
ACROSS THE AREA SAT MORNING...USHERING IN A VERY CHILLY AIRMASS.
THIS WILL PREVENT TEMPS FROM RISING MUCH THROUGH THE DAY AND WE
EXPECT THE DIURNAL RANGE WILL BE UNSEASONABLY SMALL.

AN UPPER LOW AND ITS ASSOCIATED LIFT AND ENERGY WILL BE MOVING
ACROSS THE FORECAST AREA ON SAT. A SECONDARY AREA OF SURFACE LOW
PRESSURE IS EXPECTED TO STRENGTHEN OFFSHORE OF NORTH CAROLINA ON SAT
IN RESPONSE TO THE STRONG ENERGY ALOFT. THIS LOW WILL BECOME
DOMINATE AS IT MOVES RAPIDLY TO THE NORTHEAST AND AWAY FROM THE AREA
SAT NIGHT. AS THE PRESSURE GRADIENT SIGNIFICANTLY TIGHTENS...WIND
SPEEDS IN THE 1 TO 2 KFT LAYER WILL INCREASE TO 45 TO 50 KT. NW
WINDS AT THE SURFACE WILL INCREASE TO 25 TO 35 MPH WITH THE
STRONGEST WINDS EXPECTED DURING THE LATER HALF OF THE AFTERNOON AND
SAT NIGHT. WIND GUSTS UP TO 40 TO 45 MPH ARE EXPECTED...HIGHEST
ACROSS THE NORTH CAROLINA COAST IN CLOSEST PROXIMITY TO THE
STRENGTHENING AREA OF LOW PRESSURE. PORTIONS OF THE FORECAST AREA
MAY REQUIRE A WIND ADVISORY WITH LATER FORECASTS. STRONG WINDS WILL
ADD TO THE CHILL AS HIGHS ON SAT ARE ONLY EXPECTED TO REACH THE
UPPER 40S TO LOWER 50S WITH MID 50S ALONG COASTAL NORTH CAROLINA.
LOWS SAT NIGHT WILL FALL TO THE MID 30S INLAND TO UPPER 30S AND
LOWER 40S NEARER TO THE COAST. ALTHOUGH WINDS OVERNIGHT SAT WILL BE
DIMINISHING...THEY ARE NOT EXPECTED TO GO LIGHT AND SO WE DO NOT
EXPECT A FROST EXCEPT PERHAPS IN THE MOST WIND PROTECTED INLAND
AREAS NEAR SUNRISE SUN.

CHILLY AIR ALOFT ON SAT...AROUND MINUS 25 DEG C...WILL HELP TO
INCREASE THE INSTABILITY. DRY AIRMASS WILL MOISTEN BELOW 25 KFT SAT
AFTERNOON. COUPLE THE INCREASING MOISTURE WITH THE STRONG DYNAMICS
AND WE SHOULD BE ABLE TO WRING OUT NUMEROUS TO WIDESPREAD SHOWERS.
GIVEN THE BREVITY AND RATHER SHALLOW NATURE OF THE MOISTURE
RETURN...EXPECT RAINFALL AMOUNTS WILL NOT EXCEED A QUARTER OF AN
INCH AND MOST PLACES MAY NOT EXCEED A TENTH OF A INCH. SOME OF THE
SHOWERS THAT MANAGE TO GAIN SLIGHTLY MORE DEPTH MAY BE ACCOMPANIED
BY GRAUPEL. WILL NOT INCLUDE THUNDERSTORMS AT THIS TIME GIVEN WE
EXPECT THE CONVECTION TO BE SHALLOW. MIXED LAYER CAPE VALUES WILL BE
AT OR BELOW 200 J/KG...EVEN AT THE COAST. HOWEVER...IT IS A VERY
DYNAMIC SYSTEM AND SO AN ISOLATED LIGHTNING STRIKE CAN NOT BE RULED
OUT. THE RISK FOR THUNDERSTORMS WILL BE HIGHER ACROSS THE WARMER
OFFSHORE WATERS.

COLD HIGH PRESSURE WILL SLOWLY BUILD ACROSS THE EASTERN CAROLINAS IN
THE WAKE OF INTENSE LOW PRESSURE SUN AND SUN NIGHT. THIS WILL SET
THE STAGE FOR ANOTHER UNSEASONABLY COLD DAY AND A POSSIBLE FREEZE IN
MOST LOCATIONS SUN NIGHT. WINDS WILL BE STRONGEST IN THE MORNING AND
THEN DECREASE AS THE PRESSURE GRADIENT CONTINUES TO RELAX. HIGHS ON
SUN...EVEN WITH MAINLY SUNNY SKIES...WILL BE IN THE LOWER TO MID
50S. LOWS WILL BE VERY NEAR 32 DEGREES EXCEPT FOR POSSIBLY MID 30S
VERY NEAR THE COAST AND AT THE BEACHES.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 300 PM FRIDAY...THE EXTENDED WILL FEATURE A LOT OF AMPLITUDE
AT THE MID LEVELS FOR MOST OF THE PERIOD. EARLY ON...SHARP RIDGING
WILL MOVE ACROSS THE MISSISSIPPI VALLEY AND THEN OFF THE SOUTHEAST
COAST AS DEEP TROUGHING DEVELOPS ACROSS THE SOUTHWEST THAT
EVENTUALLY CUTS OFF. BY THURSDAY A SHORTWAVE ORIGINATING FROM THE
NORTHWEST WILL MOVE ACROSS WITH A DRY FRONT AT THE SURFACE. PRIOR
TO THIS AND JUST BEYOND...SURFACE HIGH PRESSURE WILL PREVAIL.
THERE IS LITTLE TO NO POPS IN THE FORECAST...JUST SLIGHT CHANCE
WITH THIS FRONT LATE WEDNESDAY AND THURSDAY. TEMPERATURE TRENDS
SHOW A SLOW MODERATING TREND FOR MONDAY THROUGH THURSDAY WITH
VALUES BELOW CLIMATOLOGY FOR THE MOST PART ESPECIALLY MORNING
LOWS. HIGHS DO CLIMB BACK INTO THE 70S WEDNESDAY AND THURSDAY
BEFORE FALLING BACK SLIGHTLY FRIDAY.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 18Z...MAINLY NORTHERLY WINDS TODAY AS HIGH PRESSURE SLOWLY
RETREATS. TONIGHT...STRONG UPPER LOW WITH AN UNSEASONABLY COLD
CORE WILL APPROACH THE REGION FROM THE NORTHWEST. NOT MUCH WILL
HAPPEN OVERNIGHT AS WE GET DRY SLOTTED AND THE GRADIENT AND COLD
AIR ADVECTION WILL NOT COMMENCE UNTIL MORNING...SO WHILE A BRIEF
SHOWER CANNOT BE RULED OUT...THE TERMINALS WILL LIKELY REMAIN DRY
UNTIL THE MORNING. A BRIEF PERIOD OF NEAR CALM WINDS IS EXPECTED
OVERNIGHT BEFORE STEADILY INCREASING TOWARDS DAWN AND ESPECIALLY
ON SATURDAY. GRADIENT INCREASES EVEN FURTHER JUST AFTER THE END
THE FORECAST PERIOD...HOWEVER ANY SHOWERS THAT DO OCCUR SATURDAY
WILL BUMP THE WINDS UP.

