084 
fxus66 kpdt 071042 
afdpdt 


Area forecast discussion 
National Weather Service Pendleton or 
245 am PST Sat Nov 7 2009 


Short term...today through Sunday night...a broad trough over the 
eastern Pacific and subsequent onshore flow will bring another 
weather disturbance through the area today. As a result...isolated 
rain showers and scattered mountain snow showers can be expected 
this morning. A second more potent disturbance will then move into 
the region this evening...bringing at least a few hundredths of rain 
to almost all locations...and 1 to 3 inches of snow above 4000 feet. 
Breezy winds can also be expected on Saturday afternoon and evening 
with the system passage. Sunday and Sunday night will see some weak 
ridging and a southwest flow develops as a stronger front begins to 
approach the Pacific northwest coast. Therefore...the area should be 
mostly dry on Sunday...except for upslope showers into the Cascade 
crest and some lingering showers in the eastern mountains. Highs 
will be in the upper 40s to upper 50s with 40s in the mountains. 
Night time temperatures will be impacted by partly to mostly cloudy 
skies and will stay mainly in the 30s with 20s in the mountains. 82 


Long term...Monday through next Saturday...another weather system 
will move into the region on Monday with similar amounts of 
precipitation distribution as the system before it. However the cold 
front with this system will be fast moving so the duration of 
precipitation will be short. Vertical mixing with the cold front on 
Tuesday will result in locally breezy conditions which will diminish 
Tuesday night. However...this system will be quickly followed by 
another on Wednesday. This next system on Wednesday looks to be 
stronger and wetter as a more amplified upper trough moves across 
the region. Therefore expect more precipitation along with a more 
unstable atmosphere. Also precipitation duration will be longer with 
showers persisting into Thursday. Thursday night the long range 
models begin to diverge from each other more significantly. 
Depending on which model is correct could mean the difference 
between a mostly clear and dry Friday or a moist and unsettled 
Friday. Due to the uncertainty will not change friday's forecast at 
this time and leave a climatological forecast of isolated to 
scattered showers for Friday into Saturday and will wait for better 
model to model and run to run consistency before making any 
significant changes to the forecast for next weekend. 88 


&& 


Aviation...12z tafs...VFR conditions will prevail today and 
tonight. However another weather system will move across the region 
and cause some showers today. MVFR conditions are possible as a 
result of this due to decreased ceilings and/or visibility in any 
showers that do form. Breezy to windy conditions are expected today 
with wind speeds of 15 to 25 kts possible with even higher gusts to 
35 kts...especially near any showers. The winds will diminish some 
tonight...though locally breezy conditions are expected to persist 
through the night across the area. 88 


&& 


Preliminary point temps/pops... 
PDT 52 35 54 33 / 30 40 10 10 
alw 53 39 55 36 / 50 60 20 10 
psc 54 36 56 33 / 20 50 10 0 
ykm 49 31 51 30 / 20 40 10 10 
hri 54 35 55 32 / 20 40 10 0 
eln 48 32 49 30 / 20 50 10 10 
rdm 45 27 49 26 / 20 20 10 10 
lgd 47 35 50 31 / 30 30 10 0 
gcd 45 35 50 32 / 20 20 10 0 
dls 50 37 54 34 / 40 40 10 10 


&& 


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


Threat index 
today : green 
Sunday : green 
Monday : 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 


$$ 


82/88/88