Area Forecast Discussion
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FXUS62 KTAE 211710

Area Forecast Discussion
National Weather Service Tallahassee FL
110 PM EDT Thu Sep 21 2017

.AVIATION [Through 18Z Friday]...

VFR conditions will prevail outside of thunderstorms this
afternoon. Scattered storms have begun to develop across the
region and are most likely at ECP, TLH, and VLD. Late this
evening, storms should come to an end and between 06-10z MVFR/IFR
visibilities will set in across the region. Restrictions will
clear by 13z tomorrow for all terminals.



.NEAR TERM [Through Today]...

As upper-level +PV anomalies superposition and strengthen the
upper trough across the eastern CONUS today, a weak surface
reflection will lie across south-central Georgia and the Florida
Big Bend. The Tallahassee sounding this morning depicted well
above normal PWAT (1.84 in), though this area of full column
moisture generally only exists along and east of a line from
Panama City through Tifton. With moisture and forcing in place,
and forecast MLCAPE between 1500-2000J, expect a decent scattering
of storms in the above mentioned region. PoPs in this area range
from 40-60%. While isolated sub-severe water-loaded downdrafts
will be possible, wet-microbursts or any other type of severe
weather is not expected this afternoon due to low shear and the
saturated soundings. Highs today will be around 90 degrees, maybe
a few degrees lower where showers develop early this afternoon.

.SHORT TERM [Tonight Through Saturday]...

Upper ridge will remain elongated from Texas to the Great Lakes
this period while upper troughing will remain wedged between the
upper ridge and the two tropical cyclones with an eventual upper
low closing off across the area Saturday. Surface high pressure
will remain anchored to the north with ridging draped from the
northeast states southwestward to the Mississippi valley. Area
time height cross sections and point soundings indicate drier mid
level air will work in from the north Friday which will reduce
rain chances Friday. As low level easterly flow strenghtens
Saturday as Hurricane Maria moves through the Bahamas, increased
moisture and the Atlantic seabreeze will lead to an increased
chance for rainfall Saturday (40-50%). High temperatures each day
will be in the mid to upper 80s with lows around 70.

.LONG TERM [Saturday Night Through Thursday]...

Upper low will slowly move westward and weaken through Monday then
shortwave ridging builds over the area Tuesday through Thursday.
Expect an gradual decrease in precipitation chances each day with
mostly dry conditions Tuesday through Thursday. High temperatures
will slowly increase each day as well perhaps reaching back into
the lower 90s by Wednesday-Thursday.


Winds and seas will increase to moderate levels this weekend as
Hurricane Maria moves up the Gulf Stream and interacts with high
pressure across the southeast United States and the northern Gulf
of Mexico. Low end exercise caution in the far offshore waters in
the overnight hours Friday night through Sunday night is possible.


Locally low dispersion values are expected across the FL Big Bend
region, with some values below critically low thresholds. However,
high RH values and light winds will prevent any fire weather


Rainfall of a half an inch or less over the next several days will
not cause any flooding concerns. Area river levels are falling,
and that trend will continue.


Spotter activation is not requested. However, spotters are always
encouraged to safely report significant weather conditions when they
occur by calling the office or tweeting us @NWSTallahassee.



Tallahassee   70  89  71  87  69 /  20  20  10  40  20
Panama City   73  87  72  86  72 /  20  20  10  40  30
Dothan        69  88  68  87  68 /  20  30  10  30  10
Albany        70  89  69  87  68 /  20  20  20  30  10
Valdosta      68  87  68  86  68 /  20  20  10  40  20
Cross City    68  88  70  87  70 /  20  30  20  50  20
Apalachicola  73  86  72  85  72 /  20  20  20  40  40




NEAR TERM...Harrigan
LONG TERM...Scholl
HYDROLOGY...Harrigan is the U.S. government's official web portal to all federal, state and local government web resources and services.