textproduct: Pendleton

KEY MESSAGES

- Dry weather through early Saturday.

- An upper low will bring precipitation mainly to southern and central Oregon Saturday through Monday.

- An upper trough will bring additional precipitation around midweek.

DISCUSSION

A ridge of high pressure, followed by dry northwesterly flow will keep dry conditions over the Pacific Northwest through early Saturday. There will be some diurnal breeziness today, especially in the Kittitas Valley, but at this time conditions do not appear to reach advisory criteria. Wind gusts in the 25 to 35 mph range are expected.

Then, the flow will turn more southwesterly over central and southern Oregon and moisture will begin to move onshore in advance of an upper low off the coast. This low will move inland in northern California Sunday or Sunday night. Precipitation chances will increase into Saturday night then continue into Sunday before decreasing on Monday, as the low moves eastward.

Snow levels are generally expected to be between 5500 and 6500 feet, so little if any snow is expected, except at the higher elevations. QPF is mainly a few hundredths to 0.10 inches in the lower elevations and possibly up to 0.50 inches along the Cascade crest.

The rest of the region will remain dry.

An upper ridge will build in behind the departing low for later Monday into Tuesday, bringing a return to dry weather everywhere.

By Tuesday night, an upper trough will approach the Pacific Northwest and bring more widespread precipitation chances by Wednesday morning. These chances will linger mainly in the mountains into Thursday.

Snow levels initially start off fairly high....generally 4500-6000 feet area wide. However, by Thursday morning, snow levels will decrease to 3000 to 3500 feet. This could cause some accumulation at pass level, but at this point it looks to be on the lighter side, but we will have to keep an eye on this as the week progresses. Liquid equivalent QPF is generally a few hundredths in the lower elevations to around 0.75 inches in the crests of the Cascades and Blue Mountains.

It will also be a bit breezy in the normally breezy locations, the Columbia Basin, foothills of the Blue Mountains and Cascade Gaps as the trough moves inland Wednesday and linger into Thursday. Wind gusts in the 25 to 35 mph range are expected. NBM probabilities of winds >=39 mph range from the 40s to the 60s across these areas. However NBM probabilities of winds >=47 mph are generally less than 30 percent.

High temperatures look to be at or above normal for most of the upcoming week.

For those sky watchers...late Monday night/early Tuesday morning...there will be a total lunar eclipse. You will have to either be a night owl or an early riser to see this one as the eclipse doesn't even begin until after midnight Pacific Time, with the partial eclipse beginning around 2 AM and the total eclipse beginning around 3 AM. However, sky conditions look ideal for eclipse viewing.

AVIATION /18Z TAFS THROUGH 18Z SATURDAY/

VFR conditions will prevail for all sites. Guidance depicts southwest sustained winds for KALW/KPSC and northwest winds for KDLS around 12-15kts later this morning through most of today. These sites may see winds gusting to 20kts or higher during that timeframe (20-40% probability). The remaining sites will have winds at 10kts or less. Feaster/97

Preliminary Point Temps/PoPs

PDT 32 52 33 52 / 0 0 10 10 ALW 35 52 35 52 / 0 0 10 10 PSC 30 53 32 55 / 0 0 0 0 YKM 29 52 31 54 / 0 0 0 0 HRI 31 53 33 54 / 0 0 10 10 ELN 30 49 29 50 / 0 0 0 0 RDM 27 56 33 52 / 0 10 20 20 LGD 32 56 35 56 / 0 0 20 20 GCD 31 56 35 55 / 0 20 30 40 DLS 34 53 36 55 / 0 0 10 10

PDT WATCHES/WARNINGS/ADVISORIES

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