Area Forecast Discussion
Issued by NWS Tampa Bay Area, FL

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FXUS62 KTBW 251855

Area Forecast Discussion
National Weather Service Tampa Bay Ruskin FL
255 PM EDT SUN SEP 25 2016

.SHORT TERM (Tonight - Monday)...
An upper level low continues to spin over the Florida Panhandle
this afternoon, and is forecast to drift southeast towards into
the eastern Gulf of Mexico through Monday. At the surface, high
pressure over the northeastern CONUS will shift southeast into
the western Atlantic tonight and Monday as a potent trough digs
into the western Great Lakes region. For the Florida peninsula,
this will translate to light, but generally easterly low level
flow continuing, with the sea breeze turning winds onshore near
the coast in the afternoon. Moisture will remain sufficient (PW
values of between 1.5 and 1.8 inches) for scattered afternoon
thunderstorms through the rest of the afternoon/early evening
today, and again on Monday afternoon. With the weak flow, storm
motion will be rather slow, so coverage should be broadly spaced
across the area, though moisture will be a bit more favorable
south of Interstate 4.

Temperatures will remain near to a couple degrees above normal, with
highs from the upper 80s to around 90, and lows tonight in the 70s.

.MID/LONG TERM (Monday Night - Sunday)...
Some changes appear likely during the latter half of the forecast
period as the atmosphere responds to the changing seasons. A rather
amplified pattern will set up with a sharp ridge building over the
mid-west and a downstream trough digging over the eastern United
States. Global models are in good agreement on this general
scenario, but there are the usual differences in placement, timing,
and strength.

On Tuesday, the upper-level trough will still be to our north with
deep-layered ridging in place. This will lead to typical summer-like
weather with scattered afternoon showers and storms, especially east
of I-75.

By Wednesday, the upper-level trough is digging into the southeast
with an associated surface cold front moving into the Florida
panhandle. Our light and variable wind regime will gradually evolve
into a westerly wind regime, which should favor higher rain chances
over our far interior zones. The one unknown is how far south the
cold front will get during the day. For now will keep highest rain
chances over the interior again, but we could see a band of showers
and storms heading south ahead of the boundary.

By Thursday, the upper-level trough is firmly entrenched over the
eastern states and should extend well into the eastern Gulf. The
surface front will be located somewhere between central and southern
Florida, but the drier air will lag behind. Overall rain chances
will still be in the 40 to 60 percent range across our central and
south, with lower chances as you go north.

The front will probably not make it far enough to completely end
rain chances over our entire area. In fact, moisture will be
returning from south to north by the weekend. Again, rain chances
will be highest over our southern zones, while Levy county could
remain dry each day.

Daytime highs won`t change too much, perhaps topping out in the
middle 80s north to upper 80s south. What could change is the
overnight lows, with the nature coast seeing widespread mid 60s
Friday morning.


Isolated showers and storms have begun to develop this
afternoon, mostly over the interior, but a few stray showers are
developing along the west coast. Storm motion is very slow today,
but these storms are expected to gradually fill in over the
western half of the Florida Peninsula through the rest of the
afternoon, with periods of IFR or MVFR conditions possible as
storms approach area terminals.


Weak high pressure will hold north of the waters through the first
half of the week, with light and generally easterly flow turning
onshore each afternoon near the coast with the sea breeze. Winds and
seas will remain below headline criteria, with the exception of
higher winds developing near thunderstorms, mainly during the
afternoon and early evening hours.


Relative Humidity is forecast to remain above critical thresholds
through the week, with no fire weather concerns expected.


.Preliminary Point Temps/PoPs...
TPA  75  89  75  88 /  30  40  20  30
FMY  74  90  74  89 /  30  50  30  40
GIF  73  91  73  90 /  30  50  30  50
SRQ  75  88  74  89 /  30  40  20  20
BKV  71  90  70  90 /  30  40  20  30
SPG  77  89  77  87 /  30  40  20  30


.TBW Watches/Warnings/Advisories...
Gulf waters...None.


MID TERM/LONG TERM/DECISION SUPPORT...63/Jillson is the U.S. government's official web portal to all federal, state and local government web resources and services.