Updated Wednesday at 4:13 a.m.

Last grab at the vegetable garden before a killing frost occurs this weekend. We're eyeing a storm on Friday that will not only bring about a winter-like chill but also a good potential of accumulating snow in the Cascades...and for much of eastern Washington for that matter.

For now, morning lowland showers will dissipate to a partly cloudy afternoon despite ongoing light snow in the mountains. While Stevens Pass may come away with an inch or two of slush on the roads, Snoqualmie Pass will be just wet with more of a rain/snow mix.

Patchy frost on the pumpkins is possible Thursday morning as the sky clears and low temperatures bottom out in the 30's outside the city limits. Sunny, dry conditions tomorrow make for a perfect opportunity to prepare for the cold that's to come.

By Friday, a chilly rain will overspread the Interior Lowlands with heavy snow cranking out over the Cascades. Modified arctic air will surge through the Fraser Valley where gusts could top 30 mph in western Whatcom County. As the cold air seeps through the Cascades gaps, snow levels will lower below the passes. This will be an impactful snow event for pass travelers Friday into early Saturday as confidence is increasing a plowable snow will occur for all the mountain passes, including the often busy Snoqualmie Pass on a getaway day Friday.

Won't be surprised to see wet snow in our immediate foothill locations. Glacier south to Darrington may see a minor accumulation of a wet snow on the grassy surfaces, with roadways warm enough to remain just wet.

This January-like storm won't stick around for long, sky conditions clear and the cold settles in for the rest of the weekend. Widespread frost will occur Saturday and Sunday night as temperatures dip below freezing, thus ending the growing season for the year. Cold air eases through next week with daytime highs nearing 60 degrees by Halloween.

Meteorologist Kristin Clark
The KOMO4 Forecast Team