A dangerous hail threat is taking aim at parts of South Dakota, Wyoming, and Colorado on Saturday, with forecasters warning that stones could grow large enough to dent vehicles and shatter windshields in moments.
The highest risk centers on Rapid City, South Dakota, Cheyenne, Wyoming, and Akron, Colorado, where hail measuring two inches or more is expected to fall as severe storms develop during the afternoon hours.
Why this corridor is at risk
Storms are expected to build off the region’s high ground as daytime heating destabilizes the atmosphere over the elevated terrain. Cold air several miles above the surface will allow hailstones to grow unusually large, as strong updrafts repeatedly cycle them through the coldest layers of the storm before they fall to the ground. This combination of steep terrain, intense afternoon heat, and frigid air aloft is known to produce some of the largest hail seen in the country, and the pattern tends to recur across this stretch of the Plains during late spring and early summer.
Wider region also at risk
A broader swath of hail potential extends from South Dakota and Wyoming through Colorado, Nebraska, and into Kansas, touching areas near Denver, Omaha, Kansas City, and Wichita. While the danger is greatest near the higher terrain, any storm that organizes within this larger zone could still produce damaging hail.
What residents should do
Officials are urging residents across the threat zone to move vehicles into garages or covered parking ahead of the storms and to secure loose outdoor items that could become projectiles in high winds. The danger window is expected to run from the afternoon into the early evening, as storms move east across the open Plains and gradually lose strength once they pull away from the terrain that fuels them.
Residents are advised to keep a close eye on the forecast throughout the day Saturday as conditions evolve.
