textproduct: Pendleton

KEY MESSAGES

- Increasing clouds resulting in warmer overnight temperatures Tonight

- Near-normal temperatures and mostly dry conditions until a weak weather system arrives late Wednesday.

DISCUSSION

Visible satellite showed what little stratus was left after several hours of insolation was across parts of the Grande Ronde Valley. Farther southwest the split moisture windows showed arcing high level cloudiness from NW to SE moving inland in association with the more diffluent upper flow on the backside of this current upper ridge over Eastern Washington and Eastern Oregon.

Little to no weather risk is seen for the next few days. The Eastern Columbia River Gorge has not received its season ending freeze yet, and the chances are low at best with more cirrus overspreading the area Tonight and NBM minimum temperatures in the 25th to 75th percentiles falling in the 41 to 43 degree range, a high degree of confidence for no freeze Tonight. Clouds clearing the area Tuesday Night will leave slightly better setup for near freezing temps, but till the NBM QMD range is between 36 and 39 degrees from the NBM inputs.

Wind are generally light across the area, but the NBM is picking up on elevated/breezy sustained winds and gusts across the Grande Ronde Valley and the adjacent eastern mountains, Tonight, through the overnight and early Tuesday. Here, sustained south winds in the 20 mph area and gusts to around 30 mph should be common. Winds in this region will again pick up (breezy) toward Thursday night and through the weekend when the next weather system brings rain across the area. Probabilities of precipitation ramp up Wednesday Night across the Cascades Eastern Slopes with low pops over the lower elevations through Thursday morning (20-50 percent chances for measurable rainfall) . Lower confidence precipitation chances (20 to 30 percent) over the eastern Mountains and (30 to 70 percent) across the Washington Eastern Cascades slopes return Friday.

A cooler rainy period of the latter half of the week will maintain 40s to 50s in the mountains to mid and upper 50s in mountain valleys, central Oregon and the Columbia Basin. Drier conditions by the weekend point to NBM mean warming to the 60s across central Oregon and the John Day Basin.

AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/

Inherited TAFs have VFR conditions prevailing through the period. There is a 20% chance that fog will develop in the Columbia Basin tonight, leading to MVFR or lower conditions at sites ALW/PSC. Otherwise, winds will be light through the period. Lawhorn/82

Preliminary Point Temps/PoPs

PDT 36 50 30 54 / 0 10 0 0 ALW 39 50 34 53 / 0 0 0 0 PSC 38 54 31 56 / 0 10 0 0 YKM 39 57 31 56 / 0 10 0 0 HRI 38 52 30 55 / 0 10 0 0 ELN 34 52 28 53 / 0 10 0 0 RDM 31 51 23 57 / 0 0 0 0 LGD 37 56 31 58 / 0 0 0 0 GCD 36 58 31 58 / 0 0 0 0 DLS 41 58 35 58 / 10 10 0 0

PDT WATCHES/WARNINGS/ADVISORIES

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