Iowa State University's Cow helps track weather

A Cow has become a useful tool in studying historical weather warning information.

Iowa State University has produced a database of National Weather Service warnings -- Iowa Environmental Mesonet -- dating to 2005. The database is inexplicably nicknamed "Cow" and is searchable by NWS office issuing the warning, type of warning (tornado, thunderstorm, flood, etc.) and type of expected damage producer (tornado, wind, hail, etc.). It allows users to determine the number of warnings issued by county over a given period.

For 2010-2019, total tornado warnings issued for Cape Girardeau and surrounding counties and highest annual number of warnings were:

• Cape Girardeau: 54; 17 (2011).
• Bollinger: 50; 17 (2011).
• Perry: 29; six (2010).
• Scott: 39; 11 (2011).
• Alexander (Illinois): 22; seven (2011).
• Union (Illinois): 25; 10 (2011).

Cape Girardeau and Bollinger counties, the counties with the most warnings, are also the biggest counties by area of the group, 586 and 621 square miles, respectively. By comparison, Alexander County, which had 41% of the number of tornado warnings as Cape Girardeau County had in the period is 43% as large as Cape County.

The numbers of warnings varied greatly by year, with 2011 and 2012 featuring the highest annual totals in the decade. Nearly 31% of the 219 total warnings for the decade (67) came in 2011. Another 39 warnings were issued for the region in 2012. In 2016, though, only one warning was issued in the entire six-county region. The next year, 2017, was also most quiet, with only seven tornado warnings being issued in the area.

According to the National Oceanic and Atmospheric Administration (NOAA), Missouri averages 45 tornadoes per year, compared to 96 in Kansas, 51 in Iowa and 54 in Illinois. Other tornado facts:

• The most common hour of the day for a tornado to form is between 5 and 6 p.m.
• The state with the most strong-violent tornadoes is Kansas, which averages 3.1 EF-3 to EF-5 tornadoes each year.
• The state with the most strong-violent tornadoes per 10,000 square miles is Kentucky.
• The month with the most tornadoes on average is May, followed by June.