Area Forecast Discussion
Issued by NWS Wilmington, NC

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000
FXUS62 KILM 121718
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
1218 PM EST FRI FEB 12 2016

.SYNOPSIS...
LOW PRESSURE WILL MOVE ALONG THE COAST TODAY SPREADING A LIGHT MIX
OF RAIN AND WINTRY PRECIPITATION ACROSS THE AREA. AN ARCTIC COLD
FRONT WILL CROSS LATE TONIGHT AND BRING THE COLDEST AIR OF THE
SEASON THIS WEEKEND. RECORD LOWS ARE POSSIBLE SUNDAY MORNING. A
WARMUP WILL BEGIN MONDAY WITH TEMPERATURES REBOUNDING TO NORMAL
VALUES AHEAD OF A STRONG LOW PRESSURE SYSTEM WHICH WILL BRING GOOD
RAIN CHANCES ON TUESDAY. SEASONABLE WEATHER WILL FOLLOW THROUGH
LATE WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM FRIDAY...HAVE MADE NO CHANGES TO THE WINTER WEATHER
ADVISORY FOR THE MORNING UPDATE. RADAR IS SHOWING LIGHT BUT
PERSISTENT ECHOS OVER COASTAL NC WITH COVERAGE TRYING TO EXPAND
INLAND. HOWEVER THE VERY DRY SURFACE LAYER HAS SO FAR PREVENTED
MUCH EXPANSION. HAVE RECEIVED A FEW REPORTS OF LIGHT ICING ON
ELEVATED SURFACES IN COASTAL NC BUT NO REPORTS OF SIGNIFICANT
ICING. LIGHT RAIN AND FREEZING RAIN MIX WILL CONTINUE THROUGH THE
MORNING HOURS BEFORE TRANSITIONING TO ALL RAIN.

GRADUAL INTENSIFICATION OF THE LOW OFF THE COAST LATER THIS
MORNING AND AFTERNOON WILL INCREASE MOISTURE OVER THE
AREA...HELPING EXPAND THE PRECIP SHIELD. HOWEVER IT WILL LIKELY BE
A CASE OF TOO LITTLE TOO LATE AND THE BULK OF THE PRECIP...WHICH
WILL STILL NOT BE A LOT...IS LIKELY TO END UP FALLING NORTH OF THE
FORECAST AREA. TOTAL PRECIP AMOUNTS IN AREAS FORECAST TO
EXPERIENCE RAIN OR A MIX OF RAIN AND FREEZING RAIN/SLEET WILL BE
WELL UNDER 0.10 INCH.

&&

.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
AS OF 330 AM FRIDAY...EXTREMELY COLD AIR MASS IN PLACE FOR THE
WEEKEND...AND THERE IS A CHANCE FOR RECORD LOWS TO BE SET SUNDAY
MORNING...FOLLOWED BY RECORD LOW HIGHS SUNDAY AFTERNOON.

STRONG COLD ADVECTION WILL BE ONGOING TO START THE PERIOD BEHIND A
COLD FRONT AS ARCTIC HIGH PRESSURE DROPS INTO THE REGION ON THE
UPWIND SIDE OF A SHARPENING MID-LEVEL TROUGH. THIS HIGH PRESSURE
WILL MOVE OVERHEAD ON SUNDAY IN CONJUNCTION WITH SUBTLY INCREASING
THICKNESSES...BUT THIS WILL HAVE MINIMAL IMPACT ON TEMPERATURES THIS
PERIOD. NO PRECIP IS FORECAST...SO THE FORECAST CONCERN REVOLVES
AROUND THE EXTREMELY COLD AIR SET TO INVADE THE AREA.

850MB TEMPS SATURDAY WILL PLUMMET THROUGH THE AFTN AND INTO THE
EVENING...DROPPING AS LOW AS -12C SOUTHERN ZONES TO -15C NORTHERN
COUNTIES. COLD ADVECTION DURING PEAK HEATING USUALLY CREATES HIGHS
BELOW GUIDANCE...DESPITE FULL INSOLATION...AND THUS THE MOS NUMBERS
OF THE MID 40S WELL SOUTH AND AROUND 40 NORTH ARE LIKELY TOO WARM.
INHERITED HAS UNDERCUT THESE VALUES BY SEVERAL DEGREES AND WILL
MAINTAIN THIS FORECAST WITH HIGHS ONLY AROUND 35 FAR NORTHERN
ZONES...TO ABOUT 42 ALONG THE SOUTH SANTEE RIVER. THESE LOW HIGHS
AND RAPID COOLING SATURDAY NIGHT WILL PERMIT NEAR RECORD LOWS BY
SUNDAY MORNING:

