Be prepared, forecasters say that many residents of Illinois will get walloped with a rare weather phenomenon later this week.

It's called a called a 'Pneumonia Front.' Legendary TV meteorologist Tom Skilling says that on Thursday after it will hit us. Skilling says

" a temp-crashing, windshifting "pneumonia front" will arrive. So what is it ?

so-named because of the sudden manner in which it drops temps once it passes.

 

Yes a Pneumonia front is a rare occurrence and the phrase was first put into use by the Milwaukee Weather Bureau Office in the 1960's and is used to describe a sudden temperate drop

.Wikipedia defines a Pneumonia Front as:

a rare meteorological phenomenon observed on the western Lake Michigan, USA, shoreline during the warm season. These fronts are defined as lake-modified synoptic scale cold fronts that result in one-hour temperature drops of 16 °F (8.9 °C) or greater

Does a this have anything to do with catching pneumonia? Not necessarily.

Skilling says:

It's not a technical meteorological term, and it has nothing to do with pneumonia. It refers to a strong northeast-to-southwest cold front racing down the western shore of Lake Michigan, usually in the spring or early summer when the lake water is still very cold. It is accompanied by the sudden onset of gusty northeast winds and a sharp temperature drop at the lake shore, with readings sometimes plummeting more than 30 degrees from the 70s into the 40s in less than an hour. Temperature changes are less abrupt farther inland.

However, I would imagine if you took a shower and and stood out outside dripping wet when temperatures drop on Thursday, you might catch pneumonia. Don't do it!

So what can we expect on Thursday? According to Skilling, temperatures will sharply drop in the late afternoon from the 60's to the low 40's