textproduct: Pendleton

KEY MESSAGES

- Morning showers in eastern portions of the Columbia Basin

- Below-normal temperatures, breezy to locally windy west winds, and occasional light mountain showers through the week

DISCUSSION

Deep northerly flow is seen in the satellite data overnight as the area ins on the backside of the upper low now lifting across northern Montana and with SPC analysis indicating some weak moisture transport across eastern Washington with mid level clouds and light rains overspreading much of this area. Gradient induced wind gusts continue between about 25 an 35 mph across the Columbia Basin overnight and are forecast to continue the pattern through the day. Winds across the Kittitas valley look to have a weakening trend in the afternoon based on probabilities of gusts to 40 mph at 7 AM around 80% but falling to around 30% by 2 PM before up ticking in the evening to around 50%. A similar trend can be expected across the Eastern Columbia River Gorge, and the Foothills of the Blue Mountains/Oregon Columbia Basin Today and This Evening. Mid level clouds and showers will linger across southeast WA and the Oregon Blue Mountains/Wallowas though about mid afternoon while breaks of direct insolation will be found farther west and afternoon high climb back into the 80s for sections of the Lower Columbia Basin/Yakima Valley. Although weak synoptic troughing lingers across the region into Tuesday, the wind will be much lighter on Tuesday, and the character of the day drier and warmer. Winds may still be noticeably breezy to windy across the Eastern Columbia River Gorge and Kittitas Valley but more tied to locally terrain than a widespread wind episode.

Toward the end of the week, enough similarity exists between the ensembles clusters to bring fairly high confidence in any precipitation over the July 4th Holiday weekend would be relegated to the higher terrain/mountain zones an light (only a few hundredths of an inch over a 24 hour period). Additionally these clusters show little in the way of MUCAPEs, which would point to showers rather than risk of anything more than isolated thunderstorms.

AVIATION /12Z TAFS THROUGH 12Z TUESDAY/

Light rains or drizzle is being reported by some METARs form ALW to PSC and Sunnyside, and may show up at PDT over the 11 to 13z window, having little if any impact on the VFR category cigs or visibility (about 6000 ft or higher and still 10 SM). Duration is uncertain as the HRRR keeps light showers across SE WA and NE OR through early afternoon but terminals at ALW/PDT/PSC should expect VCSH though 18z. Other than these morning light showers, the breezy to gusty westerly winds will weaken in the afternoon, and undergo more significant weakening after about 6z.

FIRE WEATHER

Breezy conditions Today could impact any fire ongoing. The breezy conditions will begin to wane this afternoon leaving Tuesday with much lighter winds across the greater area. Tuesday can still see some locally breezy to gusty conditions across the Eastern Columbia River Gorge and Kittitas Valley. The cooler conditions Today will continue to mitigate the overall impact of relative humidity (keeping it elevated). An isolated thunderstorm cannot be ruled out over eastern Wallowa county Tuesday afternoon (less than 20% chance). No thunderstorm/lightning risk is anticipated for the rest of This Week.

Preliminary Point Temps/PoPs

PDT 75 52 76 45 / 40 10 0 0 ALW 76 57 77 51 / 80 10 10 0 PSC 81 58 82 51 / 50 10 0 0 YKM 83 56 83 50 / 20 10 0 0 HRI 79 56 79 49 / 30 10 0 0 ELN 75 53 74 46 / 10 0 0 0 RDM 72 41 74 34 / 0 10 0 0 LGD 70 50 75 43 / 80 10 10 0 GCD 72 48 77 39 / 20 10 0 0 DLS 73 56 72 51 / 0 0 0 0

PDT WATCHES/WARNINGS/ADVISORIES

WA...Wind Advisory until 7 AM PDT this morning for WAZ026. OR...None.