Your Weather

To update your location please enter your ZIP code, city, state, airport code or country in the field below. Weather by E-mail: Forecast storm alerts. Weather E-Mail Alert Sign Up »

Next 12 Hours

Forecast data from the National Digital Forecast Database.

5 Day Forecast

• Tuesday
• 
• High: 73 °
• Low: 37 °
• Chance of T-Storms

• Wednesday
• 
• High: 59 °
• Low: 34 °
• Chance of Rain

• Thursday
• 
• High: 59 °
• Low: 39 °
• Chance of T-Storms

• Friday
• 
• High: 63 °
• Low: 37 °
• Chance of Rain

• Saturday
• 
• High: 66 °
• Low: 41 °
• Partly Cloudy

Area forecast discussion...updated 
National Weather Service Pendleton or 
459 am PDT Tuesday may 21 2013 


Updated short term discussion 


Short term...today through Wednesday night...a large upper level 
low pressure trough seen on satellite water vapor loop digging 
southward near Queen Charlotte island will develop rapidly into a 
closed middle/upper level low pressure system today with the center of 
the low reaching the Oregon coast by late this afternoon. This cold 
low will push a cold front through the forecast area today. The 
front will move eastward across the western sections this morning 
with showers moving into the Tri-Cities and Hermiston by late this 
morning. Marginal instability ahead of and along the cold front will 
favor isolated thunderstorms possible this afternoon and this 
evening in the Blue Mountains and Grant County eastward into Idaho. 
The upper low will linger over the region through Wednesday night 
for periods of rain showers at lower elevations with snow showers in 
the mountains. Snow levels will lower late tonight to around 
2800-3500 feet for light snow showers occurring at pass levels in 
the mountains of central and NE Oregon and the Blue Mountains in 
Washington. Snow accumulations of 2-3 inches are expected in the 
Blue Mountains overnight into Wednesday morning. An late snow 
season/offseason Snow Advisory may be needed for the Blue Mountains 
for late tonight, but will defer to the day shift for a decision. 
Snow levels will lower to 3500-4200 feet by late Wednesday night. 
Polan 


Long term...Thursday through Tuesday...a large and persistent upper 
low pressure system will linger over the Pacific northwest through 
much of the extended period. There will be waves of energy rotating 
around this system with each one bringing a chance of rain showers 
and possible afternoon thunderstorms to the forecast area. Any 
thunderstorms that do form will mainly be concentrated from the Blue 
Mountains eastward and southward including central Oregon around the 
Deschutes plateau. This system has the potential to produce 
significant rainfall to some areas...mainly in the mountains...which 
will help ease the current dry spell that the County Warning Area is experiencing. 
The long range models begin to diverge significantly by Saturday 
morning with the European model (ecmwf) and GFS models placing the center of the 
upper low about 500 miles apart with the European model (ecmwf) positioned of the British Columbia 
coast and the GFS centered over north central Washington. The 
divergence between these two long range models increases but both 
keep a general trough like pattern over the County Warning Area through the extended 
period and therefore will not make any changes after day 5 
(saturday). Temperatures will be cool through the period and a 
little below normal due to the clouds and lower heights and 850 mb 
temperatures. 


&& 


Aviation...12z tafs...VFR conditions will prevail through the 
period. However conditions will deteriorate as a large weather 
system and upper low pressure system moves into the region. This may 
result in brief periods of MVFR conditions by 19z...especially at 
krdm...kbdn and kdls. These deteriorating conditions will reach the 
rest of the taf sites by 00z. Winds will begin light but they will 
increase to 20 to 30 kts at kdls and 15 to 25 kts in the lower 
Columbia Basin and Blue Mountain foothills by 18z as the weather 
system moves into the region. The breezy to windy conditions will 
persist through at least 12z Wednesday. 88 


&& 


Preliminary point temps/pops... 
PDT 64 40 59 39 / 60 70 50 20 
alw 68 43 60 43 / 60 70 50 20 
psc 71 44 65 39 / 50 60 40 20 
ykm 65 38 63 37 / 50 20 30 20 
hri 67 42 65 38 / 40 70 40 20 
eln 62 42 58 39 / 60 20 40 30 
rdm 59 31 54 32 / 50 50 40 30 
lgd 71 39 54 37 / 60 50 50 30 
gcd 69 36 56 35 / 50 40 40 20 
dls 63 44 61 42 / 70 30 50 40 


&& 


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


Threat index 
today : yellow 
Wednesday : green 
Thursday : 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 


$$ 


99/88/88