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fxus66 kpdt 180207 
afdpdt 


Area forecast discussion 
National Weather Service Pendleton or 
707 PM PDT Wednesday Mar 17 2010 


Update...an upper level ridge is building offshore. Some cirrus is 
moving through the area...but coverage is decreasing. No returns 
on radar over area except some chaff in central Oregon. Breezy 
winds have started to drop in the Kittitas Valley...and are expected 
to decrease more overnight as pressure gradients decrease. Current 
temperatures are 7-14 degrees colder than 24 hours ago. These 
trends are reflected in the current forecast and no updates are 
expected. Coonfield 


&& 


Previous discussion... /issued 200 PM PDT Wednesday Mar 17 2010/ 


Short term...tonight through Saturday...high pressure will be 
building just off the West Coast over the next couple of days. This 
will place the forecast area under a cool yet dry northwest flow 
through Friday for near normal temperatures. Then the ridge will 
shift inland on Saturday bringing warmer than normal temperatures 
back to the region. 


Long term...Saturday night through Wednesday...the ridge of high 
pressure will move east as the next system moves onshore at the 
start of the new week. Models are coming into slightly better 
agreement with the timing...though the European remains slower than 
the GFS model with bringing precipitation in Sunday night instead of 
Sunday. Changed the forecast little due to the uncertainty...with a 
slight chance of precipitation on Sunday night. The trough will then 
drop through the Pacific northwest with better chances of 
precipitation and cooler temperatures on Monday. The threat of 
precipitation will decrease on Tuesday as the trough of low pressure 
moves off to the east and another ridge builds offshore. Models 
indicate that the ridge will be short lived as other disturbances 
will move through the flow leading to a chance of precipitation for 
at least the higher terrain into the midweek. Dmh 


Aviation...00z tafs...VFR conditions will continue for the next 24 
hours at all taf sites. Scattered middle level clouds will decrease 
overnight and winds are expected to decrease during the evening 
hours as high pressure builds into the region. Dmh 


&& 


Preliminary point temps/pops... 
PDT 30 55 28 57 / 0 0 0 0 
alw 32 58 32 58 / 0 0 0 0 
psc 30 59 30 60 / 0 0 0 0 
ykm 29 57 29 60 / 0 0 0 0 
hri 28 58 28 59 / 0 0 0 0 
eln 29 58 30 59 / 0 0 0 0 
rdm 22 58 23 62 / 0 0 0 0 
lgd 27 51 26 54 / 10 0 0 0 
gcd 29 56 28 60 / 0 0 0 0 
dls 32 60 32 61 / 0 0 0 0 


&& 


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


Threat index 
Thursday : green 
Friday : green 
Saturday : green 


Green: none or limited need for watches, warnings, or advisories. 
Yellow: a few watches, warnings, or advisories possible or in effect. 
Red: numerous watches, warnings, or advisories possible or in effect. 


For additional weather information, check our web site at... 
www.Weather.Gov/Pendleton 


$$ 


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