EXTENDED OUTLOOK...BREEZY TO WINDY CONDITIONS TO PERSIST INTO SUNDAY
AFTER LOW PRESSURE DEVELOPS OFF THE CAROLINA COAST...AND
ACCELERATES TO THE NE. VFR FOR MONDAY AND TUESDAY AS THE CENTER OF
STRONG HIGH PRESSURE MOVES OVERHEAD. LIGHT MORNING FOG POSSIBLE
WEDNESDAY.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 300 PM FRIDAY...STRENGTHENING LOW PRESSURE IS CENTERED WELL
TO THE EAST OF THE NC/VA BORDER...AND WILL CONTINUE TO MOVE
NORTHEAST ALONG A STALLED BOUNDARY TONIGHT. A WEAK HIGH PRESSURE
HAS RIDGED INTO THE CAROLINAS THIS AFTN...SEPARATING THE LOW
PRESSURE OFFSHORE FROM A STRONG COLD FRONT APPROACHING FROM THE
WEST...AND THUS THE GRADIENT WILL CONTINUE TO WEAKEN TONIGHT.
CURRENT N/NE WINDS OF 10-15 KTS WILL SLOWLY EASE TO BECOME LIGHT
AND VARIABLE OVERNIGHT...BEFORE RISING ONCE AGAIN FROM THE W/SW
AHEAD OF THE NEXT COLD FRONT BY SATURDAY MORNING. SEAS HAVE BEEN
PERSISTENTLY 3-5 FT TODAY...BUT ARE EXPECTED TO FALL FOR A SHORT
TIME TO 2-4 FT TONIGHT BEFORE RISING AGAIN BY DAWN...BUT WITH THE
NE WIND WAVE REPLACED BY AN AMPLIFYING SW CHOP. A GALE WARNING HAS
BEEN ISSUED BUT WILL BEGIN SHORTLY AFTER THE NEAR TERM.

SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 PM FRIDAY...A GALE WARNING IS IN EFFECT SAT AFTERNOON
AND NIGHT WITH A PERIOD OF SMALL CRAFT ADVISORY CONDITIONS
EXPECTED INTO SUN. AS LOW PRESSURE STRENGTHENS OFF THE NORTH
CAROLINA COAST AND THE PRESSURE GRADIENT TIGHTENS...SUSTAINED
WINDS SHOULD REACH GALE FORCE WITH GUSTS AS HIGH AS 40 TO 45 KT.
THE STRONGEST WINDS ARE EXPECTED LATER SAT AFTERNOON AND
ESPECIALLY SAT NIGHT. SEAS WILL EXCEED 6 FT ACROSS PORTIONS OF THE
WATERS BY MIDDAY SAT AND UP TO 6 TO 8 FT SAT NIGHT. NEAR
SHORE...SEAS WILL BE LOWER GIVEN THE STRONG OFFSHORE FLOW. IN THE
WAKE OF INTENSE LOW PRESSURE...WINDS AND SEAS WILL SUBSIDE SUN AND
SUN NIGHT. A BLOW OUT TIDE MAY OCCUR WITH LOW TIDE SAT EVE AND
AGAIN SUN MORNING.

LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 300 PM FRIDAY...A FEW HOURS OF STRONGER NORTHWEST WINDS
WILL CONTINUE MONDAY BEFORE SETTLING DOWN TO ESSENTIALLY LIGHT AND
VARIABLE BY DAYS END. THIS AS HIGH PRESSURE SETTLES OVERHEAD. THE
LIGHT WINDS WILL CONTINUE FOR THE REMAINDER OF THE PERIOD AS HIGH
PRESSURE IS SLOW TO MOVE AND THE AXIS ELONGATES TO KEEP WINDS
BENIGN. SEAS WILL MIRROR THE LIGHT WINDS WITH ONE TO TWO FEET
THROUGH THE PERIOD.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...GALE WARNING FROM NOON EDT SATURDAY TO 6 AM EST SUNDAY FOR
     AMZ250-252-254-256.

&&

$$

NEAR TERM...JDW
SHORT TERM...RJD
LONG TERM...SHK
AVIATION...JDW/DL




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