textproduct: Pendleton

UPDATE

After collaboration with surrounding offices, have opted to issue Winter Weather Advisories for the east slopes of the Oregon and Washington Cascades, Simcoe Highlands, and north- central Oregon, valid tonight through Saturday afternoon (north-central Oregon) or evening (Cascades and Simcoe Highlands). Notably, the advisories for the east slopes of the Washington Cascades are only valid for areas south of White Pass, so do not include White and Snoqualmie passes. Additionally, despite the short lead time, ensemble NWP guidance continues to display a decent spread of solutions with regard to the magnitude and eastward extent of precipitation overnight and Saturday. This does lower confidence in the deterministic forecast, and thinking snowfall totals will be on the lower end for advisories, if not a little below our official thresholds.

Otherwise, breezy southeast winds have already developed along the slopes of the northern Blue Mountains, and through the Grande Ronde Valley. Confidence wasn't high enough to issue a Wind Advisory for the foothills of the northern Blue Mountains of Oregon for the overnight period, but have left the one for the Grande Ronde Valley in effect. 86

KEY MESSAGES

- Winter Weather Advisories in effect tonight through Saturday for the Cascades and portions of north-central Oregon and south-central Washington.

- Warming with breezy to windy conditions.

- Active weather pattern continues through midweek.

DISCUSSION

Issued 246 PM PST Fri Feb 20 2026 Current satellite shows clouds beginning to move overhead with some areas already seeing overcast skies. Radar shows no returns with ground observations showing dry conditions beneath the cloud decks. Temperatures are still on the cooler side with the north-northwest flow aloft continuing to being in cooler air. Temperatures will be in the upper 30s to low 40s for much of the region today.

Models show a surface weak warm front will make its way across the region from the south east moving to the northwest. With the winds being from the south and southeast, winds will be downsloping through the Blue bringing warmer temperatures across the eastern portion of the Basin with 50-80% of the NBM raw ensembles in agreement that the foothills of the Blues of OR and the eastern portions of the Basin will see temperatures in the low to mid 50s Sunday. This warm front will also bring an increase in winds through the Grande Ronde Valley tomorrow. In house pressure gradient models as well as deterministic models show that there will be a tightening of the pressure gradients of near 5 mb over the Grande Ronde Valley. This has lead to a wind advisory being issued from 4 AM through 10 PM Saturday for south to southeast winds between 30-35 mph and gusts nearing 45 mph with confidence is 60-90% these winds will materialize. Models then show the gradients to tighten even farther Sunday and have moved a bit farther northwest over the area which has lead to an High Wind Watch being issued for the Grande Ronde Valley and the foothills of the northern Blues of OR Saturday evening through Sunday evening with south to southeast sustained winds peaking between 40-45 mph and gusts to near 60 mph with again confidence 60-90% these high winds will materialize.

Even with the weak ridge moving in over the weekend, models still show precipitation in the for of snow will continue to fall over primarily the Cascades with light accumulations along the eastern mountains as well as the northern Blues. 48-hour snowfall chances of 2 inches is 70-90% for the Cascades and 30-50% for 4 inches. As for the eastern mountains and the northern Blues, 50-70% chances of 0.50-1" is possible over the weekend.

Lastly, models are beginning to come into better alignment with the next incoming wave trough. Models show the system to drop down from the Gulf of Alaska and reach the PacNW by Sunday night into Monday. All models show this to be a wet system bringing in continued mountain snow with some low elevation rain through the week. Clusters show that the main variances is the timing/amplitude of the system as well as with precipitation amounts. Regardless, all models and ensembles are leading to a wet start to the week ahead with 50-70% confidence. 90

AVIATION /06Z TAFS THROUGH 06Z SUNDAY/

VFR conditions have been in place at all TAF sites except for YKM, where some lingering MVFR CIGs remain. By later tonight into Saturday morning, some light snow accompanied by MVFR CIGs and/or VSBYs is forecast at DLS/RDM/BDN. Saturday afternoon, snow is expected to arrive at YKM. Confidence is low (30 percent) in RASN extending as far east as PSC, and precipitation is unlikely (10 percent chance) at PDT/ALW.

Sustained winds of 10 kts or less are currently forecast, though BDN/RDM may (70 percent confidence) see periods of 10-15 kts with gusts of 15-25 kts Saturday afternoon. 86

Preliminary Point Temps/PoPs

PDT 27 46 33 56 / 0 10 10 20 ALW 29 46 35 54 / 0 10 10 30 PSC 27 45 30 53 / 0 20 20 30 YKM 26 38 28 45 / 10 60 50 60 HRI 27 45 30 55 / 0 20 10 20 ELN 23 35 28 41 / 10 60 50 70 RDM 25 44 30 52 / 20 40 10 30 LGD 25 41 33 49 / 0 10 10 20 GCD 23 41 31 49 / 0 20 10 10 DLS 32 41 33 47 / 30 80 50 80

PDT WATCHES/WARNINGS/ADVISORIES

WA...Winter Weather Advisory from 4 AM to 10 PM PST Saturday for WAZ521>523. OR...Wind Advisory from 4 AM to 10 PM PST Saturday for ORZ049. High Wind Watch from Saturday evening through Sunday evening for ORZ049-507. Winter Weather Advisory until 10 PM PST Saturday for ORZ509. Winter Weather Advisory from 4 AM to 4 PM PST Saturday for ORZ510.