-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KILM 121836
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
235 PM EDT WED MAR 12 2014

.SYNOPSIS...
-- Changed Discussion --
A STRONG COLD FRONT WILL CROSS THE AREA TONIGHT. MUCH COLDER
TEMPERATURES ARE EXPECTED THURSDAY AND FRIDAY AS CANADIAN HIGH
PRESSURE BUILDS ACROSS THE AREA. A GRADUAL WARMING TREND WILL OCCUR
OVER THE WEEKEND. A LOW PRESSURE SYSTEM MAY BRING UNSETTLED WEATHER
BY EARLY NEXT WEEK. HIGH PRESSURE BUILDS INTO THE AREA TUESDAY
THROUGH WEDNESDAY.
-- End Changed Discussion --

&&

.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
AS OF 130 PM WEDNESDAY...A BROAD AND POTENT SOUTHWEST FLOW IS IN
PLACE ACROSS THE AREA WITH SKIES PARTLY TO MOSTLY CLOUDY. THE LATEST
VISIBLE SATELLITE IMAGERY SHOWS FEATURES DELINEATED WELL WITH A
SURFACE TROUGH BISECTING NORTH AND SOUTH CAROLINA FROM NORTH TO
SOUTH. THE ARCTIC FRONT SHOWS UP EVEN BETTER CURRENTLY MOVING ACROSS
EASTERN TENNESSEE AND NORTHERN GEORGIA. I HAVE REMOVED POPS FOR THE
NEXT FEW HOURS VIA RADAR TRENDS. THE LATEST GFS IS SHOWING THE
SIGNAL THE NAM HAS BEEN ADVERTISING WITH A NARROW LINE OF SHOWERS
MOVING ACROSS THIS EVENING. THIS SHOULD OCCUR QUICKLY AROUND 0300
UTC.

STRONG COLD AIR ADVECTION WILL BE THE STORY LATE TONIGHT WITH
850MB TEMPERATURES DROPPING TO MINUS SIX DEGREES C. THE LATEST
GUIDANCE HAS TRENDED UP EVER SO SLIGHTLY AND I HAVE FOLLOWED SUITE
ALTHOUGH REALLY THE CHANGE AMOUNTS TO ONE OR TWO DEGREES. GUSTY
WINDS WILL KEEP SURFACE READINGS FROM DROPPING TOO FAST.

LATE ADDITION...WILL ISSUE A WIND ADVISORY FOR ALL AREAS FROM NOW
UNTIL 1000 UTC THURSDAY. AS USUAL...MAY NOT MEET SPECIFIC CRITERIA
BUT LONGEVITY OF THE GUSTS AND DEBRIS...IT IS WARRANTED.
-- End Changed Discussion --

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
-- Changed Discussion --
AS OF 230 PM WEDNESDAY...BIG CHANGES AT THE ONSET OF THE SHORT TERM
PERIOD IN THE WAKE OF THE PASSAGE OF A STRONG COLD FRONT.
TEMPERATURES WILL ONCE AGAIN DROP BELOW CLIMATOLOGY. IN FACT...THU/S
HIGH TEMPS WILL RANGE SEVERAL CATEGORIES BELOW NORMAL. SLIGHTLY
WARMER TEMPS AS LOW-LEVEL THICKNESS NUDGES UPWARD AND THE AIR-MASS
MODIFIES FRIDAY. TIME-HEIGHT CROSS SECTIONS SHOW A VERY DRY COLUMN
IN PLACE WITH STRONG SUBSIDENCE THROUGH THE DAY ON THURSDAY. SOME
MOISTURE INCREASES ALOFT LATE FRIDAY BUT OVERALL SKIES WILL BE CLEAR
TO MOSTLY CLEAR THROUGH THE BULK OF THE SHORT TERM PERIOD. OTHER-
WISE...MOMENTUM TRANSFER WILL RESULT IN WINDY WEST TO NORTHWEST FLOW
THURSDAY...ESPECIALLY ACROSS THE NC ZONES. WINDS ARE EXPECTED TO
DECOUPLE THURSDAY EVENING WITH CLEAR SKIES SUPPORTING RADIATIONAL
COOLING. THUS MINS THURSDAY NIGHT WILL BE IN THE UPPER 20S WITH THE
COOL SPOTS DOWN INTO THE MID 20S. MUCH WARMER OVERNIGHT TEMPS ARE
EXPECTED BY FRIDAY NIGHT WITH WEAK SOUTHERLY FLOW AND INCREASING
HIGH CLOUDS.
-- End Changed Discussion --