RECORD LOWS (YEAR)/FORECAST FOR 2/14:

WILMINGTON: 18 (1968)/18

FLORENCE: 15 (1968)/18

NORTH MYRTLE BEACH: 17 (1955)/19

THESE WILL COMBINE WITH GUSTY WINDS TO PRODUCE ADVISORY-LEVEL
WIND CHILLS LATE SATURDAY NIGHT. CONTINUED COLD ADVECTION AND DRY-
ADIABATIC MIXING WILL KEEP WINDS UP ALL SATURDAY NIGHT...AND IN
FACT MAY BE STRONGER OVERNIGHT SATURDAY THAN DURING THE DAY. WINDS
OF AT LEAST 10-15 MPH WILL REMAIN GUSTY...AND THIS WILL PRODUCE
WIND CHILLS IN THE LOW SINGLE DIGITS. BEING 4TH PERIOD WILL NOT
HOIST A WIND CHILL ADVISORY YET...BUT EXPECT ADVISORIES WILL BE
NEEDED FOR MOST IF NOT ALL OF THE CWA.

EVEN COLDER HIGHS ON SUNDAY...AND EVEN THOUGH COLD ADVECTION SHUTS
OFF...VERY SHALLOW MIXING AND THE COLD START WILL KEEP HIGHS BELOW
FREEZING FAR NORTH...TO THE UPPER 30S WELL SOUTH. RECORD-LOW
MAXIMUMS ARE POSSIBLE AT FLORENCE (RECORD 44) BUT WILL LIKELY BE
MISSED AT WILMINGTON (RECORD 29). SUBTLY WARMER LOWS SUNDAY WILL
OCCUR THANKS TO SLOWLY DEVELOPING ONSHORE FLOW...BUILDING CLOUD
COVER...AND INCREASING MID-LEVEL THICKNESSES. EXPECT MINS SUNDAY
NIGHT TO DROP TO AROUND 25-30 DEGREES...WARMEST AT THE SC COAST.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 330 AM FRIDAY...A BIG WARMUP FOR THE FIRST HALF OF NEXT
WEEK AS HIGH PRESSURE BECOMES POSITIONED OFFSHORE AND SHORTWAVE
RIDGING SLOWLY AMPLIFIES AHEAD OF A STRONG TROUGH DIGGING INTO THE
MS VLY. AHEAD OF THIS DEEP TROUGH...STRONG SURFACE CYCLOGENESIS
WILL DEVELOP AND MOVE INLAND OF THE COAST ON TUESDAY...BRINGING A
PERIOD OF RAIN FROM LATE MONDAY THROUGH TUESDAY EVENING. NO PTYPE
ISSUES THIS TIME AROUND...BUT GOOD MOIST ADVECTION AND STRONG
FORCING SUPPORTS A HIGH QPF EVENT WHICH COULD ENHANCE OR PROLONG
ONGOING RIVER FLOODING. TEMPS TUESDAY COULD ACTUALLY RISE TO WELL
ABOVE CLIMO IN THE WARM SECTOR AS THE LOW PASSES OFF TO THE
NORTH...WHILE REMAINING WEST OF THE COAST. BEHIND THIS LOW A QUICK
SHOT OF COOLER AIR WILL FOLLOW...BUT IT WILL TAKE A REINFORCING
SHOT OF COLD AIR LATE WEDNESDAY BEHIND A SECONDARY SHORTWAVE TO
DRIVE TEMPS BACK DOWN BELOW CLIMO FOR THE END OF THE PERIOD.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 18Z...CURRENTLY KLBT IS THE TAF WITH THE MOST WINTRY MIX.
THE PRECIPITATION IS EXPECTED TO CONTINUE FOR THE 1ST 3 HOURS OF
THE FORECAST THEN CLEAR OUT. CEILING AND SKY CONDITIONS CONTINUE
TO FALL INTO THE MVFR CATEGORY WITH A FLIRT AT THE COAST WITH
SOME IFR AT THE COASTAL TAF SITES. AS LOW PRESSURE OFF THE COAST
PULLS AWAY ALL SITES SHOULD SWITCH TO IFR BETWEEN 02 AND 04 UTC.

A STRONG SURGE OF COLD AIR IS EXPECTED BY MORNING SATURDAY AND
NORTHWEST WIND OF 12 TO 16 KT ARE EXPECTED WITH WIND GUST
INCREASING AFTER 13 UTC.

