Area Forecast Discussion
Issued by NWS Tampa Bay Area, FL

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FXUS62 KTBW 220747

Area Forecast Discussion
National Weather Service Tampa Bay Ruskin FL
347 AM EDT Tue Oct 22 2019

A fierce battle is underway between an advancing cold front,
associated with a deep trough axis extending from the Gulf Coast to
the Great Lakes region, and an upper level ridge, situated over the
Bahamas and extending across the Florida Peninsula into the Eastern
Gulf of Mexico. Infrared satellite imagery continues to show
convection across the panhandle, although it has weakened
substantially. Some cloud tops reached an estimated -85 degrees
Celsius overnight, indicating very healthy and robust convection
associated with strong vertical ascent mechanisms. This is in stark
contrast with the very quiet and generally clear skies across the
southern portion of the state in the region firmly under the
influence of the ridge.

Ultimately, the far-superior ridge will win this battle. As the
front continues pushing ahead with the southward advance, the trough
axis providing the upper-level support will retreat to the north,
leaving the frontal system exposed. While some limited gains will be
made, this will be done at the expense of the cold front`s energy.
As such, some shower activity is expected, but with frontal ascent
and diurnal heating being the only lifting mechanisms in the face of
strong upper-level stability, activity will be limited. Rain chances
will generally remain highest along the Nature Coast and Tampa Bay
before diminishing further to the South. Much of SW Florida will
hardly notice the front at all, with only a very slight drying for a
day or so and a very slight drop in temperatures.

Conditions will remain fairly dry late Wednesday and Thursday across
the state, and Thursday morning in particular will feel pretty nice.
Northern areas will certainly notice Fall in the air, but this will
not last. Details grow more fuzzy as the weekend approaches, but
another shortwave trough axis propagating from the Intermountain
West will attempt to take the ridge head-on after being cut-off from
another trough axis, while an upper level low riding along the edge
of the ridge will attempt to flank the high pressue. The combination
of these systems will quickly bring moisture back into the
equation by Friday. Showers and isolated thunderstorms are
expected to develop, but the ridge will still remain, despite a
brief weakening when both systems are on the offense. Rain chances
are expected to be higher Friday, through the weekend. However,
the exact intensity of these systems and how much they influence
the ridge will play a big role in how much conditions dry out. As
the front being dragged by the trough approaches Sunday into
Monday, rain chances remain in the forecast. As is the case with
the current system, model guidance is not very optimistic in this
frontal system holding together well as it approaches. Overall,
humid and warm conditions with daily chances for rain exist
through the weekend, but a slight hint of Fall could be in the
cards again for early next week.


Patches of MVFR/IFR/LIFR being observed at terminals this morning
associated with patchy BR/FG. This should dissipate rather
quickly by mid-morning. Otherwise, VFR conditions expected
throughout the remainder of the period, but VCSH for terminals
around Tampa Bay and northward possible with a passing cold front
this afternoon. SW winds 8-11kts during the day will shift NW and
then WNW in the wake of the front during the evening hours.


Showers and isolated thunderstorms are possible in coastal waters
today, especially from Tampa Bay northward, as a front passes
through the area. Winds begin to pick up towards cautionary levels
late tomorrow night and extending into Thursday. Unsettled weather
remains possible in coastal waters into the weekend and early next
week as additional systems move into the region.


Fire weather concerns remain low as values remain above critical
levels through the week.

Fog Potential...some patchy fog is being observed across the area
this morning, but should quickly burn off by mid-morning. As
conditions dry out after the frontal passage, no further fog is
expected at this time.


.Preliminary Point Temps/PoPs...
TPA  87  67  82  70 /  30  10   0   0
FMY  89  73  87  73 /  10  10  30  10
GIF  90  68  83  70 /  20  10   0   0
SRQ  89  70  86  71 /  30  10   0   0
BKV  89  63  81  66 /  30  10   0   0
SPG  88  69  85  72 /  30  10   0   0


Gulf waters...None.


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