Power Outage in Oskaloosa, IA

Spotter reported 60 to 70 mph winds and power flashes.

Mahaska County emergency manager reported many instances of tree damage and power outages across the county. Time estimated from radar, via the center of the county.

Law enforcement reported tree limbs down, of unknown size, on power lines in Oskaloosa.

Law enforcement reported power lines down and a machine shed damaged near the intersection of Urbana Ave and Highway 23. The road was blocked due to downed power lines. This is a delayed report and time estimated from radar.

Emergency Manager reported widespread tree damage across town, mostly branches and limbs broken off. Numerous areas remained without power as well. Time radar estimated.

Power lines were downed by high winds. An elevated fuel tank was blown over and a barn door blown 20 feet. Dime size hail also fell.

Damage reported to trees and power lines.

The wind blew over an 8 X 8 unanchored metal shed. Estimated 12 inch diameter tree branches were down and power poles were bent over.

Power lines were blown down on south 3rd St.

A weak boundary was in place across southern Iowa during the morning of the 1st. The airmass was quite unstable with dewpoint temperatures in the mid 70s. An area of thunderstorms formed initially over northern Missouri. A band of thunderstorms formed northwest out of the main complex. One storm became severe in Mahaska County and produced high winds and dime size hail. The wind blew down power lines and an elevated fuel tank on a farm north of Oskaloosa. A barn door was also blown about 20 feet.

Iowa was between a quasi-stationary frontal boundary to the north and a developing warm front to the south. The airmass became quite unstable as afternoon highs reached the upper 80s to mid 90s with dew point readings in the low 70s. The lifted index fell to -7 C. by late afternoon with CAPE of 3000 to 3500 J/kg. The LCL was fairly high in the 1000 to 2000 meter range. The airmass was very warm with the freezing level around 15,300 feet. Thunderstorms developed over central and southeast Iowa during the late afternoon hours and continued into the evening. The shear environment was reasonably favorable with 30 to 40 kts of shear in the zero to 3 km layer. The storms produced spotty high winds and hail of up to an inch in diameter. Trees were downed as well as 2 power poles in Poweshiek County. In addition, a machine shed was also lifted a foot off of the ground. In Mahaska County, high winds ripped the siding off of a house west of Leighton. The storms produced heavy rainfall with precipitable water values around 2 inches. Rainfall of 1 to 3 inches occurred with the heavier storms in a period of an hour or so.