National Weather Service United States Department of Commerce

There is a threat of accumulating snow Friday night, but after that a major pattern change is expected to take place and result in a prolonged period of above average temperatures through mid March. Here are the latest long range outlooks from the National Weather Service Climate Prediction Center.

Here is the latest 6-10 day outlook which takes us into the first part of the middle of March...

 

6-10 day temperature outlook

 

Here is the 8-14 day outlook, which takes us through the remainder of the middle of March...

 

8-14 day temperature outlook

Other than the threat of some measurable snow coming up Friday night, long range models and forecasts suggest a very minimal risk of any measurable snowfall through around March 20th. So what are our chances of seeing a 1" snowfall on or after March 21st?

Here's a chart showing how quickly the daily chances of 1" snowfalls fall off during the end of March and into April...

daily snowfall frequency spring

 

Looking back at winters back to 1900 in Chicago, 52% of the years there were no 1" snowfalls on or after Mar 21st, which means that historically speaking there is still about a 50/50 chance that we could see another 1"+ snowfall after this weekend. And once we make it through the end of March, only about 1 in 4 years historically have produced a 1" snowfall after that date! So while we cannot say that the threat of additional 1" snowfalls is done after Friday night, the window of opportunity for 1"+ snowfalls will be quickly closing...