FXUS62 KILM 290207
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
907 PM EST SAT NOV 28 2009

.SYNOPSIS...
A GRADUAL WARMING TREND CAN BE EXPECTED THROUGH THE WEEKEND...AS
HIGH PRESSURE PASSES OVER THE AREA THEN SETTLES OFFSHORE. A COLD
FRONT DROPPING SOUTHEAST ACROSS THE REGION WILL BRING A CHANCE OF
SHOWERS MONDAY NIGHT INTO TUESDAY MORNING. LOW PRESSURE EMERGING
FROM THE GULF OF MEXICO COULD BRING MORE SIGNIFICANT RAINFALL TO
THE EASTERN CAROLINAS LATE TUESDAY NIGHT THROUGH WEDNESDAY. HIGH
PRESSURE IS EXPECTED TO BRING FAIR WEATHER TO THE REGION LATE IN
THE WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 9 PM SATURDAY...HIGH PRESSURE OVER SOUTHERN GEORGIA WILL MOVE 
TO NEAR THE SOUTH CAROLINA COASTLINE BY DAYBREAK SUNDAY. WINDS HAVE 
DIMINISHED TO NEAR CALM WITH TEMPERATURES PLUNGING DUE TO GOOD 
RADIATIONAL COOLING CONDITIONS THIS EVENING. CIRRUS CLOUDS ARE 
INCREASING FROM THE SOUTHWEST IN ADVANCE OF A WEAK UPPER SHORTWAVE 
TRAVERSING THE SOUTHEASTERN STATES. NO SURFACE WEATHER IS EXPECTED 
WITH THIS FEATURE...BUT THE SLIGHT INCREASE IN CLOUD COVER MAY 
IMPEDE RADIATIONAL COOLING FOR THE REMAINDER OF THE OVERNIGHT. 
SURFACE TEMPERATURES ARE ALREADY IN THE LOWER 40S IN MOST AREAS SO 
ANOTHER 5 DEGREE DROP OVERNIGHT WILL EASILY REACH PREVIOUSLY 
FORECAST LOWS. NO SIGNIFICANT CHANGES ARE NEEDED TO THE FORECAST.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 200 PM SATURDAY...DAYBREAK SUNDAY WILL BEGIN A BIT CHILLY
BUT NOT AS COLD AS PREVIOUS MORNINGS THANKS IN PART TO DEVELOPING
SW WIND FLOW IN THE BOUNDARY LAYER AND SHEETS OF HIGHER CLOUDS
SHEARING OFF AN UPSTREAM SOUTHERN BRANCH SYSTEM. THE LOWER AND
MIDDLE LAYERS OF OUR LOCAL ATMOSPHERE HOWEVER WILL REMAIN QUITE
DRY THROUGH MOST OF SUNDAY AS AN UPPER RIDGE SLIDES ACROSS THE
REGION...HELPING TO BOOST MAXIMUM TEMPERATURE READING SUNDAY
AFTERNOON A DEGREE OR TWO EITHER SIDE OF 70 DEGREES.

CLOUD COVER WILL BEGIN MORE IN EARNEST THROUGH THE COLUMN LATE
MONDAY...AS A TROUGH AXIS DROPPING SE OUT OF THE NORTHERN PLAINS
ON SUNDAY...SLIDES ACROSS THE MID-ATLANTIC AND NE STATES MONDAY.
AHEAD OF THIS TROUGH A MODERATE TAP OF GULF MOISTURE WILL SURGE
NORTHWARD INTO THE MISSISSIPPI AND TENNESSEE VALLEY REGIONS THEN
SHIFT EASTWARD AHEAD OF A COLD FRONT MONDAY AFTERNOON AND NIGHT.
HOWEVER IT LOOKS LIKE MUCH OF THIS MOISTURE TAP WILL BE EXPENDED AS
RAINFALL WEST OF THE APPALACHIAN SPINE. MODEL CONSENSUS SHOWS
0.20-0.40 INCHES OF RAIN ACROSS THE EASTERN CAROLINAS...WITH THE
GFS DRIEST AND THE NAM REPRESENTING THE UPPER END OF QPF.

IT DOES APPEAR A WINDSHIFT MAY OCCUR PRIOR TO DAWN TUESDAY WITH
COLD AIR ADVECTION HELPING TO DROP EARLY MORNING TEMPERATURES INTO
THE 40S BEFORE SUNRISE. 

