Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Tallahassee Florida
359 PM EDT Wednesday Jul 29 2015
Near term [through tonight]...
Today's convection is being forced by two separate features. The
convection west of the Apalachicola and Chattahoochee rivers is
likely due to an mesoscale convective vortex spawned from yesterday's convection over the
Ohio and Tennessee valleys. The convection to the east appears to
be generated from a residual surface outflow boundary from the
same convective cluster just mentioned. With 2500-3500 j/kg SBCAPE
around, plus marginally high dtheta-east values, there remains a
chance for some isolated strong to severe downburst winds within
the strongest storms. Additionally, unseasonably high pwats would
suggest the potential for some heavy rainfall, especially in areas
where storm motion slows due to boundary interactions.
Heat indices are still running in the 109-113 range according to
area ASOS readings, with high temperatures in the middle to upper
90s. Sunset or a thunderstorm looks to be the only relief this
afternoon. A heat advisory remains in effect for much of the
Short term [thursday through Friday night]...
The upper pattern will begin to change during this period as the
upper ridge begins to retreat westward as a trough bulges into the
southeast. At the surface a cold front will pass through the
Appalachians on Thursday, and stall out across the tri-state
region by Friday. Convection on Thursday will likely be the result
of any remnant boundaries as well as the Gulf Coast seabreezes,
with no upstream mesoscale convective system influence at this time. By Friday, the
forcing becomes a bit more complicated with influences from the
aforementioned front, a surface trough/low, and the seabreeze
fronts. In general, expect high pops each afternoon, highest on
High temperatures will remain above average tomorrow as convection
will likely hold off until the afternoon. Borderline heat advisory
conditions will be possible. On Friday, more convective coverage
on a not so diurnal time frame should keep temperatures in the
lower 90s, with heat advisory conditions not expected.
Long term [saturday through wednesday]...
It appears as though the wet pattern will continue through the
extended range forecast as several shortwaves keep the eastern
Continental U.S. Trough extending into the southeast. Additionally, at the
surface, the stalled front is expected to linger through the
period, only gradually weakening each day. Expect above normal
pops and near normal high temperatures each day.
[through 18z thursday]
VFR will prevail outside of thunderstorms this afternoon, with all
terminals keeping high rain chances through this evening. Gusty
winds around 30 knots and heavy rain are common in this
afternoon's storms. Most of the storms will have diminished by
06z, with VFR prevailing through the rest of the taf.
Southwest winds below headline levels will prevail for the next
several days. Late this week, into the weekend, there will be a
possibility for some brief cautionary level winds. Thunderstorms
will be numerous over the waters each night, with scattered storms
An active weather pattern in place will keep rain chances and
relative humidity values high, preventing US from reaching red flag
criteria for the next week.
Rain chances increase today through the rest of the week. Five day
estimated rain totals indicate that 3 to 4 inches is likely along
the coast, especially in the southeastern Big Bend. Elsewhere, 1.5
to 2.5 inches is likely. Area rivers are still below action stage.
With the heaviest rainfall expected near the coast, river flooding
is not expected.
Preliminary point temps/pops...
Tallahassee 77 91 76 90 75 / 60 50 30 60 40
Panama City 80 88 79 88 78 / 50 50 30 60 40
Dothan 76 93 75 92 74 / 30 50 40 50 40
Albany 76 93 76 90 74 / 70 50 30 50 40
Valdosta 76 90 75 89 74 / 70 50 30 60 40
Cross City 77 87 76 88 75 / 60 50 30 60 40
Apalachicola 79 88 79 88 78 / 50 50 30 60 40
Florida...heat advisory until 6 PM EDT /5 PM CDT/ this evening 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
Wakulla-Jackson- Lafayette-Leon- Liberty-Madison-north
Walton- south Walton- Washington.
Georgia...heat advisory until 6 PM EDT this evening for Baker-Brooks-
Alabama...heat advisory until 5 PM CDT this afternoon for Coffee-Dale-