If there was such thing as the little storm that could, it is, and will be Alberto. The storm that officially formed last Friday when it moved off the coast of Mexico, made its way northbound through the warm waters of the Gulf, and eventually up into the friendly fields of the Midwest.
How uncommon is it for a tropical system to get this close to Lake Michigan?
It is not terribly common, at least not while holding itself together as a tropical system. Looking back at historical data from the National Hurricane Center, there have been instances of Extra-tropical cyclones making their way across Lake Michigan, but not a true Tropical Storm or Tropical Depression.
In fact, in the image above from NOAA, it shows the path of all tropical systems going back to the mid 1840s that there was data for. (https://coast.noaa.gov/hurricanes/)
The gray lines represent extra-tropical cyclones, or those systems that have lose their tropical characteristics. The lines in blue are the tropical depression tracks across the area in blue (which I pinpointed near the Indiana dunes along Lake Michigan’s southeast shore).
In this image there is no line for Alberto yet!
Is Alberto the first tropical cyclone to hit Lake Michigan?
Doubtful…. but we shall see. First off it appears the core of this system started to pull to the northeast away from the lake late this evening.
Also, it is important to note that this system wasn’t technically a “tropical” system anyway to start off with. Yes, it was a “sub-tropical” storm, meaning it has both tropical and non-tropical low attributes to it.
But, late Tuesday night/early Wednesday the Weather Prediction Center (which had taken over the role of forecasting the inland storm) had issued a statement via tweet that the storm was now a tropical depression.
As far back as the 1970s there has been discussion as to how to name sub-tropical storms. The current naming system for sub-tropical cyclones started in 2002. The first storm was Gustav which went from a sub-tropical storm to cat-2 hurricane.
In 2004, we had our first named sub-tropical storm that did not gain strength or tropical characteristics (Nicole). The following year we had sub-tropical depression 22 also.
So, given that Alberto had gained its tropical title while over land near Tennessee, it will be interesting how this will be classified in the books.
Bottom line, this storm should go down as one of the closest reaching Tropical Depressions to Lake Michigan on record. It still was not extra-tropical yet this evening.
Even more fun, officially Atlantic Hurricane Season is still about 1 day away from starting!
If you have any questions about tropics, climate, historical data, or any other weather, email me, firstname.lastname@example.org