La Niña has developed; Colder/snowier winter in Michigan more likely

The jet stream will key to a possibly harsh winter
Posted at 4:11 PM, Sep 10, 2020
and last updated 2020-09-10 16:11:12-04

MICHIGAN — La Niña has officially developed in the Northern Hemisphere! What does this mean for our weather over the next several months?

First, let's talk about what La Niña is. La Niña is a period of time when below-average sea surface temperatures is evident across the east-central Equatorial Pacific. This usually has an impact on the jet stream here in North America.

The jet stream during a La Niña winter is potentially more active, with it diving south of Michigan for periods of time. With it diving south of the state, it would likely send in longer spells of cold air from Canada. It would also allow for more storm systems to develop around the state, meaning more rain and snow for us.

The last La Niña winter we went through was 2017 - 2018. During that winter, West Michigan experienced slightly below temperatures and slightly above average snow. La Niña, however, doesn't guarantee the winter will be colder and snowier.

Over the last 50 years, there have been several La Niña winters (see above image). While most have been near or below normal when it comes to the temperature, a few have been warmer and in extreme cases, hot. The winter/spring of 2012, when we had a plethora of 80° days in March, happened when La Niña was present.

The forecasts for La Niña to strengthen during the winter months. It will likely peak in late fall/early winter. It could then potentially start to fade as we head towards spring.

Bottom line, while a snowier/colder winter is not a guarantee, it is more likely to occur now that La Niña is present. We are Michiganders though, we can handle whatever Mother Nature throws at us. Just make sure the shovels and snowblower are ready to go.