Area Forecast Discussion
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872
FXUS62 KTAE 230833
AFDTAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
333 AM EST Sun Nov 23 2014

.Near Term [Today]...

Not much has changed with regards to the severe thunderstorm
potential today. Early this morning, a strong to severe squall
line was pushing rapidly eastward off the Texas coast. A peak gust
of 75 knots was measured on one of the elevated oil platforms
(KEMK) in the western Gulf in association with this line.
Meanwhile, a warm front was located just off the Florida panhandle
coast. This front is expected to lift northward this afternoon as
the squall line approaches the area. The shear with this system is
forecast to be quite strong, so the main question mark that will
control how much severe weather we receive over the next 12-24
hours will be how far north the warm front can return. The radar
imagery so far tonight does seem to show a northward progression
of the moderate to heavy rain shield across the area, so it still
looks like we could see enough destabilization this afternoon for
some severe storms. Given the very strong wind fields aloft
coupled with SBCAPE values possibly near or above 1000 j/kg across
the Florida panhandle and over 500 j/kg across the remainder of
the area with not too much CINH according to the mean of the CAM
guidance, storms may be more efficient in mixing down strong wind
gusts to the surface than in a typical cool season severe weather
scenario locally. In addition, isolated tornadoes are possible
given the amount of shear forecast.


.Short Term [Tonight Through Tuesday]...

The true synoptic cold front is expected to quickly translate east
from the Mississippi River Valley to about 87W longitude (Alabama)
overnight as the surface cyclone rapidly deepens in the Great
Lakes. Although daytime thunderstorms are expected to reduce the
instability across the area, numerical models indicate some
lingering weak instability in advance of the cold front through
the night, and some isolated to scattered convection redeveloping,
especially after 06Z as low-mid level forcing increases once
again. Some convection-allowing models based on the NAM show some
vigorous storms, but we believe this is because the most recent
NAM is overestimating available instability. Some of the showers
and storms may continue into Monday over the southeast half of our
area, ahead of the advancing front.

The cold front will begin to stall just southeast of our forecast
area Monday Night as the broad, high-amplitude trough over the
central CONUS maintains deep-layer southwesterly flow over our
region during that timeframe. Some showers will be possible just
behind the surface cold front over the southeast part of our area.
A strong shortwave rounding the base of the trough from the
southern Plains to Louisiana on Tuesday should increase QG forcing
sufficiently to allow rain to expand back into the forecast area.
Tuesday should be a cloudy, breezy, and cool day with rain.


.Long Term [Tuesday Night Through Sunday]...

Rain will continue into Tuesday Night and early Wednesday as the
ejecting shortwave facilitates surface cyclogenesis along the
stalled front in the vicinity of the Florida peninsula (just SE of
our area). The rain should end quickly on Wednesday as high
pressure and drier air build in. High pressure should dominate the
weather pattern for the rest of the week with no rain chances and
slowly moderating temperatures.

&&

.Aviation...

[Through 12z Monday] Moderate to occasionally heavy rain this
morning will continue to lift northeastward with a brief break
possible during the mid to late morning hours. By this afternoon,
a squall line is expected from west to east across the area with
IFR conditions and gusty winds. Some of the storms may be severe.

&&

.Marine...

No changes to the marine-related hazard products with this
forecast package, which includes a High Surf Advisory for Walton
and Bay Counties and a High Risk of Rip Currents for all of our
beaches. The Gale Warning for all but the far eastern legs of the
coastal waters still appears to be on track. Both of our 60NM
offshore buoys have recorded gale-force gusts already, with the
one south of Panama City recording a non-convective peak wind of
41 knots. Additionally, the C-Tower closer to shore just SSE of
St. George Island recently measured a 32 knot gust.

&&

.Fire Weather...

With moderate to heavy rainfall expected today, there are no fire
weather concerns for the next few days.

&&

.Hydrology...

Rain is beginning to lift out of the area, but widespread 1-2 inch
totals have occurred over most (but not all) of the area already.
The amounts were slightly higher in the vicinity of Tallahassee.
A lull in the rain seems likely for this morning, before storms
move back in during the afternoon. Fast storm motions should
reduce QPF with this next round, so flooding issues are not expected.

&&

.Preliminary Point Temps/PoPs...

Tallahassee   75  66  77  49  59 / 100  50  40  20  50
Panama City   74  65  73  50  58 / 100  40  30  10  30
Dothan        74  61  73  44  57 / 100  30  20  10  20
Albany        74  63  74  46  58 / 100  50  20  10  30
Valdosta      77  67  76  49  58 /  90  60  50  30  50
Cross City    79  68  76  52  62 /  70  50  50  40  60
Apalachicola  74  67  76  53  60 /  90  40  40  20  50

&&

.TAE Watches/Warnings/Advisories...

FL...High Rip Current Risk through late tonight for Coastal Bay-
     Coastal Franklin-Coastal Gulf-South Walton.

     High Surf Advisory from 9 AM this morning to Midnight CST
     tonight for Coastal Bay-South Walton.

GA...None.
AL...None.
GM...Small Craft Advisory until 7 PM EST this evening for Apalachee
     Bay-Coastal waters from Suwannee River to Keaton Beach FL
     out 20 NM.

     Small Craft Advisory from 7 PM this evening to 7 AM EST Monday
     for Coastal waters From Ochlockonee River to Apalachicola
     FL out to 20 NM-Coastal waters from Apalachicola to Destin
     FL out 20 NM-Waters from Suwannee River to Apalachicola FL
     from 20 to 60 NM-Waters from Apalachicola to Destin FL from
     20 to 60 NM.

     Gale Warning until 7 PM EST this evening for Coastal waters From
     Ochlockonee River to Apalachicola FL out to 20 NM-Coastal
     waters from Apalachicola to Destin FL out 20 NM-Waters from
     Suwannee River to Apalachicola FL from 20 to 60 NM-Waters
     from Apalachicola to Destin FL from 20 to 60 NM.


&&

$$

NEAR TERM...DVD
SHORT TERM...LAMERS
LONG TERM...LAMERS
AVIATION...DVD
MARINE...LAMERS
FIRE WEATHER...DVD
HYDROLOGY...LAMERS






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