690 
fxus62 ktae 050607 
afdtae 


Area forecast discussion 
National Weather Service Tallahassee Florida 
210 am EDT Sat Jul 5 2008 


Synopsis...although the earlier sea breeze induced showers and 
thunderstorms from Friday afternoon and evening have long since come to 
an end across the County Warning Area...the approaching upper level trough is helping 
to spawn some new convection over northern portions of south central 
Georgia extending quite a bit further to points north and east. These may linger 
for another hour or two...before the remaining instability 
diminishes. Thereafter...with the light SW low level flow continuing 
..expect land breeze showers and storms to initiate overnight 
across Apalachee Bay and the northern Gulf...with some of these 
likely moving onshore near the coast before sunrise. 


&& 


Short term...at this time yesterday...the main questions were how 
far south would the trough to the northwest be for Saturday...and how much 
..if any...Impact would it have on the sea breeze convection across 
the County Warning Area on Sat afternoon. Based on its actual progress to the southeast... 
along with the trends in the last few model cycles...it now appears 
that the trough will dig far enough southeastward to enhance the 
afternoon and evening showers and storms across our area both Sat 
and sun...with plenty of deep layer moisture lingering for Monday as 
well. The position and influence of this trough will likely lead to 
disturbed classifications for the sea breeze for sun and likely Monday 
as well...with today a bit more uncertain. Like Thursday and Friday...the 
1000-700mb mean layer vector wind (mlvw) will be light out of the 
west-SW (type 4) once again...so depending on how much convection forms 
independent of the trough should determine whether today ends up type 
4 or type 11 (disturbed). In any event...the above developments all 
point towards higher probability of precipitation during the next few days...so hopefully we 
can continue to cut into our rainfall deficits for the year without 
experiencing a washout for the remainder of the Holiday weekend. For 
today...modified the GFS forecast 12 UTC sounding to t=92, td=70 to get 
a surface based cape=3327 j/kg, a pw=1.85", and an li=-7.0. These 
values are about 1/2 a Standard. Deviation above type 4 climatology...so will 
likely go with a blended mav/type 4 pop that is adjusted slightly 
upward for the favorable thermodynamics. Low level lapse rates 
should also be a bit steeper today...which could result in a few 
strong storms later this afternoon...especially those which form 
from multiple boundary interactions. 


&& 


Long term...(monday night-saturday)... 
Monday night into Tuesday...the GFS and European model (ecmwf) look very similar to 
the past couple of nights and continue to show a weak tropical wave 
tracking north around the subtropical ridge axis bringing plenty of 
deep layer moisture across the County Warning Area. This will support higher probability of precipitation 
across the area into Tuesday evening. Otherwise...the deep layer 
ridge will remain in control through the extended period. Middle/late 
week...although the models do begin to show their differences...the 
GFS/European model (ecmwf) do show a weak frontal boundary stalling and laying out 
from east to west well north of the local forecast area and the 
ridge axis slightly shifting south of the County Warning Area. This will allow for 
an increase in moisture and afternoon shower chances with the mean 
low-level SW flow in place across the area. 


&& 


Aviation...a brief period with MVFR visibilities will remain possible 
around daybreak this morning in and around any patchy fog that 
develops. Showers and thunderstorms will be likely across the area 
this afternoon due to the combination of an upper trough and deep 
moist southwesterly flow across the area. Provided the support 
aloft...these storms will persist well into the evening hours and 
possibly into the overnight period. 


&& 


Marine...outside of any stronger storms...winds and seas will 
remain at typically low summertime levels over the next several 
days. 


&& 


Fire weather...with increasing low level moisture...red flag 
conditions are not expected for the next several days. 


&& 


Preliminary point temps/pops... 
Tallahassee 92 71 89 72 91 / 60 30 60 30 50 
Panama City 89 75 89 75 90 / 50 30 60 30 50 
Dothan 91 71 90 73 93 / 60 40 70 40 50 
Albany 92 72 90 72 93 / 60 40 70 40 50 
Valdosta 92 70 90 71 92 / 60 40 70 40 50 
Cross City 90 70 90 71 91 / 50 30 60 30 50 


&& 


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


&& 


$$ 


Aviation/fire weather/long term...Gibbs 
public/marine...Gould