Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Tampa Bay Ruskin Florida
242 PM EST sun Nov 29 2015
Short term (today and monday)...
a large closed low continues to drift across the western
u... broad upper riding extending from south Texas through
the northern Gulf and middle Atlantic regions. High pressure...both
aloft and at the surface...will continue to drive the weather over
the next couple of days.
Light northeast winds will continue today...as high pressure
remains firmly in place to our north. A ribbon of moisture between
850mb and 700mb is leading to a bit more cloud cover than we saw
this time yesterday. This may act to limit heating by a couple of
degrees...but temperatures are more or less expected to be fairly
similar to yesterday...with highs near or just a couple ticks
above 80 degrees. With fairly shallow moisture and continued
subsidence...odds of a stray shower will remain very slim today.
Tonight...expect very similar conditions as last night. As
surface temperatures fall beneath the subsidence inversion...we
look to again see areas of low stratus and possibly some fog as we
head into the early morning hours Monday. Lows should range from
the upper 50s north to lower 60s south.
Monday...patchy low stratus and fog should give way to mostly
sunny skies by middle morning. With surface heating...scattered
clouds will become more prevalent during the afternoon hours. A
stray shower or two may affect interior portions of the
peninsula...though most activity should remain along or just
inland of the eastern Florida coastline. Once again...we should
see temperatures rise into the lower 80s...as high pressure
continues to dominate the regional weather scene.
Middle term/long term (monday night-sunday)...
nearly zonal flow aloft the area will gradually back to
southwesterly through the week as an upper low tracks from the
Central Plains to the Gulf of Saint Lawrence - with a short wave
trough forming in it/S wake and swinging across the Gulf Coast and
into the southeastern states. During the weekend - the short wave
trough deepens into a closed low on the middle-Atlantic coast and
moves out over the Atlantic...as ridging builds north from the
Gulf of Mexico then shifts to the southeastern U.S. Coastal
Surface high pressure ridging in along the eastern Seaboard from
the Atlantic will pull away to the east as the surface reflection
of the upper low moves northeastward...dragging a cold front
across the Gulf Coast and southeastern states then to the Atlantic
and through much of Florida. High pressure initially over the western
states crosses the plains then settles in from the Gulf Coast to
The models are consistent for most of the period but then diverge
some on the last couple of days. The European model (ecmwf) is more robust and
slower with the upper features and faster with the front compared
to the GFS. For now would lean toward the European model (ecmwf).
The Atlantic ridge will provide easterly flow with enough
moisture for a slight chance of showers moving in from the east
Tuesday afternoon. Then the approaching upper trough and front will
result in increasing moisture with scattered to likely showers.
The bulk of the energy stays north of the area and limit any
thunderstorms. Temperatures above normal do cool through the
period. While the lows remain above normal the highs dip to around
normal Friday and Sat. This is more of a function of clouds and rain
rather than any cold air filtering in.
VFR conditions will prevail at all terminals through much of the
night...with scattered to broken VFR ceilings in a few locations. From 08z
to 13z...expect patchy low stratus to develop once
again...with patchy fog also possible. For now...will include
temperatures for fog/low ceilings at klal...kpgd...kfmy...and krsw. Other
terminals may also experience brief limitations to ceilings
visibilities...though areas closer to the coast should have less of a
chance. Skies should clear quickly by middle to late morning
Monday...with returning VFR conditions.
high pressure will remain parked north of the waters...resulting
in persistent east/northeast flow. Modest easterly wind surges may
yield periods of cautionary winds offshore both tonight and Monday
night...with winds decreasing during the daylight hours. The
pressure gradient will slacken by middle week with the approach of a
frontal boundary...shifting winds more to the southeast. An area
of low pressure then looks to move over the waters...generating
increased chances for showers and perhaps a few thunderstorms middle
to late week. Post frontal northeast winds will then overspread
the waters...with cautionary level winds likely for an extended
period heading into next weekend.
despite rather mild temperatures for late November...adequate low
level moisture will remain over the region to prevent humidities
from becoming conducive to wildfires. Northeast winds will shift
to the east and southeast by the middle of the coming week...as a
front slowly approaches the region. Rain chances will be on the
rise from middle week through the weekend...as the front and an area
of low pressure move across Florida. This will keep fire concerns
at Bay over the next several days.
Preliminary point temps/pops...
tpa 64 81 67 82 / 0 0 0 20
fmy 64 84 68 85 / 0 10 10 20
gif 63 82 65 83 / 0 10 0 20
srq 63 82 67 82 / 0 10 10 20
bkv 60 82 62 83 / 0 0 0 10
spg 65 80 68 82 / 0 0 10 20
Florida...Beach hazards statement through Monday evening for coastal
Short term/aviation/fire weather/marine...84/Austin
middle-long term/decision support...09/rude