textproduct: Pendleton

KEY MESSAGES

- Mountain snow through Friday

- Light mountain snow, low elevation rain and increased winds over the weekend

- Active weather patter continues through midweek

DISCUSSION

Current satellite show low and mid level clouds forming across the eastern slopes of the Cascades and through portions of central OR. Radar shows not returns across much of the region. However, Bend and Redmond observations are currently reporting light snow. This will likely continue over the next few hours with up to 0.10 inches of additional snow accumulation (70-90%).

Models show the upper level low to be to the southwest of the region bringing in a slight southwest flow and light precipitation through the remainder of the day today. Mountains will continue to see light snow showers (80-90%) with accumulations nearing 0.10-0.30" for the WA Cascades, 0.20-0.50 for the Ochoco-John Day Highlands (60-80%) and 0.30-0.40" for the Northern Blues (70-90%)

As we move into Friday, models show the leading edge of a weak upper level ridge will make its way into the region bringing with it light precipitation mainly to the high peaks of the Cascades and a bit more precipitation caused by orographic lifting to the Northern Blues. With that, models as well as HREF raw ensembles show 70-90% probabilities of the Northern Blues, Meacham, Tollgate ans Bluewood seeing an additional 1-2" of snow Friday with the slopes of the Northern Blues seeing 0.2-0.3 inches. As for the Eagle Caps and the surrounding Wallowa Mountains, HREF raw ensembles have the ridgetops seeing 1-2" (70-90%) while portions of Walla Valley could see 0.20- 0.3" (30-50%). Lastly, Union County could see light snow of 0.10- 0.20" (60-80%).

With the incoming frontal system, both the NBM and HREF are picking up on an increase in winds across the foothills of the Southern and Northern Blues, through Union County and portions of central OR on Saturday morning. HREF raw ensembles show winds to kick up after 4 AM with 70-80% probabilities of the foothills of the Blues and isolated locations through central OR seeing winds nearing 20 mph sustained with gusts to 30 mph. After noon, NBM raw ensembles pick up on winds increasing through Union County with 80-90% probabilities of sustained winds nearing 30 mph with gusts to near 40 mph. Although models are not picking up on it, pattern recognition with southerly flow over the mountains into Wallowa, we expect winds to increase through the Valley.

Models show an active pattern to persist through the long term. This pattern will bring mountain snow and low elevation rain. Clusters show the main deviation with the models is in the timing and or location of the incoming systems. Regardless, all models show precipitation accompanying the next round of systems. (50-70% confidence) 90

AVIATION /00Z TAFS THROUGH 00Z SATURDAY/

MVFR or lower conditions forecast through the period. A weak upper level weather system will bring light snow or rain/snow chances across most sites through the period. The next round of light snow will impact sites RDM/BDN around 1Z. Otherwise, PROB30 groups for light snow or rain/snow have been included at sites PDT/ALW after 6Z, site PSC after 4Z, and site YKM at 00Z. Expect CIGs and vsby to deteriorate as light precipitation develops, especially with light snow impacts. Site DLS will remain dry with VFR conditions favored through the period. There is a low chance (<20%) that CIGs may drop to or below 1kft after 06Z. Winds will be light, 12kts or less, through the period. Lawhorn/82

Preliminary Point Temps/PoPs

PDT 25 41 25 47 / 40 10 0 10 ALW 27 40 27 47 / 50 30 0 10 PSC 25 45 26 48 / 20 0 0 10 YKM 22 40 25 41 / 20 10 10 30 HRI 26 44 25 48 / 40 0 0 10 ELN 17 35 22 38 / 20 10 10 40 RDM 17 40 22 43 / 10 0 10 20 LGD 22 38 24 41 / 60 30 0 10 GCD 21 37 22 42 / 60 0 0 20 DLS 28 45 30 44 / 10 10 10 60

PDT WATCHES/WARNINGS/ADVISORIES

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