FXUS62 KILM 262052 CCA
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
452 PM EST THU NOV 26 2009
.SYNOPSIS...
A STRONG COLD FRONT WILL SWEEP ACROSS THE EASTERN CAROLINAS
TONIGHT...SPREADING CHILLY AIR AND BRISK WINDS INTO THE REGION
OVERNIGHT THROUGH FRIDAY. 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 TUESDAY...AS A COLD FRONT DROPS SOUTHEAST ACROSS THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 230 PM THURSDAY...WE CAN BE THANKFUL FOR SUNSHINE OVER MOST
OF THE ILM CWA...BUT STRATUS HAS BEEN VERY PERSISTENT OVER THE
NORTHERN AND WESTERN ZONES AND THREATENED TO MAKE THIS A REAL
TURKEY OF A FORECAST. MAIN STORY IN THE NEAR TERM IS A STRONG COLD
FRONT NOW WORKING ITS WAY INTO THE WESTERN CAROLINAS WITH SOLID
UPPER SUPPORT IN THE FORM OF A SHARP FULL-LATITUDE TROF NEAR 85W.
THIS FRONT WILL PUSH EAST ACROSS THE EASTERN CAROLINAS DURING THE
LATTER PART OF THE EVENING. MOISTURE IS QUITE LIMITED WITH
PRECIPITABLE WATER ON THE ORDER OF A HALF INCH...AND THE BEST
DYNAMICS WILL BE JUST SKIRTING THE NORTHERN PART OF THE CWA. BRIEF
WINDOW AROUND MIDNIGHT WHERE WE COULD SEE A STRAY SHOWER IN THE
NORTHERN ZONES...BUT MORE LIKELY SCENARIO IS SPRINKLES. INCLUDED A
20 POP JUST IN THE NORTH AND THINK IT WILL BE A LOW QPF EVENT IF IT
DOES HAPPEN.
TEMP FORECAST IS ACTUALLY CLOSE TO MOS GUIDANCE...WITH UPPER 30S
INLAND AND LOWER 40S ALONG THE COAST. HOWEVER NO FROST IS EXPECTED
AS WINDS WILL STAY UP THRU THE NIGHT...GENERALLY 10-15MPH...AND AT
LEAST BRIEFLY GUSTING IN EXCESS OF 20 MPH IN THE INITIAL SURGE.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 230 PM THURSDAY...BY FRIDAY DAYBREAK A SMALL SAMPLING OF
WINTER-LIKE WEATHER WILL BE FELT...AS A SHARP UPPER TROUGH PIVOTS
ACROSS THE SOUTHEAST AND MID-ATLANTIC STATES. A SUNNY BRISK DAY ON
TAP FRIDAY WITH MAX TEMPS TOPPING IN THE MID 50S. A FROST ADVISORY
MAY BE NEEDED IN THE EARLY MORNING HOURS OF SATURDAY...BUT THE
CONFIDENCE LEVEL RIGHT NOW IS NOT HIGH ENOUGH TO ISSUE A 3RD PERIOD
ADVISORY BECAUSE LINGERING WINDS IN THE LOW LEVELS MAY SERVE TO
INHIBIT FROST FORMATION. TEMPS DO NOT LOOK COLD ENOUGH AT THIS TIME
TO ISSUE A FREEZE WATCH FOR EARLY SATURDAY...THOUGH IT IS LIKELY
SOME LOCALIZED RURAL "COLD" MICRO-POCKETS WILL DIP BELOW 32 F
SATURDAY MORNING. ALTHOUGH THE SURFACE HIGH WILL STILL BE OVER LAND
SATURDAY...MINOR MODERATION OF THE AIR MASS IN PLACE SHOULD ALLOW
MAXIMUM TEMPS SATURDAY TO REACH THE LOWER 60S...WITH PLENTY SUN
BEAMING THROUGH BOTH FRIDAY AND SATURDAY.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 230 PM THURSDAY...MEDIUM RANGE FORECAST MODELS STARTING TO
COME TO A BETTER CONSENSUS FOR THE EVENTS OF NEXT WEEK. IT APPEARS
THERE WILL BE TWO SEPARATE SYSTEMS AS THE SPLIT FLOW ALLOWS TWO
DISTINCT SHORTWAVES TO PROGRESS THROUGH EACH BRANCH OF THE
WESTERLIES. THE FIRST MOVES ACROSS TUESDAY AS A SINGLE COLD FRONT.
MAINTAINED THE LOW CHANCE POPS WITH THIS SYSTEM. THE SECOND AND
MORE POTENT OF THE SYSTEMS IS RIGHT ON ITS HEELS WEDNESDAY AS A
DEEP MID LEVEL CLOSED LOW INDUCES DEEP CYCLOGENESIS IN THE GULF OF
MEXICO WHICH EVENTUALLY MOVES UP THE EAST COAST. AFTER A SMALL
DECREASE IN POPS FOR TUESDAY NIGHT/WEDNESDAY MORNING...INCREASED
POPS TO CHANCE VALUES FOR ALL AREAS WEDNESDAY AND WEDNESDAY NIGHT.
