Severe Thunderstorm Warning 26, NWS Tampa Bay, FL

WEST CENTRAL AND SOUTHWEST FLORIDA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAMPA BAY RUSKIN FL
125 PM EDT SAT JUN 24 2006

.SHORT TERM (TONIGHT-MON)...SIGNIF DIFFERENCES BETWEEN GFS AND NAM
WITH HANDLING THE LOW PRES SYSTEM TO OUR EAST. NAM WANTS TO DEEPEN
THE LOW...IN MORE OF A TROPICAL FASHION...TONIGHT AND TAKE IT INTO
NE FL SUN AFTERNOON. THIS LOOKS OVERDONE...ESP SINCE THE MODEL
INITIALIZED WITH A WELL DEFINED CLOSE SFC LOW...WHEREAS CURRENT
SAT PIX AND MARINE OBS CANT PARTICULARLY VERIFY THAT...AND THERES
A LOT OF SHEAR WITH WESTERLY WINDS ALOFT. THE GFS ON THE OTHER
HAND...SEEMS MORE REASONABLE WITH REGARD TO GRADUALLY DRIFTING
THE UPR LOW WEST OVER THE PENINSULA ON SUNDAY...INCLUDING A BROAD
AREA OF SFC LOW PRES...THEN MERGING THIS WHOLE SYSTEM WITH AN
APPROACHING LONG WAVE TROF OVER THE SE U.S.

DESPITE THE MODEL DIFFS...THE MOST LIKELY WX SCENARIO IS A
CONTINUATION OF MOISTURE ADVECTION FROM THE EAST AS THE LOW DRIFTS
WESTWARD...AND THIS WILL INCREASE OUR RAIN CHANCES AS EVIDENT BY
SPOTTY SHOWERS ALREADY REACHING OUR INTERIOR ZONES. A BAND OF
HEAVIER DOWNPOURS MAY DEVELOP LATE THIS AFTERNOON AND EVENING AS
THESE MOISTURE RICH SHOWERS FROM THE EAST INTERSECT THE WC SEA
BREEZE. THEN...MORE WIDESPREAD DEEPER MOISTURE AND ASSOC SHOWER
AND TSTM ACTIVITY SHOULD EVOLVE LATER TONIGHT AND SUNDAY...BUT
EXACT PLACEMENT OF HEAVIER ACTIVITY ON SUNDAY TOUGH TO PIN DOWN
ATTM BASED ON SATELLITE AND MODEL INDICATIONS OF DRY AIR WRAPPING
INTO THE SYSTEM. FOR NOW WILL SIMPLY CONTINUE LIKELY POPS FOR
SUNDAY FOR THE ENTIRE AREA. A FEW DEGREES COOLER ON SUNDAY WITH
CLOUD COVER AND SHOWERS...BUT STILL EXPECTING HIGHS IN THE UPPER
80S.

ON MONDAY...THE UPR LOW WILL BEGIN TO MERGE WITH THE APPROACHING
LONG WAVE TROF. WITH AMPLE TROPICAL MOISTURE OVER THE AREA...
NUMEROUS SFC MESO BOUNDARIES...AND SYNOPTIC UPR LEVEL SUPPORT...
SHOWERS/TSTMS LOOK LIKELY AGAIN OVER MUCH OF THE CWA.

&&

.LONG TERM (MON NGT - SAT)...LOW-LEVEL RIDGE OF HIGH PRESSURE
REMAINS SOUTH OF THE FORECAST AREA THROUGH WEDNESDAY. THIS RESULTS
IN A WEST TO SOUTHWESTERLY WIND REGIME...TYPICALLY FAVORING LATE
NIGHT AND EARLY MORNING SHOWERS AND STORMS NEAR THE COAST AND LATE
MORNING AND AFTERNOON THUNDERSTORMS INLAND. I MADE SOME TWEAKS TO
THE GRIDS TO REFLECT THIS SCENARIO...BUT OVERALL NO MAJOR CHANGES
WERE MADE.

