-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KILM 031726
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
1226 PM EST MON MAR 3 2014

.SYNOPSIS...
A STRONG COLD FRONT WILL BARREL ACROSS THE EASTERN CAROLINAS THIS
AFTERNOON...BRINGING AN ABRUPT END TO THE UNSEASONABLY WARM
TEMPERATURES. COLD HIGH PRESSURE WILL GRADUALLY WEDGE SOUTH ACROSS
THE AREA AND PERSIST THROUGH WEDNESDAY AS A WAVE OF LOW PRESSURE
MOVES UP ACROSS THE SOUTHEAST COAST. A STRONGER LOW PRESSURE SYSTEM
RISING OUT OF THE GULF OF MEXICO WILL TRACK NORTHEAST ALONG THE
CAROLINA COASTLINE THURSDAY INTO FRIDAY. HIGH PRESSURE WILL BUILD
IN BEHIND THIS SYSTEM FRIDAY NIGHT INTO SATURDAY. ANOTHER COLD
FRONT WILL SWEEP ACROSS THE REGION ON SUNDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM MONDAY...DEBATING SOME CHANGES TO THE FORECAST/ADVISORY
BUT NOT MAKING ANY AT THIS TIME. 12Z WRF HOLDING ONTO MAINLY
NON-MEASURABLE PRECIP LONGER AFTER TEMPS DROP BELOW FREEZING. THIS
WOULD IMPLY SOME FREEZING DRIZZLE FURTHER SOUTH THAN CURRENTLY
PORTRAYED AND THUS THE NEED FOR SOME ADDITIONAL COUNTIES TO BE ADDED
TO THE ADVISORY. LIKE PREVIOUS MODEL RUNS THE WRF SHOWS VERY DRY AIR
ALOFT INCLUDING DENDRITIC ZONE BY THE TIME THERMAL PROFILES SUPPORT
PTYPE ISSUES. THE DIFFICULTY IN THIS FORECAST IS NOT ONLY RELATED TO
HOW MARGINAL THE EVENT WILL BE FOR MOST AREAS...BUT ALSO THE FACT
THAT ICE PELLETS MAY END UP BEING MORE FAVORED THAN FREEZING RAIN AS
THE SURFACE-BASED COLD AIR WILL VERY QUICKLY ESTABLISH A THICKNESS
THAT IS CLOSE TO THE THRESHOLD FOR COMPLETE REFREEZING...ESP WITH
SUCH LIGHT PRECIP RATES. WILL AWAIT THE 12Z GFS AND SOME MORE SREF
RUNS BEFORE MAKING CHANGES...IF ANY. IT MAY ALSO END UP BEING
SOMETHING DONE CLOSER TO THE ZERO HOUR/TIME OF EVENT. PREV FOLLOWS:

AS OF 600 AM MONDAY...A WAVE OF LOW PRESSURE MOVING UP ALONG A
STRONG COLD FRONT WILL BRING INCREASING LIFT AS PRECIPITABLE WATER
VALUES CLIMB TO ABOUT AN INCH AND A THIRD. THE MOISTURE WILL BE
DEEPEST... THROUGH ABOUT 20 TO 25 KFT TODAY...AND THIS IS WHEN THE
ENVIRONMENT WILL ONLY BE ABLE TO SUPPORT LIQUID PRECIPITATION. I
WILL CARRY THE HIGHEST POPS DURING THE DAY...CATEGORICAL. I WILL
ALSO CARRY THE HEAVIEST QPF DURING THIS TIME...0.15 TO 0.30 INCHES.

A STRONG AND SHALLOW COLD FRONT WILL SINK SOUTH ACROSS THE FORECAST
AREA THIS AFTERNOON...REACHING THE NORTHERN TIER OF COUNTIES EARLY
TO MID AFTERNOON AND THEN ACROSS THE REMAINDER OF THE FORECAST AREA
LATE AFTERNOON AND EARLY EVE. ISENTROPIC LIFT WILL BE ON THE
INCREASE AS SHALLOW COLD AIR ON NORTHERLY WINDS IS REINFORCED
THROUGH ABOUT 4 KFT WITH A DEEP AND STRONG WSW TO W FLOW ABOVE THAT.

