728 FXUS66 KPDT 282225 AFDPDT Area Forecast Discussion National Weather Service Pendleton OR 225 PM PST Sat Feb 28 2026 .KEY MESSAGES... - Light rain and high mountain snow across central and eastern portions of Oregon through Monday morning. - Widespread precipitation chances return Tuesday into Wednesday, with persistent light to moderate snow in the mountains through the end of the week. - Potential for breezy to gusty winds (gusts 35-50 mph) developing Wednesday. && .DISCUSSION...Satellite imagery this afternoon shows an offshore upper low spinning mostly high clouds across OR and southern WA. Meanwhile, regional radar shows showers have developed across southwest OR and are slowly spreading northward. At this time, however, shower activity remains south of Deschutes county. Tonight through Monday Morning: Shower chances will increase across portions of central OR, John Day Basin, and the Ochoco- John Day Highlands through tomorrow as the upper low offshore continues to push east. The best chances for light rain in the lower elevation areas (Central OR and John Day Basin) will develop just before the upper low moves into northern CA Sunday afternoon and evening. By late Monday morning, precipitation chances will taper off across the affected areas as the low transitions into a trough over the CA/NV border. Snow levels will remain above 6.5kft to 7kft during a majority of the lows transit through the region, owing to the low remaining to the south of as well as directing a mild southerly flow into the forecast area. This will result in very low snow totals across mountain areas (Or Cascade peaks, Mt Bachelor, Paulina peak, Strawberry Range), with snow amounts by Monday morning totaling at best 1 to 3 inches (confidence 70-85%). Otherwise, rain showers across the remainder of the southern portions of the forecast area will result in rain amounts of around 0.1 to 0.2 inches through Monday morning. Monday through Tuesday Morning: A transient upper ridge will move over the PacNW during this period, resulting in a return of area-wide dry conditions. Some warm air advection with the upper ridge will bring temperatures closer to the lower to mid 60s across much of the Columbia Basin Monday and Tuesday afternoons. Otherwise, sky cover will begin to increase late Monday night into Tuesday morning from the west, as the next upper level trough approaches the PacNW. This may limit viewing potential for the lunar eclipse Tuesday morning, with cloud cover expected to cover the western third of the forecast area by the time of the eclipse totality (3am-4am PST). The only saving grace with the incoming cloud cover is that it may start off as a thinner or scattered cirrus deck (confidence 30-60%). Tuesday through Friday: There is great agreement amongst ensemble and deterministic guidance that an upper trough passage Tuesday evening through Wednesday night will bring widespread precipitation chances to the PacNW. Snow levels will start off above 5kft with the approach of the trough, but drop to 4kft to 5kft as the trough moves inland Tuesday night into Wednesday morning. The heaviest of the precipitation will align with snow levels just falling to or below the surface along the Cascade crest Tuesday night, resulting in wet snow accumulations of 2 to 4 inches by the end of Wednesday morning(confidence 60-70%). Through the rest of Wednesday, snow levels will continue to lower to 3kft to 4kft, resulting in more widespread snow in the mountains, though snow rates will become very light as the trough axis passes east of the forecast area. Below the mountains, most lower elevation locations will see at least a chance (35-50%) of light rain (~0.05 inches or higher) develop as the trough axis and an attendant cold front sweep through the area. Heaviest rain amounts will be along the northern Blue mountain foothills, where there is a 50-80% chance of accumulations greater than 0.15 inches through Thursday morning. Otherwise, ensemble guidance is depicting breezy winds (gusts 35-50mph) developing with the aforementioned cold front passage Wednesday (confidence 60-70%), with strongest winds along the Cascade peaks/ridges and ridges in the Columbia Basin. Thursday into Friday, there remains good agreement amongst ensemble guidance that an active northwest flow aloft will result in persistent light snow and rain/snow chances along the Cascade crest/east slopes, Northern Blue mountains, and Eagle Caps. Around half of the ensemble cluster members (ECMWF, GFS, and Canadian) also depict light rain along the Blue mountain foothills and central OR Thursday afternoon, and ~60% of members keeping the lower elevations dry Friday. Otherwise, locally breezy west winds (25-40mph) will redevelop during the day Thursday and Friday (confidence 35-60%). Lawhorn/82 && .AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...VFR conditions to prevail through the period. A system approaching the region to the south will bring CIGs down to AOA 5kft to 7kft AGL at sites RDM/BDN later this afternoon through tonight. A prob30 chance of light rain showers were included at site BDN for late this afternoon into the evening. As the offshore system approaches tomorrow morning, rain shower chances will increase at sites RDM/BDN after 19Z. Winds will be light, less than 12kts, through the period. Lawhorn/82 && .Preliminary Point Temps/PoPs... PDT 35 53 37 57 / 0 10 20 10 ALW 36 53 37 57 / 0 10 10 10 PSC 33 56 35 60 / 0 0 10 0 YKM 32 55 32 59 / 0 0 0 0 HRI 35 55 35 60 / 0 10 10 10 ELN 30 51 31 55 / 0 0 0 0 RDM 33 52 36 56 / 20 50 50 10 LGD 37 56 39 57 / 10 30 40 30 GCD 38 55 41 54 / 20 60 70 40 DLS 38 56 39 61 / 0 10 20 10 && .PDT WATCHES/WARNINGS/ADVISORIES... WA...None. OR...None. && $$ DISCUSSION...82 AVIATION...82