Preview of NWS' New Version of Forecast
This preview is not operational and should not be used for support decisions.

Area Forecast Discussion (AFD)

Issued by Pendleton, OR (PDT)

FXUS66 KPDT 240345

Area Forecast Discussion
National Weather Service Pendleton OR
845 PM PDT Tue Apr 23 2019

.UPDATE...What few showers there were over the Northern Blues have
mostly dissipated now leaving just some clouds over the CWA as a
weak weather system departs the area by Wednesday morning. Winds
will also decrease overnight. A flat upper ridge will build over
the region on Wednesday and then persist through Thursday evening.
After that another weak disturbance will move across the region
with some light rain showers by late Friday. Cooler air will then
move into the region for next weekend, with below normal 
temperatures, and possibly some rain showers, except snow in the 
higher mountains. 88


.AVIATION...06Z TAFs...VFR conditions will persist through the
next 24 hours as a weak weather disturbance departs the area and a
drier west to northwest flow develops under an upper ridge over
the region. Locally breezy winds this evening will diminish and
become light overnight of less than 10 kts. 88


.PREV DISCUSSION... /issued 119 PM PDT Tue Apr 23 2019/ 

SHORT TERM...Tonight through Friday. The weather will be
relatively benign through Friday. Isolated showers over the Blues
and Wallowas will taper off this evening, and the locally gusty
winds will diminish overnight. Currently, the strongest winds are
in the Kittitas Valley, Simcoe Highlands, and the eastern 
Columbia River Gorge where winds 20-30 mph gusting to 40 mph have 
been reported. Other areas in and around the Columbia Basin will 
have gusts 20-30 mph this evening. High pressure will strengthen
over WA/OR tonight and Wednesday. Clouds will decrease overnight, 
and Wednesday will be mostly sunny with highs mainly in the upper 
50s to upper 60s. A clear chilly night is in store Wednesday night
with lows in the 30s to lower 40s. The weather will change little
Thursday and Thursday night, although there will be more cloud
cover. A fast moving shortwave will track across the region on
Friday, and the main impact will be gusty winds--not enough to
warrant any highlights but gusts 35-45 mph are possible in the
typical windy locations such as the eastern Columbia River Gorge,
Simcoe Highlands, and the Kittitas Valley. A 20-30 percent chance
of mountain showers is also forecast for Friday. Wister 

LONG TERM...Friday night through Tuesday. Long term period begins 
with the PacNW under northwest flow Friday night behind an exiting 
short-wave. For the weekend, a stronger low/trough will slide 
southeast out of southern BC into eastern OR/WA and on towards 
ID/MT. Some minor timing and placement differences between model 
guidance, but expect a slight chance of showers for the weekend, 
mainly over the WA Cascades and the northern Blues and Wallowas. 
West to northwest winds expected to be breezy at times through the 
weekend, possibly reaching Adv criteria Saturday for the lower 
Columbia Basin/Gorge, as well as Yakima/Kittitas valleys. Temps will 
also be cooler for the weekend; mid 50s to mid 60s Saturday and then 
down to low 50s to low 60s on Sunday. If cold front is slower to 
pass through on Saturday, highs could be around 5 degrees warmer. 
Sunday night looks to see return of northwest flow as the trough 
shifts eastward. Beyond the weekend, models diverge a bit, but the 
general trend is for a reinforcing shortwave trough sliding south 
over the PacNW within a developing longwave trough over the western 
US. Expect at least a slight chance for showers Monday into Tuesday, 
mainly over the mountains. Temps look to continue the cooler 
trend with highs in the 50s to mid 60s. Winds could be gusty at 
times as well.


PDT  46  66  41  70 /  10   0   0   0 
ALW  48  67  43  72 /  10   0   0   0 
PSC  47  71  42  74 /   0   0   0   0 
YKM  42  69  43  70 /   0   0   0   0 
HRI  47  70  41  73 /   0   0   0   0 
ELN  39  64  38  66 /   0   0   0   0 
RDM  44  68  39  73 /  10   0   0   0 
LGD  45  63  37  71 /  20   0   0   0 
GCD  46  66  40  74 /  10   0   0   0 
DLS  45  71  45  73 /   0   0   0   0