AN UNSEASONABLY WARM START WILL ALLOW TEMPS TO REACH INTO THE 60S...
WELL UP INTO THE 60S TO AROUND 70 FOR AREAS ALONG AND S OF A UDG TO
CPC TO BURGAW LINE. HOWEVER...TEMPS ARE EXPECTED TO TAKE A QUICK
TUMBLE AS WINDS TURN NNE BEHIND THE SHALLOW FRONT. TEMPS WILL BE
DROPPING INTO AND THROUGH THE 30S DURING THE EVE AND BELOW FREEZING
BY MID OR LATE EVE ACROSS THE N AND ELSEWHERE OVERNIGHT. AT THE SAME
TIME THIS IS HAPPENING...THE COLUMN WILL BE SIGNIFICANTLY DRYING
WITH NO MOISTURE IN THE DENDRITIC GROWTH ZONE. THE SHALLOWNESS OF
THE MOISTURE...4 TO 5 KFT WILL ONLY ALLOW FOR LIGHT PRECIPITATION.
WILL BEGIN A WINTRY MIX THIS EVE ACROSS THE N...SLEET/SNOW GRAINS
AND EVENTUALLY FREEZING RAIN/DRIZZLE. THIS TREND WILL THEN SETTLE S
LATE EVE AND OVERNIGHT. VERY LIGHT PRECIPITATION MAY LINGER INTO
EARLY TUE AS PATCHY FREEZING DRIZZLE AS DRY AIR IS RELUCTANT TO MAKE
IT ALL THE WAY DOWN TO THE SURFACE.

GIVEN THIS SCENARIO...HAVE DECIDED TO ISSUE A WINTER WEATHER
ADVISORY FOR THE NORTHERN TIER OF COUNTIES...DARLINGTON...
MARLBORO...DILLON...ROBESON...BLADEN AND PENDER. THE ADVISORY IS
FROM 6 PM THIS EVE THROUGH 7 AM TUE. ALTHOUGH THIS IS NOT A HIGH
CONFIDENCE FORECAST...THE HIGHEST PROBABILITIES FOR MINOR ICE
ACCRETION ARE IN THESE AREAS. DO EXPECT ANY SLEET/SNOW GRAINS
TO MELT UPON IMPACT GIVEN EVE GROUND TEMPS WILL STILL BE WELL UP IN
THE 40S. FREEZING RAIN AND DRIZZLE WILL ALSO HAVE A DIFFICULT TIME
ACCRETING TO ROAD SURFACES AS THEY WILL STILL BE MANY DEGREES ABOVE
FREEZING DURING THE EVE. BRIDGES AND EXPOSED SURFACES WOULD STAND
THE BEST CHANCE OF MINOR ICE ACCRETION. THE RISK FOR ICING WILL
INCREASE AS THE NIGHT AND EARLY MORNING PROGRESSES AS TEMPS FALL
INTO THE 20S. LATER FORECASTS WILL HAVE TO FURTHER EVALUATE THE RISK
FOR WINTRY PRECIPITATION AND ICING AND IT IS POSSIBLE WINTER WEATHER
ADVISORIES COULD EXPAND TO INCLUDE OTHER COUNTIES.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 300 AM MONDAY...LOOKS LIKE A CLOUDY DAMP AND RELATIVELY COLD
MID WEEK PERIOD FOR THE COASTAL CAROLINAS. TEMPS TUESDAY WILL BE
RUNNING A GOOD 20 TO 30 DEGREES COLDER THAN PREVIOUS COUPLE OF DAYS
WITH READINGS CLOSER TO 40 DEGREES FOR THE MAX T AND MANY PLACES
REMAINING IN THE 30S MOST OF THE DAY WITH WIND CHILL TEMPS RUNNING
EVEN COOLER IN STIFF NORTHERLY FLOW WITH MOSTLY CLOUDY TO CLOUDY
SKIES. DRIER AIR WILL ADVECT IN INITIALLY BUT THIS SHALLOW COLD
NORTHERLY FLOW EARLY TUESDAY WILL BEGIN TO BE OVERRUN WITH SOUTHERLY
FLOW THROUGH THE LOW LEVELS ABOVE THE SURFACE. THEREFORE EXPECT
STRATUS DECK TO DEVELOP THROUGH TUES.

