textproduct: Pendleton

KEY MESSAGES

- Lingering precipitation in the Washington Cascades will lead to increased snow melt

- Warming trend through the week

- Continued Hydro concerns

DISCUSSION

There is lingering precipitation in the Washington Cascades early this morning. Temperatures are warming and any snow/freezing rain chances are ending. Therefore, the winter weather advisory was cancelled early. Precip chances will continue through the morning hours before decreasing/ending in the afternoon.

However, another weak system will bring a renewed shot of moisture late tonight. Snow levels will be much higher, generally above 6000 feet and climb even further during Tuesday. So all that is expected with this next system is rain.

Over the course of the week, the Washington Cascade crest will receive decent rain...over an inch and some local amounts over 2 inches, nearby areas will receive between 0.25 and 0.50 inches. The Oregon Cascade Crest and Blue Mountains will generally receive less than 0.25 inches.

High pressure will build in from the south and most of the area will be dry with a noticeable warming trend, especially Tuesday through Friday. During this time, high temperatures will be 15 to possibly 20 degrees above normal. Temperatures in the Columbia Basin, Blue Mountain Foothills, central Oregon and Yakima Valley will reach the low to mid 70s. NBM probabilities of high temperatures >=80 degrees range from 20-30 percent in most of the areas mentioned above to 70-90 percent in central Oregon during this period.

The combination of rain on snow in the Washington Cascades and warming temperatures will increase snow melt and cause rivers to rise. Current forecasts have the Naches River at Naches reaching minor flood stage late this week and several other points on the Naches and Yakima Rivers reaching Action Stage. Some are close to flood stage. If temperatures are warmer than forecast or precipitation is more than forecast, these river forecasts could be higher. If temperatures are cooler than forecast or rain less than forecast, these river forecasts could be lower. All eyes will be on hydro this week.

By Friday into Saturday, the high pressure will move eastward, and the flow will become more zonal. This will allow for temperatures to cool closer to normal by Saturday into Sunday, though the area remains fairly dry on westerly flow.

There will be gusty winds win the Cascade gaps today and some general breeziness in the normally breezy spots on Tuesday. Wind gusts of 25 to 35 mph in the Cascade gaps today, and on Tuesday wind gusts mainly 20 to 25 mph with some higher gusts.

AVIATION /12Z TAFS THROUGH 12Z TUESDAY/

VFR conditions and winds 10 kts or less are expected through the TAF period.

Preliminary Point Temps/PoPs

PDT 66 44 68 45 / 30 0 10 10 ALW 61 48 66 50 / 50 10 20 20 PSC 64 47 69 48 / 20 10 10 10 YKM 62 41 67 45 / 20 10 10 20 HRI 65 46 69 45 / 20 0 10 10 ELN 54 38 59 43 / 30 10 30 30 RDM 72 38 73 38 / 10 0 0 0 LGD 62 42 68 43 / 40 0 10 10 GCD 66 41 71 43 / 20 0 0 0 DLS 67 45 64 44 / 10 0 20 20

PDT WATCHES/WARNINGS/ADVISORIES

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