THE GFS IS FORECASTING THE LOW-LEVEL RIDGE TO LIFT NORTHWARD ON
THURSDAY AND MEANDER OVER THE STATE THROUGH SATURDAY. WITH A VERY
LOOSE PRESSURE GRADIENT IN PLACE...CONVECTION WILL BE DIURNALLY
DRIVEN AS SEA BREEZE CIRCULATIONS MOVE INLAND FROM BOTH COASTS.
MOISTURE APPEARS TO BE LACKING...BUT EXPECT AT LEAST LOW-END
SCATTERED COVERAGE WHICH IS IN THE ONGOING FORECAST ALREADY.

TEMPERATURES WILL REMAIN WITHIN A FEW DEGREES OF CLIMATOLOGY.

&&

.MARINE...UNLESS PRESSURES FALL RAPIDLY AND SOON...LOOKS LIKE PRES
GRAD WILL REMAIN WEAK ENOUGH FOR WINDS TO REMAIN AOB 15 KTS THIS
WEEKEND AS THE BROAD LOW MOVES OVER THE PENINSULA. NAM DOES SHOW SOME
STRONGER SW WINDS ON THE BACK SIDE OF THE LOW...BUT FOR NOW WERE
DISREGARDING THE NAMS DEVELOPMENT OF THIS LOW. FOR NOW WILL CONTINUE
TO ADVERTISE WINDS AOB 15KT THRU THE FORECAST PERIOD...BUT MARINERS
SHOULD PAY CLOSE ATTENTION TO UPDATES THIS WEEKEND.

&&

.AVIATION...SCATTERED TO NUMEROUS SHOWERS AND ISOLATED THUNDERSTORMS
HAVE DEVELOPED OVER THE INTERIOR AND EASTERN SECTIONS OF THE STATE.
THESE WILL MOVE WESTWARD AND RUN UP AGAINST THE WEST COAST SEA
BREEZE THIS AFTERNOON. SINCE COVERAGE IS HIGHER THAN EARLIER
ANTICIPATED...WILL ADD TEMPO MVFR/IFR CONDITIONS FOR THIS AFTERNOON
AT ALL TERMINALS.

&&

.FIRE WEATHER...RHS VALUES WILL STAY ABOVE CRITICAL VALUES THRU THE
FORECAST PERIOD.

&&

.PRELIMINARY POINT TEMPS/POPS...
TPA  75  87  76  85 /  20  60  40  60
FMY  75  88  76  87 /  20  60  40  60
GIF  75  89  74  86 /  20  60  40  60
SRQ  75  86  75  85 /  20  60  40  60
BKV  72  88  72  85 /  20  60  40  60
SPG  80  86  78  86 /  20  60  40  60

&&

.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&

SHORT TERM/MARINE...NP
LONG TERM/AVIATION...EJ

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TAMPA BAY AREA - RUSKIN FL
451 AM EDT SAT JUN 24 2006

FLZ039-042-043-048>052-055>057-060>062-065-241400-
LEVY-CITRUS-SUMTER-HERNANDO-PASCO-PINELLAS-HILLSBOROUGH-POLK-
MANATEE-HARDEE-HIGHLANDS-SARASOTA-DE SOTO-CHARLOTTE-LEE-
451 AM EDT SAT JUN 24 2006

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHWEST
FLORIDA AND WEST CENTRAL FLORIDA.

.DAY ONE...TODAY AND TONIGHT:

AN AREA OF LOW PRESSURE OVER THE EASTERN BAHAMAS EARLY THIS
MORNING WILL MOVE WEST TOWARD THE FLORIDA EAST COAST TONIGHT THEN
MOVE INTO WEST CENTRAL FLORIDA ON SUNDAY. DEEP LAYERED MOISTURE
ASSOCIATED WITH THIS LOW WILL SPREAD OVER THE FORECAST AREA TODAY.
THIS MOISTURE COMBINED WITH DAYTIME HEATING AND THE DEVELOPMENT OF
THE EAST AND WEST COAST SEA BREEZE BOUNDARIES WILL LEAD TO AN
INCREASE IN SCATTERED SHOWERS AND THUNDERSTORMS TODAY.

