Weather

509 
fxus62 ktae 071906 
afdtae 


Area forecast discussion 
National Weather Service Tallahassee Florida 
306 PM EDT sun Sep 7 2008 


Synopsis...visible satellite imagery this afternoon shows a cumulus 
field in place across the region. Doppler radar images show 
scattered showers and thunderstorms developing mainly across the 
southeastern third of the forecast area. Expect this to continue 
throughout much of the afternoon...though the intensity of these 
storms will be limited by the gradually eastward advancing drier 
air. Hurricane Ike is moving through the southeastern Bahamas and is 
approaching Cuba. Winds remain at 135 miles per hour. For more 
information...please consult advisories from the National Hurricane 
Center. 


&& 


Short term...(tonight through wednesday). 
Overall immediate short term pattern is relatively straight forward. 
Drier middle level air will continue to gradually work in from the 
northwest. Thunderstorm activity this evening will gradually 
diminish after sunset...however areas in the southeast will remain 
warm and muggy again overnight with the potential for patchy fog or 
low ceilings. 


Gradually increasing moisture from the east as Ike continues to move 
westward toward the Gulf of Mexico will increase pop chances by 
Tuesday with the potential for much higher probability of precipitation on Wednesday. The 
GFS and NAM are both showing a rather long fetch of deep layer 
moisture moving around the far northern periphery of Ike...off the 
Atlantic...into our region by Wednesday morning. This 
moisture...combined with some afternoon heating should indeed lead 
to decent coverage of showers and storms. If the track of Ike is 
further south...probability of precipitation would obviously be much lower. For much of the 
forecast...a combination of the mav/met/sref guidance was used for 
the pop forecast. The mav guidance appears to be too dry...and too 
warm by the time we get to Wednesday. 


Long term...(thursday through monday). 
The 00 UTC numerical guidance is in good agreement in taking Ike 
into the southeast Gulf of Mexico Tuesday night as the western 
portion of the Bermuda high temporarily weakens. The guidance then 
slows Ike down somewhat as the steering currents weaken. The 00 UTC 
GFS/UKMET and 12 UTC Sat European model (ecmwf) now take Ike toward the Texas coast next 
weekend. The 00 UTC GFDL takes Ike north over the eastern Gulf then 
turns Ike sharply west before reaching our area. The 00 UTC CMC 
forecasts a landfall near Mobile Alabama...and is the only model that 
brings Ike so close to our area. Thus it appears the chances for a 
direct hit to our area may be decreasing...but it is too early to 
dismiss this possibility as there is still potential for errors in 
the model runs. 


With such good agreement among the GFS and European model (ecmwf)...we plan to stay 
close to the GFS solution for our long term forecast. We will limit 
the wind and seas forecast a bit as there is still some question how 
Ike will interact with Cuba...and how that will affect its intensity 
and size. Even if Ike follows the GFS/European model (ecmwf) forecast track toward 
the Texas coast...there will likely be convergent moist flow over our 
area for much of this forecast period. 


&& 


Marine...a weak gradient will remain in place through Monday before 
the gradient rapidly tightens as Ike enters the Gulf. Increasing 
winds...seas...and swell will begin impacting the waters on Tuesday 
and continuing while Ike is in the Gulf. The potential for seas up 
to 12 feet by Wednesday evening and 20 knot winds is certainly a 
possibility...so we'll show slightly higher seas in this afternoon's 
package to trend the forecast that direction. 


&& 


Aviation...VFR conditions expected rest of this afternoon into 
evening outside of widely scattered thunderstorms. Prevailing surface winds 
will be less than 10 knots. 08z-13z expect areas of MVFR visibilities with 
isolated IFR visibilities especially at kvld. Then...VFR conds expected into 
afternoon. 


&& 


Preliminary point temps/pops... 
Tallahassee 72 92 73 90 75 / 30 20 20 40 30 
Panama City 76 92 75 90 76 / 30 20 20 30 30 
Dothan 68 93 71 90 71 / 20 30 20 30 30 
Albany 72 93 71 90 72 / 20 20 20 40 30 
Valdosta 71 93 72 90 73 / 30 20 20 50 30 
Cross City 72 93 73 91 73 / 30 30 20 50 30 


&& 


Tae watches/warnings/advisories... 
Alabama...none. 
Georgia...none. 
Florida...none. 
GM...none. 


$$ 


Aviation...block 
long term...Fournier 
rest of discussion...Godsey