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fxus62 ktbw 170841 

Area forecast discussion
National Weather Service Tampa Bay Ruskin Florida
341 am EST Fri Nov 17 2017

Short term (today-saturday)...
high pressure is ridging across the area from the north
keeping a dry NE flow across the area. This will weaken
along the coast this afternoon and allow for a weak sea
breeze. The high center shifts to the southeast over the Atlantic
tonight and will turn light winds more to the east by
morning. The high center then continues to shift east and
weaken across the state for Saturday as a cold front moves
east of the Mississippi into the deep south. Winds veer to
the southeast and then SW through the day with some patchy fog
possible in the early morning. Highs will be in the mid 70s
to lower 80s each day, with lows tonight in the lower 50s to
lower 60s.

Long term (saturday night - thursday)...
surface high pressure from the western Atlantic extending
west across the south Central Peninsula early Saturday
night will shift eastward as an amplifying upper level long
wave trough moves into the eastern U.S.. as the upper trough
moves east it will drive a cold front into the northern
Nature Coast late Saturday night and then south through west
central and southwest Florida on Sunday. A narrow ribbon of
moisture and sufficient lift accompanying the front should
support isolated to scattered showers (pops 20 to 40
percent) along and ahead of the front on Sunday as it moves
south through the region. During Sunday night much cooler
and drier air will advect into the region on a breezy
northerly wind flow in the wake of the front as surface high
pressure builds in across the southeastern U.S. And
northern Gulf with pleasant dry weather expected through
Monday night as the high slides east toward the mid Atlantic

On Tuesday the surface high will slide east off the mid
Atlantic coast into the Atlantic during the day as a short
wave trough slides eastward across the area. An increase in
low level moisture within the return easterly wind flow
around the departing surface high combined with the passing
short wave trough will bring chances (pops 30 to 40 percent)
for showers back to the area during the day along with
moderating temperatures.

During late Tuesday night into Wednesday models show another
and more vigorous positively tilted short wave trough and
possible closed low moving from the lower Mississippi Valley
southeast into the west central Gulf of Mexico. The European model (ecmwf)
and GFS differ some with the evolution of this system with
the Euro slightly slower in moving a closed low and
developing surface low eastward across the Gulf through mid
to late in the week, while the GFS is more open with the
trough and slightly more progressive in nature in moving
these features east during Wednesday night into Thanksgiving
day. Despite these differences the models do agree that
some wet weather is on tap for the forecast area from
Wednesday into Thanksgiving day as deep layered moisture
advects into the region on a deep layered southwest wind
flow and large scale lift and upper level divergence
increases across the region. Given this will use a blend of
the GFS/Euro for now and depict increasing rain chances
(pops 30 to 40 percent range) across the forecast area
during the Wednesday and Thursday time frame as this system
affects the region.

Above normal temperatures at the start of the period will
drop to below normal Sunday night into Monday in the wake
of the cold front. Temperatures will climb back to above
normal Tuesday through Thursday as the flow veers into the
east and southeast.


VFR conditions are expected through the period, with mostly
clear skies and NE winds turning to the north-northwest in the afternoon
near the coast.


light winds and seas through Saturday under high pressure. A
cold front will then move through the waters on Sunday, with
winds and seas increasing behind the front as high pressure
builds into the area. A brief scec or Small Craft Advisory may be needed
during this period. The high moves off to the east and weak
low pressure moves over the waters for Tuesday, with winds
quickly subsiding.


Fire weather...
no concerns.


Preliminary point temps/pops...
tpa 78 61 79 64 / 0 0 0 10
fmy 81 61 82 63 / 0 0 0 0
gif 78 58 81 60 / 0 0 0 10
srq 79 59 79 64 / 0 0 0 10
bkv 78 51 79 60 / 0 0 0 10
spg 76 64 77 66 / 0 0 0 10


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


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