THUNDERSTORMS ARE EXPECTED TO INITIALLY DEVELOP OVER INTERIOR LOCATIONS
BY LATER THIS MORNING...WITH THESE STORMS SPREADING WEST WITH ADDITIONAL
STORMS FIRING OFF ACROSS THE REGION DURING THE AFTERNOON AND EARLY
EVENING HOURS.

THUNDERSTORMS THAT DEVELOP TODAY WILL BE CAPABLE OF PRODUCING LOCALLY
HEAVY RAINS...FREQUENT LIGHTNING...STRONG GUSTY WINDS...AND POSSIBLY
SOME SMALL HAIL.

WHEN SKIES DARKEN...MOVE INDOORS. IF THERE IS TIME...UNPLUG APPLIANCES
AND ELECTRICAL EQUIPMENT. WAIT UNTIL THE STORM ENDS BEFORE USING THE
TELEPHONE OR RUNNING WATER.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

DEEP LAYERED MOISTURE AND ADEQUATE INSTABILITY ASSOCIATED WITH AN AREA
OF LOW PRESSURE OVER THE PENINSULA WILL SUPPORT ADDITIONAL SCATTERED
SHOWERS AND THUNDERSTORMS ON SUNDAY. THUNDERSTORMS THAT DO DEVELOP
WILL AGAIN BE CAPABLE OF PRODUCING LOCALLY HEAVY RAINS...FREQUENT
LIGHTNING...STRONG GUSTY WINDS...AND POSSIBLY SOME SMALL HAIL.

SUFFICIENT LOW LEVEL MOISTURE AND INSTABILITY WILL LEAD TO ADDITIONAL
SHOWERS AND THUNDERSTORMS MONDAY THROUGH FRIDAY MAINLY ALONG THE EAST
AND WEST COAST SEA BREEZE BOUNDARIES.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY OR TONIGHT.

JCM

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TAMPA BAY AREA - RUSKIN FL
343 PM EDT SAT JUN 24 2006

FLZ050>052-055>057-060>062-065-242030-
MANATEE-CHARLOTTE-LEE-PINELLAS-DE
SOTO-HARDEE-HIGHLANDS-POLK-SARASOTA-HILLSBOROUGH-
343 PM EDT SAT JUN 24 2006

...FUNNEL CLOUDS ARE POSSIBLE IN MANATEE...CHARLOTTE...LEE...
NORTHEASTERN PINELLAS...DESOTO...HARDEE...WESTERN HIGHLANDS...
SOUTHWESTERN POLK...EASTERN SARASOTA AND HILLSBOROUGH COUNTIES...

A LINE OF SHOWERS AND THUNDERSTORMS DEVELOPING AS THE EASTERLY FLOW
INTERACTS WITH THE WEST COAST SEA BREEZE IS CAPABLE OF CREATING
FUNNEL CLOUDS THIS AFTERNOON.

AT 315 PM EDT...EMERGENCY MANAGEMENT OFFICIALS AND SKYWARN SPOTTER
REPORTED A FUNNEL CLOUD IN POLK COUNTY...DOPPLER RADAR SHOWED THE
LINE OF STORMS MOVING SOUTHWEST AT 10 MPH.

AT 343 PM EDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
LINE OF THUNDERSTORMS...CAPABLE OF PRODUCING FUNNEL CLOUDS...FROM
SOUTHWEST POLK COUNTY INTO HARDEE THEN DOWN INTO CHARLOTTE AND LEE
COUNTIES...MOVING SOUTHWEST AT 10 MPH.

FUNNEL CLOUDS CAN BECOME BRIEF...SMALL...BUT DANGEROUS TORNADOES.
MOVE INDOORS IMMEDIATELY...AND STAY AWAY FROM WINDOWS.

THIS STORM HAS THE POTENTIAL TO PRODUCE MORE FUNNEL CLOUDS...AND
POSSIBLE A TORNADO. STAY TUNED FOR POSSIBLE WARNINGS FROM THE
NATIONAL WEATHER SERVICE.

&&

LAT...LON 2648 8145 2760 8152 2805 8204 2815 8282
      2631 8184

25