400
FXUS62 KTBW 112340
AFDTBW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAMPA BAY RUSKIN FL
740 PM EDT THU SEP 11 2025
..NEW UPDATE, AVIATION
UPDATE
ISSUED AT 737 PM EDT THU SEP 11 2025
CONVECTION CONTINUES THIS EVENING ACROSS SWFL AND THE ADJACENT
COASTAL WATERS. OVER THE LAST HOUR OR SO, THE PERSISTENT CONVECTION
OVER LAND HAS BEGUN TO WIND DOWN AS OUTFLOW RACED OUT TO THE WEST,
UNDERCUTTING THE INSTABILITY AS THE COLD POOL SPREADS OUT. NEW, BUT
SIGNIFICANTLY LESS INTENSE CONVECTION CONTINUES TO DEVELOP OFF
THE COAST; BUT AS DAYTIME HEATING WANES, THIS ACTIVITY SHOULD ALSO
CONTINUE TO WIND DOWN.
OUTSIDE OF SWFL, RADAR IS PICKING UP ON A FEW MID-LEVEL SPRINKLES
FALLING OUT OF MID-LEVEL CLOUDS. HOWEVER, THERE REALLY ISN'T MUCH
INDICATION THIS IS MAKING IT TO THE SURFACE. EARLY 0Z SOUNDING DATA
SUGGESTS THAT THERE IS A FAIRLY DRY LAYER BELOW 850MB OR SO,
SUGGESTING MUCH (IF NOT ALL) OF THE PRECIP FALLING OUT OF THESE
CLOUDS IS LIKELY EVAPORATING ON THE JOURNEY TO THE SURFACE.
CURRENT CONDITIONS ARE CONSISTENT WITH THE CURRENT FORECAST. THUS,
NO CHANGES AT THIS TIME.
AVIATION
(00Z TAFS)
ISSUED AT 737 PM EDT THU SEP 11 2025
CONVECTION ACROSS SWFL WILL CONTINUE TO WIND DOWN OVER THE NEXT
COUPLE HOURS, WITH THE EXPECTATION THAT VFR WILL PREVAIL OVERNIGHT
AND THROUGH TOMORROW MORNING. THIS IS NOT TO SAY THAT A COUPLE
ISOLATED SHOWERS OR PERHAPS SOME SPRINKLES COULD OCCUR THROUGH
MIDDAY TOMORROW, BUT THE OVERALL IMPACT SHOULD BE MINIMAL AND THUS
ARE NOT BEING MENTIONED IN TAFS AT THIS TIME. THUNDERSTORMS WILL
AGAIN BE POSSIBLE TOMORROW AFTERNOON ACROSS SWFL, WITH PERHAPS A
BIT MORE MOISTURE ACROSS THE CENTRAL INTERIOR AND THE TAMPA BAY
REGION FOR A COUPLE SHOWERS TO SNEAK INTO THE VICINITY OF
TERMINALS LATE TOMORROW. OVERALL, THOUGH, THE FORECAST IS TRENDING
DRIER IN THE DAYS TO COME, WITH A LOWER PROBABILITY OF IMPACTS
OVER THE WEEKEND AND INTO AT LEAST EARLY NEXT WEEK.
DISCUSSION
ISSUED AT 128 PM EDT THU SEP 11 2025
CURRENT WATER VAPOR IMAGERY INDICATES SOME COOLER CLOUD TOPS OVER
THE GULF WITH WIDESPREAD MID TO HIGH CLOUD COVER EXTENDING ACROSS
MUCH OF THE FLORIDA PENINSULA. AT THE SURFACE, A STATIONARY BOUNDARY
EXTENDS E-W ACROSS SOUTH FLORIDA. FURTHER TO THE NORTH, THERE IS A
TROUGH AXIS THAT EXTENDS FROM THE EASTERN GREAT LAKES TO THE
SOUTHEAST ACROSS THE TENNESSEE VALLEY. WATER VAPOR IMAGERY INDICATES
DRIER AIR TO THE NORTH OF THE BOUNDARY ACROSS THE DEEP SOUTH AND THIS
DRIER AIR IS FORECAST TO DRIFT INTO THE FORECAST AREA THROUGHOUT THE
NEXT FEW DAYS. THIS MORNINGS 12Z TBW SOUNDING IS STILL RATHER
SATURATED WITH 2.06 INCHES OF PW, HOWEVER, THE JAX 12Z SOUNDING IS
MUCH DRIER WITH 1.25 INCHES OF PW. THE 2.06 INCHES OF PW IS AROUND
THE 90TH PERCENTILE FOR MID-SEPTEMBER AND DUE TO THIS, EXPECT
PRECIPITATION CHANCES WILL REMAIN ELEVATED TODAY, ESPECIALLY ALONG
AND SOUTH OF THE I-4 CORRIDOR. DUE TO THE HIGHER PW VALUES, THERE
COULD BE SOME HEAVIER DOWNPOURS TODAY AND WPC HAS THE SOUTHERN HALF
OF THE AREA IN A MARGINAL RISK FOR EXCESSIVE RAINFALL. MOST PLACES
WILL SEE BELOW AN INCH OF RAIN TODAY BUT AN ISOLATED SPOT HAS A LOW
CHANCE OF SEEING 2-4 INCHES OF RAINFALL. MOST ACTIVITY SHOULD COME
TO AN END OVERNIGHT. LOWS WILL RANGE AROUND 10 DEGREES ACROSS THE
FORECAST AREA FROM MID 60S ACROSS LEVY COUNTY TO MID 70S ACROSS
SOUTHWEST FLORIDA.
