FXUS66 KPDT 010548 AFDPDT Area Forecast Discussion National Weather Service Pendleton OR 1048 PM PDT Sat May 31 2025 .UPDATED AVIATION... .AVIATION...06Z TAFs...VFR conditions will persist across the forecast area through the period. Winds will continue to be breezy across TAF sites DLS/PDT & YKM until 08-11Z respectively with sustained winds between 12-20kts and gusts 22-27kts. Winds will remain around 10kts at DLS through the period. All other TAF sites are already seeing winds 10kts and below. Later in the period, around 19-23Z, DLS/YKM/RDM/BDN will see another increase in winds between 11-15kts and gusts 22-25kts. CIGs will remain mostly above 20kft. Bennese/90 && .PREV DISCUSSION... /issued 357 PM PDT Sat May 31 2025/ SHORT TERM...Tonight through Monday...Satellite and radar imagery this afternoon shows a cold front boundary arriving to the west slopes of the Cascades in WA, with cloud cover generally along the WA Cascade crest and west. At the surface, pressure gradients have already tightened to 12mb between the Moses Lake and Seattle, which has resulted in strong winds developing through the Cascade gaps. Through tonight, an upper level trough and cold front boundary will make a pass through the PacNW, though little to no precipitation is expected as most of the moisture with this system is expected to stay to the north. However, breezy to windy conditions are expected to expand in coverage as the cold front boundary moves across the Columbia Basin later this afternoon and evening. Winds with this system will be strongest through the Kittitas valley, where confidence is high (75-90%) that sustained winds will be between 30-40mph and wind gusts up to 60mph through this evening. Through the eastern Gorge, Lower Columbia Basin, Simcoe Highlands, North Central OR, and the OR Blue Mtn foothills, confidence is mod-high (65-90%) that wind gusts between 45-55mph will develop with the cold front passage through this evening. Fire weather concerns will remain elevated through the Kittitas valley and portions of the Columbia Basin as relative humidities drop into the upper teens and 20s this afternoon. Tomorrow, the cold front is expected to exit the region in the morning, while the trough axis slowly passes over the PacNW. A dry northwesterly flow will develop overhead and persist through Monday, resulting in dry conditions and near to just above seasonable temperatures in the afternoons. Breezy conditions (gusts 25-35mph) will persist through the Cascade gaps each afternoon/evening as well, with afternoon temperatures in the mid 70s to lower 80s. Lawhorn/82 LONG TERM...Tuesday through Saturday...Quiet and dry weather will prevail through the extended period, with a general northwest flow. By the end of the period, ridging looks to be build in, with warming temperatures. Around Wednesday into Thursday, a trough will develop in the flow that strengthens to the south over California. While there are some differences in how the deterministic models handle this development, the impacts on our region are negligible. There will be diurnal winds in the 10 to 20 mph range in the usually breezier locations, with winds reaching 25 to 30 mph by Friday. High temperatures will average about 5 to 10 degrees above normal through the week, but will warm a few degrees each day through the period, and top out from the mid 80s to around 90 degrees in the Basin on Saturday. Some guidance does suggest that the current forecast temperatures could be too cool toward the end of the week, but a week away, there is time for the guidance to come into agreement. && .PRELIMINARY POINT TEMPS/POPS... PDT 48 75 44 77 / 0 0 0 0 ALW 50 75 48 75 / 0 0 0 0 PSC 51 80 50 80 / 0 0 0 0 YKM 49 79 48 80 / 0 0 0 0 HRI 49 79 48 80 / 0 0 0 0 ELN 46 75 45 77 / 0 0 0 0 RDM 41 73 38 75 / 0 0 0 0 LGD 48 70 42 70 / 10 0 0 0 GCD 46 72 40 73 / 10 0 0 0 DLS 51 79 50 80 / 0 0 0 0 && .PDT WATCHES/WARNINGS/ADVISORIES... OR...None. WA...High Wind Warning until midnight PDT tonight for WAZ026. && $$ SHORT TERM...82 LONG TERM....77 AVIATION...90