Monday, October 31, 2011

October 31, 1994 Halloween Tornado

I browsed tornado records back to the 1800's and could only find 1 Halloween tornado.  This tornado occurred in Johnson county in 1994 and was a brief F0 with a path length of about one tenth of a mile.  The tornado heavily damaged a barn and threw the debris into a nearby house.  An outbuilding near the barn was lifted off its anchored foundation, turned 90 degrees and deposited intact 10 feet from its foundation.





Wednesday, October 26, 2011

Revised 2011 Preliminary Tornado Count

Tornado data through July has now been confirmed.  Here are number of tornadoes by date:


2/28:  6
4/19-4/20:  29
4/23:  1
4/26:  2
4/27:  1
5/22:  1
5/23:  2
5/25:  22
6/19:  1
6/22:  1
6/26:  2
7/23:  1
9/26:  1*
9/27:  1*

*preliminary

Monday, October 24, 2011

October 24, 2001 Tornado Outbreak

Today marks the 10 year anniversary of the October 24, 2001 tornado outbreak.  This event produced 9 tornadoes in the state, killing 2 and injuring 19.

The first tornado, rated EF0, touched down in northern Warren county at 2:46 PM local time.  It was tracked by storm spotters and was on the ground for approximately one tenth of a mile and caused no damage.

The first in a series of several tornadoes to strike the northern part of the state struck La Porte county around 3:15 PM.  This twister sliced across the county from southwest to northeast and was up to a mile wide.  One woman was killed when her mobile home was destroyed. 

The next tornado touched down just southwest of Crumstown in St. Joseph county and moved northeast.  The most significant damage was across Crumstown, where EF3 damage with a path width up to 3/4 mile occurred. The tornado then moved to near the Michiana Regional Airport and across the Indiana Toll Road.  Two men were injured northwest of South Bend. One man later died from his injuries. 

Another tornado, an EF2 up to three quarters of a mile wide, touched down southeast of Mishawaka.  A separate EF1 tornado touched down about 4 miles northwest of Osceola.

An EF1 tornado touched down in extreme southeastern Marshall county and moved northeast across Kosciusko county and into Noble county where the tornado dissipated near Rome City.  The worst damage was north of Warsaw where 14 people were hurt at a factory when a wall collapsed.

The last tornado to strike northern Indiana touched down in Noble county east of Kendallville.  It produced some damage to homes and warehouses in and near the Kendallville East Industrial park.  The tornado then moved northeast into Dekalb county where EF2 damage occurred around Fairfield Center with significant damage to homes. Then tornado moved southeast of Ashley and then moved into Steuben county doing damage to a barn before lifting north of Steubenville.

Two other tornadoes hit southern Indiana.  An EF0 briefly touched down in Petersburg.  Two houses were unroofed and their windows were blown out.  Two car windshields were shattered by blowing debris.  Metal siding was deposited in power lines. The walls of two businesses were knocked down or cracked. 

The last tornado touched down at 5:29 PM.  It was an EF1 which struck northeast of Williams in Lawrence county, blowing off the roofs of 2 barns and a house.

Monday, October 17, 2011

Percentage Of Tornado Fatalities By F/EF Scale Rating

For the list of dates that had killer tornadoes, click here

The chart below shows the breakdown of Indiana tornado fatalities by Fujita rating for tornadoes from 1950-2010.  As you can see, even relatively weak tornadoes pose a threat to life but fatalities increase noticeably for F/EF3 tornadoes and rapidly increase for violent F/EF4&5 tornadoes.  This makes sense given that even well-built structures generally experience total failure in violent tornadoes. 

Our breakdown is generally similar to the national breakdown of tornado fatalities.  I did not forget about F/EF0 tornadoes - it's just that we have not had a killer tornado of that magnitude.  However, it is important to note that this chart is likely not a perfect representation of tornado fatalities in part due to lack of detail in record keeping.  For example, say a F4 tornado killed 16 people.  The practice has been to attribute all 16 fatalities to the F4 tornado when in reality not all of the fatalities may have occurred in the F4 portion.  Still, there is a valuable message and it is that F/EF4&5 tornadoes are the biggest threat to life.



Monday, October 10, 2011

June 4, 1814 - First Documented Tornado?

Tornadoes have undoubtedly been occurring since long before recordkeeping began.  One of if not perhaps the earliest account in the area is from June 4, 1814 - a time when Indiana wasn't yet a state and was known as the Indiana Territory.  Although details are limited, it appears there may have been at least 2 tornadoes that struck the southwestern portion of the Territory, one north of Vincennes and one near Patoka.  Houses were damaged or destroyed and cattle were killed.  The tornadoes were said to have been between a half mile and a mile wide.


Source:

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

Saturday, October 8, 2011

Violent Tornadoes 1900-2010

With help from the SPC database and Significant Tornadoes by Tom Grazulis, I have plotted the tracks of F4/F5 tornadoes since 1900.  Ratings from 1900-1949 are from Grazulis with ratings from 1950-2010 courtesy of the NWS.  Post 1950 ratings between Grazulis/NWS agreed in most instances with few discrepancies (which are not shown below).

It is important to keep in mind that the Fujita scale wasn't developed until the 1970's.  Thus, any tornado that occurred prior to then was rated retroactively based on damage photos and descriptions.  The lack of on-site damage surveys for older tornadoes means that the ratings are subject to substantial error and may or may not represent what actually occurred.  Additionally, a number of these tornadoes crossed state boundaries and may have done the violent damage in another state, but they are counted as Indiana hits for the purpose of this post.



Click For Larger Image




 





Wednesday, October 5, 2011