Area Forecast Discussion
Issued by NWS Tampa Bay Area, FL
FXUS62 KTBW 231808
Area Forecast Discussion
National Weather Service Tampa Bay Ruskin FL
208 PM EDT SAT JUL 23 2016
.SHORT TERM (Tonight - Sunday)...
Showers and storms should slowly wind down after sunset tonight as
boundary interactions weaken and loss of daytime heating occurs
with convective debris cloudiness thinning out with skies
becoming partly cloudy overnight. It will continue warm and muggy
overnight with low temperatures in the mid 70s inland areas, and
upper 70s along the coast.
On Sunday a large mid and upper level ridge will remain over the
south central portion of the U.S. as a cut-off upper level low
(Tutt) on the southeastern periphery of the ridge now over the
Atlantic east of Florida retrogrades slowly west-southwest across
the Florida peninsula during the day, while the surface ridge axis
to the north sinks a bit south to the north-central peninsula.
As mentioned in previous discussions some mid and upper level dry
air associated with the Tutt low will remain over the region on
Ample low level moisture combined with daytime heating though
should still support scattered diurnal sea breeze driven showers
and storms over the region during the afternoon. Cool (-9C at
500MB) and dry mid level air may support a few strong storms with
downburst winds and small hail the main hazards with the best rain
chances likely setting up across central and southern interior
zones along the east and west coast sea breeze merger late in the
afternoon, with slightly lower rain chances further to the north
and west where the driest air and subsident effects from the upper
level low will exist.
Slow and erratic storm motion will again favor some locally heavy
rainfall in some locations, along with frequent deadly lightning
strikes. Temperatures on Sunday will remain a few degrees above
normal with highs climbing to around 90 along the coast, and lower
to mid 90s inland.
.LONG TERM (Monday - Saturday)...
An upper low that was across the state during the weekend slides
west over the Gulf early in the week. Mid and upper level ridging
initially across the southeast U.S. coast and adjacent Atlantic
waters settles south...reaching northern FL and the Gulf coast for
next weekend. Atlantic high pressure broadly ridges west...with an
axis meandering through northern FL...to the gulf. Toward the
end of the week the ridge axis shift into central Fl then the
southern part of the state for the weekend.
Some limited drier air...associated with the departing upper
low...exits Monday with model PWAT values varying from around 1.6
to almost 2 inch range through the rest of the period. This
along with daytime heating and sea breeze/outflow interactions
will support scattered showers and thunderstorms. these showers
and storms will generally be afternoon to early evening and
favoring Gulf coastal locations...while the surface ridge axis
remains in northern FL with a prevailing east to southeast flow
for west central and southwest FL. But as the ridge axis moves
south during the end of the period the flow begins to veer through
the south to southwest and west which will tend to keep showers
and storms more inland.
Brief MVFR/IFR conditions from shra/tsra may impact the coastal
terminals through 22Z and 01Z at KLAL and have handled with VCTS,
otherwise VFR will prevail during the next 24 hours. Coastal
terminals will see southwest to west winds at 6 to 8 knots the
remainder of the afternoon with southeast winds at 5 to 7 knots
continuing at KLAL with gusts up to 40 knots possible in the
vicinity of tsra. Winds will become light and variable at all
terminals after 02Z tonight.
Surface high pressure will remain over the region through next
week providing a light southeast to southerly wind flow and
slight seas over the Gulf waters through the period, with a weak
pressure pattern supporting an onshore sea breeze component
developing along the coast each afternoon. Wind and seas will
higher in the vicinity of thunderstorms, otherwise no headlines
Ample low level moisture combined with diurnal scattered showers
and thunderstorms will keep humidity values well above critical
levels the remainder of the weekend and into next week with no
fire weather issues expected.
.Preliminary Point Temps/PoPs...
TPA 77 91 76 91 / 30 50 30 50
FMY 75 89 75 90 / 30 60 20 60
GIF 74 92 74 92 / 20 50 20 50
SRQ 76 89 76 89 / 20 50 30 40
BKV 72 92 72 92 / 20 40 30 50
SPG 78 90 78 90 / 30 40 30 40
SHORT TERM/AVIATION/MARINE/FIRE WEATHER...57/McMichael
MID TERM/LONG TERM/DECISION SUPPORT...09/Rude