Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

fxus62 ktbw 170750 

Area forecast discussion
National Weather Service Tampa Bay Ruskin Florida
350 am EDT Wed Oct 17 2018

Short term (today - thursday)...
mid level ridging centered just east of Florida will keep
warm and fairly stable conditions in place today and
Thursday, with afternoon high temperatures approaching
record values again this afternoon. As the ridge gradually
weakens on Thursday, temperatures will moderate slightly,
but will still remain several degrees above normal,
generally topping out around 90.

At the surface, the subtropical ridge north of Florida will
slip farther east into the Atlantic as a stronger area of
high pressure builds in from the northwest. This will keep
generally easterly winds in place, with an afternoon sea
breeze turning winds onshore near the coast. Subsidence from
the ridging aloft will keep rain chances minimal, although
some areas could see isolated to scattered showers and
storms developing this afternoon. A backdoor cold front
moving into Florida from the northeast on Thursday will
wash out north of the area, but will allow for slightly
higher rain chances north of Interstate 4.

Long term (thursday night - tuesday)...
a large upper/mid level trough will dig into the eastern
Continental U.S. During the second half of the week, displacing mid
level ridging to the south. At the surface, broad high
pressure across the eastern US will gradually shift east
into the Atlantic through the weekend, allowing generally
easterly winds to continue. As the mid level trough swings
through the eastern Seaboard during the weekend, a
weakening cold front will move south through the Florida
Peninsula Saturday night and Sunday, before low level winds
quickly turn back to easterly and northeasterly by Sunday
night, limiting the amount of cold air advection possible.
Still, temperatures are forecast to drop to near to slightly
below normal Sunday over the northern and central portions
of the forecast area, before quickly moderating again early
next week. Otherwise, dry and stable air behind the front
will keep rain chances minimal on Monday.

On Tuesday, the GFS is showing an area of low pressure
developing over the Gulf and moving east across the Florida
Peninsula, leading to scattered showers and thunderstorms
across the area. The European model (ecmwf) is considerably slower with this
feature however, keeping the forecast area mostly dry on
Tuesday. For the time being, a blend of the two solutions
was used for rain chances, but this feature will need to
continue to be closely monitored until the models come into
better agreement.


generally VFR conditions are expected to hold through the
morning hours, although some patchy ground fog cannot be
ruled out around klal, kpgd, kfmy, and krsw around sunrise,
producing MVFR or brief IFR visibilities. Isolated to
scattered showers and storms will be possible during the
afternoon, mainly around kpgd, kfmy, and krsw.


high pressure will hold just north of the Gulf of Mexico
through the week, with generally easterly winds continuing
across the coastal waters. A weak afternoon seabreeze will
setup each day, allowing winds to turn onshore near the
coast. A tighter pressure gradient Thursday night will allow
winds to increase to cautionary or perhaps low end advisory
levels, before subsiding again Friday and Saturday.


Fire weather...
no concerns, as humidity will remain well above critical
levels through the period.


Preliminary point temps/pops...
tpa 91 74 90 74 / 10 10 10 10
fmy 91 75 90 74 / 40 10 20 10
gif 93 73 90 73 / 10 0 20 20
srq 89 74 89 75 / 20 10 10 10
bkv 92 72 90 72 / 10 10 20 10
spg 91 76 89 75 / 10 10 10 10


Tbw watches/warnings/advisories...
Gulf waters...none.

National Weather Service Glossary of Abbreviations