Updated: 24th September 2021
A significant low-pressure area over Anchorage, Alaska, is being powered into the Pacific Northwest by the Polar Jet Stream, bringing with it a terrific weather front, plunging temperatures and bringing the first considerable snowfall for the north western seaboard and Rockies.
The Tetons will bear the brunt of this front in the American Rockies, with a good couple of inches coverage in far north-western Wyoming and south-eastern Montana. A few flurries will make their way into the northern edges of Colorado and Utah, but nothing of note for the major resorts near Denver or Salt Lake City
Further East, a broad weather front crosses west to east over almost the entire length of the Appalachians, but with high temperatures this will remain as rain for the eastern seaboard.