FXUS62 KILM 082118
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
344 PM EST TUE DEC 8 2009
.SYNOPSIS...
AN INTENSE LOW PRESSURE SYSTEM WILL LIFT NORTHEAST ALONG THE
MISSISSIPPI RIVER VALLEY AND THROUGH THE GREAT LAKES BY WEDNESDAY
NIGHT. THIS WILL RESULT IN A WARM FRONT MOVING NORTH ACROSS THE
REGION TONIGHT...FOLLOWED BY A STRONG COLD FRONT LATE ON WEDNESDAY.
HIGH PRESSURE WILL BUILD THURSDAY THROUGH EARLY SATURDAY. A SERIES
OF LOW PRESSURE SYSTEMS WILL BRING UNSETTLED CONDITIONS ON
SUNDAY AND AGAIN ON TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AS OF 3 PM TUESDAY...LOW PRESSURE WILL TRACK UP FROM TEXAS NORTH
NORTHEAST TO THE GREAT LAKES THROUGH WED MORNING. WEDGE OF HIGH
PRESSURE HOLDING ON INITIALLY WITH WINDS REMAINING OUT OF THE
NORTHEAST AT THE SURFACE KEEPING SHALLOW COOL POOL OVER LOCAL AREA.
COASTAL TROUGH STILL REMAINING OFF SHORE. DEW POINT TEMPS IN THE
NEARING 40 INLAND TO MID 40S ALONG THE COAST. NOT REALLY TAPPING
INTO ATLANTIC MOISTURE UNTIL LATER WHEN WINDS FINALLY SHIFT AROUND
TO THE EAST AND THEN SOUTHEAST AROUND MIDNIGHT AS COASTAL
TROF/WARM FRONT MAKES A RUN INLAND. WINDS ABOVE THE SURFACE THROUGH
THE LOWER LEVELS WILL INCREASE THROUGH THIS EVENING OVERRUNNING THE
SHALLOW COOL AIR IN PLACE. EXPECT INTERMITTENT RAIN TO OVERSPREAD
THE AREA FROM THE SOUTHWEST...MAINLY AFFECTING THE INLAND SOUTH
CAROLINA ZONES INITIALLY AND THEN OVERSPREADING THE REST OF THE
COASTAL CAROLINAS THROUGH 8 OR 9 PM. LOOKS LIKE BEST ISENTROPIC LIFT
WILL COME BETWEEN 00-04Z AS 850 WINDS INCREASE UP TO 30 TO 50 KTS
WITH BEST UPPER LEVEL SUPPORT AT THIS TIME. TEMPS SHOULD HOLD AROUND
50 THROUGH THIS EVENING.
AS LOW TRACKS NORTH THROUGH THE PLAINS TONIGHT A COASTAL TROUGH/WARM
FRONT WILL PUSH INLAND AS WARM FRONT MOVES UP FROM THE SOUTH ACROSS
THE SOUTHEAST CONUS. ONCE COASTAL TROUGH/WARM FRONT BLOWS THROUGH
AROUND MIDNIGHT...AREA GETS INTO WARM SECTOR WITH LLJ INCREASING UP
TO 50 TO 60 KTS. SHOULD SEE PLENTY OF WARM AND MOIST AIR STREAMING
IN WITH TEMPS AND DEW POINT TEMPS INCREASING THROUGH THE MORNING
HOURS UP CLOSE TO 60 INLAND AND MID 60S ALONG THE COAST. SOUTHERLY
WINDS WILL INCREASE AT THIS TIME AS WELL. NOT SURE EXACTLY HOW MUCH
WILL TRANSLATE DOWN TO THE SURFACE...BUT EXPECT WINDS UP IN THE 15
TO 20 MPH RANGE ESPECIALLY CLOSE TO THE COAST. SHOULD TAKE CARE IN
FASTENING DOWN THE CHRISTMAS DECORATIONS BEFORE MIDNIGHT.
