682 
fxus66 kpdt 232101 
afdpdt 


Area forecast discussion 
National Weather Service Pendleton or 
200 PM PDT Wednesday Jul 23 2008 


Short term...tonight through Saturday...a ridge of high pressure 
will build along the coast tonight...and then the ridge axis will 
move east of the Cascades Thursday. Thursday night a southwest flow 
with weak disturbances is expected...as the ridge continues to shift 
eastward...but with a dry stable airmass mostly sunny skies should 
prevail. By Friday evening an upper level low pressure system will 
approach the coast and a surface front may bring marine air through 
the Columbia River gorge as far east as The Dalles. Further east 
Friday will be the warmest day of the short term. There may be 
enough instability Friday for cumulus buildups over the higher 
terrain...but precipitation is not expected. The cool front will 
cross most of eastern Oregon and Washington Friday night...creating 
a cooler and more stable air mass across the area Saturday. 80 


Long term...Saturday night through Wednesday...no significant 
issues to work out through the extended. Medium range models are in 
above average agreement regarding the large scale pattern showing 
typical summertime high pressure across the southern and central 
tiers of the Continental U.S. With quasi-stationary troughing across the 
northeastern Pacific. This would place the region under a fairly dry 
southwest flow aloft. Differences remain in the details but do not 
see any major differences that would greatly affect the trends. Will 
see periods of breezy winds, particularly across the Cascades gaps 
and occasionally reaching east to the lower elevations such as the 
Columbia Basin. Temperatures will be around seasonal normals. /Jbonk 


&& 


Aviation...VFR cigs/vsbys. Reduced visibility at kpdt is due to dust from 
local field plowing activity. Actual surface visibility remains p6sm. Only 
significant aviation concern is for winds through the Colombia 
gorge. Expect westerly sustained winds to generally be in the 
20-25kt range, including kdls, with locally higher speeds expected. 
Also expect potential gusts in the 30-35kt range. Winds should back 
off around 07z tonight with much lesser westerlies lasting until 
around sunrise. Tomorrow, winds are expected to remain below 15kts 
along with some possible high clouds. /Jbonk 


&& 


Preliminary point temps/pops... 
PDT 52 89 55 92 / 0 0 0 0 
alw 56 89 60 91 / 0 0 0 0 
psc 53 94 58 96 / 0 0 0 0 
ykm 51 91 55 92 / 0 0 0 0 
hri 52 92 55 94 / 0 0 0 0 
eln 52 87 56 89 / 0 0 0 0 
rdm 35 88 46 90 / 0 0 0 0 
lgd 47 87 50 89 / 0 0 0 0 
gcd 45 88 55 90 / 0 0 0 0 
dls 53 89 59 88 / 0 0 0 0 


&& 


PDT watches/warnings/advisories... 
or...none. 
Washington...none. 
&& 


$$ 


Ti:ggg 
for additional weather information, check our web site at... 
www.Weather.Gov/Pendleton 
80/87/87