392 
fxus62 ktbw 181725 
afdtbw 


Area forecast discussion 
National Weather Service Tampa Bay Ruskin Florida 
125 PM EDT Friday Jul 18 2008 


..drier and warmer into early next week with heat index of 100 to 
105... 


Surface low off Georgia coast with narrow convergent bands of 
showers and thunderstorms extended through Daytona Beach and 
through the Tampa Bay area. Another band was in South Florida. 


Short term...(tonight - sunday)...will keep isolated precipitation 
00-02z in interior counties and Cedar Key area. Otherwise...east 
to west high pressure ridge to bi-sect the forecast area through 
the weekend. Forecast sounding shows precipitation water around 1.6 inches and 
lifted of -4c across area this weekend. Light winds and lack of 
forcing mechanisms will limit precipitation...but it is Summer in Florida 
so will continue 30 percent (normal is 40-50 percent) of mainly 
afternoon storms. It will be hot with an afternoon heat index of 
100 to 105. 


Long term (sunday night - friday)...little change from previous forecast 
philosophy during this time frame. The period will start off with two 
possible tropical systems one lifting northeast off the Carolinas and 
another moving west northwest through the western Caribbean and into 
the southwestern Gulf. Closer to home weak middle level ridging and surface 
high pressure will persist over the Central Peninsula. Similar to the 
last few days models show drier air working its way into the forecast 
area Sunday night through Tuesday with precipitable waters falling into the 1.4-1.6 
inch range. This drier air combined with a subtle increase in subsidence 
aloft should limit diurnal convective development on Monday and Tuesday 
with below normal rain (pops ~20%) chances expected. 


During Wednesday through Friday the middle level ridge will weaken some 
as it shifts east as weak middle level troughing moves across the region 
from the southeast while the surface ridge axis drifts north to the 
north-Central Peninsula. Increasing moisture (pw's increasing back 
into the 1.8 to 2" range) within a weak southeast wind flow combined 
with the middle level trough will all help to increase chances for 
scattered diurnal showers and storms along the sea breeze circulations 
(pops ~30% on Wednesday then increasing to 40% Thursday and friday) 
across the forecast area each day...during the afternoon and early 
evening hours. Less cloud cover and lower rain chances at the start 
of the period will allow temperatures to run a few degrees above normal 
before returning to near normal middle to late week as rain chances once 
again increase across the region. 


&& 


Aviation...mvrf/IFR ceilings and visibilities may briefly impact 
Tampa...Saint Petersburg and Sarasota terminals early this afternoon 
before most of the convection pushes further inland. Some brief MVFR/ 
IFR ceilings/visibilities may also affect Fort Myers and regional southwest 
terminals during middle to late afternoon otherwise thunderstorms in the vicinity should handle 
things. After the convection winds later this evening VFR conditions 
are expected at all sites overnight into Saturday morning. 


&& 


Marine...winds 10 knots or less with waves 2 feet or less through 
Wednesday. 


&& 


Fire weather...no problems expected as the humidity remains 
about 40 percent through next week. 


&& 


Preliminary point temps/pops... 
tpa 77 93 77 94 / 10 30 5 20 
fmy 75 95 74 94 / 10 30 5 30 
gif 75 95 75 95 / 20 30 5 30 
srq 75 92 75 92 / 10 30 5 20 
bkv 71 93 71 94 / 10 30 5 20 
spg 80 92 80 93 / 10 30 5 20 


&& 


Tbw watches/warnings/advisories... 
Florida...none. 
Gulf waters...none. 
&& 


$$ 


Short term/marine...Noah 
long term/aviation...jcm