Damaging Winds in Iowa, May 15, 1998

Warm and very humid air streamed north into Iowa during the afternoon of the 14th into the early morning hours of the 15th. An unseasonably strong upper level jet stream speed maximum was crossing the Rockies during the night with speeds in excess of 100 MPH. At the same time, a strong upper level disturbance moved across the Texas Panhandle and headed toward Iowa. Thunderstorms erupted over the southern high Plains and moved northeast toward Iowa at 65 to 70 MPH. A bow echo formed as it moved into Iowa. High winds were widespread over southwest into west central Iowa. Wind gusts of 60 to 75 MPH were quite common with widespread damage reported. Some of the damage, besides numerous trees and power lines, included a barn blown down west of Audubon in Audubon County, a roof taken off of a barn southeast of Buck Grove in Crawford County, and billboard sign damage in Crawford County near Denison. Western Cass County was also hard hit as the storms went through. Widespread damage occurred between Griswold and Lewis as winds in excess of 80 MPH tore through the area. Barns were downed and damage occurred on numerous outbuildings. There was also fairly widespread wind damage across the northern part of the county as the storms spread into that area as well. The storms moved northeast rapidly and finally weakened as the moved into northern Iowa.