MAY SEE SOME ELEVATED CONVECTION WITH WARM FRONT HEADING CLOSER
TO MIDNIGHT AND PCP SHOULD TURN MORE CONVECTIVE IN NATURE IN WARM
SECTOR OVERNIGHT. SHOULD SEE BEST CHC OF ANY STRONGER CONVECTION IN
VICINITY OF COASTAL TROUGH/WARM FRONT WHERE BEST LIFT AND SHEAR WILL
BE. BEST INSTABILITY WILL BE CLOSER TO THE COAST AS DEWPOINTS
INCREASE INTO THE 60S. WITH INSTABILITY LACKING MAIN THREAT WOULD BE
DAMAGING WINDS IN MORE OF A LOW CAPE HIGH SHEAR ENVIRONMENT.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
AS OF 3 PM TUESDAY...PERIOD STARTS WITH EASTERN CAROLINAS IN WARM
SECTOR OF AN EXTENSIVE FRONTAL SYSTEM WHICH DOMINATES THE ENTIRE
UNITED STATES EAST OF THE MISSISSIPPI. STRONG WARM ADVECTION IN
THE MODIFIED GULF AIR MASS WILL BRING AFTERNOON TEMPS WELL ABOVE
AVERAGE...IN THE LOWER TO MID 70S ABOUT EVERYWHERE ON WEDNESDAY.
INSTABILITY FOR THE MOST PART LOOKS MARGINAL BUT VELOCITY SHEAR
CONTINUES TO LOOK IMPRESSIVE AND WINDS WILL BE PRETTY HIGH JUST
OFF THE DECK...SAY AROUND 50 KTS AT 2000 FT. SO...WE COULD SEE
SOME STRONG WINDS MIXED DOWN IN ANY SHOWERS THAT DEVELOP DESPITE A
PAUCITY OF THUNDERSTORMS. CONFIDENCE LOW IN THIS HOWEVER AS IT IS
NOT CLEAR HOW MUCH SHOWER ACTIVITY WE WILL SEE...WITH MOST OF THE
ACTIVITY HAVING ALREADY MOVED ON THE NIGHT BEFORE. IT WILL BE
QUITE BREEZY...SUSTAINED WINDS OF AROUND 20 KTS FROM THE SW DURING
THE AFTERNOON. NOT ENOUGH FOR A WIND ADVISORY...BUT WILL BE
SOMETHING TO HIGHLIGHT. THURSDAY AGAIN A LITTLE TRICKY AS GUIDANCE
HINTS AT A SECONDARY COLD FRONT PUSHING THROUGH IN WAKE OF MAIN
COLD FROPA...WHICH IS SET FOR WEDNESDAY EVENING. MOS GUIDANCE
BRINGS SLIGHT TO LOW CHANCE FOR SECONDARY FROPA...BUT LOW LEVEL
MOISTURE IS LACKING SO DO NOT SEE RAIN AS A REAL POSSIBILITY.
STRONG COLD AIR ADVECTION IN WAKE OF COLD FROPA WILL BRING MAX
TEMPS BACK BELOW CLIMO...MID TO UPPER 50S. CLEAR SKIES AND LIGHT
WINDS ALONG WITH COLD AIR IN PLACE MEANS LOCATIONS AWAY FROM THE
IMMEDIATE COAST WILL SEE BELOW FREEZING TEMPERATURES.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 3 PM TUESDAY...THE AREA WILL BASICALLY BE UNDER ZONAL 5H FLOW
FRIDAY THROUGH SUNDAY. WILL START OUT UNDER AN AREA OF SUBSIDENCE
ALOFT AND HIGH PRESSURE AT THE SFC WHICH WILL QUICKLY GIVE AWAY TO A
RATHER FAST MOVING LOW AMPLITUDE SOUTHERN STREAM WEAK 5H S/W TROF
THAT PUSHES ACROSS SATURDAY THRU EARLY SUNDAY. LOW LEVEL FLOW HAS
BARELY ENOUGH TIME TO TAP GULF OF MEXICO MOISTURE AND/OR ATLANTIC
MOISTURE FOR CLOUDINESS LET ALONE LOW AMOUNTS EXHIBITED FOR QPF. AS
A RESULT...POPS WILL BE ON THE LOWER SIDE OF CHANCE AND OVERALL HIER
SOUTH AND EAST OF THE ILM CWA WHERE MODELS PROG THE BETTER SHOT FOR
PCPN.
