textproduct: Pendleton

KEY MESSAGES

- Low chance (<=30 percent) of showers this afternoon and evening mainly over far eastern Oregon.

- Breezy winds this afternoon and evening over the Columbia Basin, Cascade Gaps, Kittitas Valley and Simcoe Highlands.

- Dry and warmer Tuesday through Thursday, then breezy Thursday in as a weak trough moves through in advance of the next upper low which will bring the potential for more unsettled weather to the mountains over the weekend.

DISCUSSION

The persistent upper low that had been over the Pacific Northwest has moved eastward out of the region. However, lingering troughing remains and a secondary low/short wave will move though this evening. This short wave energy could touch of some showers and possibly a thunderstorm mainly over far eastern Oregon, though some activity has developed over Washington it has not been long lasting.

Breezy conditions are also expected this afternoon through the evening across the Cascade Gaps, Columbia Basin of Oregon, Columbia Gorge, Simcoe Highlands and Kittitas Valley. Winds should gust in the 25 to 30 mph range, with gusts as high as 35 mph.

However, the rest of the area will remain dry. By Tuesday, a split flow regime will develop over the area, which will become more westerly by Wednesday. Temperatures will warm to seasonal values for much of the week, after being below normal for the last several days. By the weekend, temperatures return to below normal with the trough moving through. Highs will be mainly in the 70s at that time which is about 10 degrees below normal. The EFI indicate the 60th t0 70th percentile below normal at that time.

On Thursday, some short wave energy and a weak trough will move through the flow and increase the winds, and the flow will become more northwesterly. Wind gusts will be in the 25 to 30 mph range, with gusts as high as 35 mph in the same areas as today even going into central Oregon and the foothills of the Blue Mountains. Wind gusts >=25 mph are >=70 percent in these areas. Wind gusts >=39 mph are ars high as 60 to 90 percent across portions of the Columbia Basin and Kittitas Valley and lower elsewhere.

The flow returns to westerly again on Friday, then southwest in advance of an upper low that will move across the region Saturday into Sunday, bringing precipitation chances back to the mountains. There is still some uncertainty as to the evolution of the low next weekend, but the system does appear to be progressive, but there will be at least some precipitation in the mountains, an potentially in the lower elevations, but the lower elevation rain chances appear low at this time.

AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/

VFR conditions with breezy winds in the DLS that will decrease as we go into the later afternoon to early evening hours. Not expecting and CIG or VIS issues through the TAF period.

Preliminary Point Temps/PoPs

PDT 44 77 46 82 / 0 0 0 0 ALW 51 78 52 83 / 0 0 0 0 PSC 48 80 49 85 / 0 0 0 0 YKM 51 79 52 84 / 0 0 0 0 HRI 47 80 48 85 / 0 0 0 0 ELN 46 77 48 82 / 0 0 0 0 RDM 38 76 41 85 / 0 0 0 0 LGD 43 75 46 83 / 10 0 0 0 GCD 43 77 46 86 / 0 0 0 0 DLS 52 81 55 86 / 0 0 0 0

PDT WATCHES/WARNINGS/ADVISORIES

WA...None. OR...None.