textproduct: Pendleton

KEY MESSAGES

- Rain will continue across the Washington Cascades through Friday, before lessening or ending over the weekend.

- The rain will combine with melting snow to bring rising rivers across the area.

- Much warmer temperatures can be expected through Friday.

DISCUSSION

High pressure to the south will build over much of the region over the next several days. This high will bring generally dry weather and much warmer temperatures.

The only exception will be over the Washington Cascades, where rain will linger, from an atmospheric river. Due to the warming temperatures snow levels will rise to over 8000 feet, so only rain is expected. QPF amounts are over 2 inches along the Washington Cascade crest with some amounts locally close to 3 inches. These rainfall amounts coupled with the warming temperatures will cause a rise in rivers fed by the Cascades, namely the Naches and Yakima Rivers. At this time, only the Naches River at Naches is expected to make it to flood stage, but we will watch this, as QPF amounts have trended higher. Elsewhere, across the area, the crest of the Oregon Cascades and Blue Mountains should receive around 0.25 inches. The lower elevations should be dry or receive only a hundredth or two.

The other story through Friday is the much above normal temperatures. Highs will make it into the low to mid 70s Thursday and Friday for places like central Oregon, the Columbia Basin, and Foothills of the Blue Mountains. This will be 15 to as much as 20 degrees above normal. The ECMWF EFI is keying in on these anomalies beginning today across central and southern Oregon and spreading north, with anomalies as high as 1.0. Lows are also warm, with many areas only dropping into the 40s, and by Thursday night, the Columbia Basin and Foothills of the Blue Mountains may stay in the 50s.

By Saturday, the high pressure moves eastward and the flow becomes more zonal across the Pacific Northwest. This will cause temperatures to cool back closer to normal over the area.

AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/

VFR conditions are expected through the TAF period. Winds will mainly be 10 kts or less though there could be some afternoon wind gusts to around 20 kts at BDN, RDM and PSC that will decrease by evening.

Preliminary Point Temps/PoPs

PDT 69 43 71 47 / 10 10 0 0 ALW 66 48 70 52 / 20 20 0 10 PSC 69 47 72 49 / 10 10 0 0 YKM 67 44 69 47 / 20 20 10 10 HRI 69 43 72 47 / 10 10 0 0 ELN 58 42 61 43 / 40 40 30 20 RDM 73 38 76 40 / 0 0 0 0 LGD 68 43 74 46 / 10 10 0 0 GCD 70 43 74 45 / 0 0 0 0 DLS 66 44 69 46 / 20 10 10 10

PDT WATCHES/WARNINGS/ADVISORIES

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