ISENTROPIC LIFT WILL INCREASE THROUGH LATE TUES INTO WED AS A WAVE
OF LOW PRESSURE RIDES UP FROM THE GULF. GFS SHOWS THIS LOW DEEPENING
JUST OFF THE SOUTHEAST COAST PRODUCING A PINCHED GRADIENT AND
INCREASING NORTHERLY FLOW AT THE SURFACE THROUGH WED MORNING. THIS
WILL ENHANCE THE LIFT AND MAY SEE A DECENT AMOUNT OF RAIN ON WED
ESPECIALLY ALONG THE COAST. THE ECMWF IS LESS BULLISH WITH LOW OFF
THE COAST AND THEREFORE NOT PRODUCING AS MUCH PCP FOR WED. OVERALL
WILL KEEP WITH CLOUDY DAMP AND COLD WEATHER THROUGH MUCH OF THE
PERIOD. THE SOUNDING PROFILES KEEP FZN PCP OUT OF THE FORECAST BUT
AS TEMPS DROP OFF TUES NIGHT THERE MAY BE A FEW HOURS OF BELOW
FREEZING TEMPS MAINLY NORTHWEST PORTION OF CWA MAINLY NORTHWEST OF
LUMBERTON AREA. THEREFORE HAVE INCLUDED A MIX OF RAIN OR FREEZING
RAIN IN FORECAST IN THAT AREA. THE BEST LIFT WILL REMAIN MORE
ALIGNED WITH COAST AND THEREFORE HIGHEST QPF AMOUNTS WILL BE CLOSER
TO THE COAST. THIS FIRST IMPULSE WILL LIFT OFF TO THE NORTHEAST BY
WED NIGHT AND SHOULD SEE MAINLY CLOUDS WED NIGHT. TEMPS ON WED WILL
BE SLIGHTLY WARMER BUT STILL WELL BELOW NORMAL WITH HIGHS REACHING
NEAR 50 MOST PLACES.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 300 AM MONDAY...SHORTWAVE IN THE MID TO UPPER LEVELS WILL DIG
DOWN ACROSS THE GULF COAST ON THURS WITH DEEPENING LOW PRESSURE AT
THE SURFACE. THIS LOW WILL RIDE UP FORM THE GULF COAST ALONG THE
SOUTHEAST COAST THURS INTO THURS NIGHT. THE BEST LIFT WILL ONCE
AGAIN BE ALIGNED CLOSER TO THE COAST BUT MID TO UPPER LEVEL DYNAMICS
WILL SUPPORT CHC OF PCP INLAND. THE SHALLOW COOL AIR IN PLACE WILL
MODIFY ENOUGH WITH WEDGE WEAKENING TO KEEP ALL LIQUID PCP IN
FORECAST. THE GREATEST QPF WILL BE TAKE PLACE THROUGH THE DAY ON
THURS.

THIS SYSTEM WILL LIFT OFF TO THE NORTHEAST BY EARLY FRI. KEPT SOME
PCP IN FIRST HALF OF FRIDAY BUT SHOULD SEE CLOUDS AND PCP CLEAR OUT
THROUGH THE DAY WITH A DEEP DRY AND COOL NORTHERLY FLOW DEVELOPING.
TEMPS IN THE 40S TO LOW 50S ON THURS WILL BEGIN TO REBOUND TOWARD
NORMAL BY FRI IN INCREASING AFTN SUNSHINE AND WILL BE BACK UP ABOVE
NORMAL BY SAT AS HIGH PRESSURE MOVES OVER THE AREA IN WESTERLY FLOW.

HIGH PRESSURE WILL SHIFT OFF SHORE BY LATE SATURDAY WITH A  SW
RETURN FLOW SETTING UP. A COLD FRONT WILL APPROACH FROM THE
NORTHWEST BY EARLY SUNDAY. WILL SEE INCREASING MAINLY HIGH CLOUDS
THROUGH SAT NIGHT AND A CHC OF PCP BACK IN THE FORECAST...MAINLY IN
THE WAY OF A FEW SHOWERS AS FRONT MOVES THROUGH ON SUNDAY.

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
-- Changed Discussion --
AS OF 12Z...AREA OF RAIN NOW IMPACTING KFLO AND KLBT WITH MVFR
CONDITIONS FOR VISIBILITIES. THIS AREA OF RAIN IS EXPECTED TO WORK IT
WAY TO THE COASTAL TAFS IN THE NEXT FEW HOURS. AN ARCTIC AIRMASS IS
MOVING SOUTHWARD AND IT WILL BRING IN IFR CONDITIONS AS CEILINGS
WILL LOWER LATER TODAY AND IN THE OVERNIGHT AREA. THERE IS A LOW
PROBABILITY FOR FREEZING RAIN THROUGH 06 UTC AND FREEZING DRIZZLE
FROM 06 TO 12 UTC TUESDAY. THE CONFIDENCE ON THIS FREEZING
PRECIPITATION IS LOW ENOUGH TO KEEP OUT OF THE TAFS AT THIS TIME.
CEILINGS ARE EXPECTED TO RISE INTO THE MVFR RANGE INLAND BY EARLY
TUESDAY AND MID-MORNING AT THE COAST.

