Weather

824 
fxus66 kpdt 071046 aaa 
afdpdt 


Area forecast discussion 
National Weather Service Pendleton or 
346 am PDT sun Sep 7 2008 


Updated aviation discussion 


Short term...today through Monday night. Middle level clouds between 
about 10 and 20 k feet above mean sea level are currently gathered 
east of the Cascades over the northern Columbia Basin. 
Northeasterly flow will maintain some of these clouds along the east 
slopes of the Washington Cascades overnight...and some of these 
clouds should move across the northern portion of The Blues and 
Wallowa County during early morning. Today the ridge of high 
pressure off the West Coast will build slightly eastward...for 
another day with mild conditions and an even more stable air mass 
than Saturday. Tonight the ridge is flattened slightly by a very 
weak disturbance. Late Monday and Monday night there will be a 
transition to a weak trough axis over the Pacific northwest. The 
GFS model does not show much impact from this upper-level pattern 
change...other than enough lift for some middle and high level 
cloudiness...and the European model (ecmwf) model is even less energetic. 80 


Long term...Tuesday through Saturday night...a disturbance ahead of 
a trough of low pressure over British Columbia and Alberta will move 
through the area on Tuesday...followed by the trough dropping south 
by Wednesday. The models agree on this general scenario...however 
the details differ. The GFS brings the trough over eastern 
Washington and Oregon...while the European and Canadian swing the 
trough south through the Idaho Panhandle and western Montana. The 
latter scenario seems to be the consistent one...and thus the one to 
follow. This will bring breezy conditions to the area Tuesday 
afternoon and into the late evening. Temperatures will cool Tuesday 
and Wednesday as colder air moves southward with the system. The 
ridge of high pressure off the Pacific northwest coast will then 
edge into the area on Thursday for warming conditions and clearing 
skies. Another system will approach the Pacific northwest coast 
Thursday night and move through the area on Friday. This system 
appears to be dry...and likely will only bring an increase in clouds 
and wind to the area. The ridge will then rebuild behind the system 
on Saturday. Dmh 


&& 


Aviation...12z tafs...VFR conditions with mostly clear skies will 
continue for the next 24 hours. Surface winds are expected to remain 
10 kts or less through the day and overnight. Dmh 


&& 


Preliminary point temps/pops... 
PDT 80 49 81 49 / 0 0 0 0 
alw 81 53 82 54 / 0 0 0 0 
psc 84 49 84 51 / 0 0 0 0 
ykm 82 50 82 50 / 0 0 0 0 
hri 82 46 83 47 / 0 0 0 0 
eln 81 48 83 51 / 0 0 0 0 
rdm 81 41 83 42 / 0 0 0 0 
lgd 77 43 81 43 / 0 0 0 0 
gcd 79 46 84 48 / 0 0 0 0 
dls 85 53 87 55 / 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 
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