


Area Forecast Discussion
Issued by NWS Pendleton, OR
Issued by NWS Pendleton, OR
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792 FXUS66 KPDT 121147 AFDPDT Area Forecast Discussion National Weather Service Pendleton OR 446 AM PDT Sun Oct 12 2025 .Updated Aviation Discussion. .DISCUSSION...The PacNW finds itself in the transition zone between two upper-level waves early this morning, stemming from a parent low centered over western Canada. Satellite imagery this morning shows some clearing in the Basin as the forecast area lies between these two waves, with the resulting pressure gradient making for some gusty winds through the Cascade Gaps spilling into the Basin. Once this wave passes through the region, making for widespread precip chances, a cold, trough pattern will envelop the area for much of the upcoming work week, making for mild daytime highs and chilly overnight lows bordering on freezing for many areas that have still yet to see a season-ending hard freeze. The more northerly origin of this next wave will cause snow levels to drop to around 3500 ft in the Washington Cascades and 4500 ft elsewhere as cold air rushes in from behind. Expect the Cascades to see its first round of accumulating snowfall, especially for areas above 4000 ft. Winter Weather Advisories remain in effect for our upper Cascade zones in Washington and Oregon through Monday morning. Current thinking is that Snoqualmie Pass will largely be spared of any meaningful accumulating snowfall, but White, Blewett, and Santiam Passes may see a few inches from this system. Elsewhere, models have become a bit more bullish on lowland precip with the system, with NBM probabilistic guidance suggesting 60-70% chances for even the lower Basin to receive wetting rains by Monday morning. With this combination of widespread rain and mountain snow and colder air following, the hope is that this weekend`s action will help further draw this wildfire season to a close. With ensembles in good agreement on this parent trough being followed up by cool northwesterly flow, followed by another trough later in the week, temperatures are expected to drop Monday through the midweek, with light precip lingering through the week across the mountains. Did opt to issue a Freeze Watch for the Kittitas Valley for Tuesday morning, as the Valley is quite sensitive to these northerly flow events and the NBM already depicts Ellensburg dropping to 29 Monday morning. The Yakima Valley and Simcoe Highlands will also flirt with an overnight freeze, especially Tuesday morning, but with the flow more northwesterly in nature, will be interesting to see how much cloud cover spills over from the Cascades into the lowlands and complicates the temperature forecast. 74 && .AVIATION...12Z TAFS...VFR conditions currently across all sites, but conditions will be degrading to MVFR for most sites due to reduced visibilities of 5SM for KRDM/KBDN and decreased ceilings of 2-3kft for KDLS/KPDT/KYKM/KPSC toward the end of the period. This is a result of a dropping system offshore that will bring periods of light rain to all sites beginning this afternoon, and extending overnight into Monday morning. 75 && .PRELIMINARY POINT TEMPS/POPS... PDT 55 39 55 34 / 70 70 50 10 ALW 54 42 58 38 / 80 80 50 10 PSC 58 41 59 37 / 50 80 50 0 YKM 57 37 52 36 / 50 80 80 0 HRI 57 42 58 37 / 70 80 50 0 ELN 51 34 51 29 / 60 90 70 10 RDM 51 32 48 27 / 50 80 70 20 LGD 49 37 53 34 / 80 70 70 20 GCD 51 37 53 34 / 60 80 70 10 DLS 57 43 55 40 / 80 80 80 10 && .PDT WATCHES/WARNINGS/ADVISORIES... OR...Winter Weather Advisory from 2 PM this afternoon to 1 PM PDT Monday for ORZ509. WA...Winter Weather Advisory from 2 PM this afternoon to 1 PM PDT Monday for WAZ522. Freeze Watch from Monday evening through Tuesday morning for WAZ026. && $$ SHORT TERM...74 LONG TERM....74 AVIATION...75