Happy first day of Winter! You wouldn’t know it, as March-like temperatures continue on Saturday. A Pacific trough of low-pressure offshore will send several weak disturbances via a SW flow into the region on Sat PM/Sun, Sun PM/Mon, and again on Tue PM into Christmas Day. The latter comes with a much-needed cold front. Instability continues into next weekend when a stronger storm moves inland.

Winter Solstice! The moisture train is very long, chugging along slowly in the PNW and BC all week. It moves south to the Sierra by storm ski 9-14 inches by Tuesday. The Train moves east over the Rockies as it speeds up, dumping moderate snow on many areas. Extended is slightly cooler in the PNW, with many more rounds of snow that look a bit better for the Rockies by next weekend with colder air.

High pressure will lead to mild conditions over the West on Friday and Saturday, but the pattern will gradually trend cooler and more active early next week with snow chances ramping up. The East will see cold temperatures over the next 5 days with periods of light snow, followed by a warm-up after Christmas.

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.