Area Forecast Discussion
Issued by NWS
FXUS62 KTAE 042357
Area Forecast Discussion
National Weather Service Tallahassee FL
657 PM EST Sun Dec 4 2016
.AVIATION [Through 00Z Tuesday]...
MVFR conditions prevailing at most terminals this evening,
becoming IFR/LIFR at times as rain continues to push east. A few
embedded thunderstorms are still possible, although rain showers
are the expected norm overnight. In addition there is a chance
for patchy early morning fog further reducing visibilities. A
slight lull in activity is expected Monday morning before another
round of showers and thunderstorms in the afternoon.
.PREV DISCUSSION [354 PM EST]...
.NEAR TERM [Through Tonight]...
A complicated low-level pattern exists across the local area this
afternoon. A frontal boundary lies southwest to northeast from
Destin through Fitzgerald along a differential heating zone created
by the veering isentropic ascent regime through the 305K surface. At
some point near the Big Bend, it appears as though a warm front
along a moisture gradient merges in with the aforementioned boundary
to the north and continues westward to Louisiana. Over the course of
the evening, the line of storms along the front over southeast
Alabama and the Florida panhandle will very slowly move eastward in
the southwesterly steering flow. Convection should begin to diminish
once daytime heating comes to an end and the thermal gradient
weakens. Decent low/mid level shear will continue the marginal
threat for an isolated strong to severe storm over the next couple
of hours when the meager surface based instability drops off
completely. Lows tonight will range from the middle to upper 60s
along and southeast of a line from Valdosta through Panama City, and
around 60 degrees northwest of the line.
.SHORT TERM [Monday Through Tuesday Night]...
The +PV anomaly over NE Mexico will eject into the Arklatex Monday
night, with the surface low deepening and lifting over the lower
Mississippi valley. This will allow the front of warm, moist air
over the Gulf to push northward through our area Monday afternoon
with dewpoints approaching 70 across much of the area. Low level
wind shear will remain quite weak (15 kts or less) through the
daytime hours, but 0-6 km shear will be around 40-50 kts, which,
combined with modest instability (MLCAPE of 600 J/kg or less) along
the Panhandle coastline could allow isolated supercell thunderstorms
to develop in the warm sector. During the afternoon hours, the main
threat would be damaging wind gusts. After midnight, however, the
surface low will deepen as it lifts northeastward and our 0-1 km
wind shear will increase to 20-30 kts. The local environment will
become more favorable for the development of isolated tornadoes late
Monday night/early Tuesday morning.
As the sun comes up Tuesday morning and the system continues to lift
northeastward, local instability and shear values will rise,
continuing the threat for isolated tornadoes and damaging wind gusts
through Tuesday morning. One thing that will limit the severe
potential, however, will be the speed at which the system is taking
off. The upper level disturbance will eject quickly off toward the
mid-Atlantic coastline, with the surface cold front expected to
sweep across the area west to east quickly Tuesday morning, exiting
the forecast area early in the afternoon.
.LONG TERM [Wednesday Through Sunday]...
A weaker upper level disturbance will swing from the Great Plains
into the Great Lakes Wednesday through Thursday night, pushing a
cold front through our area on Thursday. With the energy for this
system remaining displaced well to our north, we are not expecting
much rain from this system (likely less than a half inch), but a
much colder, drier airmass will move in behind it for the weekend.
Lows will drop to the 30s Friday morning, and into the upper 20s on
Saturday morning, with afternoon temperatures peaking in the 50s
Friday and Saturday.
As a cold front approaches our coastal waters Monday night, south
winds will increase to advisory levels with seas rising to around 5
feet. On Tuesday, as the front crosses through, winds will become
west and winds and seas will begin to lower. Beyond that, light
north-northwest winds will prevail with 2 to 3 foot seas until our
next front approaches on Thursday.
No fire weather concerns are expected as a moist airmass and
periods of rain will move into our area through the next few days.
Most areas west of Valdosta, GA/Perry, FL will see 2-3 inches of
rain through Tuesday, with closer to 3-4 inches most likely along
the FL Panhandle. If storms train, as they currently are just to our
west, they may produce locally higher totals over short periods that
could cause flash flooding. This threat, however, appears to be
contained mostly to the Panhandle area and diminishing after
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 67 76 69 77 51 / 70 80 80 60 0
Panama City 68 76 69 73 53 / 70 80 70 40 0
Dothan 61 70 63 72 49 / 80 80 80 50 0
Albany 61 69 63 76 51 / 90 80 90 60 0
Valdosta 67 76 68 80 51 / 70 80 80 60 0
Cross City 67 78 69 77 52 / 10 60 60 50 0
Apalachicola 70 75 69 76 53 / 50 70 70 40 0
FL...High Rip Current Risk until midnight EST /11 PM CST/ tonight for
Coastal Bay-Coastal Franklin-Coastal Gulf-South Walton.