'Pneumonia Front' On Tuesday Near Lake; Rainy Weather Ends Week In IL

ILLINOIS — Weather this week will be "typical late spring weather," the National Weather Service Chicago said on its Twitter.

Temperatures will be mostly in the 70s all week, and it should be dry most of the week, except when a chance of rain moves into the area on Thursday night and Friday.

Monday will have a high of 73 degrees, Tuesday a high of 80, Wednesday a high of 72, Thursday a high of 76 and Friday a high of 77.

The weather service said a "strong lake-charged cold front" will move through the area on Tuesday afternoon, bringing temperatures down, especially near the lake.

This "pneumonia front" will bring temps from near 80 into the 50s in minutes, the weather service said. A more subdued temperatures drop will be expected the farther inland the cold front gets.

The NWS coined the term "pneumonia front" in the 1960s to describe the dramatic temperature drop along the lakefront.

Later in the week, rain could move into the area on Thursday night, and chances continue on Friday and Friday night, according to the weather service.

AccuWeather gave a high of 71 on Friday for Joliet, and said there could be a "couple of showers and a thunderstorm" during the day. The private forecaster gave an 88 percent probability for precipitation and a 53 percent probability for storms.