Scientific Forecaster Discussion
fxus62 ktae 170959
Area forecast discussion
National Weather Service Tallahassee Florida
559 am EDT Tue Sep 17 2019
[through 12z wednesday] VFR conditions are expected to prevail
through the period with light winds generally under 10 knots.
Previous discussion [235 am edt]...
Near term [through today]...
Dry conditions with above average temperatures will prevail again
today with high pressure and light northerly flow. Afternoon high
temperatures are expected to reach the mid to upper 90s for most
areas with heat index values peaking in the upper 90s to lower 100s
this afternoon. We will likely be within a degree or two of the
daily record highs across most of the area.
Short term [tonight through thursday]...
The main story will continue to be the heat on Wednesday
including a chance of thunderstorms, then much cooler
temperatures return for Thursday.
Deep layer ridging with 500 hpa heights near 590 decameters
and a dry offshore flow will keep the heat on into Wed. High
temps around 10 degrees above normal, ranging from the middle
to upper 90s. The daily high temperature record for Sep 18
in Tallahassee is 98f, set in 2005.
Heat indices in the Florida Panhandle on Wednesday will range from
around 100 to 105 degrees.
A weak gradient on Wed will allow a sea-breeze to develop.
Meanwhile, a shortwave and accompanying backdoor cold front
will approach from the northeast. These features will help
pool moisture and instability across portions of southwest
Georgia and the Florida Big Bend. Mixed layer cape approaches 1.5k
j/kg with the mid-level flow around 20 knots. Both of these
parameters are above normal per Storm Prediction Center sounding climatology.
Thunderstorm coverage will be limited by the amount of
mid-level dry air, as evidenced in downdraft cape over 1k
j/kg, which is significant. Overall, thunderstorms that are
able to develop across southwest Georgia and The Big Bend will
be capable of gusty winds, with possibly an isolated severe
thunderstorm. Activity will quickly diminish around sunset.
Fair weather on Thursday with temperatures a few degrees
below normal in the mid to upper 80s and low humidity.
Long term [thursday night through tuesday]...
High pressure will build across the region on Friday and
Saturday. Easterly flow at the surface could advect some
Atlantic moisture eastward, leading to isolated, diurnal
showers over the southeast Big Bend. Otherwise dry with
Deep layer ridging should persist over the area Sunday
through Tuesday. The lack of lift and deeper moisture
keeps any precipitation potential minimal at this time,
so the forecast remains dry outside of a slight chance
of showers mainly confined to coastal zones. Temps will
moderate, returning to slightly above seasonal levels.
Tranquil boating conditions are expected through Wednesday
with light winds and low seas. Northeast winds will increase
Wednesday night and remain elevated through Saturday night,
with the potential for cautionary conditions around 20 knots
at times. Seas will also increase to around 7 feet west
of the Ochlockonee River during this time frame.
Although red flag conditions are not expected for the next several
days, conditions are expected to remain dry with relative humidity
values dropping into the low to mid 30s this afternoon. In addition,
northeast winds may get into the 10-15 mph range by Thursday and
A dry stretch of weather is anticipated through early next week
with precipitation well below average. In addition, most local
rivers are experiencing stream flows below normal levels. No
flooding concerns anticipated through the period.
Spotter information statement...
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.
Preliminary point temps/pops...
Tallahassee 98 72 98 70 86 / 0 0 40 20 0
Panama City 94 76 95 74 87 / 0 0 20 20 20
Dothan 97 71 97 70 86 / 0 0 10 10 0
Albany 97 74 95 69 84 / 0 0 20 10 0
Valdosta 96 71 94 68 86 / 0 0 40 10 0
Cross City 95 72 94 70 87 / 0 0 50 20 10
Apalachicola 92 76 93 74 85 / 0 0 20 30 20