EF1 tornado in Franklin County, Iowa

This tornado was captured on video along with reports from the emergency manage. High resolution satellite imagery also helped in determining the final path. This tornado developed shortly after the first tornado in Franklin county and moved mostly south for the duration of the path. The tornado did encounter a hog confinement building producing EF1 damage. Otherwise, the bulk of the path remained in rural cropland.

A cold front sank south across Iowa during the afternoon and evening of July 28th. The environment was primed for severe storms with warm moist air in place; as temperatures climbed into the 90s and dewpoints into the 70s. By afternoon MLCAPE values of 3000 J/kg were in place across much of Iowa with deep layer shear exceeding 40 kts. Such an environment supported rapid storm development along the boundary by late afternoon. Storms produced ping-pong ball to baseball sized hail along with two tornadoes, damaging confinement pens and creating easily identifiable tracks on high resolution satellite imagery through surrounding fields. As storms pushed south into the evening, the hazards transitioned to a wind threat. A micro burst occurred in Marshall County very near the ASOS, resulting in an isolated pocket of 80 to 90 mph winds.