AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
955 AM EST Tue Jan 29 2013

…The slight risk for severe weather continues for tomorrow…

.NEAR TERM [Through Tonight]…

Deep layer ridging continues to dominate the Tri-State region this
morning. With the stretching of the ridge with height, winds veer
from southeast at the surface, to southwest above 700mb. A thin
saturated layer just below the inversion has yielded a scattered
to broken cloud deck around 100kft. Expect these clouds to
continue their northeast movement through the day and only
gradually scatter. Most of the low cloud cover has and will remain
on the outskirts of the forecast area. Isentropic ascent along
the 295K surface has generated a few light showers this morning,
primarily offshore and west of Bay county. These showers will
slowly spread north along our western fringes today, bringing an
isolated threat for a sprinkle or two across the Panhandle and
southeast Alabama. Even though mid level clouds will only slowly
scatter today, deep layer ridging will still promote above average
warmth this afternoon. Upper 70s to near 80 degrees will be common
across inland locations, with lower 70s along the coast.

Tonight, elevated southerly flow will preclude any fog
development over land, however, low clouds are expected to overspread
the region and keep temperatures moderated in the low 60s for most
spots. Isentropic rain showers are expected to continue, and
perhaps become more numerous, primarily west of the Apalachicola
and Chattahoochee rivers. Sea fog, will be a possibility
overnight as southerly flow transports a moist/warm airmass over
the cooler shelf waters of the Bay. Some advection inland can be
expected, however, expect the inland penetration to be minimal.

&&

.SHORT TERM [Wednesday Through Thursday]…

The short term period will continue to be focused on the potential
for strong to severe thunderstorms associated with the next storm
system that will sweep through the local region on Wednesday. A
squall line will develop ahead of a strong cold front and move into
the western zones by late Wednesday morning spreading across the
remainder of the CWA in the afternoon and early evening. The
forecast area will reside in the right-entrance region of a strong
upper level jet streak exceeding 100 kt. The low level jet is
forecast to be in the 50-60 kt range and the 0-6 km shear values are
still forecast to be near 50 knots in the warm sector. The primary
severe threat continues to be straight line damaging wind gusts but
a tornado or two cannot be ruled out, especially for our Florida
Panhandle counties and SE Alabama.

By late Wednesday, the cold front should already be east of our FA
with surface high pressure and a much drier air filtering in
Thursday. Temperatures will be well above normal on Wednesday with
near or slightly below seasonal levels for Thursday.

&&

.LONG TERM [Thursday Night through Monday]…

An uneventful long term period is expected with surface high
pressure remaining the dominant feature locally. Guidance is in
good agreement on a dry airmass with near seasonal temperatures
through the period, and the official forecast made no significant
deviations from the guidance consensus.

&&

.AVIATION [Beginning 15Z Tuesday]…

Most sites have returned to VFR as of 15z this morning. Expect
KABY to return to VFR within the hour. Thereafter, scattered to
broken mid level clouds will persist through the day. Overnight,
MVFR, and eventually IFR ceilings will overspread the region.
Light showers will be possible at both KECP and KDHN through the
night. Tomorrow, a line of showers and isolated thunderstorms will
pass from west to east across all terminals through the afternoon.
The threat for damaging winds at the surface exists for primarily
KDHN and KABY, with mostly rain expected for all other sites. Low
level winds will be very strong, with up to 50 knots expected
below 2kft for most sites at some point during the day.

&&

.MARINE…

Winds and seas will gradually increase to cautionary and then
advisory levels later today into Wednesday as they veer to the
south and southwest ahead of a strong cold front. Winds will then
remain elevated for a short time after the frontal passage
Wednesday night before diminishing below headline criteria by
Thursday afternoon.

&&

.FIRE WEATHER…

Red Flag conditions are not forecast through Wednesday as minimum
relative humidities are expected to be well above critical levels
throughout the forecast area. Showers and thunderstorms will bring
wetting rains…gusty winds and high dispersion indices to the
forecast area ahead of a Wednesday cold frontal passage. Drier air
will arrive behind the front for Thursday through Saturday. Our FL
zones will need to be monitored for possible red flag conditions on
those days.

&&

.HYDROLOGY…

The upcoming system on Wednesday is expected to be progressive and
bring a general half inch to inch of rain across the area. The
highest amounts are expected across portions of southeast Alabama
and adjacent southwest Georgia and the Florida Panhandle. The
lowest amounts are expected across the southeast Big Bend.
Flooding problems are not currently expected.