FXUS62 KMLB 010128
AFDMLB
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MELBOURNE FL
825 PM EST MON NOV 30 2009
.DISCUSSION...
CURRENT-OVERNIGHT...HIGH LEVEL CLOUDS ASSOCIATED WITH A STRONG JET
MOVING QUICKLY ACROSS THE SOUTHEAST U.S. WILL OVERSPREAD CENTRAL
FLORIA AFTER MIDNIGHT. IN THE LOWER LEVELS...A WEAKENING FRONTAL
BOUNDARY PUSHING ACROSS THE GULF COAST...FL PANHANDLE...NORTH FL AND
SOUTHERN AL/GA WILL FORCE A WEAK RIDGE OF HIGH PRESSURE INTO THE
ATLANTIC RESULTING IN WINDS VEERING TO THE SOUTH THEN SOUTHWEST
OVERNIGHT. FORECAST SOUNDING SUGGESTING GOOD CHANCE OF LATE NIGHT
STRATUS DEVELOPING AS THE SOUTHWEST FLOW JUST ABOVE THE SURFACE
STRENGTHENS AFTER MIDNIGHT. MORE OF AN AVIATION CONCERN ATTM. SOME
ADJUSTMENTS TO WIND AND ASSOCIATED GRIDS.
PREVIOUS DISCUSSION...
TONIGHT/TUE...WEAK FRONTAL BAND NEARING THE WESTERN FL PANHANDLE
THIS AFTERNOON WILL MOVE INTO N FL OVERNIGHT THEN LOSE SOUTHWARD
PUSH ACROSS THE CENTRAL PENINSULA ON TUESDAY. BOUNDARY WILL BEGIN TO
LIFT BACK NORTH BY LATER IN THE DAY AS LOW PRESSURE BEGINS TO TAKE
SHAPE ALONG THE BOUNDARY IN THE WESTERN GULF OF MEXICO. RAIN CHANCES
OVER THE NEXT 24 HOURS STILL NOT LOOKING TOO IMPRESSIVE IN LOCAL
AREA AND HAVE KEPT SLIGHT MENTION IN FOR NORTHERN SECTIONS ONLY ON
TUESDAY. TEMPS BOTTOMING OUT IN THE MID/UPPER 50S MOST LOCATIONS
TONIGHT EXCEPT FOR A FEW NR 60/LOWER 60S ALONG IMMEDIATE COAST. MAX
TEMPS ON TUES RANGING FROM MID 70S NORTH TO AROUND 80 SOUTH INTERIOR.
TUE NIGHT...THICKENING CLOUDS WITH SLIGHT SHOWER CHANCE AS WARM
ADVECTION INCREASES. MIN TEMPS NEARLY 10 DEGREES ABOVE MINS TONIGHT.
WED-FRI...GFS/ECMWF FAIRLY CONSISTENT IN HANDLING OF LARGE SCALE
PATTERN...ALTHOUGH ECM REMAINS SLIGHTLY SLOWER AND WEAKER IN REGARDS
TO MOVEMENT OF SQUALL LINE ACROSS CENTRAL PENINSULA. WEAK GULF LOW
EXPECTED TO MOVE ONSHORE NEAR LA/MS/AL COAST EARLY WED THEN LIFT
NORTHWARD TOWARD TN WHILE STRENGTHENING INTO A SUB 995MB LOW BY
EARLY EVENING. ALTHOUGH STILL EARLY...BELIEVE CONVECTIVE LINE WILL
MOVE ONSHORE FLORIDA GULF COAST MID-LATE AFTERNOON AND APPROACH
INTERIOR OF EAST CENTRAL FLORIDA 21-00Z...THEN CONTINUE SE THROUGH
CWA DURING THE EVENING/OVERNIGHT. STRONG/VEERING WINDS FIELDS WILL
LIKELY RESULT IN AT LEAST MODERATE HELICITY...WHICH ALONG WITH WEAK
INSTABILITY SUGGESTS THREAT FOR SOME DAMAGING THUNDERSTORM WINDS AND
POSSIBILITY OF AN EMBEDDED SHORT-LIVED TORNADO. HELICITY PROFILE
ALSO APPEARS FAVORABLE AT THIS POINT FOR POTENTIAL SUPERCELL
DEVELOPMENT AHEAD OF LINE LATE WED AFTERNOON/EVENING. WILL CONTINUE
TO ASSESS AND UPDATE POSSIBLE SVR WX THREAT DETAILS AS EVENT DRAWS
CLOSER.
