FXUS62 KILM 271135
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
635 AM EST FRI NOV 27 2009

.SYNOPSIS...
GUSTY NORTHWEST WINDS WILL USHER IN PLENTY OF DRY AND COLD AIR
AS HIGH PRESSURE BUILDS IN BEHIND COLD FRONT THROUGH TODAY.
DAYTIME WINDS WILL EASE BY SATURDAY AS A DEEP SURFACE LOW OVER NEW
ENGLAND PULLS FARTHER AWAY. TEMPERATURES WILL REBOUND SUNDAY AND
MONDAY AS HIGH PRESSURE PASSES OVERHEAD AND SETTLES OFFSHORE. THE
NEXT CHANCE FOR RAIN WILL BE LATE MONDAY INTO EARLY TUESDAY...AS A
COLD FRONT DROPS SOUTHEAST ACROSS THE AREA. HIGH PRESSURE MAY
BUILD IN BRIEFLY TUESDAY AFTERNOON BEFORE ANOTHER STORM SYSTEM
MOVES INTO THE AREA FROM THE GULF COAST BY WEDNESDAY INTO
THURSDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM FRIDAY...FREEZE WARNING IS IN EFFECT FOR ALL COUNTIES 
WITH THE EXCEPTION OF THE IMMEDIATE 5 COASTAL COUNTIES. 

THE AREA REMAINS UNDER THE INFLUENCE OF CYCLONIC FLOW SFC THRU
ALOFT...AS A NEGATIVELY TILTED UPPER TROF ACROSS THE AREA CLOSES
OFF AND IS THEN PROGGED BY THE MODELS TO LIFT SLOWLY ENE THROUGH
TONIGHT. WITH WNW FLOW SFC THROUGH ALOFT...ANY LEFTOVER MOISTURE
AT ANY LEVEL WILL BE SCOURED OUT DUE TO THE UNIFORM DOWNSLOPE
TRAJECTORY IN THE WIND FIELD. THIS WILL RESULT IN A SUNNY DAY WITH
LIKELY NO CLOUDS TO OBSERVE OTHER THAN THE CU/SC OVER THE OFFSHORE
ATLANTIC WATERS DUE TO THE COLD AIR ADVECTION OVER THE WARMER
SSTS. MAX TEMPS TODAY WILL BE RATHER UNIFORM 50S DEGREE READINGS
ACROSS THE AREA DUE TO THE STRONG CAA. THE TIGHTENED SFC PG WILL
RELAX SOME TONIGHT...ESPECIALLY INLAND AND SW PORTIONS OF THE ILM
CWA DUE TO THE APPROACH OF THE UPPER RIDGE AND GULF COAST HIGH.
HOWEVER...AT THIS POINT NOT STRONG ENOUGH FOR WINDS TO TOTALLY
DECOUPLE. AS A RESULT...HAVE KEPT WINDS AT A MINIMUM OF 5 MPH.
THIS IS EXTREMELY IMPORTANT TO OVERNIGHT LOWS SINCE ALL OTHER
PARAMETERS FAVOR AN EXCELLENT NIGHT FOR RADIATIONAL COOLING.
THINKING IS THE NIGHT-TIME WILL REMAIN MIXED ENOUGH TO PRECLUDE
THAT FROM OCCURRING. OTHERWISE...THE FREEZE WARNING WOULD HAVE
INCLUDED THE COASTAL COUNTIES. WITH DEWPOINTS PROGGED BASICALLY IN
THE 20S...EXCEPT THE IMMEDIATE COAST...THE FREEZE WARNING INSTEAD
OF A FROST ADVISORY WAS CHOSEN. IF CONDITIONS CHANGE FOR THE
COASTAL COUNTIES...IE SFC BASED INVERSION TO DEVELOP AND BECOME
MUCH STRONGER THAN MODELS DICTATE RESULTING IN SFC WINDS
DECOUPLING...THEN A FROST ADV/FREEZE WARN MAY BE NEEDED FOR THE
COAST.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY...HIGH PRESSURE WILL MIGRATE EASTWARD THROUGH THE 
SHORT TERM PERIOD. LATEST MODEL RUNS CONTINUE TO SHOW A SHORTWAVE 
RIDING THROUGH THE SOUTHEAST WITH A BROADER RIDGE OVER THE EAST 
COAST. WITH PLENTY OF DRY AIR IN PLACE...EXPECT NOTHING MORE THAN A 
FEW CLOUDS POSSIBLE OVERNIGHT SAT INTO EARLY SUN. THIS MAY AFFECT 
THE POTENTIAL FOR THE TEMPS TO DROP AS MUCH AS THEY COULD UNDER 
CLEAR SKIES...BUT EXPECT TEMPS IN THE 30S ONCE AGAIN OVERNIGHT SAT. 
WARMING TREND WILL BEGIN ON SUN AS HIGH PRESSURE SLIPS OFF SHORE AND 
RETURN FLOW SETS UP THROUGH SUNDAY. THIS WILL HELP TO BRING WARMER 
AND MOISTER AIR BACK INTO THE AREA. PCP WATER VALUES WILL INCREASE 
UP ABOVE A HALF INCH BY SUN AFTN...BUT NOT EXPECTING ANY PCP UNTIL 
AFTER THE SHORT TERM PERIOD. OVERALL SHOULD SEE PLENTY OF SUNSHINE 
AND WITH AIR MASS MODERATING EXPECT AFTN HIGHS IN THE UPPER 60S AND 
OVERNIGHT LOWS SUN NIGHT INTO EARLY MONDAY TO BE SLIGHTLY 
WARMER...IN THE 40S WITH LOWER VALUES IN 
TRADITIONALLY COOLER PLACES

