textproduct: Pendleton

UPDATE

Added dense fog advisories over central and north central Oregon zones as area roadcams show dense fog in addition to RDM and BDN having visibility reduced to 1/4sm and M1/4SM over the last hour or two. Advisories in effect until 18z leveraging best LAV guidance.

PREV DISCUSSION

/issued 412 AM PST Thu Dec 25 2025/

DISCUSSION...

An offshore low is providing southwesterly winds and weak moisture transport across the region. This low is forecast to move onshore Tonight wile filling and becoming absorbed by a sharp upper trough along the PAC NW Coast by midday Friday. Some of the most impactful weather will be the potential for mountain pass level snow, that while is ongoing in light amounts, will see accumulations ramping up beginning around Friday morning and persisting through at least Saturday. NBM/WPC snow accums suggest high level advisory criteria for that day and a half period as accums begin to push past one inch per hour rates Friday morning with RRFS snow ensembles plumes indicating occasional higher potential than one inch per hour rates. Still with the NBM pops drying up on Saturday, we have limited the time frame for a new winter weather advisory, starting around 12z Friday through about mid morning Saturday. Winter Storm Severity Index pegs these areas as high confidence, (70-90%) for minor impacts including winter driving conditions. Once this system slides east of the region this weekend, a large 588DM anticyclone develops over the eastern Pacific which builds a ridge into western North America for about the first half of nest week.

AVIATION...

An offshore low is providing southwesterly winds and weak moisture transport across the region. One band of showers is now lifting north across north central Oregon and DLS, while another is off SW Oregon for later Today and Tonight. HREF is showing decent probabilities (50 to 60%) for IFR to LIFR category Ceilings or vsbys at PSC this morning which is reflected with 300 to 700 ft ceilings though around 17z. On and off showers will bring brief MVFR ceilings for the duration of the TAF period.

PRELIMINARY POINT TEMPS/POPS

PDT 53 35 49 31 / 40 40 70 60 ALW 52 37 49 32 / 50 50 80 70 PSC 47 32 48 31 / 40 40 60 30 YKM 43 30 44 25 / 50 30 40 20 HRI 48 33 49 31 / 30 40 60 40 ELN 38 26 38 24 / 70 40 50 40 RDM 51 28 46 24 / 10 40 50 30 LGD 50 35 44 28 / 50 40 90 80 GCD 50 35 43 28 / 40 60 80 70 DLS 46 36 46 36 / 60 50 70 70

PDT WATCHES/WARNINGS/ADVISORIES

OR...Winter Weather Advisory from 4 AM Friday to 7 AM PST Saturday for ORZ502-509.

Dense Fog Advisory until 10 AM PST this morning for ORZ510-511.

WA...Winter Weather Advisory from 4 AM Friday to 7 AM PST Saturday for WAZ030-522.