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 200 PM SATURDAY...LATEST GFS HAS FALLEN MORE IN LINE WITH 
RECENT ECMWF/CANADIAN SOLUTIONS REGARDING THE STORM AFFECTING THE 
EASTERN US MID WEEK. HIGH PRESSURE BUILDING INTO THE AREA TUE WILL 
SHIFT NORTHEAST AND OFFSHORE TUE NIGHT INTO WED. WEAK COASTAL TROF 
DEVELOPS LATE TUE INTO WED KEEPING LOW LEVEL FLOW NORTHEAST FOR MUCH 
OF WED AND ENSURING MORE STRATIFORM PRECIP EVENT WITH SOME ELEVATED 
CONVECTION. LOW PRESSURE DEVELOPING OVER THE NORTHERN GULF OF MEXICO 
WILL LIFT NORTHEAST...THROUGH THE TN/OH VALLEYS WED INTO WED NIGHT. 
WARM FRONT ASSOCIATED WITH THE SURFACE LOW MOVES ACROSS THE REGION 
WED EVENING WITH PRECIP BECOMING MORE CONVECTIVE IN NATURE. COLD 
FRONT MOVES THROUGH WED NIGHT INTO THU...BUT SOME DIFFERING OPINIONS 
ON STRENGTH OF COLD ADVECTION BEHIND THE FRONT. 12Z GFS AND 00Z 
CANADIAN DROP HEIGHTS/THICKNESS THROUGH THU NIGHT...ENDING UP IN THE 
540S FRI AFTERNOON. THE 00Z ECMWF IS SHOWING MINIMAL THICKNESS 
DROP...WITH THE DIFFERENCE BETWEEN THE 2 SOLUTIONS ABOUT 20 DM IN 
HEIGHT. A BLEND OF THE 2 IDEAS WOULD RESULT IN TEMPERATURES NEAR 
CLIMO THU NIGHT THROUGH THE END OF THE PERIOD...BUT THERE IS PLENTY 
OF POTENTIAL FOR TEMPS TO BE 5-10 DEGREES WARMER OR COOLER DEPENDING 
ON WHICH SOLUTION IS CORRECT.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
HIGH PRESSURE OVER THE AREA WILL KEEP VFR AT ALL THE TERMINALS 
THROUGH THE TAF PERIOD. HIGH LEVEL CI WILL BEGIN TO OVERSPREAD THE 
REGION TONIGHT AND WILL LOWER TOMORROW BUT ONLY TO AROUND 15K FEET.

BEAUTIFUL EVENING UNDER SKC AND LIGHT WINDS. HIGH LEVEL CIRRUS 
BEGINNING TO FILTER IN ACROSS SC...AND ALL TERMINALS WILL DEVELOP 
SCT 25K FOOT CI OVERNIGHT. WINDS BEGINNING TO SUBSIDE AND WILL 
DECOUPLE TO NEAR CALM TONIGHT UNDER THE INVERSION. 
HOWEVER...DEWPOINT DEPRESSIONS WILL REMAIN FAIRLY HIGH SINCE THE 
COLUMN IS SO DRY...SO NO FOG IS EXPECTED EVEN WITH ALMOST IDEAL 
RADIATIONAL COOLING. TOMORROW WILL FEATURE SCT AC LOWERING TO AROUND 
15K FEET...BUT NO FLIGHT RESTRICTIONS. HAVE GONE ABOVE GUIDANCE ON 
WINDS TOMORROW FOR PERSISTENCE AND SINCE THE DRY COLUMN WILL ALLOW 
SIGNIFICANT MIXING. EXPECT WINDS FROM THE W/SW AT AROUND 10 KT.

EXTENDED OUTLOOK...VFR THROUGH MONDAY. POSSIBLE IFR WITH RAIN MONDAY 
NIGHT INTO TUESDAY. MORE IFR POSSIBLE WITH A LOW PRESSURE SYSTEM 
WEDNESDAY.

&&

.MARINE...