FOR LATE SUNDAY INTO MONDAY...SOME SEEPAGE OF THE COLDER/POLAR FROM
A PIECE OF SFC HIGH DROPPING SOUTH FROM THE PLAINS IN THE WAKE OF
THE DEPARTING SOUTHERN STREAM SYSTEM...AND A DEPARTING NORTHERN
STREAM SYSTEM WHICH IS AIDING ITS SOUTHWARD EXTENT. ALTHOUGH MODEL
MOS GUIDANCE DOESNT INDICATE THE LOWER TEMPS FOR MONDAY INTO
TUESDAY...WOULD TEND TO LOWER ATLEAST A CATEGORY GIVEN THE SETUP
GOING INTO TUESDAY AND THE SOURCE REGION FROM WHICH THIS COLD AIR
JUST MIGRATED FROM. DAMMING EVENT LIKELY TO START OUT TUESDAY WITH A
MUCH MORE DYNAMIC SOUTHERN STREAM S/W TROF TO BECOME QUITE AMPLIFIED
BY LATE TUESDAY...WITH EVEN THE POSSIBILITY OF THE NORTHERN STREAM
BECOMING INVOLVED AND CONCLUDING WITH A FULL LATITUDE TROF BY LATE
TUESDAY INTO WEDNESDAY. BUT...THIS IS 7-8 DAYS OUT AND MANY
IN-BETWEENS WILL OCCUR BEFORE THIS HAS A REMOTE CHANCE OF
HAPPENING. NEVERTHELESS...BOTH THE GFS AND ECMWF HAVE BEGUN
INDICATING THIS POSSIBILITY AND WILL NEED TO BE MONITORED.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AS OF 18Z...TERMINALS ARE VFR WITH LOW VFR CEILINGS 3-3.5K
PERSISTING AT ILM. RADAR INDICATES SOME LIGHT STRATIFORM RAIN
NORTHWEST AND WEST OF FLO/LBT AND DEVELOPING SOUTH OF MYR.
A COASTAL TROUGH WILL REMAIN OFFSHORE AS A WARM FRONT APPROACHES
FROM THE SOUTH. LIGHT RAIN WILL OVERSPREAD THE TERMINALS THIS
AFTERNOON BUT THINK SIGNIFICANT RAINS WILL HOLD OFF UNTIL LATE
AFTERNOON AT FLO/LBT AND EARLY EVENING AT ILM AND LBT. AS RAINS
SATURATE THE INVERSION LEVEL AT 2-3K THIS AFTERNOON EXPECT MVFR
CEILINGS TO RE-DEVELOP.
THE WARM FRONT WILL MOVE THROUGH LATE THIS EVENING AND EARLY
WEDNESDAY. SHOULD BE A GOOD CHANCE OF MODERATE TO HEAVY RAINFALL/IFR
CEILINGS AND VISIBILITIES/LLWS/AND POSSIBLY ISOLATED ELEVATED
CONVECTION JUST OFFSHORE OF THE COASTAL TERMINALS PRIOR TO WARM
FROPA. ONCE THE WARM FRONT MOVES THROUGH EXPECT CEILINGS IMPROVING
TO MVFR...ISOLATED SHOWERS...AND GUSTY SOUTH TO SOUTHWEST WINDS. THE
COLD FRONT WILL BE JUST NORTHWEST OF FLO/LBT IN THE PRE-DAWN HOURS
WITH CONVECTIVE ACTIVITY ALONG AND AHEAD OF IT. THIS MOVES EAST
THROUGH THE PRE-DAWN AND MORNING HOURS BUT LATEST PROGS SHOW
ACTIVITY DECREASING AS IT MOVES EAST. AFTER THE INVERSION BREAKS
13-14Z EXPECT GUSTY SOUTH SOUTHWEST WINDS TO DEVELOP WITH GUSTS TO
30-35 KNOTS POSSIBLE. CEILINGS ARE EXPECTED TO BE IN THE MVFR RANGE
ALTHOUGH COULD IMPROVE TO VFR BY MID MORNING AT FLO/LBT.
