Area Forecast Discussion
Issued by NWS
FXUS62 KTAE 280723
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
323 AM EDT Mon Jul 28 2014
.Near Term [Through Today]...
Shortwave energy diving into the base of the deep and broad
eastern trough will drive a cold front towards the Gulf Coast
today. Showers and thunderstorms will likely develop ahead of the
front and move into the northern zones by mid-afternoon, reaching
Florida by late afternoon or early evening. Given the presence of
a reasonable forcing mechanism and an unstable atmosphere, the
statistical guidance seems unreasonably low with PoPs for this
afternoon and evening (less than 30 percent). Ensemble of CAM
guidance appears to have a better handle of the expected
convective evolution, so have weighted the forecast PoPs heavily
in this direction.
While mid-level flow will be rather modest (20-25 knots), mid-
level lapse rates will be reasonably high (6.5-7C/km) and low
level moisture will be plentiful (dewpoints in the lower to mid
70s). This combination will yield 2500-3500J/kg of CAPE across the
region this afternoon. With some dry air in the mid-layers, this
should set the stage for some strong to severe storms. Damaging
straight-line winds should be the primary threat. However, some
large hail cannot be ruled out.
With the expected late onset of precip over the southern half of
the forecast area, expect temperatures to reach the upper 90s
once again. High dewpoints will help push the heat index to near
108 degrees along the I-10 corridor early this afternoon.
Therefore, have issued a Heat Advisory for these areas.
.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
.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
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.
[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
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.
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.
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 97 73 94 66 93 / 50 60 10 0 10
Panama City 90 76 92 72 91 / 40 60 10 0 10
Dothan 96 69 92 66 90 / 60 50 0 0 10
Albany 98 71 91 66 92 / 60 40 0 0 10
Valdosta 97 72 93 65 93 / 50 60 10 0 10
Cross City 93 76 94 67 93 / 30 40 30 10 10
Apalachicola 91 76 92 70 90 / 30 50 20 0 10
FL...Heat Advisory from 2 PM EDT /1 PM CDT/ this afternoon to 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-
High Rip Current Risk through late tonight for Coastal Bay-
Coastal Gulf-South Walton.
GA...Heat Advisory from 2 PM this afternoon to 6 PM EDT this evening
AL...Heat Advisory from 1 PM to 5 PM CDT this afternoon for Geneva-