August 13th 2005 Tornado

Preliminary Finding of F1 Tornado in Fulton County, IN

A storm survey team from the National Weather Service Northern Indiana Office investigated reports of damage in Fulton County, Indiana near the town of Fulton which occurred on Saturday August 13th. Preliminary findings indicate a 3/4 mile long and 75 yard wide tornado track with a maximum intensity of F1 on the Fujita Scale. An F1 tornado produces winds of 73 to 112 mph. The tornado only lasted for about 2 minutes.

The tornado touched down at around 351pm EST about 1/2 mile west of the town of Fulton along Indiana State Route 114. Damage at this location included several large trees and power lines down and a utility trailer which rolled over. There was also minor damage to several homes. This damage was consistent with a tornado of F1 intensity. The tornado continued for about 3/4 mile to just south of the town of Fulton along county road 100W before lifting off the ground. There was damage to a roof near the end of the tornado path which was consistent with F0 damage. A portion of the roof was blown off and impacted another home and also severely damaged a vehicle. There was also damage to a pool deck and garage. The 3/4 mile long tornado path was not continuous, with evidence of the tornado skipping as the rotation occasionally made contact with the ground. A map of the path of the tornado can be found by clicking here

The following are radar images from near the time of the tornado. The left image is a 4 panel reflectivity image of the lowest 4 elevation angles. Clockwise from top left are the 0.5, 1.5, 2.4, and 3.4 degree elevation angles. This is the angle of elevation of the radar beam above the horizon. The right image is a 4 panel image of storm relative velocity, showing wind velocities within the storm. Again, clockwise from top left are the 0.5, 1.5, 2.4, and 3.4 degree elevation angles. At this time the radar was operating in mode VCP-11, which takes a total of 14 elevation angles from 0.5 degrees to 19.5 degrees every 5 minutes. With this scanning strategy the horizontal and vertical structure of a storm can be seen.

Click on the thumbnail for a larger image.

As the images show, the storm which produced the tornado was poorly organized and very weak. The tornado most likely occurred due to a storm scale interaction between the storms' updraft and a boundary which was in the area. This boundary was a distinct wind shift line which provided a source of low level helicity, or spin, for the updraft to stretch into a brief and weak tornado. There may have also been an additional outflow boundary, which was produced by storms just east of Fulton, that may have added to this low level source of spin.

The following are pictures of the damage produced by this brief F1 tornado. Click on the thumbnail for a larger image. Hover over the thumbnail for a description of the photo.

JPH/LF 8/17/05