EXTENDED OUTLOOK...MVFR/CHANCE SHOWERS THROUGH THE PERIOD. BEST
CHANCE PRECIPITATION/IFR WED AND THURS EVNG THROUGH FRI.
-- End Changed Discussion --

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM MONDAY...WIND A LITTLE SLOWER TO RAMP UP AS EVEN BUOY
41013 STILL ONLY SHOWING 15KT...BUT STILL EXPECTED TO RAMP UP
PRECIPITOUSLY NEXT FEW HOURS AS COLD FRONT AND LOW PRESSURE APPROACH
FROM THE NW. OTHER THAN THE SLIGHT ADJUSTMENT TO INITIAL CONDITIONS
THERE ARE NO CHANGES TO THE FORECAST OR THE GALE WARNING. PREVIOUS
FOLLOWS:

AS OF 600 AM MONDAY...WILL RAISE A GALE WARNING WITH THIS PACKAGE.
SW WINDS WILL INCREASE AHEAD OF A STRONG COLD FRONT APPROACHING FROM
THE NORTH. WARM AIR OVERRIDING CHILLY SEA SURFACE TEMPS WILL CREATE
A RATHER STABLE ENVIRONMENT AND THIS WILL HELP MITIGATE THE WIND
SPEEDS REALIZED AT THE SURFACE. SURFACE WIND SPEEDS PRIOR TO FRONTAL
PASSAGE ARE EXPECTED TO INCREASE TO 20 TO 25 KT WHILE WINDS AT
AROUND 5 KFT WILL INCREASE TO MORE THAN 50 KT. SW WINDS WILL SHIFT
ABRUPTLY TO N AND THEN NNE BEHIND THE SOUTHWARD PROGRESSING FRONT
THIS AFTERNOON AND EARLY EVE. THE PRESSURE GRADIENT WILL SHARPLY
TIGHTEN. THE STRONGEST SUSTAINED WINDS ARE EXPECTED THIS EVE AND
TONIGHT...UP TO 20 TO 30 KT WITH FREQUENT GALE FORCE WIND GUSTS AS
HIGH AS 35 TO NEARLY 40 KT...HIGHEST ACROSS THE OUTER WATERS. SEAS
WILL BUILD TO 5 TO 7 FT TODAY AND UP TO 8 TO 9 FT ACROSS THE OUTER
WATERS TONIGHT.

SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 300 AM MONDAY...STIFF NORTHERLY WINDS UP TO 20 TO 25 KT
EARLY TUES WILL GRADUALLY DIMINISH TO 10 TO 15 KT BY TUESDAY
NIGHT.  THIS WILL ALLOW SEAS UP TO 5 TO 7 FEET WITH SCA CONDITIONS
EARLY TUES TO SUBSIDE DOWN TO 3 TO 5 FT BY TUESDAY NIGHT.

NORTHERLY FLOW WILL CONTINUE THROUGH WEDNESDAY AND WILL SPIKE UP
AGAIN AS WAVE OF LOW PRESSURE MOVES UP THROUGH THE SOUTHEAST
TIGHTENING THE GRADIENT WITH WINDS UP AROUND 15 KTS AND SEAS UP TO 4
TO 5 FT. SHOULD REMAIN BELOW SCA THRESHOLDS THROUGH WED.

LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 300 AM MONDAY...A MORE POTENT LOW WILL TRACK UP THE SOUTHEAST
COAST ON THURS. SHOULD SEE AN INCREASING NORTHERLY FLOW UP TO 20 KTS
WITH SEAS INCREASING UP TO 5 TO 7 FT...BACK INTO SCA THRESHOLDS.
THE FLOW MAY VARY DEPENDING ON EXACT TRACK OF LOW AS IT MOVES UP
ALONG THE SOUTHEAST COAST. A DEEPER DRIER NORTHERLY FLOW WILL
DEVELOP ON FRI AS HIGH PRESSURE BUILDS DOWN BEHIND LOW AS IT LIFTS
OFF TO THE NORTHEAST. WINDS WILL BEGIN TO DIMINISH AND SEAS WILL
FALL DOWN TO 4 TO 6 FT THROUGH FRI MORNING AND DOWN TO 2 TO 4 FT BY
THE END OF DAY AS HIGH PRESSURE SHIFTS CLOSER OVERHEAD.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
SC...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 7 AM EST
     TUESDAY FOR SCZ017-023-024.

NC...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 7 AM EST
     TUESDAY FOR NCZ087-096-105-106.

MARINE...GALE WARNING UNTIL 6 AM EST TUESDAY FOR AMZ250-252-254-256.
-- End Changed Discussion --

&&

$$

NEAR TERM...RJD
SHORT TERM...RGZ
LONG TERM...RGZ
AVIATION...DRH