Severe Thunderstorm Warning 132, NWS Tallahassee, FL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
421 PM EDT Tue Jun 10 2014

.Near Term [Through Tonight]...
An upper level low is clearly seen in water vapor imagery over the
Ozarks with a downstream ridge over the Bahamas. Surface analysis
shows that the surface reflection of the upper low is occluded over
Missouri with the cold front extending southwestward to the TX Gulf
Coast. The subtropical ridge extends westward across FL and the
central Gulf of Mexico. Moisture return between the two systems has
pushed 70+ degrees dew point air northward from the Gulf into Middle
Tennessee. Numerous thunderstorms are aligned in the theta-e ridge
across Alabama. A few of these are severe. Our local WRF's 12Z run
is our model of choice for the evolution of convection overnight.
Most of the strong to severe storms should continue to evolve to the
ENE. However, another linear MCS is expected to develop over the
North Central Gulf states and reach our western zones as early as
09Z.

.Short Term [Wednesday Through Thursday Night]...
The aforementioned convection will progress eastward across the
forecast area with isolated storms developing out ahead of the main
line. SB Cape will be in the 1500-2500 J/kg range and 500-mb temps
around -11C per the GFS result in mid level lapse rates around -7C.
SPC has the western portion of the forecast area in a 5% risk area
for severe storms. Providing we can get some breaks in the clouds to
enhance low level instability (uncertain at this time), the severe
threat could extend further east than that. For now, we have decided
to include isolated T+ in the grids with damaging winds and hail the
primary threats, particularly during the afternoon hours. Afternoon
temps will not be quite as hot as recent days, mainly in the mid to
upper 80s. Scattered convection will linger into the evening hours.
By 12Z Thursday, the upper trough axis will be over or just upstream
of the forecast area with the best QG forcing across our eastern
zones. PoPs will therefore be higher east than west. Highs will be
around 90 inland and in the mid to upper 80s at the coast.

.Long Term [Friday Through Tuesday]...
Wet scenario to continue into extended period. The larger scale
pattern shows a mid level trough moving into the Lower MS Valley on
Fri with this feature developing into a low over MS on Sat. A
surface ridge will remain south of the area through the period. This
will increase onshore (mainly SW) flow across Gulf region. Then the
models diverge so confidence not as high. GFS is slowest and
furthest west. If it verifies, low will open up and lift NEWD by Sun
with upstream mid level ridge increasingly overspreading Gulf region
thru Tues from W-E with decreasing rainfall. However is noticeably
faster ECMWF verifies, low will move Ewd to Srn AL/GA for a much
wetter period locally thru at least the weekend before lows moves
further Ewd with a decrease in POPs. For now will take a blend for
POPs. Will go with 40-60% Fri, 50% Sat and Sun, 30-40% Mon and 30%
on Tues. Expect inland highs 89-92 each day.

&&

.Aviation...
[Through 18Z Wednesday] Convection is expected to remain isolated
today and is only mentioned in the vicinity of the terminals. Some
MVFR ceilings may develop during the predawn hours. We expect the
next round of convection to overspread the region from southwest
to northeast Wednesday morning, starting as early as 09Z at ECP and
as late as 15Z at VLD. MVFR conditions will be possible in any
convection.

&&

.Marine...
Light to moderate onshore winds will continue across the waters
for the next several days. Seas will generally be 3 feet or less.

&&

.Fire Weather...
No fire weather concerns are expected through the next several days.

&&

.Hydrology...
All area rivers are below flood stage. Some locally heavy rainfall
could occur across the Florida panhandle late tonight into
Wednesday, but amounts still do not look excessive at this time
with up to a few inches expected. For the end of the week into
the weekend we expect just typical summer diurnal convection so
river rises again will not be of concern.

&&

.Preliminary Point Temps/PoPs...

Tallahassee   71  88  70  89  69 /  30  70  30  50  20
Panama City   74  84  73  87  73 /  50  60  30  40  20
Dothan        71  87  69  90  70 /  30  60  30  40  20
Albany        71  89  69  90  68 /  20  70  30  50  20
Valdosta      70  90  69  91  68 /  20  70  30  50  30
Cross City    70  87  70  88  68 /  30  70  30  50  30
Apalachicola  74  85  74  86  73 /  50  60  30  40  20

&&

.TAE Watches/Warnings/Advisories...

FL...High Rip Current Risk until 11 PM CDT this evening for Coastal
     Bay-South Walton.

GA...None.
AL...None.
GM...None.

&&

NEAR TERM...WOOL
SHORT TERM...WOOL
LONG TERM...WOOL
AVIATION...WOOL
MARINE...WOOL
FIRE WEATHER...WOOL
HYDROLOGY...DVD/MCDERMOTT