EXTENDED OUTLOOK...IFR/ISOLATED THUNDERSTORMS WEDNESDAY. CHANCE IFR
LATE FRIDAY AND SATURDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM TUESDAY...CURRENT BUOY OBS SHOWING NEAR 6 FT AT FRYING
PAN AND STILL 1 FT AT OCEAN CREST PIER WHICH IS SHELTERED FROM THE
NE SWELL. NORTHEAST WINDS AROUND 15 KTS NEAR SHORE AND UP TO 20 KTS
IN THE OUTER WATERS THIS AFTERNOON. NORTHEAST FLOW WILL VEER AROUND
BECOMING ONSHORE INTO THIS EVENING AS COASTAL TROF/WARM FRONT MOVES
WEST ACROSS THE WATERS. LATEST GUIDANCE SUGGESTS TROUGH WILL MOVE
ACROSS THE WATERS LATE THIS EVENING WITH WINDS COMING AROUND TO THE
SOUTHEAST AFTER MIDNIGHT AND INCREASING IN STRENGTH THROUGH THE
MORNING BEHIND COASTAL TROUGH. EXPECT LLJ INCREASING UP TO 50 TO 60
KTS WITHIN A FEW THOUSAND FT OF THE SURFACE. ANY CONVECTION
DEVELOPING OVERNIGHT COULD MIX DOWN THESE WINDS BUT THE COOLER SSTS
SHOULD KEEP THE STRONGEST WINDS ALOFT. AT THIS TIME WILL SHOW WINDS
INCREASING UP TO 25 KTS OVER MOST WATERS AFTER MIDNIGHT. SEAS WILL
RISE THROUGH THIS EVENING RISING ABOVE SCA IN THE OUTER WATERS AND
THEN INCREASING ABOVE SCA IN THE NEAR SHORE WATERS ONCE THE WINDS
SHIFT AROUND BEHIND COASTAL TROUGH AS IT PUSHED INLAND. SCA
CONDITIONS WILL PERSIST THROUGH WEDNESDAY.
SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 3 PM TUESDAY...STRONG SWLY WINDS IN ADVANCE OF A COLD FRONT
ADVANCING ACROSS THE EASTERN SEABOARD WILL GENERATE SEAS UP TO
AROUND 8 TO 10 FT OVER MUCH OF THE WATERS WEDNESDAY. SEAS WILL
BEGIN TO DIMINISH WEDNESDAY NIGHT AFTER FRONT MOVES ACROSS THE
WATERS AND WINDS TURN MORE OFFSHORE. WINDS AND SEAS SHOULD BE
BELOW SMALL CRAFT CRITERIA BY DAYBREAK THURSDAY.
LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 3 PM TUESDAY...UPPER SOUTHERN STREAM POLAR WESTERLIES WILL
KEEP AN ACTIVE 3 DAY PERIOD ACROSS THE WATERS. WITH FRIDAY BEING THE
LESS ACTIVE SO TO SPEAK. MEANING SFC HIGH PRESSURE WILL BE THE MAIN
INFLUENCE FOR FRIDAY BUT WILL SLIDE OFF THE NC COAST LATE IN THE
DAY. WINDS/SEAS SHOULD BE ON THE DIMINISHING SIDE INITIALLY
THROUGHOUT THE DAY...AS WINDS VEER IN DIRECTION DUE TO THE HIGHS
MOVEMENT. BY SATURDAY...WEAK COASTAL TROF/FRONT TO DEVELOP JUST
BEYOND THE COASTAL WATERS BUT IS NOT PROGGED TO PROGRESS INLAND AS
AS THE SOUTHERN STREAM S/W TROF PUSHES ACROSS THE SE STATES AND OFF
THE COAST...SFC LOW IS PROGGED TO DEVELOP ALONG THE COASTAL TROF
THEN ACCELERATE TO OFF CAPE HATTERAS EARLY SUNDAY. WILL LIKELY FCST
SCEC OR SCA WINDS DURING THIS TIME FRAME...WITH WIND DRIVEN LOW
PERIOD SEAS RESULTING. IN THE WAKE OF THE LOW SUNDAY...SHOULD GET A
DECENT COLD SURGE COMBINED WITH A TIGHTENED SFC PG. THIS LIKELY TO
CONTINUE LATE SUNDAY WHICH COULD RESULT IN HIER WINDS THAN WHAT
MODELS ARE SHOWING. WILL ALTER WIND SPEEDS SLITELY HIER INTO SUNDAY
NITE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM WEDNESDAY TO 7 AM EST THURSDAY
FOR AMZ254-256.
SMALL CRAFT ADVISORY UNTIL 7 AM EST THURSDAY FOR AMZ250-252.
&&
$$
SYNOPSIS...KREITNER
NEAR TERM...GROSS-ZOUZIAS
SHORT TERM...KREITNER
LONG TERM...HOEHLER
AVIATION...ROSS
