Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Tampa Bay Ruskin Florida
258 PM EST sun Dec 4 2016
aloft - a robust low was over north-central Mexico...a short wave
trough reached over the upper Midwest from Canada...and a ridge
centered over Cuba extended across the eastern U.S. To Hudson
Bay. Surface - high pressure near the 4-corners region sprawled to
the Mississippi Valley...a wavy front stretched along the Gulf
Coast from south Texas to the Georgia/FL border...and high pressure over
Quebec ridged across the mid-Atlantic coast to the Bahamas.
Short term (rest of today-monday)...
the closed low over Mexico lifts up over the central/South Plains
as an open trough...flattening and shifting the upper ridge east
although it still dominates the area overnight. As a result the
frontal boundary slides east along/offshore the Gulf Coast as a
low forms on the western end...with a cold front trailing down
over the western Gulf. The eastern surface ridge re-locates over
the Atlantic and extends west across Florida to the central Gulf.
Through the evening hours rather pleasant weather continues...with
an increase in clouds and some modest gusts. Then over night south-
easterly low level flow will increase and bring in additional
moisture mainly at the lower layers...with considerable cloudiness
and patchy to areas of fog. Some of the fog may become locally dense
especially for the Nature Coast. The fog lifts during the morning
while the cloudiness continues. By the afternoon there will be
enough deepening moisture and instability...as the upper trough
and associated surface low approach from the west for slight
chance to chance showers and slight chance thunderstorms to spread
in from the Gulf.
Middle term/long term (monday night-sunday)...
the overall forecast remains unchanged as a shortwave moves
northeast across the southeast states Monday night and Tuesday
ahead of a developing longwave trough. This trough will cross the
central states midweek and then and out into the Atlantic late in
the week. Meanwhile at the surface, a low pressure system will
move northeast across the lower Mississippi Valley and southeast
U.S. Monday night and Tuesday with abundant moisture being drawn
northward into the forecast area leading to our first decent
chance of rain in nearly two months. However, it will also bring
the threat of a few strong to severe storms mainly from the Tampa
Bay area northward late Monday night and Tuesday. The cold front
will move down the Florida Peninsula late Tuesday and Tuesday
night before stalling over South Florida Wednesday. This will
allow some drier and slightly cooler air to move into most of the
region bringing an end to the precipitation for all but the
southern interior and southwest counties where a linger shower
could occur into Wednesday. Then during Thursday and Thursday
night another stronger cold front associated with the longwave
trough will sweep across the area bringing a chance of more
showers. Behind this second front much cooler drier air is
expected to overspread the region to end the week.
04/19z-05/18z. VFR prevails into the evening...as clouds begin to
increase during the afternoon along with some gusts. MVFR with local
IFR spread in after midnight with low ceilings the dominate problem...
patchy br generally MVFR. Both ceilings/visibility lift late morning.
concern in the near term may be sea fog later tonight into Mon
morning...especially near the coast. A couple of cold front
moving through...Tue-Wed...and late in the week will bring showers
and thunderstorms along with some prevailing higher winds and
seas. Small Craft Advisory conditions will be likely at times.
increasing moisture with slight chance-chance showers and storms
through the early part of the week will preclude any low relative humidity
concerns. Patchy to areas of fog...some locally dense at
times...is expected later tonight.
Preliminary point temps/pops...
tpa 69 79 72 79 / 10 40 50 70
fmy 69 83 72 82 / 10 20 20 50
gif 67 82 71 82 / 10 40 40 60
srq 68 78 72 79 / 10 40 40 70
bkv 66 81 73 80 / 10 50 50 70
spg 68 78 70 79 / 10 40 50 70
Florida...Beach hazards statement through Monday evening for coastal
Synopsis/short term/aviation/marine/fire weather...09/rude
middle term/long term/decision support...69/close