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
AS OF 230 PM WEDNESDAY...A WEAK SURFACE PRESSURE PATTERN ON SATURDAY
WITH HIGH PRESSURE WELL OFF THE COAST PAIRED WITH ZONAL MID LEVEL
FLOW ON SATURDAY. EXPECT SEASONABLE TEMPS BUT ALSO PERHAPS
INCREASING CLOUD COVER IN THE LOW LEVEL WAA. UPPER PATTERN BECOMES
QUITE COMPLEX BY SUNDAY WITH THREE JET STREAM BRANCHES. ONE WILL BE
AROUND POLAR VORTEX OVER HUDSON BAY...THE SECOND AROUND A CUTOFF
OVER MEXICO...AND THE THIRD DIVING ACROSS THE PLAINS AND OHIO
VALLEY. THE MEDIAN JET STREAM WILL BE THE MOST INSTRUMENTAL LOCALLY
AS IT GENERATES LOW PRESSURE ALONG A COLD FRONT SUNDAY NIGHT INTO
MONDAY. THERE DOES APPEAR TO BE AN APPRECIABLE INFLUX OF ATLANTIC
AND GOMEX MOISTURE PRECEDING THIS SETUP LEADING TO SOME FAIRLY GOOD
RAINFALL CHANCES AND PERHAPS AMOUNTS. ONE THING THAT DOES LOOK
DIFFERENT IN THE EXTENDED IS THE CLEANLINESS OF THE FROPA. THE
BOUNDARY WAS PREVIOUSLY PROGGED TO LINGER AND KEEP THE WEATHER
UNSETTLED WHEREAS NOW IT MAY BLOW THROUGH AND ALLOW GOOD DRYING BY
TUESDAY AFTER BRINGING A MONDAY AND MONDAY NIGHT THAT WILL BE COLDER
THAN PREVIOUSLY PORTRAYED.
-- End Changed Discussion --

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 18Z...ISOLATED PATCHES OF SHOWERS ARE POSSIBLE THIS
AFTERNOON...HOWEVER COVERAGE ONLY WARRANTS A VCSH MENTION. SOUTHWEST
WINDS WILL INCREASE THROUGH THE AFTERNOON HOURS AS LOW PRESSURE AND
A STRONG COLD FRONT APPROACH THE REGION. THE NAM IS HINTING AT A
SMALL BAND OF SHOWERS ALONG THE FRONT THIS EVENING...AND HAVE ADDED
A TEMPO GROUP FOR SHOWERS ALONG THE COAST. POST FRONTAL...LOOK FOR
STRONG WEST NORTHWEST WINDS WITH THE STRONG COLD AIR ADVECTION. VFR
CONDITIONS WILL PREVAIL THROUGH THE OVERNIGHT HOURS INTO THURSDAY
WITH A CONTINUED GUSTY NORTHWEST WIND.

EXTENDED OUTLOOK...VFR EXPECTED THURSDAY AND FRIDAY. CHANCE OF
SHOWERS ON SATURDAY. UNSETTLE WEATHER SUNDAY INTO MONDAY WITH
INTERMITTENT RAIN AND POSSIBLE MVFR/IFR CONDITIONS.

&&

.MARINE...
-- Changed Discussion --
NEAR TERM /THROUGH TONIGHT/...
AS OF 130 PM WEDNESDAY...THE MAIN ISSUE FOR THE NEAR TERM WILL BE
THE GALE WARNING WHICH IS ON SCHEDULE TO BEGIN AT 6 PM. THE LATEST
GUIDANCE HAS TRENDED A LITTLE SLOWER WITH THE FRONT...BUT AT THIS
LATE HOUR WILL NOT TWEAK THE TIME. WITH THE LATER TIMING WINDS AND
SEAS ARE LAGGING A BIT THIS AFTERNOON BUT WILL RESPOND RATHER
QUICKLY.

SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 230 PM WEDNESDAY...STRONG OFFSHORE FLOW THURSDAY MORNING WILL
GRADUALLY DIMINISH ACROSS THE COASTAL WATERS THURSDAY NIGHT AS THE
FLOW VEERS FROM THE WNW TO A NNE DIRECTION. LIGHT/VARIABLE FLOW WITH
SURFACE RIDGE IN THE VICINITY FRIDAY MORNING WILL BECOME SOUTHERLY
BY FRIDAY AFTERNOON AS THE RIDGE AXIS SHIFTS OFFSHORE. SW WINDS WILL
INCREASE TO 10-15 KT (CLOSER TO 15 KT CAPE FEAR) FRIDAY NIGHT. A
LARGE RANGE OF SEAS WILL EXIST THURSDAY WITH A STRONG OFFSHORE
TRAJECTORY. SEAS WILL BE HIGHEST OFF CAPE FEAR WHERE THE FETCH IS A
LITTLE LONGER. SEAS WILL QUICKLY SUBSIDE LATE THURSDAY NIGHT INTO
FRIDAY MORNING AS THE AFOREMENTIONED RIDGE TAKES CONTROL. A NICE
BOATING DAY FRIDAY WITH ATYPICAL OCEAN CONDITIONS FOR MARCH UNDER
RIDGE OF HIGH PRESSURE.

LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 230 PM WEDNESDAY...SOUTHWESTERLY RETURN FLOW MORE TYPICAL OF
THE WARM SEASON ON SATURDAY AS HIGH PRESSURE SITS WELL OFF THE
COAST. CHANGES EXPECTED HOWEVER AS COLD FRONT APPROACHING FROM THE
NW AND A COMPLEX FLOW PATTERN ALOFT EVOLVES. SURFACE LOW APPROACHES
FROM THE WEST AS IT CUTS ACROSS THE GULF STATES ON SUNDAY...POSSIBLY
HANGING UP THE FRONT THIS FAR EAST RIGHT OVER THE REGION LEADING TO
SOME UNCERTAINTY AS TO HOW SUNDAYS WINDS WILL PAN OUT. FROPA IS
SLATED FOR SUNDAY NIGHT LEADING TO A MODERATE NORTHERLY WIND ON
MONDAY AS THE HIGH BUILDS IN. NO ADVISORIES EXPECTED THROUGH THE
PERIOD. THE BEST CHANCE FOR SOME 5 FT SEAS LOOKS LIKE MONDAY BUT THE
OFFSHORE FLOW WILL KEEP THEM RELATIVELY CONFINED TO OUTER WATERS
WHILE WAVE SHADOWING LEADING TO SMALLER SEAS NEAR SHORE PRECLUDES
SCEC HEADLINES.
-- End Changed Discussion --

&&
.FIRE...
-- Changed Discussion --
AS OF 230 PM WEDNESDAY...GUSTY WINDS THURSDAY IN THE POST-FRONTAL
REGIME RESULTING FROM THE PRESSURE GRADIENT AND MOMENTUM TRANSFER
WILL BE CLOSE TO RED FLAG CRITERIA ACROSS A PORTION OF THE FORECAST
AREA (WINDS STRONGEST ACROSS THE NC ZONES). MEANWHILE...MIXING WILL
ALLOW DRIER CONDITIONS ALOFT TO FILTER TO THE SURFACE RESULTING IN
VERY LOW RELATIVE HUMIDITY DURING THE DAY. RECENT RAINFALL DID NOT
CONTRIBUTE MUCH TO FUEL MOISTURES PER NFDRS LOCATIONS...HOWEVER THE
COOL MID-MARCH TEMPERATURES EXPECTED THURSDAY ARE NOT SUPPORTIVE OF
IGNITION. PER COORDINATION...PLAN ON ISSUING A FIRE DANGER STATEMENT
FOR THE SC ZONES TO HEIGHTEN AWARENESS OF THE CONDITIONS FOR
WILDFIRES. GIVEN WINDS ARE EXPECTED TO BE A LITTLE STRONGER ACROSS
OUR NC ZONES PER COORDINATION WILL ISSUE A FIRE WEATHER WATCH
GENERALLY FROM 15-22Z THURSDAY.
-- End Changed Discussion --

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
SC...WIND ADVISORY UNTIL 6 AM EDT THURSDAY FOR SCZ017-023-024-032-
     033-039-053>056.

NC...WIND ADVISORY UNTIL 6 AM EDT THURSDAY FOR NCZ087-096-099-
     105>110.

     FIRE WEATHER WATCH FROM THURSDAY MORNING THROUGH THURSDAY
     AFTERNOON FOR NCZ087-096-099-105>110.

MARINE...GALE WARNING UNTIL 6 PM EDT THURSDAY FOR AMZ250-252-254-256.
-- End Changed Discussion --

&&

$$

NEAR TERM...SHK
SHORT TERM...SRP
LONG TERM...MBB
AVIATION...DL/SHK
FIRE...SRP