90th Anniversary of the Tri-State Tornado: Illinois’ Worst Tornado Disaster

I am a little late in posting this, but March 18, 2015, marked the 90th anniversary of the Tri-State Tornado that struck Missouri, Illinois, and Indiana, on March 18, 1925 (map below).

This was the deadliest tornado in U.S. history with 695 lives lost and occurred long before there were systematic forecasts and warnings of tornadoes. While it predated the common F-scale used to measure tornadoes, it was considered by experts to be an F-5 event.  A few years ago there was a push to decide if this was one continuous track or not by examining all the evidence and interviewing survivors. It was hard to decide since there was no weather radar to track the storm. Some of the areas were very sparsely populated, leaving little documentation on the possible track.

735px-Tri-State_Tornado_map
Figure from Wilson, John W., and Stanley A. Changnon, Jr. (1971). Illinois Tornadoes. Circular 103. Illinois State Water Survey: Urbana-Champaign, IL.

Continue reading “90th Anniversary of the Tri-State Tornado: Illinois’ Worst Tornado Disaster”

Four Odd Tornado Seasons in a Row for Illinois

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Click to enlarge. Source NOAA Storm Prediction Center.

So far the 2015 tornado season in Illinois and the rest of tornado alley is incredibly quiet. There are no tornadoes to report this year, except in the far Southeast and one in California. However, this quiet start is no reason to relax if the past few years are a guide.

Historically, the heart of the Illinois tornado season is March to June with two-thirds of our tornadoes occurring during those months. However, in the last few years, we have had more tornadoes occur outside of this period than inside.

And a lot of these tornadoes have been concentrated in just a few days of the year. In fact, 69 percent of the tornadoes in 2012-14 occurred on just 5 days. These high concentrations can put extra strain on forecasting, warning, and recovery operations.

Here is how 2012, 2013, and 2014 looked, compared to the historical averages. Continue reading “Four Odd Tornado Seasons in a Row for Illinois”

Wet Week in Southern Illinois, Warm Across Illinois

In the last 7 days, Illinois has received 1 to 3 inches south of Interstate 70 (map below). Most of that came from storms last weekend. However, the precipitation amounts dropped off rapidly northward in Illinois. Areas in the northern third of the state received little to no precipitation. We are keeping a close eye on the continuing dry conditions in northern Illinois. That area has been persistently dry for several months despite this winter’s snowfall.

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Continue reading “Wet Week in Southern Illinois, Warm Across Illinois”