241
FXUS62 KTBW 201151
AFDTBW

Area Forecast Discussion
National Weather Service Tampa Bay Ruskin FL
751 AM EDT Wed Aug 20 2025

...New UPDATE, AVIATION...

.UPDATE...
Issued at 750 AM EDT Wed Aug 20 2025

The forecast is on track this morning as Erin passes off the FL East
coast. A northerly wind has settled across the peninsula as
powerful, dangerous swells impact the Atlantic Coast. The western
half of the peninsula, despite having sufficient moisture in the
column to support convection, finds itself in the subsidence region
to the west of Erin. Thus, convection should be suppressed and
fairly minimal, despite morning ACARS soundings showing PWATs of
1.8 to 2 inches. If anything, the 20% to 40% across the region
today may be overdone. For now, will monitor and see how things
evolve through the day - but the expectation is for a warm and
humid day across the region.

&&

.AVIATION...
(12Z TAFS)
Issued at 750 AM EDT Wed Aug 20 2025

Sinking air across the western half of the FL peninsula will keep
the probabilities of convection too low for any mention at TAF
sites. If an isolated storm does form, the most likely window would
be 18Z to 22Z today. Better chances for convection will return early
tomorrow morning as Erin moves farther away and additional moisture
is pulled across the region. With the flow expected to go WSW from
the more northerly direction today, this will favor earlier
convection for coastal sites, and make the likelihood of actual
thunderstorms lower. This will continue into the weekend.

&&

.DISCUSSION...
Issued at 300 AM EDT Wed Aug 20 2025

A northwesterly flow will setup across the area today with some
relatively drier air moving into most of the forecast area, with
the exception being across southwest Florida. Isolated to
scattered showers and thunderstorms will be possible with the
highest rain chances over the interior and eastern half of the
Florida peninsula.

For Thursday through Sunday, upper level troughing will move into
the eastern U.S. keeping the ridge axis across the Florida
Straits as a weakening cool front settles into north Florida and
gradually dissipates. This will establish a west to southwest flow
across the region with a plume of deeper moisture, precipitable
water 2 inches or more, stretching across the Deep South and
northern Gulf leading to increased shower and thunderstorm
activity across most of the region. This pattern will favor the
timing of the highest rain chances to overnight and morning over
the coastal waters and near the coast then moving inland and into
the interior and eastern half of the Florida peninsula during the
afternoon and evening hours each day. However, with such deep
moisture expected, especially from around Tampa Bay north, a
shower or thunderstorm could occur at almost anytime.

Early next week, a second stronger cool front will move into the
Deep South and possibly as far south as the central Florida
peninsula by midweek before stalling and washing out. The west to
southwest flow will continue for Monday, then transistion to east
northeast by Wednesday as high pressure moves across the eastern
U.S. bridging the boundary. Not matter what though, the deep
moisture will remain across the region with scattered to numerous
showers and thunderstorms expected each day.

&&

.MARINE...
Issued at 300 AM EDT Wed Aug 20 2025

Winds will become northwesterly today then shift to west to
southwest for the remainder of the week into the weekend. Slightly
drier air will limit rain chances today, but during Thursday
through Sunday moisture will return leading to increased shower
and thunderstorm activity along with potential impacts.

&&

.FIRE WEATHER...
Issued at 300 AM EDT Wed Aug 20 2025

Some drier air along with northwesterly flow will limit the overall
shower and thunderstorm activity today. Relative humidity values will
remain well above critical thresholds and winds should remain less
than 15 mph. For the remainder of the week through the weekend a west
to southwest flow sets up with moisture returning along with
higher shower and thunderstorm chances. There are no significant
fire weather concerns at this time.

&&

.PRELIMINARY POINT TEMPS/POPS...
TPA  93  82  93  81 /  20  20  50  20
FMY  93  79  92  79 /  30  20  40  20
GIF  95  78  95  77 /  40  10  60  10
SRQ  92  79  92  79 /  30  20  50  30
BKV  93  75  93  75 /  20  20  50  20
SPG  90  81  89  81 /  20  20  50  30

&&

Sea Breeze Thunderstorm Regime For Wednesday: 8
Sea Breeze Thunderstorm Regime For Thursday: 4

For additional information on sea breeze regimes, go to:
     https://www.weather.gov/tbw/ThunderstormClimatology

&&

.TBW WATCHES/WARNINGS/ADVISORIES...
FL...None.
Gulf waters...None.

&&

$$

Flannery