Area Forecast Discussion
Issued by NWS
FXUS62 KTAE 010148
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
848 PM EST Sat Feb 28 2015
.Near Term [Through Tonight]...
A fairly simple southwesterly flow regime continues aloft across
the Southeast this evening. At the surface, a wedge of high
pressure remains intact along the Eastern Seaboard all the way
through the Tri-State region to the Gulf coast. The near surface
northeasterly flow and the very shallow cool, stable layer barely
extends to 1kft before wind starts to veer and the air warms about
5 degrees. With northeasterly trajectories expected to continue
overnight, the cool stable airmass will only be reinforced. Just
above this layer however, heights will begin to rise tonight as
the deep layer synoptic pattern amplifies in response to a
developing low over the Southwest. This will act to compact the
near surface cool layer and steepen the nose of the wedge front.
As it does so, expect the coverage of isentropic drizzle or light
rain to increase. As low-layer flow veers through the night, the
area of drizzle and light rain will halt it`s northwestward spread
and begin to move north, then northeast. This will mean that the
best rain chances through the night will be spread across the Big
Bend of Florida and southern Georgia, with lesser coverage across
the Panhandle and southeast Alabama. QPF amounts are expected to
be quite low as an average, though still went with near 100 PoPs
as confidence is relatively high that most locations will receive
at least 0.01" through the night. Some of the hires guidance
suggests there may be a few locations that could receive around a
tenth of an inch. Lows tonight will range from near 40 degrees
across our northernmost GA counties to around 50 degrees along the
Gulf coast and the southeast Big Bend.
[Through 00Z Monday]...
All terminals have fallen to IFR ceilings as of 01z. Expect
ceilings to lower to between 001-004ft through the night. Light
rain or drizzle should be expected at all terminals. Rain will
gradually come to an end tomorrow from southwest to northeast,
with ceilings possibly improving to low-end MVFR by the late
.Prev Discussion [301 PM EST]...
.Short Term [Sunday Through Monday Night]...
So the big question is whether the cool wedge in place across the
region will begin to breakdown on Sunday as indicated in some of
the models. The GFS is very aggressive with eroding the wedge as
high pressure over the Mid Atlantic weakens and then shifts out
into the Western Atlantic. The NAM keeps the wedge in place across
Southern Georgia with some erosion of the cool air across the
Florida zones. Typically, models tend to be a bit too quick to
erode the inversion, so will lean the forecast for Sunday closer
to the NAM solution and show another cool and cloudy day across
the area, with perhaps only some late day improvement in the
By Monday, southerly flow becomes more established at the surface
with the mid level pattern shifting to a ridge building across
the Western Gulf. A weak impulse will pass to the north of the
area allowing only for a slight chance of showers across our
northern areas. Though mostly cloudy skies are expected, the
building mid level ridge and southerly flow will help temperatures
to finally break into the 70s across much of the area.
.Long Term [Tuesday Through Saturday]...
The first portion of the long term period will feature a warm
stretch of weather through Wednesday with the mid level ridge
shifting to the Florida Peninsula. By Thursday, a cold front will
move into the region bringing a chance of rain and a return to
cool and cloudy days possibly persisting through Friday. Beyond
that time, the models differ on whether the surface frontal
boundary will dissipate across the area, allowing for cool but
sunny skies next weekend, or remain in place, waiting for the next
southern stream impulse to deliver more rain.
Borderline advisory conditions will continue through tonight
before quickly diminishing on Sunday morning as high pressure
weakens across the Mid Atlantic. Generally light winds and low
seas are expected through mid week. By late Wednesday, onshore
flow will increase ahead of an approaching front and then quickly
shift offshore by Thursday behind a cold front. Advisory
conditions are likely behind this cold front Thursday afternoon.
Hazardous fire weather conditions are not expected over the next
several days. However, very low dispersion indices are expected
through at least Monday. In fact, dispersion indices tonight may be
higher than the maximum dispersions tomorrow. This is a result of
weakening transport winds, low ceilings, and relatively low mixing
Area streamflows remain above normal. The Ochlockonee and
Withlacoochee Rivers are now in action stage at each of the
forecast points. Minor flooding is possible for the Withlacoochee
River at Valdosta early tomorrow.
No significant rainfall is expected for the next few days, so no
additional river flooding is anticipated at this time.
.Preliminary Point Temps/PoPs...
Tallahassee 46 62 54 75 56 / 100 10 10 10 10
Panama City 49 65 55 68 58 / 60 10 10 10 10
Dothan 43 60 51 71 56 / 60 10 10 20 10
Albany 40 53 49 70 56 / 100 20 10 20 10
Valdosta 44 58 53 75 57 / 100 20 10 10 10
Cross City 50 71 56 76 57 / 90 10 10 10 10
Apalachicola 52 65 57 68 59 / 90 10 10 10 10
GM...Small Craft Advisory until 7 AM EST Sunday for Coastal waters
From Ochlockonee River to Apalachicola FL out to 20 NM-
Coastal waters from Apalachicola to Destin FL out 20 NM-
Waters from Suwannee River to Apalachicola FL from 20 to 60
NM-Waters from Apalachicola to Destin FL from 20 to 60 NM.