FXUS66 KPDT 151147 AFDPDT Area Forecast Discussion National Weather Service Pendleton OR 447 AM PDT Wed Apr 15 2026 .KEY MESSAGES... - Mountain snow will persist through Thursday morning - Breezy conditions in the lower elevations through Thursday - Near to below freezing morning lows Thursday and Friday for the lower elevations && .DISCUSSION...Today through Thursday: Satellite and regional radar imagery show a cold front slowly pushing southeast across the PacNW this early morning, with snow showers along the Cascade crest and across the Blue mountains. The cold front has mostly stalled along the Cascade crest this morning, which has resulted in moderate snow showers impacting the Cascade passes. The cold front is expected to pass over the Cascade crest later this morning and continue to push southeast across the forecast area through this evening, while a closed low is expected to arrive to the region by this afternoon. The best chances for precipitation in the lower elevations will be associated with the frontal passage today, with many locations only seeing rain throughout the day. However, snow levels plummeting to around 2kft behind the frontal boundary and anticipated post-frontal showers will bring chances (30-40%) of light snow to portions of central OR this evening. By tonight, the upper low will move over the forecast area, cutting off precip chances in the lower elevations. AS for the mountains, moderate to locally heavy snow showers will continue to develop across the Cascade crest and the northern Blues through this evening, with snow tapering off late tonight into Thursday morning. Multiple winter weather headlines are in effect today through tonight and early Thursday morning in anticipation of impacts from the heavy mountain snow. There remains high confidence (85-90%) in snow accumulations totaling between 6-12 inches for the OR Cascade east slopes above 4000 feet, 4-8 inches for the upper east slopes of the WA Cascade east slopes, and 5-10 inches for the Northern Blues above 4500 feet. The heaviest snow accumulations are expected to occur with the cold front passage this morning, becoming light to locally moderate through the remainder of today. Breezy winds will continue to impact the region through Thursday as the cold front passage and continued cold air advection into the forecast area result in tightened pressure gradients. Confidence is moderate-high (60-85%) that westerly winds will remain between 15-30mph and gusts 25-45mph. That said, wind-prone areas in the Columbia Basin and Blue mountain foothills will see a 65-85% chance of gusts exceeding 45 mph today as the cold front boundary moves through the region. Otherwise, clearing skies, dry surface conditions, and cold air advection into the region will result in near to below freezing morning temperatures Thursday and Friday. Of particular concern are the Kittitas and Yakima valleys, where there is 80-90% chance of morning lows below freezing both days; the northern Blue mountain foothills of OR are also a concern where there is a 60-80% chance of below freezing lows, especially in areas prone to cold-pooling. Freeze warnings have been issued in these areas for Thursday morning, and will likely need to be reissued for Friday morning. Friday through Tuesday: Ensemble guidance is in good agreement of upper level ridging sliding across the PacNW with dry conditions and light winds by Friday (confidence 75-90%). The forecast area will remain under the influence of the ridge through Saturday, but ensemble members disagree on the evolution of the synoptic pattern Sunday into early next week. That said, there is good agreement in some form of upper low bringing another round of precipitation chances across the PacNW, but confidence is low (15-25%) in timing, intensity, and p-type. Lawhorn/82 && .AVIATION /12Z TAFS THROUGH 12Z THURSDAY/...VFR conditions to prevail through the period. A cold front moving through the region will bring rain shower impacts to all sites this morning, with associated showers diminishing around 18Z. Post frontal rain showers may impact sites DLS/PSC between 22-03Z, while showers may start off as a mix and transition to snow at sites RDM/BDN between 01-04Z. Winds will increase to 12-20kts with gusts 20-35kts at all sites this morning, with these winds prevailing at sites PDT/ALW late into the evening. Winds will shift to the west/northwest behind the frontal passage this morning and early afternoon. Winds will become light, 12kts or less, at sites DLS/RDM/BDN/YKM/PSC around or after 03Z. Lawhorn/82 && .Preliminary Point Temps/PoPs... PDT 51 31 54 33 / 90 40 10 0 ALW 51 34 54 35 / 100 60 30 0 PSC 58 34 61 34 / 70 20 0 0 YKM 55 30 59 30 / 30 10 0 0 HRI 56 33 59 34 / 70 20 0 0 ELN 47 29 51 30 / 20 10 0 0 RDM 49 22 49 22 / 90 30 0 0 LGD 49 29 46 30 / 90 60 50 10 GCD 50 26 45 25 / 100 70 50 10 DLS 53 35 57 36 / 80 20 0 0 && .PDT WATCHES/WARNINGS/ADVISORIES... WA...Winter Weather Advisory until 11 PM PDT this evening for WAZ030-522. Freeze Warning from 11 PM this evening to 9 AM PDT Thursday for WAZ026-027. OR...Winter Weather Advisory until 11 PM PDT this evening for ORZ502. Freeze Warning from 11 PM this evening to 9 AM PDT Thursday for ORZ507. Winter Storm Warning until 5 AM PDT Thursday for ORZ509. && $$ DISCUSSION...82 AVIATION...82