Chicago’s latest winter storm moves in; the view from near Montrose Harbor late Monday afternoon
Huge snowflakes with the Chicago area’s latest winter storm were falling late Monday— the flakes were wet and sticking together as they fell to earth through an air mass with temperatures near or just above 32-degrees. This shot, relayed to us by Tracey Surface in the Montrose Harbor area, shows the visibility dropping as the rain and sleet changed to snow. (Thanks Tracey!). We expect 4-7” to accumulate across the Chicago area through Tuesday morning amid strengthening NE to N winds.
Lake enhancement of the snowfall is likely in the morning in Chicago and other northeast Illinois lakeside communities—and bands of lake effect snow are forecast to sweep the Indiana snowbelt much of Tuesday as colder arctic air wraps into the storm’s backside. The cooling process sets up steep vertical temperature declines through the atmosphere, encouraging moisture laden lake air to ascend and enhance clouds and snowfall development. The build-up of late winter season lake ice on the west side of Lake Michigan in a northeast wind flow, like the one accompanying this storm, often reduces the extent of ice-free lake surface able to feed moisture into the atmosphere. This can cut into the amount of moisture the lake provides storms like this one. But, it is still likely at least some lake enhancement of snowfall will take place—especially in northwest Indiana. The storm is likely to contribute 3-5” of snow to this system while Lake Michigan contributes another 1-2” to accumulations in areas closest to the lake.
More tonight here on our blog and on WGN’S Nine O’ Clock News program. More snow could hit later Thursday into Thursday night and two week snowfall estimates from the 8 most recent runs of the National Weather Service’s Global Forecast System (GFS) model range from 5” to 13”—well ahead of the long term average of 4.1” for the coming 2 week period ending Tuesday, March 11.
Tom Skilling
Chief Meteorologist, WGN-TV Weather
Photo courtesy: Tracey Surface
