FXUS66 KPDT 270510 AFDPDT Area Forecast Discussion National Weather Service Pendleton OR 1010 PM PDT Sun Oct 26 2025 .EVENING UPDATE...A convergence zone has established itself along Snoqualmie Pass this evening, in light of strong NW flow through the Cascades. While the lower elevations of the forecast area will dry out overnight as the mid-level winds become more zonal, pockets of heavy snow are expected to continue for the Cascades. The ongoing Winter Weather Advisory has been extended to 5 AM Monday as a result. Should note that impacts to Snoqualmie Pass are limited to right along the summit given the borderline temperatures, but road closures have been reported along I-90 due to slide-offs. Travel will be difficult through Santiam and White Passes as well. Confidence is not so high in advisory-level snow for the northern Blues, with ODOT road obs suggesting only 2 to 4 inches having fallen along Tollgate this evening, but will leave the current advisory in place as the synoptic pattern does favor at least light upslope snow showers through the overnight. Overall forecast messaging outside mountain snow remains the same, however. 74 .AVIATION...06z TAFs...VFR conditions are expected through the period. Low sct-bkn cigs will gradually clear out heading into Monday morning, leaving all sites with persistent westerly winds less than 15 kts. 74 && PREV DISCUSSION... /issued 333 PM PDT Sun Oct 26 2025/ DISCUSSION...Today through Tuesday: Based on current satellite and radar imagery, a frontal system is sweeping across the WA/OR Cascades, Foothills of the Northern Blues-OR and the Lower Columbia Basin with breezy winds and rain showers. Mountain snow will continue to linger this evening through tomorrow morning with snow accumulations up to 8 inches (>70% chance). The raw ensembles do favor a 40-50% probability for the Northern Blues of WA/OR reaching to 5 inches overnight. Additional snow may develop over the Cascades but, models have shown precip activity to be mostly wet along with relatively warming temperatures that would cause additional snow to not stick around. Therefore, we decided to not extend the Winter Weather Advisories and keep them in effect for the WA/OR Cascades and Northern Blues of WA/OR until tomorrow morning. But, the advisory had to pushed back to 3pm this afternoon for the Northern Blues of OR/WA due to a delayed onset for snowfall based on web cameras and earlier observations. This weather should begin to gradually cease around this evening with lingering rain and mountain snow as the troughing pattern starts leaving our forecast area. Tomorrow, we may have a break with the trough leaving the PacNW as an upper level ridge gradually builds over the PacNW Tuesday. The Upper Slopes of WA Cascades may have a slight chance of snow showers (<30% chance) along with the Northern Blues of WA/OR through tomorrow evening, though the remaining locations will be dry. Dry conditions will continue through Tuesday as well. However, a frontal system associated with a low over the BC coastline that might sweep along the Cascade gaps. Confidence is low on the impact (<20%). Gusty winds (25-35 mph) will continue through overnight and over the Cascade gaps and Foothills Blues of OR. Based on the NBM CONUS, there is a 30-50% probability for gusts up to 35 mph over the aforementioned areas. Tomorrow will have light to breezy conditions in the afternoon hours, though decreases later in the day. May see gusty winds (20-30 mph) return Tuesday evening hours across the eastern mountains (40-60% prob). Wednesday through Sunday: Through Thursday, dry conditions will persist with an upper-level ridge over the PacNW. A zonal pattern will arrive Friday onward with a frontal system returning an unsettled, wet pattern. Winds will remain light through Thursday but could become slightly breezy starting Friday into the weekend (30% confidence). Feaster/97 && .PRELIMINARY POINT TEMPS/POPS... PDT 36 54 32 58 / 70 10 0 0 ALW 38 53 35 55 / 90 10 0 10 PSC 36 57 31 54 / 40 10 0 0 YKM 29 55 30 50 / 20 0 10 20 HRI 36 57 31 55 / 40 10 0 0 ELN 28 51 26 47 / 40 10 10 20 RDM 24 51 26 63 / 30 0 0 0 LGD 31 49 26 53 / 90 20 0 0 GCD 28 49 28 57 / 80 0 0 0 DLS 39 57 38 55 / 50 20 10 20 && .PDT WATCHES/WARNINGS/ADVISORIES... OR...Winter Weather Advisory until 8 AM PDT Monday for ORZ502. Winter Weather Advisory until 5 AM PDT Monday for ORZ509. WA...Winter Weather Advisory until 8 AM PDT Monday for WAZ030. Winter Weather Advisory until 5 AM PDT Monday for WAZ522. && $$ SHORT TERM...74 LONG TERM....97 AVIATION...74