How rare is major November tornado outbreak?

The scenes from Illinois and Indiana are nothing short of gut wrenching.

Jeremy Janssen of Mackinaw Fire Department works among the debris after a tornado struck Washington, Ill., Nov. 17. Several tornadoes touched down across the Midwest today with at least three people reported dead in Illinois. (Tasos Katopodis/Getty Images)

Sunday’s major outbreak spawned 81 preliminary tornado reports from the National Oceanic and Atmospheric Administration’s Storm Prediction Center.

(Image: NOAA Storm Prediction Center)

The numbers show Sunday’s major November tornado outbreak was big, but not unprecedented.

November features a “second season” for severe weather and tornadoes in the U.S. as powerful pre-winter cold fronts sweep south and east. There is often an increase in tornado numbers in late fall after a lull in late summer.

Looking back at November tornado numbers, it appears four of the past 12 years have featured November tornado outbreaks in line with Sunday’s event. This tweet from the Weather Channel’s Jim Cantore puts the numbers in perspective.

Hoosier Alley? Redefining tornado alley

We hear about “tornado alley” in the spring from Oklahoma to Iowa. In the fall it’s called “Dixie Alley” as tornado frequency often shifts to the southern states. Sunday’s outbreak occurred further north, north of the Ohio River in so-called “Hoosier Alley.”

(Image: Michael Frates, University of Akron via Discovery.com)

Well forecast event

Sunday’s tornado outbreak while devastating was a major forecast success.

NOAA’s Storm Prediction Center placed a high risk for tornadoes north of the Ohio River. It may have been the farthest north a high risk has been forecast so late in the season. There is little doubt that the risk areas, and NOAA’s Particularly Dangerous Situation tornado watches and timely warnings saved numerous lives Sunday.

Image: NOAA

Here are the so-called “rotation tracks”‘ from the Chicago (Romeoville) National Weather Service Doppler radar from Sunday. Some of the twisters may have been “long track” tornadoes with tracks over 50 miles long.

(Image: Chicago NWS)

Out of bounds for November?

Sunday’s outbreak, while not extremely rare for November, did occur unusually far north. Here’s a look at tornado climatology for November 17th vs. the location of Sunday’s outbreak from Climate Central.

Image: Climate Central

 

 

  • Paul Weimer

    I wonder, Paul, as climate change continues to change weather patterns and frequencies if we are going to see a shift, enlargement or other change to where and when these “alleys” manifest.

  • NOTOWTO

    Only the last paragraph says what was unusual, and that was in reference to where the storms occurred.
    The article simply doesn’t try to contextualize or answer the title question. “How Rare…..?”. Only the placement of the storms farther north is mentioned is passing in the last paragraph. The headline and the article aren’t correlated at all.
    Is this because “unusual” weather has a potential political component that turns weathermen to thinking about their jobs rather than lay out the facts that would attempt to detail an answer to the headline?