textproduct: Pendleton

KEY MESSAGES

1. Lingering mountain showers Thursday

2. Drier and cooler temperatures begin Thursday

3. Potential freeze Saturday morning

DISCUSSION

Current radar shows no returns across the region this morning. Ground observations from yesterday show plenty of rainfall occurred across the region with some of the highest amounts occurring along the foothills. Pendleton measured 0.63 inches for the 24 hour period. A PNS statement was put out regarding the rainfall amounts. Winds are still breezy for a few areas like the Gorge, Pendleton, Yakima and Kittitas Valley with observations showing these areas having sustained winds of 20-25 mph and gusts near 40 mph. These will begin to taper off through the morning. The minor flooding for the Umatilla at Gibbon has begun to recede with the latest water height coming in at under 7 feet. This keeps the river in action stage but below minor. It is forecasted to continue to decrease dropping below action stage Friday morning.

Models show the upper level low to be off to the east of the region and northwest flow aloft to be over the region. Models then show that by mid-day another upper level low will clip the northeast portion of the CWA bringing mountain showers to the Northern Blues and across the Wallowas today with NBM showing amounts near 0.10 along the crests and 0.02 in the valley with 60-80% probabilities. Snow levels will still be below 45500 feet so some light snow accumulations at Tollgate and Ski Bluewood are likely with 30-50% probabilities of seeing 0.10-0.5 inches.

After Thursday, models show continued northwest flow with drier and cooler conditions. In house seasonal temperature comparisons show that temperatures will be anywhere form 10 to 20 degrees below seasonal average with this flow pattern. NBM shows temperatures to be in the mid 50s through the weekend with isolated locations in the Basin seeing low 60s with 50-70% confidence. By Monday, models show a slight warming trend.

With the incoming cooler temperatures from the cold air aloft and models showing the cold air mixing to the surface, NBM is showing minimum temperatures to be hedging towards freezing overnight temperatures. The coldest temperatures are expected to be Saturday morning with NBM showing temperatures across the vast majority of the region being at or below freezing. With that said, the potential for freezing on Saturday is moderate/high with 60-90% confidence. 90

AVIATION /12Z TAFS THROUGH 12Z FRIDAY/

Vfr conditions will persist through the forecast period. Winds are still affecting DLS/PDT/ALW with sustained winds of 15-25 kts and gusts between 20-30 kts. All other sites are seeing winds below 12 kts. Winds at DLS/PDT/ALW will steadily decrease through the period. 90

HYDROLOGY

Rivers are beginning to recede with Umatilla at Gibbon decreasing below minor flood stage this morning. Naches at Cliffdell and Naches remains at action as well as Umatilla at Pendleton. All rivers are expected to go below action stage at the earliest early Friday morning. 90

Preliminary Point Temps/PoPs

PDT 59 37 56 32 / 10 20 0 0 ALW 59 38 57 34 / 30 40 10 0 PSC 66 38 62 33 / 10 20 0 0 YKM 67 38 60 34 / 0 10 0 0 HRI 64 38 60 32 / 0 10 0 0 ELN 60 34 56 32 / 0 10 0 0 RDM 63 29 58 26 / 0 0 0 0 LGD 55 35 52 28 / 20 50 10 0 GCD 57 33 53 27 / 0 10 10 0 DLS 65 42 63 37 / 0 0 0 0

PDT WATCHES/WARNINGS/ADVISORIES

WA...Flood Watch through this evening for WAZ029. OR...Flood Watch through this evening for ORZ502-507-508.