Area Forecast Discussion
Issued by NWS
FXUS62 KTAE 211450
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
1050 AM EDT Thu Aug 21 2014
.Near Term [Today]...
The 9 am EDT regional surface analysis showed a 1022 mb high
pressure system centered at Dothan, and a weak trough from coastal
NC to north GA. Vapor imagery and upper air data showed a region
of higher heights centered near the LA coast, and a small, weak
vorticity max near Tallahassee. Precip Water values were slightly
below climatology across our region, and the deep northerly flow
will keep the sea breeze fronts pinned at the coast until late
afternoon. Other than the weak vorticity max, the synoptic steup
for today would suggest below-average PoPs. The only NWP guidance
that generates much deep moist convection, and does it ever, is
the 09 UTC local WRF run. The other WRFs and various MOS keep PoPs
low (20% or less) this afternoon. We`re going to assume that the
subtle vorticity max over our area will not be a significant
player, and that the 09 UTC WRF is an outlier; so we will stick
with the 20% PoP we inherited.
Based on our 8 am EDT KTAE sounding and recent numerical
guidance, we lowered the forecast dewpoints a little for this
afternoon. This would keep much of our forecast area below heat
advisory levels (except in the FL Panhandle, where dewpoints will
remain higher) this afternoon. However, since heat index values
will still be on the high side (generally around 105) we will
leave the inherited heat advisory up for our entire forecast area.
The actual highs for this afternoon will be around 100 degrees,
except lower 90s at the beaches.
[Through 12Z Friday]...Other than isolated TSRA this afternoon and
evening, generally unlimited cigs and unrestricted vis are
expected into the overnight hours. Brief peiod of light fog/haze
are possible around dawn Friday. Except for an onshore sea breeze
near 10 KT late this afternoon at KECP, winds will be light from
.Prev Discussion [236 AM EDT]...
.Short Term [Tonight Through Saturday]...
Very hot and much drier than normal conditions will continue with
the deep layer ridging in place. High temperatures will be at
record or near record levels both Friday and Saturday afternoon.
Max temps are expected to reach or exceed 100 degrees at most
inland areas with heat indices in the 105-110 range throughout the
Tri-state region. Thus, the Heat Advisory will continue at least
through the short term period. Overnight lows will be warm in the
mid 70s. Rain chances will be 20% or less.
.Long Term [Saturday Night Through Thursday]...
It will continue to be hot and relatively dry over the coming
weekend as ridging persists and builds inland. With this fairly long
stretch of hot days and mild nights Heat Advisories are again
likely, although heat indices will become more dependent upon
afternoon cloudiness as we move into the early part of the week. An
east-west surface trough will begin to settle south across the
region late in the weekend into early next week as an upper level
trough digs southward across the western Atlantic on the front side
of the strong upper ridge. This may increase precipitation chances
early in the week as well as cloud cover which would suppress
daytime heating somewhat. The main story will be what happens
midweek into the latter part of next week with the potential
development of a tropical system moving into the Gulf. Global
models are not in agreement with each other, nor are they showing
much run-to-run consistency at this time, but this will be
monitored carefully in the next several days.
Light west to northwest winds will continue through the weekend
and then swing around to the east early next week. Seas will be 2
feet or less.
Despite the very hot temperatures today and Friday, dewpoints will
remain high enough to keep humidity values above critical levels.
Red Flag conditions are not expected at this time.
The next few days will be drier with no significant rain expected.
With all area rivers below action stage, no flooding is expected.
.Preliminary Point Temps/PoPs...
Tallahassee 99 75 100 76 100 / 20 10 20 10 20
Panama City 95 78 97 79 97 / 20 10 20 10 20
Dothan 98 76 99 75 101 / 20 10 20 10 20
Albany 100 75 101 75 101 / 20 10 20 10 20
Valdosta 99 74 100 74 101 / 20 10 20 10 20
Cross City 97 75 98 76 98 / 20 10 20 10 20
Apalachicola 95 77 95 78 94 / 20 10 20 10 20
FL...Heat Advisory until 8 PM EDT /7 PM CDT/ Saturday for Calhoun-
Central Walton-Coastal Bay-Coastal Dixie-Coastal Franklin-
Coastal Gulf-Coastal Jefferson-Coastal Taylor-Coastal
Wakulla-Gadsden-Holmes-Inland Bay-Inland Dixie-Inland
Franklin-Inland Gulf-Inland Jefferson-Inland Taylor-Inland
GA...Heat Advisory until 8 PM EDT Saturday for Baker-Ben Hill-Berrien-
AL...Heat Advisory until 7 PM CDT Saturday for Coffee-Dale-Geneva-