000
FXUS62 KILM 061158
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
658 AM EST TUE JAN 6 2009
.SYNOPSIS...
A STRONG COLD FRONT WILL SWEEP ACROSS THE REGION WEDNESDAY...USHERING
IN COLDER AND DRIER WEATHER THURSDAY. A REINFORCING SHOT OF COLD
ARI WILL MOVE IN FOR FRIDAY. A SECOND COLD FRONT WILL MOVE ACROSS
THE AREA SATURDAY NIGHT...BRINGING ANOTHER SHOT OF COLD AIR ON
SUNDAY AND MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 6 AM TUESDAY...SOUTHERN EXTENT OF RAIN HAS PUSHED NORTH OF A
FLO-ILM LINE AND WILL CONTINUE TO SHIFT NORTH THROUGH THE DAY. POP
FCST HAS BEEN TWEAKED BUT TREND REMAINS THE SAME...ENDING FROM SOUTH
TO NORTH THROUGH LATE MORNING/EARLY AFTERNOON...WITH AREAS SOUTH OF
FLO-ILM REMAINING DRY. HIGHEST ENSEMBLE GUIDANCE INDICATES MID 70S
FOR MAX TEMPS TODAY...AND THIS IS MOST LIKELY TO OCCUR OVER
WILLIAMSBURG AND GEORGETOWN COUNTIES WHERE IR IMAGERY INDICATES A
POTENTIALLY SUNNY START TO THE DAY. REST OF THE CWA SHOULD STILL
REACH OR EXCEED 70 DEGREES WITH LITTLE TROUBLE.
AS STORM SYSTEM LIFTS NE OUT OF THE MISSISSIPPI RIVER VALLEY...
EXPECT THE STALLED FRONT TO OUR NORTH TO LIFT NORTH AS A WARM FRONT.
WINDS WILL CONTINUE TO INCREASE OUT OF THE S-SW THROUGH TONIGHT.
INCREASING SOUTHERLY WINDS WILL CONTINUE TO CARRY WARM AND MOIST AIR
INTO AREA THROUGH TONIGHT WITH OVERNIGHT LOWS HOLDING ABOVE 60 MOST
LOCATIONS.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 3 AM TUESDAY...COLD FRONT SET TO CROSS THE AREA ON WED WILL
ARRIVE IN WRN PART OF THE CWA BY MID MORNING...REACHING THE COAST
JUST AFTER MIDDAY. FORECAST SOUNDINGS DO NOT VERY PROMISING WITH
RESPECT TO TSRA DEVELOPMENT...THOUGH IF ANY OCCUR THEY WILL LIKELY
ALONG THE COAST. HIGHS WED WILL BE IN THE UPPER 60S TO LOW 70S BUT
LOTS OF ERROR POTENTIAL IN THE TEMP FORECAST...WHICH WILL BE HIGHLY
DEPENDANT ON FROPA TIMING.
WEAK COLD ADVECTION INITIALLY BEHIND THE FRONT WED EVE AND INTO THE
OVERNIGHT BEFORE COLDER AIR ARRIVES EARLY THU. WINDS OVERNIGHT WILL
HELP KEEP TEMPS IN THE UPPERS 30S TO LOW 40S DESPITE 850 TEMPS
DROPPING TO -2C AND COOLER BY THU AM. NW SFC FLOW SHIFTS TO WSW ON
THU AS SECONDARY COLD FRONT/SFC TROF AND SHORTWAVE APPROACH FROM THE
NW. NO PRECIP FROM THESE FEATURES...LOWER LEVELS ARE TOO DRY...BUT
THERE WILL BE A CLOUD DECK BETWEEN 10K AND 15K THAT WILL WORK TO
HOLD TEMPS DOWN A BIT WITH HIGHS FALLING JUST SHORT OF CLIMO.
COLDEST AIR ARRIVES LATE THU INTO FRI AS SFC RIDGING BUILDS IN AND
WIND SPEEDS DECREASE. 850 TEMPS THU NIGHT FALL INTO THE -4 TO -6 C
RANGE BY MORNING SUGGESTING LOWS IN THE MID TO UPPER 20S IF WINDS
WERE TO BE LIGHT TO CALM. LOOKS LIKE SFC WINDS WILL BE A LITTLE HIGH
AND THUS HOLD TEMPS IN THE LOW 30S. EXPECT SHELTERED AREAS AND
TYPICAL COLD SPOTS BOTTOMING OUT IN THE MID 20S.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 3 AM TUESDAY...SFC HIGH SETTLES INTO THE CAROLINAS ON FRI
AND SLIPS OFFSHORE FRI NIGHT WITH RETURN FLOW SETTING UP FOR SAT.
COLD FRONT WILL DROP INTO THE AREA FROM THE NW SAT NIGHT INTO SUN
THOUGH TIMING IS STILL IN QUESTION. LATEST GFS SUGGESTS AN EARLIER
FROPA WITH LIMITED PRECIP CHANCES ALONG THE FRONT. 00Z ECMWF IS 6
TO 12 HRS SLOWER THAN THE GFS AND MUCH WETTER. DIFFERENCES
CONTINUE BEYOND FROPA WITH 00Z GFS BRINGING COLD HIGH OVER THE
AREA WHILE THE ECMWF KEEPS THE FRONT CLOSER TO THE COAST AND
DEVELOPS A SFC WAVE THAT TRAVELS NE ALONG THE BOUNDARY. GIVEN THE
UNCERTAINTY CONCERNING THE FORECAST DID NOT SEE REASON TO MAKE
SIGNIFICANT CHANGES TO THE GOING FORECAST. TEMPS WILL START OUT
BELOW CLIMO FRI THEN RUN NEAR TO BELOW CLIMO FRI NIGHT ON.
