958 
fxus61 kctp 211857 
afdctp 


Area forecast discussion 
National Weather Service State College PA 
257 PM EDT Thursday Aug 21 2008 


Synopsis... 
high pressure will continue fair and dry weather through the first 
part of the weekend. Temperatures will moderate to above normal 
late this week as the high moves off the East Coast. A cold front 
will bring the next chance for showers and thunderstorms from 
Sunday into Monday. 


&& 


Near term /through tonight/... 
very minor changes from previous forecast...mainly in the cloud/wind 
and temperature dept. 


Surface high pressure just off the middle Atlantic coast and a sharp 
upper ridge/mild temperatures aloft across the NE US will mean above 
normal temperatures for this afternoon combined with light easterly to southeast 
winds...and a nearly cloud free sky. 


&& 


Short term /Friday through Saturday night/... 
anomalous surface high pressure will provide fair and dry weather through 
Saturday as it slowly drifts east...and then northeast away from 
the New England coast by Saturday. Temperatures will climb above 
normal by Friday...but humidity levels will remain comfortable. 
Minimal spread displayed in the ens 2m temperature plume diagrams 
suggests a high confidence forecast. 


&& 


Long term /Sunday through Thursday/... 
the main weather feature in the medium to long range still looks 
to be a sharp cloud fnt...poised to move across the region Sunday 
into Monday. At this range there is still some uncertainty 
pertaining to the exact timing of the frontal passage. However...the latest 
gefs data continues to focus the highest probability of precipitation 
around 25/00z over western and central PA. 


The 12z GFS and European model (ecmwf) bring ts Fay back into the fold for the 
middle of next week...bringing the remnants of the tropopause cyclonic northeastward 
from the southeast U.S. Meanwhile...the gefs keep brings high pressure 
into the region from the Great Lakes following the passage of the 
aforementioned cloud fnt. Have kept the forecast dry at this point 
siding with the ens guidance as models have been having considerable 
difficulty with ts Fay up to this point. 


&& 


Aviation /19z Thursday through Tuesday/... 
for late today...expect to see near unlimited visibility with the only 
clouds (sct-bkn/shallow cumulus with bases 3.5 to 4.5 agl) forming 
within a zone of higher moisture in the 3-5kft above ground level layer over 
scent Penn and the Laurel Highlands. This will be noted generally 
SW of a line from kunv to kmdt. Otherwise...sky clear will prevail 
through tonight. 


Excellent flying weather will continue for the next several days 
with only brief...and highly localized IFR/MVFR ceilings and visibilities 
possible around daybreak Friday and Sat at kipt (and perhaps 
kunv and kaoo) due to valley fog. 


An anomalous surface high pressure ridge over the northeast U.S. Will 
continue to provide dry and VFR weather through Saturday as it 
slowly drifts eastward. Winds will be light from the east or 
southeast...but may briefly be in the 8-10 kts range during the early/middle 
afternoon hours Friday and again on Saturday...when they will 
slowly veer around to the south. 


Low level moisture from the south...and high level moisture from the 
west will gradually increase Sat afternoon into Sunday. Still the dual 
(strato cumulus and cirrus) cloud layer will still be VFR. Since 
heights aloft will be increasing with middle level lapse rates 
on the low side (less than 5c/km for much of the time)...the chance/S 
for rain showers/thunderstorms and rain will remain out of the central PA region through Sat 
afternoon (except for kbfd which could see an isolated rain showers/thunderstorms and rain 
pop up along the southeast edge of the Lake Erie breeze late saturday). 


A cold frontal boundary will sweep east across the lower glakes 
region and adjacent central Appalachians late Sunday and Monday. 
This weather feature will be accompanied by a few shra/tsra. 


The front could stall out just southeast of the region early next week. 
This may allow the remnants of ts Fay to creep NE along the 
Appalachians/frontal boundary and bring more significant 
rains/adverse flying conditions for the midweek period. 


&& 


Ctp watches/warnings/advisories... 
none. 


&& 


$$ 
Synopsis...devoir 
near term...devoir/Lambert 
short term...devoir/steinbugl 
long term...steinbugl 
aviation...Lambert