Cold Plunge to Bring a Taste of Fall to the Plains, Rockies, Upper Midwest; Mountains Could See Snow

Jonathan Belles
Published: September 10,2016
With more than a week of summer left, a taste of winter is on the way for the northern and central Rocky Mountains early next week.

Surface Pattern for Monday

When Will The Cold Air Arrive?

For Montana, Wyoming and parts of the Dakotas, the colder air will arrive Monday as a cold front plunges southward from Canada.
Highs Monday in the northern Rockies could be as much as 25 degrees colder than mid-September averages, with afternoon temperatures not rising out of the 50s or even 40s in some lower elevation locations.

Forecast Highs and Departures from Average

The coldest temperatures will arrive Tuesday morning for the northern Rockies. Temperatures will drop into the upper 20s and 30s in many spots.
(FORECAST: Yellowstone | Great Falls, Montana | Provo, Utah | Idaho Falls ) 

Forecast Low Temperatures

These Tuesday morning lows are forecast to be as much as 20 degrees below average in parts of the northern High Plains.
The cold front will slide east and south through Tuesday and Wednesday, slowly losing steam along the way.
(MAPS: 10-Day Forecast Highs/Lows)
High temperatures will be 10 to 20 degrees below average in the northern Plains and in the Upper Midwest Tuesday and Wednesday, with 60s for highs stretching as far south as western Kansas.
The cool air will finally bring relief to the sweltering Northeast by Wednesday into Thursday before the front washes out.
(MORE: Record Heat Before Next Week's Relief in the Northeast)

Early Season Snow?

Although a few spots have already seen snow this season, quite a few more will see their first snows of the season.
The Bighorns, Tetons and Wind River Range are likely to see accumulating snow, with totals up to a foot possible over the higher peaks, generally above 5,000 feet.
Parts of Yellowstone, Grand Teton and Glacier National Parks should also see accumulating snow, spreading south from Sunday into Monday night.
Snow could be seen as far south as the higher peaks and passes in Colorado and the Uinta Mountains of Utah.
(FORECAST: Aspen, Colorado | Telluride, Colorado | Jackson, Wyoming )

Forecast Snowfall

Setup for a Taste of Winter

A deepening trough (dip in the jet stream) will enter the Pacific Northwest late Sunday into Monday bringing with it a quick burst of cooler air.

Cool Air Setup

The coolest air will only make a glancing blow to the northern tier of the country, but a slight chill could be felt into the southern Plains.
The trough will erode by midweek, but will pull the jet stream south just enough to allow the Northeast to get in on some cooler temperatures.

MORE: Rocky Mountain Snowfall