Hail in Stillwater County, Montana

A southeast low-level surface flow advected very moist air from the central plains westward across southeast and south-central Montana. Dewpoints were in the 50s to lower 60s across the Billings Forecast Area. At the same time, a very strong jet max moved across central and south central Montana. In addition to the above, lapse rates were steep across the area along with high CAPE values. Strong speed and directional shear was in place over the Billings forecast area resulting in organized, rotating updrafts. As a result, storms across the area produced very large hail and damaging winds.

Significant damage was done to Shepherd schools. There was roof damage and extensive damage to the bus barn. In addition, all the west side windows were broken out from combined hail and wind.

Storm damage also occurred to a few commercial planes at the Billings Airport. Frontier and Alaska Airlines both had planes damaged by the hailstorm. In addition, fallen trees and branches knocked out power to about 1,500 residents and emergency crews responded to a car wreck in the Heights with reports of people trapped in an elevator.

The storm also destroyed one-third of the barley and wheat crop, approximately $400,000 worth, at a farm in Molt.

In addition, The storm killed and maimed 11,000 to 13,000 waterfowl and wetland birds at the Big Lake Wildlife Management Area west of Molt. Montana Fish, Wildlife & Parks biologists picked up dead ducks and shorebirds with broken wings, smashed skulls, and internal damage and other injuries consistent with massive blunt-force trauma. They reported thousands of additional dead or badly injured waterfowl and wetland birds in and around the lake. An estimated 20 to 30 percent of the birds at the lake were killed or injured.