Severe Thunderstorm Warning 36, NWS Tampa Bay, FL

WEST CENTRAL AND SOUTHWEST FLORIDA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAMPA BAY AREA - RUSKIN FL
309 PM EDT SUN JUL 16 2000

MODIFIED KTBW SOUNDING DATA INDICATES A WEAK CAP CONTINUES TO
SUPPRESS CONVECTIVE DEVELOPMENT OVER THE FORECAST AREA EARLY THIS
AFTERNOON DESPITE SUFFICIENT LOW LEVEL MOISTURE AND INSTABILITY.
HOWEVER AS THE AFTERNOON CONTINUES THE CAP SHOULD WEAKEN AND AS
WEAK VORT LOBE AND SHEAR AXIS OVER THE NORTH CONTINUES TO SAG SOUTH
ALONG WITH ANY OUTFLOWS FROM ONGOING STRONG TO SEVERE TSTMS TO THE
NORTH THE THREAT OF LATE AFTERNOON AND EVENING CONVECTION STILL LOOKS
GOOD...ESPECIALLY NORTHERN ZONES AS INSTABILITY IS RELEASED. WITH
THIS IN MIND PLAN TO ADVERTISE CHANCE CATEGORY POPS FOR THE TONIGHT
PERIOD LIKELY ENDING LAST OVER THE MY FAR SRN ZONES. WILL ALSO KEEP
MENTION OF GUSTY WINDS AS WELL AS ANY STORMS THAT GET GOING MAY BE
STRONG.

FORECAST...MODELS ARE AGAIN FAIRLY SIMILAR WITH RESPECT TO SURFACE
AND UPPER LEVEL FEATURES THIS FORECAST CYCLE. DEEP UPPER TROUGH
ALONG THE U.S. EAST COAST WILL GRADUALLY GET KICKED EAST AS UPPER
RIDGE NOW OVER THE CENTRAL U.S. EXPANDS AND BUILDS EAST OVER THE
SERN U.S. DURING THE NEXT FEW DAYS. IN THE INTERIM THOUGH MODELS
DIFFER SOME WITH RESPECT TO NEXT SHEAR AXIS/VORT LOBE WHICH WILL BE
MOVING SEWD INTO NORTHERN FA ON MONDAY AND THROUGH THE REMAINDER OF
THE FA MONDAY NIGHT. THE AVN IS THE MOST AGGRESSIVE LOOKING WITH
RESPECT TO THIS FEATURE HAVING THE MOST INFLUENCE ON THE FA...WHILE
THE ETA AND NGM KEEP BULK OF THE PVA TO THE EAST OF THE CWA. SEEING
THAT THE MODELS HAVE NOT BEEN HANDLING THESE FEATURES TO WELL AM
INCLINED TO TAKE THE MIDDLE ROAD AND USE A BLEND OF ALL THREE WHICH
WOULD SUGGEST KEEPING POPS ABOVE THE LOW LOOKING FWC POP GUIDANCE...
AND WILL STAY CLOSER TO FAN NUMBERS OR CHANCE CATEGORY. GUIDANCE MINS
HAVE BEEN A BIT LOW LAST FEW NIGHTS...SO WILL GO ABOVE FOR THE NEXT
FEW DAYS WITH AND USE A BLEND FOR MAXS.

EXTENDED...TUESDAY NIGHT-FRI...INCREASING SUBSIDENCE AND WARMING 50H
TEMPS ASSOCIATED WITH EXPANDING AND BUILDING UPPER RIDGE SHOULD
RESULT IN LOWER POPS ACROSS THE BOARD. WITH THE SURFACE RIDGE AXIS
PROGD TO REMAIN OVER THE SRN PENINSULA THROUGH THE PERIOD A WESTERLY
FLOW REGIME SHOULD CONTINUE...WHICH WILL FAVOR MORNING AND EARLY
AFTERNOON COASTAL AND AFTERNOON INTERIOR POP TIMING ON WHAT PRECIP
CAN DEVELOP...AND WILL ADVERTISE AS SUCH THROUGH THE PERIOD.

MARINE...SOUTHWEST TO WESTERLY FLOW AT 10 TO 15 KNOTS WILL CONTINUE
THIS FORECAST PERIOD. NO HIGHLIGHTS EXPECTED.

PRELIMINARY NUMBERS
TPA BB 079/091 079/092 3422
FMY BB 079/093 078/094 3423

.TBW...NONE.

MCMICHAEL