FXUS66 KPDT 211127 AFDPDT Area Forecast Discussion National Weather Service Pendleton OR 427 AM PDT Mon Sep 21 2026 .KEY MESSAGES... - Temperatures continue to warm further today with highs reaching the low to mid 80s by the late afternoon hours. - Cooler pattern with possible rain chances, especially along the mountains later this week. - Diurnal winds with general breezy winds developing Tuesday and Friday, especially near the Cascade gaps. && .DISCUSSION... Radar and satellite imagery continues to display dry conditions with clear to mostly clear skies thanks to the upper level ridge of high pressure continuing to effect the area. This will allow temperatures to continue warming a few more degrees through today, with temperatures in most of the lower elevation areas to rise in the low to mid 80s. The upper level ridge will continue bringing warm southwest flow before another system enters the area by Tuesday. On the fire weather side, winds remain light and variable today, but will pick-up Tuesday afternoon with breezy winds developing across the Columbia Basin, Kittitas Valley, and Cascade gaps. Minimum relative humidities will continue to drop into the 20 to 30 percent range, with locally lower values down to 15 to 20 percent near Central Oregon. By Tuesday, guidance is in good agreement we'll see our next system push through as a trough offshore will move in British Columbia and push through the rest of the week (>90% chance). What's a bit tricky is how the trough will set-up with timing and strength determining the amount of precip we'll get. For example, the cluster analysis by Friday afternoon has 52% of the clusters having the trough strong enough to bring some precip across our region. Of that 52%, only 22% have widespread precipitation across the CWA while the Cascade mountain region encompasses all 52% of the members. The remaining 48% has a drier set-up with a weaker trough axis across the PacNW, resulting in none, if not very little, QPF's. Chances of rain remain higher in the Cascade mountains at 50 to 70 percent. Meanwhile, chances for widespread QPF's across the Blues, Basin and other lower-elevation sites, chances of rain for those areas remain lower at around 15 to 25 percent through Friday. && .AVIATION /12Z TAFS THROUGH 12Z TUESDAY/... VFR conditions prevail through the period with the exception of YKM experiencing some temporary MVFR conditions due to passing haze. Will see this lifting in the later morning hours as atmospheric mixing improves by 14Z. Otherwise, not expecting any other CIG or VIS conditions with winds generally light to moderate. && .Preliminary Point Temps/PoPs... PDT 84 52 76 48 / 0 0 0 0 ALW 85 57 77 53 / 0 0 0 0 PSC 86 54 80 49 / 0 0 0 0 YKM 85 54 79 48 / 0 0 0 0 HRI 85 55 78 49 / 0 0 0 0 ELN 80 50 70 44 / 0 0 0 0 RDM 83 44 75 38 / 0 0 0 0 LGD 84 52 79 46 / 0 0 0 0 GCD 85 51 80 46 / 0 0 0 0 DLS 86 56 77 51 / 0 0 0 0 && .PDT WATCHES/WARNINGS/ADVISORIES... WA...None. OR...None. && $$ DISCUSSION...95 AVIATION...95