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fxus66 kpqr 041531 
afdpqr 


Area forecast discussion 
National Weather Service Portland or 
830 am PDT Sat Jul 4 2009 


Synopsis...a strong upper level ridge of high pressure will remain 
over the Pacific northwest through the Holiday weekend...with 
continued hot temperatures through Sunday. An upper level trough will 
approach the area Sunday night...ushering in a fairly strong marine 
push and a quick 15 to 20 degree cool down for most inland areas by 
Monday morning. 
&& 


Short term...visible satellite imagery shows that low clouds have 
come up the Columbia River as far as Kelso this morning. Models 
consistent in slight offshore in the low level winds this morning 
becoming only northerly in the afternoon while the 850 mb 
temperatures rise to Thursday levels. So continued very warm today. 


It looks like we see a change to more onshore Sunday afternoon with 
the main surge coming late in the day and in the evening. So...slight 
cooling with relative humidity up some and the main cooling Monday with deepening 
marine layer. 


Models not impressive with instability late Sunday...will back 
thunderstorm threat back to the Cascade crest. Likens 


Long term...no changes. Previous discussion follows...an upper level 
trough of low pressure will establish itself over the forecast area 
the first part of next week and will persist through the week. This 
will bring cooler temperatures and a chance of showers. 
&& 


Aviation...IFR stratus along the coast and in the coastal gaps this 
morning will burn back to the beach later in the morning. Clouds 
should even break up along the coastline this afternoon as the 
surface gradients turn northerly. IFR stratus will return to the 
coast tonight in weak onshore flow. Clear skies are expected 
elsewhere for the next 24 hours. 


Kpdx and approaches...no significant weather impacts expected. 


&& 


Marine...seas running 5 to 6 feet. However...with short period wind 
waves sea conditions will remain a little choppy. No advisories 
expected through the weekend. Winds will shift to the south to 
southwest on sun as a trough swings inland and surface high pressure 
builds in from the southwest. 


&& 


Pqr watches/warnings/advisories... 
or/WA...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.