Area Forecast Discussion Issued by NWS
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054
FXUS62 KTAE 021359
AFDTAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
959 AM EDT Wed Oct 2 2013
.NEAR TERM [Through Rest of Today]...
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The large scale longwave pattern indicated a nearly zonal flow over
Nrn stream, a weak trough over Wrn Gulf region with cutoff low over
AR/LA border, and a broad H5 ridge from Ern plains to the mid-Atlc
Swd over Gulf region. Deep layer low assocd with tropical
disturbance in NW Carib Sea. Local area between both lows allowing
for SSW flow above H6 to advect moisture north from Cuba/FL Straits
but Nrn extent has only reached S/Cntrl FL. At surface, main
features are 1020mb high over Cntrl Appalachians and tropical
disturbance to our south. This translates to light and dry E/NE flow
near the surface. Radar indicated showers moving NWWD across
Panhandle waters in area of relatively deeper moisture. This
reflected in area soundings. i.e. RAP13 this aftn with 1.30 inch
PWAT at TLH compared to 1.10 inch PWAT at DHN.
During the rest of today, upper low will open up and lift into
Mid-South nudging Ern ridge towards Atlc. All HI RES models show
some precip remaining over Panhandle coast, with HRRR/local WRF
faster in removing it than local CAM/ARW/NM4. Some showers aided by
daytime heating may form over Panhandle Coast. Cant rule out isold
Tstms although instability indices not impressive. Inherited
forecast looks dry, except for 10-40% NE-SE POPS Panhandle coast
thru WRN offshore waters. Expect highs in the mid to upper 80s with
lowest temperatures across more cloudy Panhandle area.
All eyes remain focused on low pressure disturbance over NW Carib
Sea. Per latest NHC guidance, It is expected to move NNW today and
could impact our local region later in the week. The afternoon
forecast product, aided by the latest model guidance, will provide
more details.-- End Changed Discussion --
&&
.SHORT TERM [Tonight through Friday]...
Mainly dry conditions are expected through Thursday, except for
coastal areas where a 20-30% PoP remains in place. By Friday and
beyond, the forecast starts to depend more on the tropical
disturbance in the northwest Caribbean, which is forecast to move
into the Gulf of Mexico. For now, we have leaned more towards the
02/00z ECMWF and UKMET scenarios, which are weaker and farther to
the west as compared to the stronger 02/00z GFS scenario that takes
the system to Panama City. However, considerable uncertainty remains
and forecast confidence is low. Expect gradually increasing rain
chances towards the end of the week and into the weekend in either
scenario, especially for western areas.
&&
.LONG TERM [Friday Night through Tuesday]...
Deep layer moisture from the tropical disturbance mentioned above
will likely be advecting NE from the Gulf towards our area.
Significant model differences remain with the handling of this,
and confidence remains low, although the official forecast
currently downplays the 02/00z GFS solution, which is strongest
and furthest east of any of the main global guidance. No changes
were made to the previous long term forecast grids, which had
30-50% PoPs for Sunday through Tuesday.
&&
.AVIATION [Through 12 UTC Thursday]...
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We expect unlimited vis/cigs through the period except possibly
marginal MVFR vis towards sunrise Thurs. Expect E-NE winds of 4 to 8
KT. SHRA/TSRA are too low to consider for TAFS but if any occur it
would likely be at KECP rest of this morning.-- End Changed Discussion --
&&
.MARINE...
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The surface high pressure ridge to our north will keep the pressure
pattern supportive of light to moderate easterly winds through
this evening with possible cautionary level conditions developing
by tonight and Thursday across the offshore zones. Thereafter,
considerable uncertainty remains depending on what happens with a
tropical disturbance in the northwest Caribbean, which is forecast
to enter the southern Gulf of Mexico by Thursday morning. All
marine interests are urged to keep abreast of the latest forecasts
and outlooks from the National Weather Service and National
Hurricane Center for the potential development of this system.
Should development occur, mariners should be prepared for rapidly
deteriorating conditions over a relatively short amount of time.-- End Changed Discussion --
&&
.FIRE WEATHER...
Red Flag conditions are unlikely through at least this weekend.
&&
.HYDROLOGY...
River flows remain above base levels for early October with area
soils still quite moist from the summer rains. The incoming system
this weekend will need to be closely monitored. A more organized
tropical system could easily produce enough rainfall to result in
a fair amount of areal and riverine flooding into next week.
However, if the storm system is more disorganized as indicated in
some of the latest guidance, then flooding would be less of a
threat.
&&
.PRELIMINARY POINT TEMPS/POPS...
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Tallahassee 88 65 88 69 87 / 10 10 10 10 20
Panama City 84 71 86 73 85 / 20 20 20 20 40
Dothan 86 64 88 67 88 / 10 10 10 10 20
Albany 87 63 88 63 88 / 0 0 0 10 10
Valdosta 86 61 87 64 87 / 0 0 10 10 10
Cross City 88 65 88 67 88 / 0 0 10 10 20
Apalachicola 83 72 84 73 83 / 20 10 20 20 40-- End Changed Discussion --
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
Near Term/Aviation...Block
Fire Wx...Fournier
Short Term...DVD
Marine...BLOVK/DVD
Long Term...DVD/Gould
Hydrology...DVD/Godsey