May 28 took us to northwest Nebraska and southwest South Dakota to play an advancing trough out of the Rockies. It became apparent again that moisture would be the issue as has been the case for most of the season. Storms formed along a boundary in western Nebraska and raced into South Dakota. Two supercells formed that we chased, both producing high winds and hail, but little else. We encountered intense winds with a bow echo east of Rapid City late in the evening that was quite spectacular.