Area Forecast Discussion
Issued by NWS

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29

733
FXUS62 KTAE 281529
AFDTAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
1129 AM EDT Mon Jul 28 2014

.Near Term [Through Today]...
An unusual setup for late July is unfolding across the region
today. A cold front, analyzed across Central Alabama and into
Middle Georgia is moving southward toward our region. West
southwesterly flow ahead of this front continues to keep dewpoints
in the mid to upper 70s. Aloft, a trough moving out of the Ohio
Valley continues to amplify while approaching the Mid Atlantic
States. With the increased dynamical forcing combining with the
summertime instability expect numerous showers and storms to
develop later this afternoon ahead of the frontal boundary and
move southward toward the coast. Modified soundings of 97/74 show
over 4000 J/kg of SBCAPE with model guidance indicating the deep
layer shear increasing to 25 to 30 kt. Soundings at KTAE/KFFC also
reveal the presence of some mid level dry air, which will likely
help support more sustained and intense downdrafts from the
stronger storms. As a result, the primary concern for this
afternoons storms are damaging winds. Freezing levels are getting
high (15.8-16.1kft) but with so much instability and 700-500 mb lapse
rates approaching 7degC/km, can`t rule out some large hail this
afternoon in the most intense storms.

Given the good agreement between the high resolution guidance
members, have increased pops to around 70 percent for our northern
zones in the 21z-00z timeframe with around 60 percent after 00z
for the counties along the I-10 corridor. Expect the severe threat
to continue for a couple of hours after sunset as the synoptic
forcing will help provide a focus for storms as the instability
diminishes.

The heat advisory remains in effect. Temperatures already this
morning are a little warmer than forecast, and with storm
development not anticipated til after 2 pm, heat indices in the
108 to 111 degree range are likely from late this morning through
the afternoon hours.

&&

.Prev Discussion [323 AM EDT]...

.Short Term [Tonight Through Wednesday]...
By this evening, the cold front will be bisecting the forecast
area and continuing to move steadily southeastward. A few strong
to severe storms will remain possible out ahead of it through the
evening hours with a gradual weakening trend expected overnight.
The front should be through most of the area by dawn on Tuesday
with the exception of the far southeast big bend. Significantly
drier air in its wake will allow low temperatures to reach the mid
60s over most of the area by Wednesday morning with PoPs below
20%.


.Long Term [Wednesday Night Through Monday]...
The full latitude eastern CONUS trough will continue to amplify
through the period. The front which will move across the area
early in the week will usher in much drier and cooler air through
Thursday, with the possibility of reaching some record morning
lows. The long standing records for this period at Tallahassee
are:

July 30 - 67 (1927)
July 31 - 63 (1896)
Aug 1 - 64 (1993)

Expect generally dry and relatively cool conditions for Wednesday
and Thursday with very low PoPs. Thursday and Friday morning lows,
July 31st and Aug 1st, will range from 65-70.

By late Thursday, moisture will begin to increase once again across
the forecast area as another upper disturbance within the main
upper trough moves into the forecast area. For Friday through the
weekend expect a return to scattered showers and thunderstorms
each afternoon and evening. The increased convection for the end
of the week and weekend will keep high temperatures in the 85 to
90 range across the area.


.Aviation...
[Through 06Z Tuesday] Expect VFR conditions into the early
afternoon at all terminals. Thunderstorms will likely impact all
terminals during the afternoon and evening hours, spreading from
north to south. A few a these storms could have very strong wind
gusts. Activity should be south of all terminals by around 02Z
tonight.


.Marine...
The pressure gradient between the subtropical ridge to the south
and the approaching cold front to the north will maintain
westerly winds at exercise caution levels at times through
tonight. Winds will gradually diminish and become offshore by
Tuesday night into Wednesday.


.Fire Weather...
Red flag conditions are not expected for the next couple of days.
Drier conditions will move in on Tuesday in the wake of a front
and continue through Thursday, with minimum relative humidity
values dropping into the lower 30s.


.Hydrology...
Thunderstorms along a cold front could bring some locally heavy
rainfall to the area this afternoon and this evening, but the
system will remain progressive and widespread impacts from heavy
rain are not expected.

&&

.Preliminary Point Temps/PoPs...

Tallahassee   98  73  94  66  93 /  50  60  10   0  10
Panama City   90  76  92  72  91 /  50  60  10   0  10
Dothan        96  69  92  66  90 /  70  40   0   0  10
Albany        97  71  91  66  92 /  70  40   0   0  10
Valdosta      99  72  93  65  93 /  50  60  10   0  10
Cross City    93  76  94  67  93 /  30  50  30  10  10
Apalachicola  90  76  92  70  90 /  40  50  20   0  10

&&

.TAE Watches/Warnings/Advisories...

FL...Heat Advisory until 6 PM EDT /5 PM CDT/ this evening for Calhoun-
     Central Walton-Coastal Bay-Coastal Franklin-Coastal Gulf-
     Coastal Jefferson-Coastal Wakulla-Gadsden-Holmes-Inland Bay-
     Inland Franklin-Inland Gulf-Inland Jefferson-Inland Wakulla-
     Inland Walton-Jackson-Leon-Liberty-Madison-South Walton-
     Washington.

     High Rip Current Risk through late tonight for Coastal Bay-
     Coastal Gulf-South Walton.

GA...Heat Advisory until 6 PM EDT this evening for Baker-Berrien-
     Brooks-Colquitt-Cook-Decatur-Early-Grady-Lanier-Lowndes-
     Miller-Mitchell-Seminole-Thomas.

AL...Heat Advisory until 5 PM CDT this afternoon for Geneva-Houston.

GM...None.

&&

$$

NEAR TERM...GODSEY
SHORT TERM...DVD
LONG TERM...HOLLINGSWORTH
AVIATION...CAMP
MARINE...DVD
FIRE WEATHER...CAMP
HYDROLOGY...DVD




USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.