RECENT MODEL TREND HAS BEEN TO OPEN CLOSED LOW AND LIFT FEATURE
NORTHWARD TOWARD OHIO VALLEY BY LATE WEDNESDAY...WHICH WOULD SLOW
CONVECTIVE LINE UPON APPROACH TO LAKE OKEECHOBEE REGION...CAUSING
CLOUDS AND PRECIP TO LINGER ACROSS SE CWA THROUGH LATE WEEK. HAVE
NOT YET FULLY COMMITTED TO THIS RECENT CHANGE...BUT HAVE INTRODUCED
SMALL SHOWER PROBABILITY TO COUNTIES ADJACENT TO LAKE OKEE THU AND
THU NIGHT. FURTHER ADJUSTMENTS MAY BE NEEDED WITH NEXT FORECAST
CYCLE.
EXTENDED...THE WORK WEEK WILL END WITH COOLER AND DRY CONDITIONS FRI
(EXCEPT POSSIBLY FAR SOUTH) WITH COLDEST TEMPS SAT AND SUN
MORNINGS...ESPECIALLY NORTHERN INTERIOR...AS HIGH PRESSURE BUILDS
INTO THE SOUTHEAST BEHIND THE DEPARTING LOW. THE HIGH PRESSURE
CENTER WILL SLOWLY MOVE ACROSS THE CAROLINAS PROVIDING LOCAL VEERING
OF WIND TO STABLE NORTHEAST FLOW SATURDAY WITH A MORE EASTERLY WIND
REGIME SUNDAY AND ONSET OF WARMING TREND MONDAY.
&&
.AVIATION...VFR UNTIL 09Z WHEN SCT-BKN012 SHOULD DEVELOP IN THE
LIGHT SOUTHWESTERLY FLOW AND THE STRONGER SOUTH TO SOUTHWEST FLOW
JUST ABOVE THE INVERSION. VFR AFTER 14Z.
PREVIOUS DISCUSSION STOOD TEST OF TIME...VFR THROUGH
01/08Z THEN TEMPO AREAS MVFR/LCL IFR REDUCTIONS. WITH BL WINDS A
LITTLE HIGHER OVERNIGHT LOW STRATUS EXPECTED TO BE MORE OF A PROBLEM
VERSUS DENSE FOG. BECOMING PREVAILING VFR AFT 01/14Z WITH ISOLD SHRA
CONFINED MAINLY NORTHERN SECTIONS NEAR KLEE-KDAB.
&&
.MARINE...BUOYS RECORDING WEST SOUTHWEST WINDS 10 TO 12 KNOTS AND
SEAS 2 FEET OR LESS. WINDS SHOULD STAY OFFSHORE AS WEAKENING FRONTAL
BOUNDARY PUSHING ACROSS THE PANHANDLE AND THE NORTHERN GULF OF
MEXICO KEEPS HIGH PRESSURE DISPLACED INTO THE WESTERN ATLANTIC.
FRONT DISSIPATES AS IT MOVES DOWN THE PENINSULA TUESDAY AND HIGH
PRESSURE OVER THE SOUTHEAST STATES SHOULD PRODUCE NORTHEAST WINDS
FIRST PART OF THE DAY THEN EXPECT THE WINDS TO VEER MORE TO THE EAST
AS THE HIGH PRESSURE SLIDES INTO THE WESTERN ATLANTIC OFF THE
CAROLINA OUTER BANKS REGION TUE AFTERNOON/EVENING. NO SIGNIFICANT
CHANGES ON THE EVENING UPDATE TO THE MARINE FORECAST.
PREVIOUS MARINE DISCUSSION.
RELATIVELY LIGHT SWLY COMPONENT OVER LOCAL WATERS TONIGHT.
AS FRONT MOVES INTO THE LOCAL WATERS AND WEAKENS ON TUESDAY WINDS
WILL BECOME NELY TUE MORNING AND VEER TOWARD THE EAST-ESE AND START
TO PICK UP A BIT DURING THE AFTERNOON AS THE BOUNDARY BEGINS TO PUSH
BACK NORTH. INCREASING GRADIENT AHEAD OF SURFACE LOW WILL CAUSE SCA
CONDITIONS TO DEVELOP BY MIDNIGHT TUE OVER THE OFFSHORE WATERS...
SPREADING TO NEARSHORE WATERS BY DAYBREAK. SOLID SCA (SOUTHERLY)
WINDS/SEAS EXPECTED WED/WED NIGHT ALL WATERS. WINDS/SEAS WILL
GRADUALLY LESSEN (ESPECIALLY NEARSHORE) THU BEHIND FRONT AS FLOW
BECOMES SW.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
WIMMER/CRISTALDI