&&
AVIATION /12Z TUESDAY THROUGH SATURDAY/...
THE TERMINALS WILL REMAIN SOUTH OF A STATIONARY FRONT TODAY. THE
FRONT SHOULD DRIFT FURTHER NORTH AS A WARM FRONT LATER TODAY.
SIGNIFICANT PRECIPITATION AND LOW CEILINGS WILL REMAIN ALONG AND
NORTH OF THE BOUNDARY WHERE THE BEST LIFT IS...BUT THROUGH 15Z DUE
TO PROXIMITY TO THE FRONT LBT WILL HAVE PERIODS OF LIGHT RAIN AND
TEMPO VISIBILITIES 3-5 MILES BUT CEILINGS SHOULD REMAIN VFR. A CLOUD
DECK AT 1K-2K WELL WEST OF FLO IS ADVANCING RAPIDLY TO THE EAST.
EXPECT THIS TO REACH THE FLO/LBT TERMINALS AROUND 15Z. ATTM ONLY
TEMPO MVFR CEILINGS EXPECTED AS THIS CLOUD DECK SHOULD GRADUALLY
LIFT AND ERODE AS IT ADVANCES EAST. OTHERWISE VFR EXPECTED THROUGH
WEDNESDAY MORNING AT ALL TERMINALS. WINDS WILL BE SOUTHWEST BECOMING
10-20 KNOTS BY LATE MORNING.
EXTENDED...A BRIEF PERIOD OF IFR ASSOCIATED WITH SHOWERS WILL BE
POSSIBLE LATE WEDNESDAY MORNING INTO EARLY AFTERNOON AS A COLD FRONT
MOVES ACROSS THE TERMINALS. A STRONG PRESSURE GRADIENT WILL PRODUCE
WINDY CONDITIONS THURSDAY AND EARLY FRIDAY BEFORE HIGH PRESSURE
BUILDS IN FROM THE WEST. VFR WEATHER EXPECTED THROUGH SATURDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM TUESDAY...SEAS STILL HOLDING AROUND 2 TO 3 FT ACROSS THE
LOCAL WATERS. WINDS HAVE PICKED OUT A SW UP TO 15 KTS AND WILL
CONTINUE TO INCREASE THROUGH THE DAY TODAY. INCREASING SOUTHERLY
WINDS THROUGH TODAY WILL PUSH SEAS UP INTO SCA CRITERIA BY LATE
AFTERNOON INTO EARLY THIS EVENING. THEREFORE STARTED SCA FOR TUES
NIGHT AND KEPT IT GOING. WINDS INCREASE UP TO SCA CRITERIA NEAR 25
KTS BY MIDNIGHT TONIGHT. SEAS WILL STEADILY BUILD TO 3 TO 5 FT
THROUGH THIS AFTERNOON REACHING SCA THRESHOLDS BY EARLY EVENING.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 3 AM TUESDAY...SRLY WINDS NEAR GALE FORCE AT THE START OF THE
PERIOD WILL CONTINUE INTO WED AFTN BEFORE COLD FRONT CROSSES THE
WATERS AND WINDS BECOME MORE WSW. VERY LITTLE DROP IN SPEEDS POST
FRONT WITH GRADIENT OVER THE WATERS REMAINING TIGHT. STRONG WINDS
CONTINUE WED NIGHT AND THU WITH A SLIGHT SHIFT TO MORE SRLY THU
MORNING BEFORE SFC TROF AND SHORTWAVE CROSS THE AREA THU
AFTN...CAUSING A SHIFT TO NW WINDS THU EVE. ONCE FLOW BECOMES NW
SPEEDS WILL START TO DIMINISH AS GRADIENT SLOWLY RELAXES.
POSSIBLE GALE EVENT FOR WED AND WED NIGHT REMAINS MARGINAL SO DID
NOT OPT TO RAISE GALE WATCH FOR NOW...WILL INSTEAD KEEP SCA GOING
FOR ALL ZONES THRU THU AFTN. REGARDLESS OF GALE WARNING BEING RAISED
OR NOT...CONDITIONS WILL BE TREACHEROUS. ANTICIPATE EXTENSION OF SCA
INTO THU NIGHT OR FRI MORNING LATER TODAY.
LONG TERM /FRIDAY THROUGH SATURDAY/...
AS OF 3 AM TUESDAY...IMPROVING CONDITIONS FRI AND FRI NIGHT AS
SFC HIGH BUILDS OVER THE AREA AND THEN SHIFTS OFFSHORE. RETURN
FLOW DEVELOPS SAT WITH CENTER OF SFC HIGH OFF THE COAST. GRADIENT
WILL TIGHTEN UP A BIT AS NEXT COLD FRONT DROPS IN FROM THE
NW...BUT FOR NOW LOOKS LIKE CONDITIONS WILL REMAIN BELOW HEADLINE
CRITERIA.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 PM EST
THURSDAY FOR AMZ250-252-254-256.
&&
$$
NEAR TERM...CRM/RGZ
SHORT TERM...III
LONG TERM...III
AVIATION...MRR
