textproduct: Pendleton

AVIATION

06Z TAFS...Except for BDN and RDM and possibly PSC conditions are expected to be MVFR or IFR during much of the TAF period due to low clouds, fog and or rain. Winds will mainly be 10 kts or less, but due to some stronger winds aloft, LLWS is possible at PDT, RDM, BDN, PSC through the overnight hours.

PREV DISCUSSION

/issued 258 PM PST Sat Jan 3 2026/

DISCUSSION...Latest visible satellite imagery depicts a trough centered just off the coast of the PacNW. This trough will instill SW flow aloft through the region, making for intermittent showers and breezy winds through central Oregon and the base of the Blue Mountains. Snow concerns will be limited until the midweek, as warm air advection from this upper-level flow pattern will keep snow levels generally elevated at above 5000 ft. This system also lacks the moisture punch needed to bring precipitation to the lowlands, so wind will be the primary sensible weather concern outside of the mountains through the weekend.

While some hi-res guidance depicts a bullseye across the base of the southern Blue Mountains for particularly gusty winds (isolated spots of 40-60% wind gusts exceeding 45 mph, according the the NBM), opted not to issue any wind advisories as impacts aren't expected to be widespread and long-lasting enough to justify headlines. May need to re-assess this later tonight, when guidance has winds ramping up once again, but unless gusts start flirting with criteria along I-84 at the base of the Blues in particular, think it's better to hold off and play the 'wait and see' approach for now.

This broad trough eventually shifts inland during the day Sunday. Some of our higher mountain passes (namely Santiam) may see light accumulating snow during the early morning hours, but otherwise precip is expected to taper off throughout the day Sunday, with Monday looking dry as drier, more northerly air filters in. Tuesday onward becomes more active, however, as global models depict a return to a progressive westerly pattern that will support persistent showers across our mountain zones. With colder air coming in, snow levels are expected to drop down to the 1500-3000 ft range, allowing for our mountain passes to receive a steady dose of snow through much of the rest of the work week. Rain-shadowing looks to be strong enough to preclude any decent precip chances for the lowlands (confidence 30-40%), but headline-worthy snow looks very likely (80-90% confidence) across both the Cascades and eastern mountains starting around Tuesday. 74

AVIATION...With this next system arriving, KDLS/KYKM will continue having low clouds through Sunday morning, making them MVFR. However, KYKM may become IFR this evening into overnight hours. The remaining sites will be VFR, but KPSC could drop to LIFR around 05Z due to lingering low clouds. Light rain will develop over KDLS/KRDM/KBDN/KYKM during evening hours as this system passes through (30-40% chance). KPDT/KRDM/KBDN/KPSC may have breezy sustained winds of 12-20kts with gusts at 20-30kts for these evening hours. However, these gusts may return Sunday morning hours up to 25 kts (<40% chance). Thanks to the south-southwesterly wind aloft, low- level wind shear could continue with winds at 30-55kts. Feaster/97

PRELIMINARY POINT TEMPS/POPS

PDT 41 53 34 47 / 40 40 30 20 ALW 43 52 36 46 / 60 60 50 30 PSC 35 52 34 48 / 50 40 20 10 YKM 33 48 29 45 / 80 40 20 0 HRI 36 52 33 48 / 50 30 20 10 ELN 31 40 26 38 / 80 50 30 10 RDM 36 48 27 43 / 40 30 20 10 LGD 40 48 34 43 / 40 60 40 40 GCD 41 48 33 42 / 30 50 40 30 DLS 38 48 35 45 / 90 70 60 20

PDT WATCHES/WARNINGS/ADVISORIES

OR...None. WA...Dense Fog Advisory until 10 AM PST Sunday for WAZ029.