By Sarah Pridgeon
As the unusual weather continues well into the summer, Crook County was once again hit by a severe storm on July 17. But while some areas in the storm’s path experienced enough hail that the National Weather Service (NOAA) reports snow plows were needed to clear inches of it from the roads, northeastern Wyoming had it relatively easy.
According to reports from NOAA, thunderstorms developed over the Black Hills during the afternoon of July 17, some becoming severe. Along with the small hail, the heavy rain caused flash flooding that was made worse by the hail-covered roads.
Those storms eventually moved southeast, but were replaced by more thunderstorms moving into northeastern Wyoming that also produced large hail, strong winds and heavy rain that led to flash flooding. These merged into one storm system that then spread into South Dakota.
The largest hail was reported in Pennington County at around 4 p.m., measuring 1.75 inches. Meanwhile, in Crook County, the hail reached the area around Beulah at about 5:30 p.m. and again an hour later, measuring a reported inch in diameter.
Wind speeds reached 70 mph near Edgemont and Fairburn during the evening. Crook County’s spotter was driving between Belle Fourche and Colony, where he encountered 65 mph gusts and heavy rain two miles southeast of Colony at 6:30 p.m.
In Alva, winds reached 60 mph according to NOAA, with a chain link fence blown down, patio furniture blown across decks and a dog house blown across the yard. Wind speeds southwest of Beulah were measured at 57 mph. The 24-hour rain totals for the day of the storm came in at 2.25 inches southwest of Beulah, sending Sand Creek over its banks and causing flooding while, according to Road & Bridge Foreman Morgan Ellsbury, creating minor road damage but not causing any roads to be closed or become impassable. This was the second highest total rainfall after Fall River County at 2.7 inches. Sundance saw 0.81 inches of rainfall during the same period.
At Rapid City Airport, a record rainfall was recorded by NOAA for July 17 at 1.39 inches, breaking the previous record of one inch set in 1999.