A ‘delicate and complex’ winter storm system headed for the Chicago area on Friday could bring heavy rain and snow accumulation – NBC Chicago

From tornadoes to 60 degree temperatures to possible heavy snow in the forecast, the first week of spring weather in the Chicago area will be interesting.

Thursday is expected to be calm, quiet and dry, with temperatures in the low 30s to upper 40s, according to the NBC 5 Storm Team. However, a “delicate and complex storm system” moving in from the southwest will slide into the Chicago area on Friday, bringing uncertain winter weather effects ranging from heavy rain to heavy snow accumulations.

In addition, different weather patterns leading up to the event show different information about snow totals and locations affected. As these patterns are changing, as of Thursday morning, here’s what they show.

Watch the winter storm

A winter storm watch is in effect for several counties in the Chicago area from 6 a.m. to 11 p.m. Friday as a wintry weather system begins to form to the south and west.

According to the National Weather Service, counties included in the watch include Kane, DuPage, LaSalle, Kendall, Grundy, Kankakee, Cook and Will counties in Illinois and Lake, Porter, Newton and Jasper counties in Illinois. ‘Indiana.

According to the NWS, rain and snow could fall in those areas, with five to eight inches of snow falling.

In addition, wind gusts of up to 45 mph are expected.

Lake, DeKalb and McHenry counties are not currently on the clock. However, that could change as forecast patterns change, the NBC 5 Storm Team warns.

How much snow and how much rain can fall?

According to the NBC 5 Storm Team, snowfall will depend on two factors: temperature and exactly where the forecast snowpack will be located.

Previous forecast models indicated that the snow band would be located in the northern counties. However, new models show that southern counties, including those in northwest Indiana, will be hit hard by heavy and fast snowfall of up to one to two inches per hour.

In addition, some areas could see temperatures above 32 degrees on Friday, meaning precipitation will remain liquid, which could lead to heavy downpours.

The NBC 5 Storm Team uses a variety of models to help predict weather, two of which are the European model and the global model. Although Thursday’s models show closer agreement on where the snow will fall — with higher totals predicted for southern and southeastern counties — forecast snow amounts still show a wide range.

For example, one model shows between one and three inches of snow expected at O’Hare International Airport. However, the other shows six or even more than 10 inches.

The moment of the storm

According to the NBC 5 Storm Team, the system is expected to be a “midday event,” which could affect the afternoon and evening commute.

Temperatures are expected to be in the upper 30s on Friday morning, with showers expected. However, around 2 p.m., when temperatures drop into the low 30s, that precipitation is expected to change to heavy snow falling at a rate of about an inch or two per hour.

According to the NBC 5 Storm Team, forecast models are currently calling for heavy snow to continue in southern Cook, Will, Kankakee counties, as well as Jasper counties in Illinois until 5 p.m. , Porter, Newton and Lake in Indiana.

The storm should move away by Friday evening. Temperatures are expected to be in the low 40s on Saturday and Sunday.

Assumptions remain the same

As patterns change, forecasts remain volatile, the NBC 5 Storm Team warns.