TEMPERATURES SHOULD BE SLIGHTLY ABOVE CLIMATOLOGY EARLY...SUNDAY
AND MONDAY WITH READINGS TRENDING DOWN FROM THAT POINT ON DUE TO
THE INCREASE IN MOISTURE AND A BRIEF INTRUSION FROM COOLER HIGH
PRESSURE IN THE WAKE OF THE FIRST SYSTEM.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
LOW PRESSURE...NOW ONE HUNDRED MILES OFFSHORE OF CAPE HATTERAS...IS
MOVING UP THE ATLANTIC SEABOARD TODAY. A DRY COLD FRONT WILL SWEEP
THROUGH THE AREA TONIGHT BY 04Z.
FOG AND LOW CEILINGS PERSISTING OVER THE TAF TERMINALS AND IS
SLOWLY ERODING. BUT WILL BE VFR BY 20Z AT ALL TAF SITES. INVERSION
WILL BREAK AS DRIER AIR ALOFT MIXES DOWN. VFR THROUGH THE REST OF
THE PERIOD. OVERNIGHT DEWPOINTS DROP AFTER FRONTAL PASSAGE WITH
GUSTY NORTHWEST WIND USHERING IN DRIER AIR. THIS WILL INHIBIT ANY
FOG FORMATION.
EXTENDED OUTLOOK...VFR THROUGH MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 230 PM THURSDAY...WEAK GRADIENT OVER THE COASTAL WATERS WITH
WINDS GENERALLY OUT OF THE N/NW AT LESS THAN 10 KT. HOWEVER...SHORTWAVE
SFC RIDGE HAS SHIFTED OFF THE SOUTH CAROLINA COAST AND WE SHOULD
SEE WEST WINDS BY SUNSET.
UPSTREAM OBS SHOW THE COLD FRONT JUST BARELY WORKING INTO THE
WESTERN CAROLINAS AT 19Z. STILL EXPECT IT TO PUSH OFF THE COAST LATE
THIS EVENING WITH A DRAMATIC AND IMMEDIATE W-NW SURGE BEHIND IT.
WINDS SHOULD PICK UP TO AT LEAST MARGINAL SCA LEVELS...WITH A BRIEF
PERIOD OF SOLID 25 KT AND GUSTS NEAR GALE FORCE. CURRENT ADVISORY
STRUCTURE LOOKS LIKE IT WILL HOLD UP WELL.
SEAS ARE TRICKY AS WE ARE RIGHT ON THE EDGE OF HAVING ENOUGH
WESTERLY COMPONENT TO GET A LONGER FETCH ON FRYING PAN SHOALS.
THINK THIS WILL BE BRIEF BEFORE WINDS COME AROUND TO NW...BUT JUST
ENOUGH TO GET 6 FOOTERS NEAR THE SHOALS AND 7 FOOTERS AT 41013 LATER
TONIGHT. OTHERWISE FORECAST SEAS ARE ABOUT A FOOT BELOW WHAT IS
ADVERTISED BY SWAN...AT LEAST INITIALLY DUE TO WHAT SEEMS TO BE A
BULLISH INITIALIZATION.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 230 PM THURSDAY...SMALL CRAFT ADVISORY FLAGS FROM MIDNIGHT
TONIGHT THROUGH FRIDAY NIGHT FOR GUSTY WNW WINDS. THE ADVISORY
MAY EXTEND INTO SATURDAY MORNING FROM CAPE FEAR TO SURF CITY
DUE TO A FEW MORNING GUSTS TO 25 KNOTS OFFSHORE. IN THIS ROBUST
OFFSHORE FLOW...THE NEAR SHORE SEAS WILL REMAIN FAIRLY DAMPENED
BUT OFFSHORE SEAS WILL BECOME HAZARDOUS. BEYOND OUR LOCAL 0-20NM
WATERS...THE OCEAN PREDICTION CENTER HAS POSTED GALE WARNINGS.
SMALL CRAFT ARE ADVISED NOT TO VENTURE IN THE GULF STREAM FRIDAY
THROUGH FRIDAY NIGHT.
LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 230 PM THURSDAY...A RATHER BENIGN GRADIENT WILL YIELD 10 KNOTS
OR LESS FROM THE SOUTHWEST INITIALLY ACROSS THE COASTAL WATERS.
WINDS WILL GRADUALLY INCREASE THROUGH TUESDAY TO A HEALTHY 15-20
KNOTS AS A COLD FRONT APPROACHES FROM THE WEST. SEAS WILL FOLLOW A
SIMILAR PATTERN WITH TWO FEET INITIALLY BUILDING TO POSSIBLY SCEC
CRITERIA...FIVE FEET BY LATER TUESDAY ESPECIALLY ACROSS THE OUTER
WATERS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 1 AM EST
SATURDAY FOR AMZ252-254-256.
SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 7 AM EST
SATURDAY FOR AMZ250.
&&
$$
NEAR TERM...RAS
SHORT TERM..MJC
LONG TERM...SHK
AVIATION....MDC
