Temperatures are remarkably warm on Tue AM... near 50º in Jackson with freezing levels of 9,500-10,000 ft. on the east side (slightly lower west side). A few showers are possible Tuesday PM, then a quick-hitting storm will move thru Wed AM with light amounts of dense snow up high with a rain/snow mix in the valleys. Colder air arrives Thu, followed by a strong storm Thu night to Sat AM.

The Atmospheric River continues through the end of this week. Initial focal points are from the Sierra extending north into Idaho and Wyoming. Periodic cold fronts Wednesday over the Sierra and Northern Rockies, and again Friday will bring better quality. Cold air for the Rockies hits later this week, with snow pushing south into northern Utah and Colorado.

A deep low-pressure circulation off the PNW coast will tap into a SW flow of sub-tropical moisture that looks to override a cold Arctic airmass in place, bringing a prolonged winter storm event through Weds. The first punch comes Mon PM – Tue AM, with the knockout likely Tues PM and continuing through Weds. ‘Feathery’ storm totals of 1 to 2 feet by Thurs for the mountains along and south of I-90.

An active pattern will continue across the West this week with storms favoring the Northwest, Sierra, and Northern Rockies. Temperatures will be warm from the Sierra to Central Rockies early in the week but will trend colder later in the week. The Great Lakes and New England will also see several storms, though mixed precipitation could sneak in at times.

Thanks for reading this summer! For the rest of this week, a cold front moving across the Central Rockies will bring showers & t-storms to WY, CO, & NM Wed-Thu while the West Coast states will see a late-season heat wave. Next week, isolated to scattered showers & t-storms develop across the West with continued mild temps. Heading into mid-month, the PNW will trend wetter and cooler.