767 
fxus61 kcle 211842 
afdcle 


Area forecast discussion 
National Weather Service Cleveland Ohio 
242 PM EDT Thursday Aug 21 2008 


Synopsis... 
high pressure will remain over the region through Saturday. A cold 
front will begin to move across the Great Lakes on Saturday night and 
through the forecast area Sunday. 


&& 


Near term /through tonight/... 
high pressure over the region will keep the weather fairly quiet 
overnight. Moisture and precipitation to the west over Illinois/in will remain 
to the west. Some high clouds may spread over the western sections 
of the area but mostly clear to partly cloudy in store for most 
areas. 


Short term /Friday through Sunday night/... 
high pressure will remain on Saturday. A cold front will push 
towards the forecast area Sat night and Sunday. The 12z GFS has 
slowed the front down from the previous run and has come more in 
line with the NAM. The slower run would suggest less precipitation on 
Sat/Sat and a better chance on Sunday afternoon. Current forecast has 
the mention of precipitation late in the afternoon Sat. With the current 
model trends this may be a little optimistic. Scattered precipitation Sat 
night and Sunday. Cold front and precipitation will move east of the 
forecast area Sunday night. Upper level dynamics are weak and the 
front appears to be lacking moisture...therefore I do not expect 
widespread precipitation. I will keep all probability of precipitation in chance category at this 
time. 


&& 


Long term /Monday through Thursday/... 
models consistent on showing high pressure moving from Lake Superior 
area Monday morning to just east of Maine by late Thursday. 
Differences are in the handling of the remnants of ts Fay as this 
system may be the only chance for any precipitation during this period. 
Both models show moisture from Fay pushing north into our area around 
Wednesday with the GFS a bit faster of the two. The ecmfw shows a more 
organized surface through upper level low system leftover that moves 
north into western Ohio Wednesday night into Thursday. Will introduce a chance 
for precipitation Wednesday and carry through Thursday but keep chance in the 20 to 
30% range. 


&& 


Aviation /18z Thursday through Tuesday/... 
high level moisture will continue to stream into the area from the S 
and SW ahead of an upper level trough to our west. Limited lower 
level moisture may allow some cumulus to be scattered around the area 
this afternoon and again around midday Friday...otherwise expect to 
see scattered to locally broken cirrus throughout the taf period with most of the 
cirrus fairly thin. 


A lake breeze should shift the predominate southeast flow to NE at cle and 
eri this afternoon. The light southeast flow tonight should limit any fog 
formation to just a few hours of MVFR fog at most and probably just 
in the western tafs where the dewpoints rise more through daybreak. 


Outlook...except for an isolated rain showers or thunderstorms and rain in the around tol dry 
conditions and VFR should prevail into Saturday. Late Sat through 
Sunday afternoon a weakening cold front should move into the area 
and may produce scattered thunderstorms and rain leading to local areas of MVFR or lower in 
the heavier precipitation. A return to dry and widespread VFR is expected 
Monday into Tuesday. 


&& 


Marine... 
high pressure will continue to affect Lake Erie through Saturday 
night. A cold front will move east across the lake Sunday. Winds 
will increase out of the north to northeast Sunday night and small 
craft advisories will likely be needed Sunday night into Monday. 
Otherwise...rest of the periods should remain below small craft 
criteria. 
&& 


Cle watches/warnings/advisories... 
Ohio...none. 
PA...none. 
Marine...none. 


&& 


$$ 
Synopsis...Garnet 
near term...Garnet 
short term...Garnet 
long term...Adams 
aviation...Adams 
marine...Lombardy