Marine Weather and Tide Forecast for Klickitat, WA

FXUS66 KPDT 291745 AFDPDT

Area Forecast Discussion National Weather Service Pendleton OR 945 AM PST Sat Nov 29 2025

UPDATED AVIATION
18Z TAFs
RDM/BDN/PSC are all LIFR due to very low CIGs . This will persist over the next few hours before steadily lifting through the day before degrading again later in the period as the shortwave moves over the area. DLS/PDT/YKM/PSC are all VFR for now before all but YKM will see lowering CIGs and VSBY as the snow showers move across the sites. PDT/ALW will see a rain/snow mix around 03Z and lasting through 07Z while PSC/DLS have a 30% probability of also seeing a rain/snow mix during the same timeframe. The only site not plagued with FG/low CIGs and low VSBY is YKM which will remain VFR through the period. CIGs and VSBY will affect the remaining TAF sites through the entirety of the period. Low confidence on the timing (30%) when CIGs and VSBY will lift and then degrade will be the challenge through the period as well. 90

PREV DISCUSSION... /issued 329 AM PST Sat Nov 29 2025/

DISCUSSION...Dry conditions are present region-wide this morning as the forecast area is under a dry northwesterly flow aloft. 00Z and 06Z soundings from SLE, UIL, MFR, and OTX all show a bone dry layer aloft, ranging in altitude from approximately as low as 800 hPa to as high as 500 hPa. This dry layer has shown up on high- elevation, ridgetop surface observations (RAWS and CWOP) to the tune of dew points in the -15 to -30 degrees Fahrenheit range.
It's a different story in the lower levels with nighttime microphysics RGB imagery showing fairly widespread low stratus peaking out beneath scattered to broken cirrus. At the surface, some patchy dense fog has persisted in portions of central Oregon, most notably south and east of the Bend metro along US 97 and US 26.

Looking ahead, ensemble guidance shows a persistent northwesterly flow aloft through the middle of the week, with a couple embedded shortwaves passing overhead. This pattern favors near- to below- normal temperatures, and some upslope snow with each passing shortwave.

The first of the aforementioned shortwaves will arrive later this afternoon, passing over the Pacific Northwest overnight into early Sunday morning. The cool air mass coupled with the timing of the shortwave favor a light wintry mix for the forecast area, though ensemble-mean PWATS in HRRR, REFS, and global ensembles all suggest a relatively moisture-starved system which should hinder efficient precipitation production. Recall that dry layer aloft on observed soundings? There is still a decent bit of ensemble spread among the HRRR and REFS with regard to how well that layer will saturate through the late afternoon and evening. Moreover, ensemble-mean QPF has trended downward in successive runs the past 24 hours, so thinking precipitation with this system will be limited. That said, snow levels are forecast to dip down to 1000-1500 ft MSL so a dusting to an inch of snow across the Blue Mountain foothills, central and north-central Oregon, and the basins within the Blue Mountains is still a distinct possibility.
NBM guidance generally paints low (less than 20 percent) chances of measurable snow in the Columbia Basin/Gorge, low-medium (10-50 percent) chances for the Blue Mountain foothills and central/north-central Oregon, and medium-high (50-90 percent)
chances for the Grande Ronde Valley and Blue Mountains region.

Dry conditions are expected to return by late Sunday morning, lasting into or through Monday. The second shortwave is then advertised for late Monday through Tuesday afternoon or night, with some notable ensemble spread in timing. Snow chances are reduced across the lower elevations with this system, but a better moisture tap should facilitate better chances of advisory- level snow for the Blue Mountains.

By the end of the week, ensemble solutions begin to diverge with regard to pattern details, but in general a transition to a more zonal upper-level pattern is present among all ensemble clusters.
As far as tangible weather, this would result in warmer, wetter, breezier conditions.
Show more