textproduct: Pendleton

KEY MESSAGES

- Showers and isolated thunderstorms along the Cascade crest Today and Saturday

- Breezy winds over the lower elevations Today and Saturday

- Dry conditions Sunday before an active weather pattern returns through the middle of next week

DISCUSSION

Diffluent flow aloft was in place across Washington and Oregon ahead of a 540 dm upper low near 52N and 135W. This upper low is forecast to pivot southeast reaching the the PAC NW coast on Friday Night. And spreading inland an shearing out as an amplified through through Saturday Night. This will bring sensible weather including winds, rains, potentially thunderstorms and wetting rains to the higher mountain zones.

As for Today, there is a short duration from mid afternoon through about 6 or 7 pm for potential (up to 60% chances) for low end advisory level sustained wind speeds of 30 mph and gusts around 40 mph between The Dalles and Goldendale, in the Eastern Columbia River Gorge.

Dry conditions will begin to give way to by late Today across the Washington Cascade crest and the Oregon crest through Saturday- Morning. This upper low does not develop far enough south to bring wetting rains to the eastern Mountains, leaving them virtually dry as Cascade showers end Saturday afternoon. Sunday will remain dry, as a shortwave ridge shifts across the area in a progressive pattern that sets up another upper cold core low to spread , farther south this time, across the Interior NW late Monday through Tuesday afternoon. This second upper low, with its farther southward track has a greater probability for spreading rains, even wetting rains across the eastern mountains Monday into Tuesday. Slightly cooler temperatures due to the weather system in the weekend and early next week, characterized by mean NBM high temps in the low to mid 70s across the Columbia Basin/River Gorge and Yakima Valleys, to upper 60s in the Kittitas valley and central Oregon, and mid much cooler 50s in most of the mountain zones. Russell/71

AVIATION /12Z TAFS THROUGH 12Z SATURDAY/

No ceilings to deal with during this TAF period as a dry diffluent flow aloft is in place with only high level mountains showers later Tonight. Winds will get windy however in the Columbia River Gorge around KDLS, where afternoons sustained speeds near 30 mph and gusts to around 40 mph have about a 50% chance of occurrence form around 20z to 01z. Russell/71

FIRE WEATHER

Dry and Breezy conditions will overlap This Afternoon across the Eastern Columbia Gorge and Oregon Columbia Basin where combined probability for RH and wind speeds of 20% or less and 15 mph respectively area around 40 to 60%. Fuels are not quite cured enough for red flag concerns in these zones, yet. Farther north over the Washington Columbia Basin where fuels have cured more, combined probabilities on Friday for these rh and winds are around 5-25%. Russell/71

Preliminary Point Temps/PoPs

PDT 72 44 66 41 / 0 0 0 0 ALW 74 50 67 45 / 0 0 0 0 PSC 77 48 71 42 / 0 0 0 0 YKM 74 44 68 40 / 0 0 20 0 HRI 74 46 69 41 / 0 0 0 0 ELN 66 39 60 36 / 0 0 40 0 RDM 73 38 62 29 / 0 0 0 0 LGD 74 43 63 38 / 0 0 0 10 GCD 79 41 64 36 / 0 0 0 10 DLS 71 49 66 44 / 0 10 30 10

PDT WATCHES/WARNINGS/ADVISORIES

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