Tornadoes and Flood in Iowa, May 15, 1998

As the system mentioned above continued to evolve, a widespread outbreak of severe weather took place over Iowa. Strong upper level dynamics moved over the state over the top of an unstable air mass. Surface dew point temperatures were in the low 70s with actual temperatures in the upper 70s to low 80s. CAPE values rose to between 2500 and 3500 J/kg. The situation became complex during the afternoon as several bands of severe thunderstorms developed. Some areas of the state were affected three times during the day as the storms raced northeast around 60 MPH. The main severe feature with the storms was high wind. There were numerous reports of wind gusts of 60 to 75 MPH. Some were even higher. One of the highest reports came from Atlantic in Cass County. Ninety one MPH winds there threw several cars and a few semi-tractortrailer trucks off of Interstate 80. High winds in Kossuth County at Algona resulted in roof damage at a nursing home there. Part of the roof was removed by the winds with the damage estimates to the building places at around $200,000. Another cluster of storms moved into north central Iowa and caused widespread damage in Cerro Gordo and Worth Counties. Both were hit with winds around 70 MPH. There were numerous other reports of damage to farm buildings around the state ranging from corn cribs damaged to barns being destroyed. Damage to trees and power lines was extensive. North of Algona, along U.S. Highway 169, seventy eight power poles were downed by the high winds resulting in a four day closure of the highway. Utility damage around the county was estimated at between $600,000 and $800,000, while insurance adjusters estimated damage around the county at $1.2 million. There were some reports of hail, especially during the first few hours of the event. The largest hail was around golf ball in size. In addition to the wind and hail, there were several tornado touch downs in the state. A tornado touched down in Kossuth County and did over $1 million in damage. The tornado destroyed 2 houses with another 10 sustaining major damage. Fifteen farmsteads were destroyed as well. Kossuth County was later declared a disaster area. There was also considerable damage to barns and other farm buildings across the county. The outflow from the tornadic storm in Kossuth County pushed an 85 MPH wind gust south into Humboldt County. The high winds blew over 41 railroad cars of the Union Pacific Railroad south of Ottosen. A band of 80 to 90 MPH winds swept across Franklin and Butler Counties. Damage was widespread. There was one report of the wind carrying the family dog over one half mile from home. The dog was later found safe and healthy. Another of the stronger tornadoes included one in Wright County that was on the ground for over 10 miles. It damaged several farm buildings along its path. Several 2 x 4's were driven into the ground north of Clarion by the tornado. Another fairly strong tornado touched down in Crawford County. The rope tornado touched down southeast of Denison. It hit a train about 3 miles east of Denison and derailed nine cars of the Union Pacific freight train. The engineer saw it coming and thought it was so small that nothing would happen. There was also minor damage to 1 house and several out buildings. There were a few other brief touch downs around the state, however no damage was reported with them. The rapid movement of the storms prevented a lot of the flooding that would have otherwise occurred. Repeat thunderstorms passing over Kossuth County did cause some urban flooding. Damage was relatively minor, however several homes reported minor flooding. As the storms moved across Hancock County, lightning struck a house in the town of Britt. The kitchen sink was blown away from the wall and all of the appliances and the electrical equipment in the house was damaged. Lightning struck very close to another house in Wright County in Belmond. A 75-year old woman received minor injuries as she was struck by lightning as she unplugged her TV near a large window.