Severe Thunderstorm Warning 72, NWS Tampa Bay, FL

WEST CENTRAL AND SOUTHWEST FLORIDA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAMPA BAY AREA - RUSKIN FL
155 PM EDT FRI AUG 25 2000

LOOKS LIKE A BEACHY WEEKEND IN STORE FOR MUCH OF THE REGION.  IN
GENERAL...THE CWFA REMAINS ON THE DRY SIDE OF THINGS AS PERSISTENT
SUMMER PATTERN OF N FLOW ALFT RETURNS AS E NOAM TROFFINESS PREVAILS
WITH ELONGATED RIDGE HOLDING ACROSS THE CENTRAL U.S.

FOR THIS PACKAGE...PREFER THE AVN/ETA.  THE RAIN-HAPPY AVN...WHICH
EARLIER WANTED TO DEVELOP SFC WAVE ON TUTT AXIS SLIDING FROM THE
BAHAMAS TO OFFSHORE OF NAPLES...NOW HAS A REALITY CHECK AS ONGOING
H50-H25 NNW FLOW WILL LIKELY PIN THE TUTT FEATURE TO SE FL/BAHAMAS
FOR THE NEAR FUTURE.  THE ETA HAS HINTED AT THIS ALL ALONG...AND
ITS 12Z RUN IS IN LOCK STEP WITH THE AVN.  THE NGM WAS TOSSED AS
IT WANTS TO SHOVE TUTT FEATURE INTO THE UPPER NNW FLOW...WHICH IS
UNREASONABLE.

THE FCST:  THIS EVE/TONIGHT...APPROACHING SHEAR AXIS ACTING ON WCSB
FIRING OFF FAIRLY DECENT CELLS ACROSS THE N.  DIFF DIABATIC HEATING
BETWEEN CLEAR SLOT TO THE N AND APPROACHING MOISTURE SHIELD/SPEED MAX
IN SRN AL/GA WILL CRANK THIS AREA BEFORE 3 PM.  SOME OF THE ACTIVITY
MAY SPILL INTO OUR N CWFA FOR THE LATE AFTN.

FARTHER S...ADVANCING BAND OF ENHANCED CLDS FROM THE SE WILL LIKELY
BECOME A CLUSTER OR LINE OF TSTMS AS IT MOVES INTO THE S CWFA LATE
THIS AFTN.  EXPECT A FAIRLY ACTIVE LATE AFTERNOON...ESP FOR THE
COASTAL COS.  THEREAFTER...ACTIVITY SHOULD WIND DOWN...FASTEST UP N.
S ACTIVITY COULD CONTINUE TOWARDS MIDNIGHT...SO WILL WORD
ACCORDINGLY.  THEREAFTER...SKIES SHOULD BECOME MCLR.

SAT/SAT NIGHT...RELATIVELY DRY AMS AND WEAKENING SHEAR AXIS...WITH
ONLY WCSB CONVERGENCE TO WORK WITH...SHOULD KEEP LOWEST POP ACROSS
THE N (AFTN/EARLY EVE).  FARTHER S...A SMIDGE HIGHER POP SIMILAR TO
THIS EVENING.

SUN...AS TUTT CELL BEGINS TO SLITHER WNW...CLOUDS AND PCPN WILL
PROBABLY INCREASE OVER SW FL.  GIVEN UPPER FLOW IM RELUCTANT TO
PUSH THE PESSIMISM ANY FARTHER N...SO WILL ROLL PTLY SUNNY WITH
ONLY AN UPTICK IN THE POP VALUE.

EXTENDED...IVE MODIFIED THE 00Z MRF WET SOLN BACK TOWARD THE
AVN/ETA CAUTIOUSLY DRIER SOLN.  AFTER THE LAST (STRONG) SHORT WAVE
DIGS THE TROUGH INTO THE MID ATLC EARLY MON...EXPECT RIDGE TO
EXPAND E...ALLOWING UPPER FLOW TO GRADUALLY VEER TO THE ENE.   AS
IT DOES...SFC-H70 FLOW SHOULD GO MORE ESE...ALLOWING AT LEAST SOME OF
THE TROPICAL MOISTURE TO ADVECT NW.

PLAYING IT SAFE...WILL CALL IT V/C...SCT SHWRS/TSTMS (NO TIMING).
TEMPS THROUGHOUT THIS FCST WILL BE SEASONABLE.

MARINE:  QUIET THROUGH SUN.  AGAIN...HAVE MODIFIED THE MRF ON THE
CONSERVATIVE SIDE BASED ON ABOVE REASONING.  WILL BUMP HIGHEST
WINDS TO THE N LEG WHERE GRADIENT SHOULD BE TIGHTEST.  THIS MEANS
JUST UNDER SCEC CRITERIA...GIVING US WIGGLE ROOM SHOULD CHANGES
OCCUR WITH LATER RUNS.

FIRE WX:  RH VALUES IN THE 45-55 RANGE DURG THE DAYTIME...SO NO FLAGS
ATTM.

PRELIM NUMBERS:
TPA BB 075/091/075/091 2324
FMY BT 074/091/074/090 3445 88

.TBW...NONE.

GOLDSMITH

FLZ039-252030-

WEST CENTRAL AND SOUTHWEST FLORIDA HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TAMPA BAY AREA - RUSKIN FL
255 PM EDT FRI AUG 25 2000

...SEVERE THUNDERSTORM WATCH FOR LEVY COUNTY UNTIL 8 PM...

AT 255 PM...A LINE OF STRONG TO SEVERE THUNDERSTORMS EXTENDED
ACROSS EXTREME NORTHERN FLORIDA...FROM SAINT MARY'S TO JUST
SOUTHEAST OF MARIANNA.

THIS LINE WAS MOVING SOUTH AT AROUND 20 MPH...AND WILL AFFECT AREAS
OF NORTHERN FLORIDA THROUGH LATE AFTERNOON.

AS THE LINE MOVES SOUTH...IT WILL ENCOUNTER INCREASINGLY UNSTABLE
AIR BETWEEN TALLAHASSEE AND GAINESVILLE.  SOME INTENSIFICATION OF
THE STORMS IS LIKELY...WITH DAMAGING WIND GUSTS THE PRIMARY THREAT.

THE LINE WILL APPROACH NORTHERN LEVY COUNTY BETWEEN 5 AND 6 PM.

IN ADDITION TO THE GUSTY WINDS...THESE STORMS WILL CONTAIN TORRENTIAL
RAINS...FREQUENT LIGHTNING...AND PERHAPS SOME SMALL HAIL.

RESIDENTS OF LEVY COUNTY SHOULD KEEP AN EYE TO THE SKY...AND BE
PREPARED TO MOVE TO SAFETY IF SEVERE WEATHER WARNINGS ARE ISSUED.

STAY TUNED TO NOAA WEATHER RADIO OR YOUR LOCAL MEDIA FOR FURTHER
INFORMATION.

GOLDSMITH