Cold air will plunge into the Rockies allowing for snow this week, foreshadowing things to come in winter.
A cold front swept the Northwest for the early part of the week, starting off fall on a chillier note.
The cool air mixed with moisture from a storm moving out of the central Rockies will produce the first significant snowfall of the season across Idaho, Montana and Wyoming.
The lower valleys will still be too warm to see snow, but elevations from about 5,000 feet and higher will be seeing snowflakes for the middle of the week.
Snowfall at this low of a level will cause travel delays across the area with slick, snow-covered roadways in the passes, especially along I-90 and I-15.
After some days with highs in the upper 80s in the middle of September, this cool shot will seem like a drastic change. Although temperatures will be slightly below average, snow this time of year in the northern Rockies is not that uncommon.
AccuWeather.com Expert Senior Meteorologist and Long Range Expert Paul Pastelok commented that "it's usual for them to get snow this time of year, assuming that pattern also allows moisture."
Furthermore, Pastelok implied that more of the white stuff could be on the way for fall, with a snowy period expected into October.
"This is the start of what could be a colder and snowier winter, especially for Montana," Pastelok said.
The official AccuWeather.com 2013-2014 winter forecast will be released in the near future, October 9.