THE TROUGH TO THE NORTH DRIFTS SOUTHEASTWARD ON FRIDAY AND WILL
STRETCH FROM THE MID-ATLANTIC TO THE SOUTHWEST TO THE NORTHERN
GULF COAST. CLOSER TO HOME, UPPER AND LOW LEVEL FLOW WILL NOT
CHANGE TOO MUCH AND EXPECT SIMILAR CONDITIONS ON FRIDAY AS TODAY.
THE FRONT SHOULD REMAIN IN A SIMILAR LOCATION WITH MOST OF THE
SHOWERS/STORMS SOUTH OF I-4. ONCE AGAIN, HEAVIER PRECIPITATION
WILL BE A THREAT WITH PW VALUES OVER 2 INCHES.
THE STALLED BOUNDARY FINALLY BEGINS TO MOVE LATE IN THE DAY FRIDAY
AND INTO THE DAY ON SATURDAY AS THE TROUGH DIGS FURTHER TO THE
SOUTHEAST INTO THE FLORIDA PENINSULA. MODELS INDICATE PW VALUES WILL
DROP BELOW 1.5 INCHES. THESE VALUES ARE AROUND THE 25TH PERCENTILE
FOR MID-SEPTEMBER. DESPITE THE DRIER AIR, POPS AROUND 20-40% WILL
CONTINUE IN THE FORECAST. THE UPPER LEVEL TROUGH WILL MOVE OVERHEAD
OVER THE WEEKEND WITH CYCLONIC FLOW ALOFT. FORECAST MODEL SOUNDINGS
INDICATE DECENT LAPSE RATES ALOFT WITH THE UPPER LOW OVERHEAD
SUPPORTING AT LEAST SOME LOW MENTION FOR AFTERNOON SHOWERS/STORMS
OVER THE WEEKEND AND INTO EARLY NEXT WEEK.
MODELS INDICATE THAT THIS UPPER LEVEL LOW EVENTUALLY CLOSES OFF NEAR
THE GA/SC/NC COAST EARLY NEXT WEEK. THERE ARE SOME INDICATIONS OF
ANOTHER POTENTIAL FRONT LATE IN THE FORECAST PERIOD. OVERALL, THE
FORECAST WILL BE ON THE DRIER SIDE WITH THE THE THREAT FOR
ISOLATED TO SCATTERED AFTERNOON SHOWERS/STORMS. MORNING LOWS WILL
REMAIN A BIT ON THE COOLER SIDE IN THE UPPER 60S TO LOW 70S FOR
MUCH OF THE UPCOMING WEEK.
MARINE
ISSUED AT 128 PM EDT THU SEP 11 2025
SHOWERS AND STORMS WILL CONTINUE TO DEVELOP OVER THE WATERS AS A
FRONT REMAINS STALLED ACROSS SOUTH FLORIDA SUPPORTING WINDS IN
THE OFFSHORE WATERS AROUND 10 TO 15 KNOTS. THIS TREND WILL
CONTINUE THROUGH FRIDAY. AFTER THAT A STRONG UPPER LEVEL TROUGH
WILL PUSH THROUGH CAUSING THE FRONT TO PUSH SOUTH. THIS WILL HELP
TO KEEP US MOSTLY DRY FOR THE WEEKEND HOWEVER WINDS WILL STILL
STAY AROUND 10 TO 15 KNOTS.
PRELIMINARY POINT TEMPS/POPS
TPA 75 89 74 89 / 20 30 10 30
FMY 75 88 74 89 / 50 60 30 50
GIF 74 89 72 89 / 20 40 10 40
SRQ 74 88 72 89 / 30 40 20 30
BKV 69 88 69 89 / 10 20 0 30
SPG 75 87 74 87 / 20 30 10 30
SEA BREEZE THUNDERSTORM REGIME FOR FRIDAY: 2
SEA BREEZE THUNDERSTORM REGIME FOR SATURDAY: 2
FOR ADDITIONAL INFORMATION ON SEA BREEZE REGIMES, GO TO:
HTTPS://WWW.WEATHER.GOV/TBW/THUNDERSTORMCLIMATOLOGY
TBW WATCHES/WARNINGS/ADVISORIES
FL...NONE.
GULF WATERS...NONE.
UPDATE/AVIATION...FLANNERY
PREVIOUS DISCUSSION...ANDERSON
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