Area Forecast Discussion
Issued by NWS Tampa Bay Area, FL

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FXUS62 KTBW 301832

Area Forecast Discussion
National Weather Service Tampa Bay Ruskin FL
232 PM EDT Thu Mar 30 2017

.SHORT TERM (Tonight - Friday)...
A progressive split flow upper air pattern will continue across the
Conus during the short term period. High pressure surface and aloft
will continue to shift eastward over the Atlantic tonight as a
closed low and attendant surface low over the mid Mississippi valley
moves east-northeast toward the Ohio valley/northern Appalachians
region through Friday. As the aforementioned storm system moves east
a trailing cold front from it will move east through the Florida
Panhandle later tonight before it begins to slow down as it moves
into the northern Florida peninsula early on Friday, and then into
the central forecast area Friday night as the main upper support
pulls away well to the north and the front becomes parallel to the
upper level flow. A slow increase in moisture combined with enough
instability and lift ahead of the front should support increasing
chances for some much needed rain with some scattered showers and a
few storms (Pops 30 to 40 percent) possible over northern portions
of the forecast area later tonight as the front approaches, and then
across the remainder of the forecast area on Friday as the front
sinks south into the region during the day with breezy, warm, and
muggy conditions expected.

Temperatures tonight and Friday will remain above normal with lows
tonight in the 60s area-wide, with daytime highs on Friday again
reaching the mid 80s over inland locations, except cooler readings
along the immediate coast due to a breezy onshore flow.

.LONG TERM (Friday night - Thursday)...
A closed upper low sits over the four corners region and associated
trouging extends south into the eastern Pacific. Upper ridging
extends from Louisiana northward through the Dakotas. Another closed
low sits over northern Virginia, with a more zonal pattern over
Florida through Saturday morning when ridging moves east over the
area. This ridging will move east through the weekend into the
beginning of next week as another closed low and deep troughing
approaches the southeast U.S. This troughing will lend support to
the next weather system that is expected to move through the Florida
peninsula on Monday and Tuesday next week.

On the surface, an area of low pressure sits over the eastern Great
Lakes region and extends a cold front south along the
eastern seaboard through southeast Florida. Weak high
pressure moves into the Gulf of Mexico in the wake of this
front and will bring sunny skies and unseasonably warm
temperatures to the area through the weekend. The next
weather system will develop over Mississippi by early
Monday. This low moves east-northeastward and will trail a
cold front through the Gulf of Mexico toward western Florida
by Monday evening. This will bring a 30-40 percent chance
of showers and storms to the area beginning Monday afternoon
and continuing through Tuesday afternoon. As this front
moves over southern Florida, high pressure builds back into
the area bringing clearing conditions through Wednesday
night next week.


VFR will prevail at all terminal sites during the next 24 hours. An
approaching cold front will bring increasing chances for shra/tsra
to the terminals after 13Z on Friday and have added VCSH to all
sites to account for this for now. A slow increase in mid and high
level clouds can be expected tonight into Friday, with lower cigs in
the 050-070 range expected after 15Z. South to southwest winds in
the 10 to 15 knot range this afternoon will diminish to 6 to 8 knots
after 02Z tonight, then increase into the 15 to 20 knot range with
some gusts up to 25 knots possible after 14Z on Friday.


High pressure moving east over the Atlantic combined with a cold
front approaching from the west will support an increasing south
to southwest wind flow over the Gulf waters tonight through Friday
with a period of cautionary headlines likely across the offshore
waters by later tonight through Friday a the cold front approaches
and sinks south into the eastern Gulf waters through the period.

Lighter winds and lower seas will return to the waters Friday night
into the upcoming weekend as high pressure re-builds in over the
region with an onshore sea breeze component again developing along
the coast each afternoon. On Monday winds may again increase toward
cautionary or small craft levels as they become southeast to south
as yet another cold front approaches from the west with this front
then sinking south through the waters during Monday night and
Tuesday with winds shifting to the southwest and west.


Increasing 20 foot winds and transport winds will support elevated
dispersion indices across the region on Friday. Humidity values will
remain above critical levels on Friday as moisture and rain chances
increase across the region. Drier air will filter in during the
upcoming weekend which will support a few hours of critically low
humidity values below 35 percent over interior locations each
afternoon, however light winds and ERC values below 37 should
preclude Red Flag conditions.


.Preliminary Point Temps/PoPs...
TPA  68  79  66  82 /  10  30  10  10
FMY  65  82  67  86 /  10  30  10   0
GIF  64  85  63  87 /  10  30  10   0
SRQ  67  77  64  80 /  10  30  10   0
BKV  64  83  57  85 /  10  30  10   0
SPG  68  79  68  82 /  10  40  10  10


Gulf waters...None.


MID TERM/LONG TERM/DECISION SUPPORT...74/Wynn is the U.S. government's official web portal to all federal, state and local government web resources and services.