FXUS62 KMLB 041007
AFDMLB
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MELBOURNE FL
507 AM EST FRI DEC 4 2009
.DISCUSSION...
...WIDESPREAD SOAKING RAINS DEVELOPING TODAY INTO TONIGHT...
...STRONG STORMS POSSIBLE LATE TONIGHT AND SATURDAY SOUTH OF
ORLANDO...
TODAY...INCREASING S/SW FLOW OVERRUNNING THE FRONTAL BOUNDARY
STALLED ACROSS THE FL STRAITS WILL PRODUCE VERY STRONG ISENTROPIC
LIFT. MID LEVEL TROUGH WILL DEEPEN OVER THE WESTERN GULF OF MEXICO
AND ENTRANCE REGION OF VIGOROUS UPPER JET WILL ADD STRONG MID AND
UPPER FORCING TO AN ALREADY SATURATED ATMOS. AS A RESULT...
WIDESPREAD RAINFALL...HEAVY AT TIMES...WILL OCCUR ACROSS EC FL.
ALTHOUGH THE PRECIPITATION WILL BE LARGELY STRATIFORM...THE
DYNAMICS IN PLAY SHOULD PRODUCE RIBBONS OF ENHANCED RAINFALL WITH
OCCASIONAL RUMBLES OF THUNDER POSSIBLE FROM ELEVATED CONVECTION.
THE FOCUS FOR THE HEAVIEST RAINS SHOULD INITIALLY BE ACROSS
CENTRAL SECTIONS (BREVARD/OSCEOLA)...SHIFTING NORTHWARD THIS AFTN
AND TONIGHT AS FRONTAL BOUNDARY LIFTS NORTHWARD. TOTAL
ACCUMULATIONS OF 1-2 INCHES WILL BE COMMON WITH LOCALLY 3-4
INCHES. ALTHOUGH IT'S A LOT OF RAIN...IT IS MUCH NEEDED AND WE
SHOULD BE ABLE TO HANDLE IT SINCE IT WILL OCCUR OVER A RATHER LONG
TIME PERIOD (~24 HOURS). SO WILL NOT ISSUE A FLOOD WATCH. BUT
URBAN FLOOD ADVISORIES ARE QUITE POSSIBLE.
MAX TEMPS WILL RANGE FROM AROUND 60 NORTH LAKE/VOLUSIA COUNTIES TO
AROUND 80 IN MARTIN COUNTY.
TONIGHT...SFC LOW IS FCST TO DEVELOP OVER THE GULF OF MEXICO ALONG
THE STALLED FRONTAL BOUNDARY INDUCED BY STRONG SHORTWAVE TROUGH
MOVING EAST ACROSS TX/LA. CORRESPONDING INCREASE IN 850 MB SW FLOW
(LOW LEVEL JET) SHOULD LIFT THE FRONTAL BOUNDARY NORTHWARD INTO
OUR SOUTHERN COUNTIES LATE. THIS INCREASE IN DEEP LAYER SHEAR
WILL PRESENT A THREAT FOR ORGANIZED STORMS IN VICINITY OF THE WARM
FRONT. BUT LIMITED INSTABILITY MAY KEEP COVERAGE OF ANY
STRONG/SEVERE STORMS LOW. WILL HIGHLIGHT A VERY LOW THREAT FOR
SEVERE WIND/TORNADO IN THE HWO/GHWO FROM INDIAN RIVER AND
OKEECHOBEE SOUTHWARD OVERNIGHT.
SAT...EXITING 250MB JET CORE...500MB VORTICITY MAX MOVING OVERTOP OF
CENTRAL FLORIDA AND A DEVELOPING WAVE ALONG THE FRONTAL BOUNDARY
MOVING ACROSS DOWN THE CENTRAL AND SOUTHERN PORTIONS OF THE FLORIDA
PENINSULA WILL PRODUCE WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS
PRIMARILY SATURDAY MORNING. WESTERLY LOW LEVEL JET AROUND 40 KNOTS
COULD BE ENOUGH TO PRODUCE SOME STRONGER STORMS DURING THE MORNING
HOURS. RISK OF STRONGER STORMS SHOULD DIMINISH LEAVING CENTRAL
FLORIDA WITH SHOWERS DURING THE AFTERNOON AS THE UPPER AND LOW
LEVEL JETS LIFT NORTHEAST WHILE THE SURFACE BOUNDARY DROPS INTO
SOUTHERN FLORIDA. FRONT SHOULD BE CLEAR OF CENTRAL FLORIDA BY THE
EVENING WITH HIGH PRESSURE BUILDING DOWN THE PENINSULA. BRISK NORTH
NORTHWESTERLY WINDS ALONG THE COAST FOR THE EVENING AND OVERNIGHT
HOURS.