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 3 AM FRIDAY...HIGH PRESSURE CONTINUES TO SLIP FARTHER OFF 
SHORE ON MONDAY AS NEXT STORM SYSTEM APPROACHES FROM THE WEST. 
SHOULD SQUEEZE OUT ANOTHER DRY WARM DAY ON MONDAY IN AN INCREASING 
SW RETURN FLOW. LOW LEVELS REMAIN VERY DRY AS WINDS HAVE STRONG 
WESTERLY COMPONENT TO THEM. TEMPS SHOULD REACH UP NEAR 70. SHOULD 
JUST SEE INCREASING HIGH CLOUDS INITIALLY BUT PCP SHOULD HOLD OUT 
UNTIL LATER ON MON. BEST CHC OF PCP WILL COME MON NIGHT INTO EARLY 
TUES. COLD FRONT SHOULD CLEAR THE COAST TUES WITH HIGH PRESSURE 
BUILDING IN BEHIND IT ON TUES. THE FRONT SHOULD GET FAR ENOUGH SOUTH 
THAT WE MAY SEE CLEARING BY AFTN ON TUES. A COOLER AIR MASS WILL BE 
IN PLACE WITH TEMPS DOWN 5 TO 10 DEGREES FROM THE DAY BEFORE. BOTH 
GFS AND ECMWF NOW SHOW BRIEF HIGH PRESSURE BUILDING IN ON TUES...BUT 
A LOW PRESSURE SYSTEM MOVES UP FROM THE GULF COAST ON WED BRINGING 
PCP BACK INTO THE FORECAST FOR WED. COULD TURN OUT TO BE A DECENT 
QPF EVENT ON WED BEFORE LOW TRACKS OFF TO THE NORTHEAST ON THURS 
WITH HIGH PRESSURE BUILDING IN BEHIND IT LATE THURS INTO FRI.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
HIGH PRESSURE HAS REACHED THE DEEP SOUTH AND SETTLED OVER 
LOUISIANA. THE HIGH WILL SLIDE EAST AS LOW PRESSURE OVER THE 
NORTHEAST WILL DEEPEN AND MOVE NORTHEAST. THE GRADIENT BETWEEN THE 
TWO SYSTEMS WILL BRING GUSTY WEST NORTHWEST WIND TO ALL TAF SITES 
FOR THE FIRST HALF OF THE PERIOD. BY 00Z...WIND DIMINISHES BUT 
REMAINS STEADY OUT OF THE WEST AT 6 TO 12 KNOTS. BY THE WAY...VFR 
AND CLEAR SKIES UNDER THE INFLUENCE OF HIGH PRESSURE.

