Thunderstorm Wind — Butler, Iowa
2017-05-17 · near Parkersburg, Butler, Iowa
Event narrative
Coop observer reported very high winds estimated at over 70 mph. Power reported out in Parkersburg, semi overturned on Highway 57 resulting in one fatality, and numerous tree limbs down on roads. A 3 foot diameter tree also downed in Parkersburg.
Wider weather episode
After a cold front stalled out across northwest Iowa the previous night, much of Iowa was firmly within the warm sector of an approaching surface low. As a result, winds were strong out of the south, helping keep dew points in the mid to upper 60s. While temperatures were only in the 70s, with the relatively high dew points SBCAPE values were able to eclipse 2000 J/kg in an uncapped environment. Storms began to initiate in the early afternoon, primarily producing funnel clouds and hail. As a weak boundary ahead of the parent cold front moved through, storms organized linearly and became primary wind gust and damaging wind producers as they traveled north/northeast.
View location on OpenStreetMap → (42.5800, -92.7800)
Source: NOAA Storm Events Database, event_id 698304. Narrative written by the NWS forecast office that issued the report.