August 9 - Tornado near Clare, IA

Unique situation occurred yesterday over portions of northwest Iowa, with several small thunderstorms developing along a weak cold frontal boundary that was draped over that portion of the state. The thunderstorms that developed were fairly weak, no hail or damaging winds were expected, and they remained fairly low-topped (image below). The very steep lapse rates that were noted throughout the low levels, did create the unique situation in which it allowed the fast stretching of the column of air. This stretching combined with some low level shear, allowed for several funnels to form with these thunderstorms. Areas around Mason City had a thunderstorm with several funnels reported around 4:30 PM yesterday. Other storms developed after 5 PM, with additional funnels being reported near Lake Park, IA and the Spirit Lake, IA area around 6 PM.

The highlight of the day came with another storm, developing after 6 PM and being isolated to the northwest of Fort Dodge. This storm had enough stretching and good enough updraft to sustain this funnel, and allowed for a few brief touchdowns. This did prompt a tornado warning for portions of Webster county, as the tornado was reported by several sources, including a pilot who as on his way to land at the Fort Dodge airport.

Being a Saturday afternoon, it seemed like everybody had their camera with them and snapping pictures of this funnel near Clare, IA and Barnum, IA. You supposedly could see this funnel and storm from nearly 30 miles away as it was quite isolated. To view the entire list of emails and pictures with all of the funnels yesterday, take a look at the case file from the Iowa Environmental Mesonet.

I've also uploaded a few pictures from the Clare, Barnum, and Fort Dodge area for you to enjoy to look at.


Image taken by Jim Gargano, near Clare, IA just after 7 PM.


Image taken by Mark Phillips, from the Deer Creek Golf Course.


Image by Lois Shimon, taken just after 7 PM near Fort Dodge, IA.


Image taken by Michael Larsen; Funnel/rainbow located near Manson, IA.