EXTENDED OUTLOOK...NEXT CHANCE FOR OTHER THAN VFR IS MONDAY
AFTERNOON AS COLD FRONT MOVES THROUGH THE AREA.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM FRIDAY...SMALL CRAFT ADVISORY TO CONTINUE ACROSS ALL 
WATERS INTO TONIGHT. RATHER LARGE AMPLITUDE NEGATIVELY TILT UPPER 
TROF ACROSS EAST COAST THIS MORNING TO CLOSE OFF ACROSS NEW ENGLAND 
AND LIFT SLOWLY ENE. INTENSIFIED SFC LOW IS PROGGED OFF NEW ENGLAND 
WITH ITS EXPANSIVE CIRCULATION TO EXTEND ACROSS THE AREA 
WATERS...AND IN COMBO WITH THE APPROACH OF THE SFC HIGH FROM THE 
GULF COAST STATES. THIS WILL RESULT IN A TIGHTENED SFC PG ACROSS THE 
AREA THIS MORNING THAT WILL CONTINUE WELL INTO TONIGHT. CYCLONIC 
CIRCULATION THRU THE ATMOSPHERE WILL RESULT IN GUSTY WEST TO 
NORTHWEST WINDS AND A LOCALLY PRODUCED RANGE OF VERY SHORT PERIOD 
WIND DRIVEN SEAS DUE TO THE OFFSHORE TRAJECTORY IN THE WINDS FIELD. 
DIMINISHING AND SUBSIDING TRENDS WILL OCCUR TONIGHT FIRST ACROSS THE 
SOUTHERNMOST WATERS BEFORE FINALLY REACHING THE NORTHERNMOST WATERS 
LATE. THIS A RESULT OF THE UPPER TROF/CLOSED LOW LIFTING TO THE ENE 
AND THE AREA BECOMING UNDER THE ANTICYCLONIC INFLUENCES OF THE 
APPROACH OF THE GULF COAST SFC HIGH AND EVENTUAL UPPER RIDGE. THE 
NAM WAS THE MODEL OF CHOICE FOR WIND USAGE...WITH TWEAKS OF 
ADDITIONAL MPH ADDED DUE TO OBSERVATIONS AND TRENDS OVER THE WATERS 
DURING AND AFTER THE CFP. WAVEWATCH3 PREFERRED OVER LOCALLY PRODUCED 
SWAN DUE 2 ITS HIGHER SEAS OUTPUT INITIALLY EVENTHOUGH GFS WAS NOT 
ILLUSTRATING THE HIGHER WIND FIELD LOCALLY.

SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY...AS HIGH PRESSURE MIGRATES EASTWARD THROUGH 
SAT...GRADIENT WILL WEAKEN AND CAA WILL SHUT OFF AND THEREFORE WINDS 
AND SEAS WILL DIMINISH. SEAS SHOULD DROP BELOW 3 FT BY SAT AFTN AND 
WILL ONLY INCREASE SLIGHTLY STARTING SUN AFTN AS HIGH PRESSURE SLIPS 
OFF SHORE AND RETURN FLOW SETS UP. SW WINDS WILL INCREASE UP TO 10 
TO 15 KTS OVERNIGHT SUN INTO EARLY MON AND THEREFORE SEAS WILL 
INCREASE UP TO 2 TO 4 FT.

LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 3 AM FRIDAY...HIGH PRESSURE WILL SHIFT FARTHER OFF SHORE AS 
STORM SYSTEM APPROACHES FROM THE WEST. WINDS WILL INCREASE UP TO 15 
TO 20 KTS BY MON AFTN IN THIS TIGHTENED GRADIENT FLOW. SEAS JUST 
STARTING TO RISE BY LATE SUN AND THEN INCREASING THROUGH MON WITH 
TIGHTENED GRADIENT FLOW AHEAD OF APPROACHING FRONTAL SYSTEM. SHOULD 
REACH JUST NEAR SCA CRITERIA IN OUTER WATERS MON NIGHT BEFORE FROPA 
HEADING INTO TUES MORNING. THE OFF SHORE FLOW BEHIND FRONT SHOULD 
ALLOW SEAS TO DECREASE ESPECIALLY NEAR SHORE THROUGH TUES.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...FREEZE WARNING FROM 1 AM TO 8 AM EST SATURDAY FOR SCZ017-023-
     024-032-033-039.

NC...FREEZE WARNING FROM 1 AM TO 8 AM EST SATURDAY FOR NCZ087-096-
     099.

MARINE...SMALL CRAFT ADVISORY UNTIL 1 AM EST SATURDAY FOR AMZ252-254-
     256.

     SMALL CRAFT ADVISORY UNTIL 7 AM EST SATURDAY FOR AMZ250.

&&

$$
SYNOPSIS...RGZ
NEAR TERM...DCH
SHORT TERM...RGZ
LONG TERM...RGZ
AVIATION...MDC