Scientific Forecaster Discussion
fxus62 ktae 220015
Area forecast discussion
National Weather Service Tallahassee Florida
815 PM EDT Fri Jul 21 2017
Convection continues to wane across the tri-state region at this
hour, with isolate showers and thunderstorms lingering across
mainly southern Georgia at this hour. Expect this activity to
diminish within the next few hours. Patchy light fog is possible
overnight, particularly in locales that received rainfall this
afternoon and evening. Low temperatures in the low to mid 70s
Previous discussion [749 PM edt]...
Near term [through tonight]...
Vapor imagery reveals a weak upper low moving across the marine
area this morning and this will provide at least some assistance
to developing thunderstorms this afternoon. The ktae sounding is
much more unstable than 24 hours ago. Lapse rates above 850 mb are
a little steeper with the 850-500 mb layer at 6.6c/km. A modified
surface parcel of 95/73 yields around 2800 j/kg of SBCAPE.
Additionally the airmass has moistened a little from yesterday
morning with the precipitable water up to 1.82 in. While the 1000-700 mb flow is
still fairly light, the easterly flow will provide for increased
convergence along the Florida Panhandle sea breeze.
Given that a little more convection is expected today, especially
across the western half of the region, will show temperatures in
the low to mid 90s in the western portion of the region, but in
the mid 90s in the eastern half of the region. Heat indicies will
peak near 105 degrees or so.
Showers and thunderstorms will diminish right around sunset, and
are expected to redevelop over the northern Gulf after midnight.
Overnight lows will dip in the lower to middle 70s.
Short term [saturday through Sunday night]...
As a shortwave moves through the Great Lakes region, the eastern
Continental U.S. Trough will gradually amplify into the Tennessee Valley and
the mid-Atlantic. At the surface, westerly flow over the
Appalachians will result in Lee troughing into the southeast.
Locally, however, it appears as though these features won't have
much of an effect. Instead afternoon convection will continue to
be driven by the seabreeze fronts. Pops will be near normal (in
the 40-60% range) for the southwesterly steering flow regime.
Highs are forecast to be in the lower 90s with heat indices in the
upper 90s to near 100 degrees.
Long term [monday through friday]...
The aforementioned upper-level and surface troughs will be at
their closest point to the region on Monday and will mix with the
Gulf seabreeze fronts to result in slightly above average pops.
Thereafter, the trough will lift northeast with ridging taking
over once again. Pops should be near normal during the week,
forced by the Gulf and Atlantic seabreeze fronts. High will
continue to remain in the lower to middle 90s each day.
Aviation [through 00z sunday]...
Showers and thunderstorms have generally dissipated or moved out
of our area, with only a few light showers remaining near aby and
vld. VFR conditions are expected to prevail overnight, with some
brief patchy fog possible in the early morning at vld but no
significant visibility restrictions are anticipated. Scattered
showers and thunderstorms are again possible during Saturday
afternoon and evening, but any reductions in visibility should be
short-lived. Otherwise, VFR conditions will prevail.
Relatively light winds and low seas will prevail over the next
several days. Minor wind and chop enhancements near the coast in
the afternoon seabreeze will be possible each day. Showers and
thunderstorms will be most likely between midnight and noon.
Hazardous fire weather conditions are not expected.
A typical summertime scattering of storms is not expected to
produce any river flooding. Isolated minor flooding could be
possible in urban locations under slow moving storms.
Preliminary point temps/pops...
Tallahassee 74 91 74 91 75 / 10 60 10 60 20
Panama City 78 87 78 87 79 / 20 30 30 40 30
Dothan 74 91 74 90 74 / 20 40 20 40 20
Albany 74 93 74 91 74 / 20 30 20 30 20
Valdosta 74 93 74 92 75 / 20 40 10 40 20
Cross City 73 90 74 89 74 / 20 50 40 60 20
Apalachicola 77 87 78 87 78 / 20 40 30 50 40