Area Forecast Discussion
Issued by NWS Pendleton, OR
Issued by NWS Pendleton, OR
078 FXUS66 KPDT 262235 AFDPDT Area Forecast Discussion National Weather Service Pendleton OR 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 && .AVIATION...00z TAFs...Variable conditions continue as low cigs persist across PDT, PSC, ALW, DLS, and YKM. Only BDN and RDM remain VFR this afternoon, however that could change as another round of light rain makes its way through the forecast area tonight. Rain is expected to be light, but light winds combined with moisture will make conditions ideal for low clouds and fog to redevelop or persist heading into tomorrow morning. Another system is then expected to move through Thanksgiving morning, providing for another chance of light rain. Again, rain will be light, and is expected to cease by the late afternoon, however, conditions will still be favorable for MVFR cigs or worse. BDN and RDM, however, are largely expected to remain VFR through the period, especially with winds forecast to pick up tomorrow afternoon for both sites. Confidence is high (90-100%) in sites outside of RDM/BDN seeing at least MVFR conditions this period, with confidence moderate to high (50-60%) in low cigs / fog redeveloping overnight tonight into early tomorrow morning. 74 && .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. && $$ SHORT TERM...82 LONG TERM....99 AVIATION...74