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Area Forecast Discussion (AFD)

Issued by Pendleton, OR (PDT)

FXUS66 KPDT 162041

Area Forecast Discussion
National Weather Service Pendleton OR
141 PM PDT Tue Apr 16 2019

.SHORT TERM...Tonight through Friday...An upper level trough is 
exiting the region this afternoon and a ridge of high pressure is 
building into the area from the west. There is a shortwave riding 
over the ridge that will spread a little moisture over the region 
tonight and early Wednesday for a few showers along the Washington 
Cascade crest and the northeast Oregon and southeast Washington 
mountains. The ridge will intensify enough late Wednesday and 
Thursday to keep precipitation west and north of the forecast area. 
We will see warming temperatures through Thursday with highs 
approaching 80 in the lower COlumbia Basin by Thursday. The ridge 
will break down Friday and allow a cold front to sweep through the 
region and bring some precipitation back into the forecast area and 
cool temperatures.  

.LONG TERM...Friday night through Tuesday. Long term begins with a 
cold front continuing to drop south and east of the region Friday 
evening with showers over the mountains and Central OR dissipating 
through the night. Gusty winds during the evening hours will 
decrease through the night. Mainly dry and cooler conditions 
expected over the weekend with ridging building in behind the cold 
front. Next chance for precip looks to be early to mid next week as 
the pattern looks to become more westerly zonal, allowing for an 
increase of Pacific moisture and cloudiness over the PacNW. While 
there looks a be a chance for a few showers Monday and Tuesday as a 
couple of weak waves move through the upper flow, but looks like the 
better chance for precip will be towards mid-week with a more 
energetic short-wave approaching. Model consensus is rather poor for 
next week, so leaned towards the GEFS ensemble mean. Expect cooler 
but still seasonable temps behind the front with highs in the upper 
50s to 60s and lows in the mid 30s to mid 40s for the weekend into 
early next week.

Snow melt from daytime highs in the upper 50s and 60s in the Blues 
Thursday and Friday coupled with additional rainfall (potentially up 
to half an inch) Friday afternoon/evening will yield an additional 
bump up on many rivers, creeks and streams draining the Blues but at 
this time only the John Day River at Service Creek and the Grande 
Ronde at Troy are expected to rise above flood stage. 


.AVIATION...00Z TAFs...A few mid to high level clouds expected 
through the period with a slight chance of showers over of the 
mountains. Can't rule out a shower or two near the TAF sites but 
more likely just falling as virga. Winds 10-15kts at DLS, PDT, PSC 
and ALW with winds 5-10kts at RDM, BDN and YKM.


PDT  45  66  46  76 /  10  10   0   0 
ALW  45  68  47  76 /  10  10   0   0 
PSC  49  72  48  79 /   0  10   0   0 
YKM  43  70  46  76 /  10  10   0   0 
HRI  47  71  49  79 /   0  10   0   0 
ELN  42  62  43  71 /  10  10   0  10 
RDM  37  66  43  76 /  10  10   0   0 
LGD  38  58  40  71 /  20  20   0   0 
GCD  36  62  41  73 /  10  10   0   0 
DLS  45  67  47  77 /  10  10   0   0