NEAR TERM /THROUGH TONIGHT/...
AS OF 9 PM SATURDAY...HIGH PRESSURE IS CENTERED OVER SOUTHERN 
GEORGIA THIS EVENING. DEEP LOW PRESSURE OVER SOUTHEASTERN CANADA IS 
MOVING NORTHEAST AND FARTHER AWAY. WINDS ACROSS THE COASTAL WATERS 
RANGE FROM NEARLY CALM AT THE BEACHES TO A SUSTAINED 15 KNOTS OUT AT 
THE FRYING PAN SHOALS BUOY AND THE CORMP OFFSHORE LEJEUNE BUOY. 
MODELS SHOW THE STRONGER WINDS OFFSHORE AND NORTH OF CAPE 
FEAR...WITH RAPIDLY DIMINISHING WIND SPEEDS TO THE SOUTH CLOSER TO 
THE CENTER OF THE HIGH. THE HIGH WILL MOVE TO NEAR THE SOUTH 
CAROLINA COAST BY DAYBREAK WITH WIND SPEEDS DROPPING OFF TO AROUND 5 
KNOTS. 

SEAS RANGE FROM 1 FT OR LESS ALONG THE COAST TO 3 FT OUT AT FRYING 
PAN SHOALS. THIS IS MAINLY A DIMINISHING WIND WAVE FROM THE STRONGER 
WINDS OF THE PAST COUPLE OF DAYS AND SHOULD DIMINISH FURTHER THROUGH 
DAYBREAK.

SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 200 PM SATURDAY...LIGHT 5-10 KT SOUTHWEST WINDS SUNDAY MORNING
WILL INCREASE TO MODERATE SPEEDS OF 15-20 KT SUNDAY NIGHT...THEN
VERY CLOSE TO SMALL CRAFT ADVISORY SPEEDS MONDAY AHEAD OF A COLD
FRONT ON THE APPROACH. RIGHT NOW IT LOOKS LIKE A WINDSHIFT ASSOCIATED
WITH FRONTAL PASSAGE WILL OCCUR SOMETIME AROUND MIDNIGHT MONDAY
NIGHT....BUT THIS COULD CHANGE SEVERAL HOURS EITHER WAY. WIND
FIELDS AND THERMAL PROFILES INDICATE WE WILL LIKELY HAVE NEAR
EQUAL GUSTINESS OF NEAR ADVISORY LEVELS BOTH AHEAD OF AND BEHIND
THE COLD FRONT...WITH THE WINDIEST PERIOD MONDAY AFTERNOON THROUGH
MONDAY EVENING.

LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 200 PM SATURDAY...LIGHT NORTHEAST FLOW TUE WILL INCREASE A 
LITTLE TUE NIGHT AS LOW PRESSURE DEVELOPS OVER THE NORTHERN GULF OF 
MEXICO. WEAK COASTAL TROF FORMS TUE NIGHT AND MOVES TO THE COAST WED 
AS LOW PRESSURE LIFTS NORTHEAST THROUGH THE TN VALLEY. ONSHORE FLOW 
DEVELOPS BEHIND THE TROF AND SPEEDS INCREASE AS GRADIENT TIGHTENS. 
NOT SOLD ON ONSHORE FLOW APPROACHING GALES ON WED...STRONG LOW LEVEL 
JETTING IN WARM ADVECTION IS USUALLY UNABLE TO MIX TO THE SURFACE 
WITH A MORE STABLE BOUNDARY LAYER. FOR NOW WILL KEEP SPEEDS ON THE 
LOW END OF SMALL CRAFT. SEAS WILL RUN WELL ABOVE SCA THRESHOLDS AND 
WILL LIKELY MOVE INTO THE DOUBLE DIGIT REALM BY WED EVENING. COLD 
FRONT PASSES WED NIGHT WITH FLOW BECOMING OFFSHORE. POST FRONT COLD 
ADVECTION MAY REQUIRE HEADLINES BEING CONTINUED THROUGH THU...BUT 
PRESENCE/STRENGTH OF COLD ADVECTION REMAINS IN QUESTION. OFFSHORE
FLOW WILL BE QUICK TO KNOCK SEAS DOWN...3 TO 5 FT BY THU MORNING.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...

SC...NONE.
NC...NONE.
MARINE...NONE.

&&

$$

SYNOPSIS....MJC
NEAR TERM...MBB
SHORT TERM..MJC
LONG TERM...III
AVIATION....JDW