Severe Thunderstorm Warning 56, NWS Tampa Bay, FL

WEST CENTRAL AND SOUTHWEST FLORIDA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAMPA BAY AREA - RUSKIN FL
155 PM EDT FRI JUN 15 2001

CURRENT FCST TRENDS IN FINE SHAPE...AND WILL MAKE FEW CHANGES TO THE
OVERALL GIST OF THE PACKAGE.  IN GENERAL...A DRY WEEKEND UPCOMING
BY MID JUNE STANDARDS IN FL...BUT MODEL TRENDS CONTINUE TO INDICATE
A GRADUAL INCREASE IN CHANCES AND COVERAGE OF PCPN FOR NEXT WEEK.

MODELS ARE IN GOOD AGREEMENT THROUGH 24H.  APPEARS THAT AVN BEST
HANDLED SLOW N CREEP OF ALLISONS REMAINS.  NOW...ALL MODELS
QUICKLY ENVELOP THE SHORT WAVE INTO THE APPROACHING SYSTEM BY SAT.
FOR US...THE PRIMARY MODEL DIFFERENCE BEYOND 24H IS THE HANDLING OF
SHORTWAVE ENERGY SLIDING INTO THE MIDWEST TONIGHT THEN DIVING SE
TOWARD FL LATER SAT AND SUN.  NGM IS THE WEAKEST WHILE ETA
STRONGEST...WITH AVN IN BETWEEN.  WITH SYSTEM SLIDING INTO AN
EXISTING WEAKNESS AT H50 BELIEVE THE NGM A BIT TOO FAST TO DAMPEN...
BUT ETA MAY BE OVERDONE ATTM.  FAVOR THE AVNS BIG PICTURE THIS TIME
AROUND.

SHORT TERM:
WILL MONITOR ISOLD/SCT AFTN CONVECTION FOR WIND/HAIL EVENTS.
THEREAFTER...SKIES SHOULD CLEAR OUT ONCE AGAIN.  TRICKY CALL NEAR
THE COAST AS CURR FCST CARRIES ISOLD LATE NIGHT PCPN.  NEW RUNS SHOW
N TO NW FLOW DEEPENING TWD DAWN...BUT MOISTURE IN THE NW FLOW REGIME
IS LIMITED SO WILL REMOVE.  FOR SAT...SOUNDINGS ARE SIMILAR TO THIS
MORNINGS OBSERVED...ONLY WITH SLIGHTLY LOWERED CAPE/LI AND A
DEFINITIVE NW FLOW.  THE EXCEPTION IS THE SW CORNER WHERE LIGHTER
WINDS PREVAIL.  WILL BACK OFF TO ISOLD PCPN.  A TURN TO THE WNW
COMBINED WITH INCREASING LOW LVL MOISTURE ARGUES FOR A BETTER SHOT
AT PCPN NEAR THE COAST COME EARLY SUN.

SUN ITSELF COULD GET INTERESTING AS MID LEVEL DRY AIR MOVES IN...AT
LEAST ACROSS THE N 2/3 OF THE CWFA AND SHORT WAVE APPROACHES IN NNW
FLOW ALOFT.  FOR NOW A BIT TOO SOON TO SPECULATE...AND WOULD RATHER
ERR ON THE SIDE OF CAUTION...SO WILL BUMP PCPN CHANCES UP A TAD IN
ALL AREAS.

EXTENDED:
OLD SFC TROUGH GIVES WAY TO LIGHT...BUT IMPORTANT...E FLOW.
INITIALLY RETROGRADED UPPER RIDGE EXPANDS BACK TO THE E...N OF THE
STATE...AND THIS SHOULD HELP DEEPEN THE E FLOW.  OLD POOLED
MOISTURE WOULD HELP THE CAUSE.  IN BRIEF...WILL LEAVE GIST OF EFP
ALONE WITH EXPECTATION OF MORE TYPICAL TEMP/PCPN PATTERN MON THROUGH
FRI.

MARINE:  CURR FCST TREND LOOKS RIGHT ON...SO ONLY A FEW TWEAKS
PLANNED.

FIRE WX:  DRIER AIR MIXING TO SFC WILL CREEP AFTN RH VALUES TWD 35-40
PERCENT IN CENTRAL ZONES SAT...BUT STILL NOT ENOUGH FOR WATCH
CRITERIA DESPITE AN OCCASIONAL GUST TO 15 MPH.  HOWEVER...ISOLD/SCT
TSTMS CAN STILL PROVIDE FIRE IGNITIION FROM LIGHTNING STRIKES.
UNTIL DEEP AND WIDESPREAD PCPN OCCURS...THIS WILL REMAIN AN ONGOING
THREAT.

PRELIM NUMBERS:
TPA BB 077/092/077/091 -113
FMY BB 075/093/075/092 1313

.TBW...NONE.

88/GOLDSMITH