Low pressure organizing in southeast Colorado this evening will push out into the plains tonight...and curve toward the northern plains on Tuesday and Tuesday night. Leading into the event tonight, areas of freezing drizzle will create slick roadways as cold air slowly pushes eastward across the remainder of southwest Minnesota and northwest Iowa. To the west, the freezing drizzle will mix and change to light snowfall.
As low pressure strengthens on Tuesday approaching the region, northerly winds will increase and a more widespread area of precipitation will develop across the area. Periods of heavy snowfall will develop mainly west of interstate 29 early in the day, spreading north and east. Freezing rain is likely across much of northwest Iowa where ice accumulations of one to two tenths of an inch are possible, before precipitation changes over to snow. The greatest snowfall is likely to lift north of interstate 90 during the afternoon, and retreat into areas north of a line from Huron to Pipestone to Jackson, Minnesota by evening. Snow accumulations by late evening are expected to range from 4 to 6 inches along highway 14 from Huron to Tracy, 2 to 4 inches near interstate 90, and an inch or less from Sioux City eastward.
The northerly winds will pick up to a gusty 25 to 35 mph during the day, and will produce considerable blowing snow in areas north of interstate 90, with areas of blowing snow to the south. Visibilities will be as low as a quarter to half mile at times in open areas, especially during falling snow. In addition to the blowing snow, below zero wind chills will spread from west to east as winds increase and temperatures continue to fall, with wind chills likely from 15 below to 25 below zero by later Tuesday night.
The expected snowfall totals for the event: