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fxus66 kpqr 090433 
afdpqr 


Area forecast discussion 
National Weather Service Portland or 
826 PM PST Monday Feb 8 2010 


Synopsis...an upper level trough will approach the coast tonight 
bringing an area of low pressure to southern Oregon late this 
evening. Much of the associated energy with the system will dive 
south into southern Oregon and California...thus giving a chance for 
precipitation to the south part of the forecast area late tonight 
through Tuesday. Another weather system will approach the coast 
Wednesday afternoon making precipitation more likely across the 
entire area as the jet stream guides the first of a series of fronts 
into the Pacific northwest. 


&& 


Short term...upper flow continues to drive the main energy from the 
approaching trough south into California. Upper trough is stretching 
apart with little eastward progress of the system tonight. Minimal 
threat of any precipitation over northwest Oregon from this system. 
As the weak trough approaches expect stratus to reform tonight in 
most of the central and south Willamette Valley...and some patchy 
fog as well. An upper level ridge will move in late Tuesday and 
Tuesday night. Models in good agreement on the shortwave trough 
moving in Wednesday and Wednesday night. This comes as the jet 
stream shifts north with more focus on the Pacific northwest over 
the coming week. Schneider 




Long term...no changes. Previous discussion follows...models agree 
on a more active weather pattern for our area through the 
weekend..with systems rolling through every 24 to 36 hours. 
Anticipate probability of precipitation to trend a little higher than climatology...as 
systems push rapidly into the Pacific northwest. However...ridging 
appears to be in the offing for next week for another change in the 
overall weather pattern. Kwelson 


&& 


Aviation...a mix of IFR and MVFR is expected for the central and 
south Willamette Valley tonight. Ceilings should rise to VFR by 18 
to 20z. Otherwise...expect VFR conditions continue through Tuesday 
afternoon. 


Kpdx and approaches...VFR conditions will continue through Tuesday 
afternoon with increasing clouds. However...there is a 40 percent 
chance of brief MVFR conditions after midnight and before sunrise. 
Ramirez 


&& 


Marine...seas should remain between 7 and 10 feet for the next 
several days at least. A very weak frontal system will move through 
the waters overnight then dissipate as it shifts inland. Quiet 
conditions will continue until Wednesday or Thursday when the next frontal 
system moves over the waters bringing the potential for gales. 
Additional frontal systems will track into the area Friday and Sat 
beginning a trend towards more active weather. 


&& 


Pqr watches/warnings/advisories... 
or...none. 
Washington...none. 
Pz...none. 


&& 
$$ 


More weather information online at... 
http://weather.Gov/Portland 


This discussion is for northwest Oregon and southwest Washington from 
the Cascade crest to 60 nautical miles offshore. The area is commonly 
referred to as the forecast area.