The winter storm pounding the southern Plains this Christmas weekend will take aim at the Midwest early in the new week with windswept snow, a treacherous icy mix and heavy rain.
Millions of commuters or those heading home from Christmas destinations will face travel disruptions and nightmares, both on the ground and in the air, as the storm tracks from the central Plains to the Great Lakes on Monday into Monday night.
Windswept snow will fall on the storm's northwestern flank from Kansas to northern Michigan. Rain will pour down south of I-80 with an icy mix in between.
Monday will commence with the adverse weather and travel nightmares focusing on Omaha, Nebraska, and St. Louis, and spreading into Chicago and Indianapolis. Conditions will deteriorate for the afternoon and evening in Detroit and Minneapolis.
After slamming the Midwest, the storm will bring the first widespread snow and ice event to the Northeast on Monday night into Tuesday.
JUMP TO: Wind-swept snow to clog roads from Omaha to Minneapolis to Green Bay | Icy mix to target Kansas City, Chicago and Detroit | Rain to slow travel, raise flood risk in St. Louis and Indianapolis
Snow streaking away from the southern Plains will spread into the Upper Midwest for Monday and Monday night.
"A large swath of quick-hitting heavy snow will come down across Iowa, southeastern South Dakota, southern Minnesota, Wisconsin and northern Michigan," said AccuWeather Meteorologist Evan Duffey. Sleet will mix in on the southern fringe of this zone.
"A solid stripe of 6-12 inches of snow will fall with the Twin Cities being the largest population center in the swath."
The substantial snow will also spread from Dodge City and Salina, Kansas, to Omaha, Nebraska; Sioux City and Des Moines, Iowa; Rochester, Minnesota; Green Bay, Wisconsin; and Marquette, Michigan.
There is even the potential for the snow to top a foot, centering around Sioux City.
For the northern half of this zone, Monday's storm will add to the several inches that fell at the start of this weekend.
Stretches of interstates 29, 35, 80, 90 and 94 will become clogged with snow and treacherous ice. The snow will fall heavy at times, potentially reaching rates of 2 inches per hour.
Gusty winds will further worsen the situation for motorists by whipping the snow around, reducing visibility and creating blizzardlike conditions at times. That is especially true from Minneapolis and points to the southwest.
South of the heaviest snow zone, the combination of subfreezing temperatures at the surface and warmer air above will lead to an icy mix from eastern Kansas to the lower Great Lakes.
Sleet will mix with snow on the northern fringe with a brief period of ice changing to rain on the southeastern edge and a more extended period of sleet and/or freezing rain in between.
More freezing rain than sleet could result in sporadic power outages and downed tree branches, but an accumulation of sleet will still make travel treacherous.
"An ice accumulation of up to a quarter inch is possible across the region with Milwaukee, Wisconsin, and Grand Rapids and Saginaw, Michigan, seeing the worst of the icing," said Duffey.
"Even in Chicago and Detroit, however, there could be enough ice to lead to slick spots, especially on elevated surfaces."
Due to air flowing in off the mild waters of Lake Michigan, there will be more rain and less road issues right at the western lakeshore (including in downtown Chicago) than slightly inland.
The rain and accompanying low-hanging clouds and gusty winds that follow the icy mix could allow the travel delays to persist in Chicago and Detroit.
The Ohio Valley will escape the cold and wintry side of the storm, but not the rain that will slow travel and heighten the risk of flooding.
The rain will sweep from west to east across the I-70 corridor on Monday into Monday night. While the threat for severe weather will exist south of the Ohio River, a rumble of thunder cannot be ruled out.
Motorists will face slower travel as wet roads will heighten the risk of vehicles hydroplaning at highway speeds and reduced visibility from both downpours and spray from other vehicles. Airline travelers should prepare for flight delays.
Worse than slowing down travelers, the rain will further the risk of flooding after the soaking rain this weekend leaves the ground saturated and causes initial flooding issues.
AccuWeather meteorologists have identified the corridor from St. Louis to Indianapolis at greatest risk of widespread flooding along streams and in low-lying and urban areas.
Rain amounts by the end of Monday will approach or exceed 3 inches. Major flooding is a serious concern around St. Louis and down the I-44 corridor to Springfield, Missouri, as totals around or greater than 6 inches are expected.
Large rivers will also rise, including after the rain comes to an end, threatening to inundating neighboring land and communities.
The Mississippi River south of St. Louis is one of the rivers that is expected to reach major flood stage.