Area Forecast Discussion
Issued by NWS Pendleton, OR
Issued by NWS Pendleton, OR
213 FXUS66 KPDT 270558 AFDPDT Area Forecast Discussion National Weather Service Pendleton OR 958 PM PST Wed Nov 26 2025 .Updated Aviation Discussion. .AVIATION...06Z TAFS...Variable conditions across sites, with VFR at KRDM/KBDN, MVFR at KDLS/KYKM/KPSC, and LIFR at KPDT/KALW due to reduced ceilings of .5kft and visibilities of 1/4SM respectively. These LIFR conditions are expected to persist through the majority of the period as a system passes through the region. KYKM is also forecast to reach IFR conditions in the early morning hours due to ceilings of .7-.9kft, which will extend through Thursday evening. Winds will stay light and below 10 kts, with the exception of KRDM/KBDN which will experience sustained winds of 10-12 kts and gusts of 20-22 kts late Thursday morning through the afternoon associated with the frontal passage. Light rain will also impact all sites by late morning and again toward the end of the period. The only terminals to stay dry will be KRDM/KBDN. 75 && .PREV DISCUSSION... /issued 235 PM PST Wed Nov 26 2025/ DISCUSSION...Today through Friday: Satellite and radar imagery show a warm front boundary across the northern tier of OR this afternoon, with light rain being observed from the Gorge south to Madras, as well as across the OR Cascade crest. The warm front boundary will gradually continue to lift north and east through tonight, with light rain and high mountain snow developing behind the boundary. In addition to rain/snow, smaller valleys along the WA Cascade east slopes may see very light freezing rain develop this evening and tonight as the warmer airmass initially extends over these areas. Thanksgiving day, a cold front then an associated vertically stacked low pressure system will swing into the PacNW, bringing with it a round of light rain and mostly a rain/snow mix above 5kft in the mountains (mainly snow above 6-6.5kft). The low will exit the region by Friday afternoon, with drying conditions setting up as remnants of a ridge slide southeast across the region late Friday. Snow accumulations through Friday will be very light at pass level, with the chances of 1 inch of snowfall less than 10% at Snoqualmie and Santiam passes, ~15% over the northern Blues, and only a 30% at White pass. Saturday through Sunday: Ensemble cluster solutions are in good agreement that a shortwave trough will dive down the backside of ridging in the northeast Pacific on Saturday, but that`s about where the agreement ends. Ensemble cluster members (ECMWF, GFS, Canadian ensemble suites) are in disagreement in whether the trough arrives to the region Saturday morning or Saturday evening, and whether there will be widespread light snow, or the light snow will be limited to central OR and the Blue Mountain foothills. As to how light the snow may be in the lower elevations, the NBM is only showing a 10-25% chance of 0.1 inches of snow across the Blue Mountain foothills, central OR, Kittitas valley, and ridges around Yakima valley. Meanwhile, chances in the mountain zones only reach 50% through Sunday morning. Overall, confidence is moderate (45-65%) that precipitation will remain light as this system impacts the forecast area, however, confidence precip type and timing is low (15-30%) given the timing differences amongst ensemble solutions, and deterministic guidance for that matter. By Sunday afternoon, there is good consensus that dry, cold conditions will return to the forecast area as the shortwave trough exits to the southeast and ridging offshore places the region under a northerly flow aloft. Dry conditions under the northerly flow will continue into Monday, with Sunday night low temperatures in the mid 20s in the lower elevations (confidence 35-60%). Monday through Tuesday: Good agreement amongst ensemble solutions continues into early next week, as ensemble model guidance depicts the upper ridge offshore flattening as a trough swings up and over into the PacNW (confidence 40-55%). This system will bring another round of light snow to the mountains(confidence 30-50%), though confidence is low (15-20%) in whether the lower elevations will see any of precipitation with this system. Lawhorn/82 && .PRELIMINARY POINT TEMPS/POPS... PDT 34 49 37 46 / 60 40 70 70 ALW 37 49 38 44 / 60 60 90 80 PSC 35 46 36 49 / 60 60 80 50 YKM 36 44 36 50 / 70 80 80 20 HRI 36 47 37 48 / 60 40 70 60 ELN 32 42 32 46 / 60 90 90 20 RDM 27 58 31 51 / 0 10 20 10 LGD 35 49 35 44 / 60 20 70 80 GCD 33 55 34 46 / 20 10 30 50 DLS 41 49 42 52 / 70 80 90 60 && .PDT WATCHES/WARNINGS/ADVISORIES... OR...None. WA...None. && $$ DISCUSSION...82 AVIATION...75