EXTENDED OUTLOOK...PREDOMINATELY VFR. UNSETTLED WEATHER ON MONDAY
AND TUESDAY WITH PRECIPITATION.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM FRIDAY...SEAS 1 TO 2 FT CONTINUE ACROSS THE WATERS
THIS MORNING BUT NORTHEAST WINDS HAVE STARTED TO PICK UP A BIT.
THIS TREND SHOULD CONTINUE DURING THE NEXT FEW HOURS AS DEVELOPING
LOW OFF THE COAST BECOMES MORE DEFINED. LOW WILL MOVE NORTHEAST
THIS AFTERNOON WITH WINDS BACKING TO NORTH AND THEN NORTHWEST IN
THE AFTERNOON. BRIEF PERIOD WHERE WINDS COULD GUST INTO THE 20 KT
RANGE BUT BY EVENING GRADIENT WILL BE DECREASING AND WINDS/SEAS
WILL BE ON A DOWNWARD TREND. MINIMAL CHANGES NEEDED FOR MORNING
UPDATE.

SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 330 AM FRIDAY...GUSTY NW WINDS SATURDAY WILL CREATE CHOPPY
SEAS ACROSS THE COASTAL WATERS. WIND SPEEDS WILL BE 15-25 KTS
SATURDAY AND SATURDAY NIGHT...DRIVING WAVE HEIGHTS TO 3-5 FT...WITH
ISOLATED 6 FTERS POSSIBLE. THESE ARE MARGINAL SCA CONDITIONS...AND
IT IS POSSIBLE A SMALL CRAFT ADVISORY WILL BE NEEDED SATURDAY. ON
SUNDAY...HIGH PRESSURE WILL MOVE JUST NORTH OF THE WATERS AND OFF
THE MID-ATLANTIC COAST...CAUSING THE GRADIENT TO RELAX AND WINDS TO
EASE TO AROUND 10 KTS WHILE VEERING TO THE EAST SUNDAY NIGHT. WINDS
WILL REMAIN LIGHT THROUGH THE END OF THE PERIOD...BUT A SUBTLE
INCREASE WILL BE NOTED VERY LATE AHEAD OF AN APPROACHING STORM
SYSTEM FROM THE WEST. SEAS SUNDAY WILL INITIALLY BE 3-5 FT THANKS TO
A SHORT PERIOD NORTHERLY WIND WAVE...BUT WILL FALL TO 1-2 FT LATE
WITH A 10 SEC SE SWELL INCREASING.

LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 330 AM FRIDAY...LOW PRESSURE SYSTEM WILL STRENGTHEN AND
MOVE QUICKLY ACROSS THE SE STATES...REMAINING WEST OF THE
WATERS...BEFORE LIFTING NE INTO NEW ENGLAND LATE TUESDAY. THIS
WILL DRIVE INCREASING WINDS ON MONDAY UP TO 15-25 KTS WHILE
VEERING FROM EAST TO SOUTH...AND THEN INCREASING EVEN FURTHER TO
20-25 KTS FROM THE SW THE FIRST HALF OF TUESDAY. AS THE LOW MOVES
OFF TO THE NORTHEAST LATE...ITS COLD FRONT WILL DRAG ACROSS THE
WATERS...ACCOMPANIED BY A WIND SHIFT TO THE NW BUT WITH STILL
ELEVATED SPEEDS. SEAS WILL BUILD VERY RAPIDLY MONDAY FROM 1-2 FT
MONDAY MORNING TO 4-7 FT MONDAY NIGHT...AND THEN POTENTIALLY AS
HIGH AS 10 FT TUESDAY WHEN THE LOW MAKES ITS CLOSEST APPROACH.
THIS MAY BE SLIGHTLY OVERDONE DUE TO THE SHORT DURATION OF THE
STRONGEST WINDS...BUT THE LONG FETCH AT LEAST PRESENTS THE
OPPORTUNITY FOR SUCH HIGH SEAS. WAVES WILL FALL QUICKLY BEHIND THE
COLD FRONT...BUT MUCH OF THE EARLY WEEK PERIOD WILL FEATURE POOR
MARINE CONDITIONS WITH HEADLINES A NEAR CERTAINTY.

&&

.TIDES/COASTAL FLOODING...
HAVE ISSUED YET ANOTHER COASTAL FLOOD ADVISORY FOR MINOR FLOODING
FOR THE LOWER CAPE FEAR RIVER. GUIDANCE INDICATES THAT THIS WILL
CONTINUE FOR THE NEXT SEVERAL HIGH TIDE CYCLES.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
     SCZ017-023-024-032-033-053-054.
NC...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
     NCZ087-096-099-105>110.
     COASTAL FLOOD ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR
     NCZ107.
MARINE...NONE.

&&

$$
SYNOPSIS...JDW
NEAR TERM...III
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...HAWKINS


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