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Area forecast discussion 
National Weather Service Tampa Bay Ruskin Florida
726 am EDT sun Sep 25 2016

some patchy MVFR visibilities are being reported early this
morning, although the taf sites have so far remained VFR. VFR
conditions should generally hold through the rest of the morning,
then isolated to scattered thunderstorms will develop this
afternoon. The highest chances for category restrictions will be
during the late afternoon and early evening hours as thunderstorms
build back to the coast. Brief IFR/MVFR ceilings and visibilities
will be possible as thunderstorms approach individual terminals.


Prev discussion... /issued 319 am EDT sun Sep 25 2016/

Short term (today - monday)...
a mid and upper level low will meander over the western Florida
Panhandle and northern Gulf Coast region today. This low will then
drift southeast to be over the eastern Gulf of Mexico offshore
the Tampa Bay area on Monday, while weak surface high pressure
remains in place across the north Central Peninsula. Adequate low
level moisture (highest across southern most zones) will remain
in place over the forecast area through Monday. This moisture
combined with daytime heating, the sea breeze circulations, and
added upper level divergence from the upper level low will support
scattered to numerous showers and thunderstorms over the region
today and again on Monday, with highest rain chances (pops 40 to
50 percent) focusing along and to the east of the I-75 corridor
each day during the afternoon and early evening hours.

A weak steering will favor slow moving storms both days with
torrential downpours likely along with some gusty winds and
frequent deadly lightning strikes. Rather cool mid level
temperatures (-8 to -9c at 500mb) associated with the upper level
low may also support a few strong storms with strong downburst
winds and small hail. In addition to the rain chances light winds
and ample ground moisture from the daily rain will favor some
patchy shallow fog development over inland locations the next few
nights, but overall coverage along with visibility restrictions
should be minimal.

Temperatures today and Monday will remain above normal with highs
climbing into the upper 80s to around 90 along the coast, and
lower 90s inland with lows tonight falling into the lower to mid
70s over inland areas, and mid to upper 70s along the coast.

Middle/long term (monday night - saturday)
in the mid/upper levels, high pressure ridging extends from near
Bermuda northward just off the eastern Seaboard into the New
England region. A deep upper low sits over the Great Lakes region
with troughing extending southward through the Mississippi River
valley. This upper low will shift slowly southeast by mid week and
the troughing will further extend into the eastern Gulf of
Mexico. On the surface, a large area of high pressure sits off the
New England coastline. A surface low sits over the Great Lakes
region and extends a cold front southward along the appalachian
mountain chain. The surface low will move slowly southeast and
fill by mid week. Another low develops along the boundary near
Maine while the front moves off the eastern Seaboard. A little
closer to home here in Florida, weak high pressure will be the
predominant weather influence through the week. Rain chances will
remain average for this time of year with afternoon probability of precipitation from
30-60%. Temperatures will also remain near seasonal average with
daytime highs in the upper 80's and overnight lows in the low to
mid 70's.

tranquil boating conditions will continue over the Gulf waters
today through the middle of next week as high pressure remains
in control with light winds and slight seas expected with a weak
pressure pattern supporting an onshore sea breeze component
developing along the coast each afternoon. Higher winds and seas
will be possible in the vicinity of thunderstorms otherwise no
headlines are anticipated.

Fire weather...
humidity values will remain well above critical levels into next
week with no fire weather concerns expected.


Preliminary point temps/pops...
tpa 90 75 90 75 / 40 30 30 20
fmy 90 74 91 74 / 50 40 30 20
gif 90 73 91 72 / 40 30 50 30
srq 90 75 90 75 / 40 30 30 20
bkv 91 72 90 71 / 30 30 30 20
spg 89 77 90 77 / 30 30 30 20


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



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