textproduct: Pendleton

KEY MESSAGES

- Ongoing rain across the region through the afternoon.

- Gusty winds through the afternoon hours.

- Generally dry with below normal temperatures for most of the week.

DISCUSSION

An area of low pressure was moving northeastward across the region and by tonight will be in southern Canada. Dry northwesterly flow will move in behind the departing low.

Latest radar showed rain, mainly across Washington, at this time. Some of the guidance suggests there could be a lull in the rain through the morning hours across portions of the area, especially the Columbia Basin, before the return flow precipitation this afternoon. There is also a low (<20 percent) chance of a thunderstorm this afternoon, mainly in Wallowa County. By late afternoon, rain will begin to wind down and be over completely during the night. Central Oregon should receive the be mostly dry, though there will be some rain mainly in the morning.

Winds will be gusty especially across the Columbia Basin, Gorge, Simcoe Highlands and Foothills of the Northern Blue Mountains. Winds are expected to gust in the 25 to 30 mph range, with some areas gusting as high as 35 mph. NBM probabilities of wind gusts >= 25 mph are greater than 90%. NBM probabilities of wind gusts >=39 mph are 30-40 percent.

QPF values today range from 1.00 inches plus in the Washington Cascades and surrounding locations, to around 0.75 inches along the crest of the Blue Mountains to around 0.25 inches in most lower elevation areas to less than 0.10 inches across central Oregon and elsewhere. The ECMWF EFI shows a broad area of 80th to 90th percentile for QPF across a large swath of eastern Washington. Within that is an area of 90th to 95th percentile for QPF across the Washington Columbia Basin and Yakima Valley heading up towards the Cascades and within that is an area of 95th to 99th percentile. Shift of tails is 1 to 2.

Another upper low will drop down from Canada later Tuesday into Wednesday and could trigger some showers over the mountains.

High pressure will then build in behind the departing low.

High temperatures will struggle in the lower 60s today. This is 15 to 20 degrees below normal. Highs will rebound into the 70s Monday through Wednesday. These temperatures will be about 5 to 10 degrees below normal. By Thursday and Friday, temperatures will return to close to normal.

AVIATION /12Z TAFS THROUGH 12Z MONDAY/

Mainly VFR conditions are being forecast for the TAF sites. However, if moderate to heavy rain moves across an area than MVFR, or even IFR is possible. The most likely location for MVFR or lower would be YKM, where some MVFR conditions are included this morning. While no rain is forecast at BDN and RDM, RA should end at all sites by late afternoon, early evening, with improving conditions.

Winds are expected to gust in the 20 to 25 kt range at most sites except YKM and 15 to 20 kts at BDN and RDM.

Preliminary Point Temps/PoPs

PDT 62 44 69 45 / 60 50 0 0 ALW 62 49 70 49 / 70 70 0 0 PSC 63 45 73 44 / 60 40 0 0 YKM 61 44 68 46 / 90 10 0 0 HRI 64 44 72 42 / 60 40 0 0 ELN 57 41 66 42 / 100 20 0 0 RDM 61 33 70 36 / 10 10 0 0 LGD 61 42 70 41 / 60 70 0 0 GCD 61 40 70 41 / 40 20 0 0 DLS 65 50 74 49 / 50 10 0 0

PDT WATCHES/WARNINGS/ADVISORIES

WA...Flash Flood Watch through this evening for WAZ030. OR...Flash Flood Watch through this evening for ORZ502.