SUN...HIGH CENTERED OVER THE MIDDLE OF THE EASTERN COAST MOVING INTO
THE ATLANTIC ALLOWS WINDS TO SHIFT TO THE EAST. BEST SHOT AT ANY
PRECIP WILL BE OVER THE EXTREME SOUTHERN PORTIONS OF BOTH THE
MAINLAND AND COASTAL WATERS.
MON-WED...EXTENSION OF THE HIGH IN THE ATLANTIC STRETCHES ACROSS
CENTRAL FLORIDA AND MERGES INTO A DEVELOPING LOW OVER THE CENTRAL
GULF. SKIES REMAIN CLOUDY AS SOUTHWEST FLOW ALOFT CONTINUES TO FEED
MID AND UPPER LEVEL MOISTURE...CLOUDINESS...ACROSS THE AREA.
VORTICITY MAXIMA MOVING OVERTOP CENTRAL FLORIDA ARE EXPECTED TO BE
STRONG ENOUGH TO PRODUCE A CHANCE/30 POP OF RAIN EACH DAY.
THU-FRI...SLIGHT CHANCE OF SHOWERS THURSDAY AS A WEAK FRONT MOVES
DOWN THE PENINSULA THEN CLEARING OVERNIGHT AS HIGH PRESSURE BUILDS
OVER THE STATE.
&&
.AVIATION...
DETERIORATING CONDS TODAY AS CIGS LOWER WITH PREVAILING IFR/MVFR
CIGS DEVELOPING 16Z-20Z AND PERSISTING THRU AT LEAST 06Z. SOUTHERN
TERMINALS MAY IMPROVE TO VFR CIGS AFT 06Z.
&&
.MARINE...
TODAY...STALLED FRONTAL BOUNDARY DRAPED ACROSS THE FLORIDA STRAITS
WILL BEGIN TO LIFT NORTHWARD AS A WARM FRONT. NORTH WINDS 10-15
KNOTS ACROSS THE NORTHERN (VOLUSIA) AND CENTRAL (BREVARD) WATERS.
SOUTHERN WATERS WILL SEE LIGHTER AND MORE VARIABLE WINDS ESP THIS
AFTN AS FRONTAL ZONE APPROACHES. LARGE AREA OF RAIN WILL DEVELOP
ESP NORTH/CENTRAL WATERS. TONIGHT...NORTHERLY WIND COMPONENT WILL
CONTINUE ACROSS N/C WATERS WITH PGRAD SUPPORTING ONLY AROUND 10
KNOTS. A SOUTHERLY WIND COMPONENT WILL DEVELOP OVER THE SOUTHERN
WATERS BEHIND RETREATING FRONTAL BOUNDARY.
SAT...WILL NEED SMALL CRAFT ADVISORY FOR AT LEAST THE OFFSHORE
WATERS SATURDAY AFTERNOON THROUGH THE OVERNIGHT HOURS AS NORTH
NORTHWEST WINDS FRESHEN DUE TO HIGH PRESSURE BUILDING DOWN THE
COASTAL WATERS. WAVE WATCH LOOKS TO HAVE UNDER FORECAST SEAS AT 4 TO
5 FEET SO USED THE WIND WAVE HEIGHT TOOL FOR THIS TIME PERIOD AND
CAME UP WITH A MORE REPRESENTATIVE 6 TO 7 FOOT SEAS BEYOND THE 40
MILE MARK WITH CHOPPY SHORT PERIOD SEAS.
SUN-TUE...EASTERLY WINDS LESS THAN 15 KNOTS BECOMING VARIABLE 10
KNOTS OR LESS TUESDAY AS HIGH PRESSURE RIDGE AXIS BUILDS ACROSS THE
COASTAL WATERS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 62 53 65 47 / 100 100 70 10
MCO 65 55 67 48 / 100 90 70 10
MLB 70 58 71 52 / 100 90 70 10
VRB 75 60 74 53 / 100 80 70 10
LEE 62 53 64 43 / 100 100 70 10
SFB 65 55 65 46 / 100 100 70 10
ORL 65 56 66 47 / 100 90 70 10
FPR 75 63 75 55 / 90 80 70 10
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM...KELLY
LONG TERM....WIMMER
