textproduct: Pendleton

KEY MESSAGES

- Unseasonably warm temperatures through Friday

- Cooler, more normal temperatures beyond Friday

- Continued rain over the Washington Cascades will keep rivers running high.

DISCUSSION

Visible satellite imagery showed a broken band of cloud cover spreading across Washington while indications of more middle layer moisture was evident with clouds developing off the Oregon Cascades and spreading into the Columbia basin. The moisture, associated with a stalled atmospheric river that will persist through at least Thursday. The Eastern Slopes of he Washington Cascade crests is forecast to receive about another 2 to 4 inches of rainfall, given very high snow levels from 8 to 9k ft AGL though this week. As a result, hydrologic impacts include within bank rises for most of the tributaries and main stems of Yakima and Naches with at least the NACW1 having a minor flood forecast by late Friday into Saturday. A flood watch has been hoisted for the reach of the Naches River at Naches.

Despite the presence of the atmospheric river (mostly Washington counties) is anomalously warm temperatures through Thursday with NBM forecasting expected highs in the 70s for all non mountain zones. Basin and river valleys, and even central Oregon can hit around 80. As of 1 pm Today, several ODOT obs in the John Day basin have hit 77-78 degrees, and 79 degrees was observed at the Bend and Madras airports. In fact, high confidence in temps around 80 for Thursday is supported by a 25th to 75th percentile NBM ens members of 80 to 82F. Little more uncertainty exists in areas like the Lower Columbia Basin where Hermistons similar stats are 75 to 81F.

Trends for winds uptick across the Simcoe Highlands and Yakima Valley (parts of Klickitat and Yakima counties) on Thursday afternoon followed by the frontal boundary late Friday that will no doubt bring in stronger westerly boundary layer momentum. NBM mean shows gusts averaging from 30 to 50 knots across the Simcoe Highlands. Russell/71

AVIATION /06Z TAFS THROUGH 06Z FRIDAY/

VFR conditions currently across all sites, which will stay the course through the period. Breezy winds are expected for KPSC/KDLS/KRDM/KBDN Thursday afternoon with gusts of 20-25kts. Elsewhere, winds will hover at or below 10kts. 75

FIRE WEATHER

Much warmer than normal temperatures as as well as dry conditions for this week continue over parts of central Oregon. Winds in the afternoon have the capability to gust between 20 and 30 mph, by the mean NBM values. This combination of strong winds, low relative humidity, and warm temperatures can contribute to fire spread. Expect a cold front to sweep across the Interior Northwest late Friday or Friday night, giving recover from low RH. Grasses that have not greened up will experience elevated fire weather risk. Any fire that develops can catch and spread quickly. Outdoor burning is not recommended each afternoon This Week over central Oregon into the John Day/Ochoco Highlands. Russell/71

Preliminary Point Temps/PoPs

PDT 47 73 50 75 / 0 10 0 0 ALW 52 73 55 74 / 0 10 10 10 PSC 51 74 53 75 / 10 10 0 0 YKM 46 71 49 69 / 10 10 10 30 HRI 48 73 51 75 / 0 10 0 0 ELN 43 62 45 60 / 20 20 30 50 RDM 40 75 44 76 / 0 0 0 0 LGD 46 74 48 76 / 0 0 0 0 GCD 43 75 47 76 / 0 0 0 0 DLS 48 72 51 68 / 0 10 10 30

PDT WATCHES/WARNINGS/ADVISORIES

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