April 25, 1961 Tornado

On April 25, 1961, at least one powerful F4 tornado swept across portions of east central Indiana.  Touching down in Shelby county a few miles north of Shelbyville, this tornado passed over I-74 with eyewitnesses reporting multiple vorticies.  The tornado destroyed barns and homes in Shelby and Rush counties.  Additional heavy damage occurred near the town of Boston where homes were destroyed.  The tornado eventually passed into Ohio.  Several people were injured but fortunately there were no fatalities.

This event may have actually been two separate tornadoes but it is not clear.


Source:

Thomas P. Grazulis, Significant Tornadoes 1680-1991 (Environmental Films, 1993).

November 22, 1992 Tornado Outbreak

Today is the anniversary of the November 22, 1992 tornado outbreak.  This outbreak spawned 15 tornadoes in central Indiana and is the largest November tornado outbreak on record here.  Here is a writeup from the NWS in Indianapolis:

http://www.crh.noaa.gov/ind/?n=nov22_1992tor

November 15, 2005 Tornadoes

Four tornadoes struck the state on this date in 2005.  Two of them were rated F3 and produced over 30 injuries but fortunately no fatalities.

The first F3 tornado touched down in Daviess county near Washington and proceeded northeast for 12 miles, lifting at Crane Naval Base in Martin County. The tornado was up to 1/4 mile wide at times. The worst damage occurred 4 miles northeast of Montgomery. Despite the amount of damage, only one of the 31 reported injuries was considered serious.  The tornado was only on the ground for 2 miles in Martin County, and was significantly weaker and smaller.

An F1 tornado touched down briefly in northern Lawrence county, damaging two homes. This tornado came from the same supercell that spawned a F3 tornado in Daviess and Martin counties.  The tornado had a path length of 0.2 miles.

The third tornado, F3, touched down in northern Bartholomew county and continued into southeast Shelby county, where it would do the majority of its damage. No one was killed by this powerful tornado, despite areas of severe damage, and only one minor injury was reported. A resident sustained an ankle injury when moving quickly down into his basement with his family to take cover. The worst damage along the tornado's path took place along and near Vandalia Road just east of the town of Geneva, where a large hog farm was severely damaged, and an old farm house was blown off its foundation. The structural integrity of the destroyed home was insufficient to justify a violent rating. Around 25 properties were damaged in this largely rural area, with six declared total losses.
 
The fourth and final tornado touched down in Grant county southwest of the intersection of county roads 200 north and 600 east, traveled northeast and lifted near the intersection of county roads 400 north and 800 east. Damage was confined to a house suffering roof damage, several trees and power lines and grain elevator augers being overturned. The tornado crossed Interstate 69, just north of mile marker 66, which resulted in a semi truck being blown off the highway.  This tornado was rated F1 and had a path length of 3 miles.

A History Of July 4 Tornadoes

July 4 is a day that we celebrate by lighting off fireworks, but nature has been known to occasionally provide its own fireworks with tornadoes and other forms of severe weather here.  I was curious to find out just how common Independence Day tornadoes have been over the years.  Although I browsed tornado records back to the 1800's, I could not find any July 4 tornadoes before 1957.  This seems rather improbable and is likely due to poor documentation in earlier years, but I can only post what I know.  I found a total of 7 tornadoes and they are listed and mapped below.  In one instance there was a discrepancy with location which I have noted.

Tornadoes Per 100 Square Miles Per County, 1950-2010

I used the NCDC Storm Events database and Severeplot 3.0 to construct this map. Since each county varies in size, we have to try to level the playing field.  To that end, I did some calculations to find the number of tornadoes per 100 square miles per county from 1950-2010.  Here is what I found:

Not surprisingly, population bias is pretty noticeable.  It's not a perfect relationship but there is a general tendency for higher populated counties to report more tornadoes which makes sense.  More people=greater chance of someone seeing it.

Here are the top 5 counties in terms of tornadoes per 100 square miles:

Marion - 10.35
Tippecanoe - 8.40
Vanderburgh - 7.67
Shelby - 7.03
Elkhart - 6.90


Here are counties ranked by population. Notice that 4 of the above listed counties appear in the top 8 (out of 92) in terms of population. Curiously, Shelby county ranks much farther down on this list.

1. Marion
2. Lake
3. Allen
4. Hamilton
5. St. Joseph
6. Elkhart
7. Vanderburgh
8. Tippecanoe
.
.
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32. Shelby