Tornado and Hail in Iowa, April 26, 1994

Thunderstorms had moved out of Iowa for the most part during the late evening hours as the dry slot advanced over the state. During the early morning hours, three other features combined to once again produce severe weather in the state. The surface dry line was advancing east across Kansas and southeast Nebraska. At the same time a strong low level jet had become established with speeds in excess of 55 kts. Above this a strong jet stream was in place in the upper levels. What is known as a speed maximum (a jet streak) rotated around the upper trough and ejected toward Iowa. This set the stage for rekindling of strong thunderstorms. At this time, moisture was much more limited so thunderstorms were more of the pulse variety and were not able to maintain their strength as in a supercell storm. Hail and winds were the trademarks of these storms. Hail of three-quarters of an inch to one inch in diameter pelted Adams and Adair Counties. Many of the other storms only produced pea- to occasional marble-size hail. One storm became quiet strong for a while. It was the southern most storm in the line. It produced 60 mph winds as it passed through both Greenfield and Corning. Another storm developed a couple hours later and moved into central Iowa. High winds blew into the west part of Ames causing damage to trees and buildings. A tornado developed on the southwest part of the storm a short time later. It tracked through the western parts of the city. It touched down near new United States Highway 30 and lifted as it crossed old Highway 30. Several buildings were damaged or destroyed. Windows were broken out on several houses and cars in the area. Power was knocked out in the area as well.

Thunderstorms had moved out of Iowa for the most part during the late evening hours as the dry slot advanced over the state. During the early morning hours, three other features combined to once again produce severe weather in the state. The surface dry line was advancing east across Kansas and southeast Nebraska. At the same time a strong low level jet had become established with speeds in excess of 55 kts. Above this a strong jet stream was in place in the upper levels. What is known as a speed maximum (a jet streak) rotated around the upper trough and ejected toward Iowa. This set the stage for rekindling of strong thunderstorms. At this time, moisture was much more limited so thunderstorms were more of the pulse variety and were not able to maintain their strength as in a supercell storm. Hail and winds were the trademarks of these storms. Hail of three-quarters of an inch to one inch in diameter pelted Adams and Adair Counties. Many of the other storms only produced pea- to occasional marble-size hail. One storm became quiet strong for a while. It was the southern most storm in the line. It produced 60 mph winds as it passed through both Greenfield and Corning. Another storm developed a couple hours later and moved into central Iowa. High winds blew into the west part of Ames causing damage to trees and buildings. A tornado developed on the southwest part of the storm a short time later. It tracked through the western parts of the city. It touched down near new United States Highway 30 and lifted as it crossed old Highway 30. Several buildings were damaged or destroyed. Windows were broken out on several houses and cars in the area. Power was knocked out in the area as well.