CHICAGO — What has been an abnormally quiet period since mid-November is about to ramp up in a big-time.
Easily winter 2019-20’s biggest storm to date arrives Friday afternoon and evening with a multitude of significant threats: heavy rain/flooding, ice storm potential, lakeshore flooding and finally heavy snow.
A Winter Storm Watch has been issued for northern Illinois and the Chicago area starting Friday night. Counties including Boone, DuPage, Cook, Kane, Kendall, La Salle, Lake, Lee, McHenry, Ogle and Winnebago are all included in the watch.
But first, a Flood Watch goes into effect Friday afternoon for the following counties: Cook, DuPage, Ford, Grundy, Iroquois, Kankakee, Kendall, Livingston, and Will. In northwest Indiana, Benton, Jasper, Newton, Lake, and Porter.
The National Weather Service has also issued a Lakeshore Flood Warning which is in effect from midnight Friday night to 6 a.m. Sunday.
Periods of moderate to heavy rainfall are likely to cause flooding of area rivers and poor drainage areas.
A full January typically sees 1.73” of liquid precipitation. Some areas could more than double that amount inside of 24 hours. This is almost unprecedented for the month of January.
Then the Winter Storm Watch kicks in late Friday night and runs through early Sunday morning. Rainfall will transition areawide (first across the far north and northwest suburbs) to a period of freezing rain and sleet. The most significant ice accumulations are likely to occur in areas well west and northwest of the city of Chicago.
Precipitation will then change to a period of heavy, wind-whipped snow Saturday evening, ending early Sunday morning.
NAM And Euro seem to be handling the weekend snow forecast best. Lake Michigan temp of 36° is not likely to deposit those high amounts near the shore. pic.twitter.com/HA6PIty9Wt
— Demetrius Ivory (@DIvory_WGN) January 9, 2020
The most significant snow accumulations are likely to occur near the Illinois/Wisconsin border where local 12-plus inch snow totals are possible. Amounts will diminish to little or no accumulation across northwest Indiana. This is a dynamic weather situation and any fluctuation in the storm track can alter the placement of snow/ice amounts.
Saturday has the potential to be a nightmarish day at O’Hare. Strong winds alone (40mph+) may severely restrict runway/flight operations.
In addition to the wind- add heavy rain, ice, snow, + de-icing to the equation.
— Mike Hamernik (@MikeHamernik) January 9, 2020
For the latest forecast and more visit wgntv.com/weather.