Northwest Iowa — KIWA Radio was forced to interrupt usual programming on Wednesday night to bring coverage of the first severe thunderstorm warnings of 2023 as they rumbled through the broadcast area bringing hail and strong winds.
There had been a previously-issued severe thunderstorm watch for the area, however it was cancelled shortly before the warnings began to appear across the area. The storm cells moved quite slowly through the broadcast area, tracking north, or northeasterly along the Highway 60 corridor from the greater Sioux City area, exiting at the Minnesota state line.
The first warning that came into the broadcast area came as a cell was just north of Ponca, Nebraska at 7:47 in the evening. The cell was moving north at around 30 miles per hour. The radar imagery indicated ping-pong ball sized hailstones, or roughly an inch and a half in diameter. The cell threatened Akron, Alcester, and Hawarden.
Less than 15 minutes after the first warning was issued, the National Weather Service in Sioux Falls issued a severe thunderstorm warning at 8:01pm for central O’Brien county, as well as southeastern Osceola county. The cell that prompted this warning was located over Paullina, and moved north at 45 miles per hour, the fastest moving warned storm of the evening. The storm cell rumbled through Primghar at around 8:10, and made its way north, weakening substantially before crossing US Highway 18 between Sanborn and Hartley at around 8:20. This cell also had strong winds, and radar indicated half-dollar sized, or an inch and a quarter sized, hail.
As to not be outdone, eight minutes later, at 8:09, another severe thunderstorm warning was issued, this time for northwestern Plymouth, and southwestern Sioux counties. The cell that prompted the 8:09 warning was just west of Le Mars, moving into the broadcast area impacting the Ireton area with half-dollar sized hail and 60-mile-per-hour winds.
A cell began to organize just to the east of the 8:09 thunderstorm warning, and it was a half hour later, at 8:39, that it prompted its own severe thunderstorm warning as it was located over Merrill for northeastern Plymouth and southeastern Sioux counties. That cell stayed organized for longer than other previous cells that prompted the warnings in the evening, and it moved very slowly, at around 20 miles per hour to the northeast along Highway 60, and was near LeMars nearly 20 minutes later at around 8:55.
Two minutes later, at 8:41, yet another severe thunderstorm warning was issued. This warning was the result of of the cell that prompted the first warning of the evening, as it regained strength near Hawarden, prompting a warning for southwest Lyon and northwest Sioux counties. The cell threatened the towns of Canton, South Dakota, as well as Inwood, Iowa with its radar-indicated 60-mile-per-hour wind gusts and half-dollar sized hail.
At 9:04, a cell that was part of the system prompting the 8:09 and 8:39 warnings, prompted its own severe thunderstorm warning as it was over Remsen for northwestern Cherokee, northeastern Plymouth, southeastern Sioux, and southwestern O’Brien counties, and took direct aim at the town of Granville. The cell threatened Granville with wind gusts of 60-miles-an-hour and half-dollar sized hailstones as it moved northeast at a crawl of about 25 miles per hour.
The seventh, and final warning of the evening came at 9:11, as a cell over Rock Valley was dropping hailstones and blowing 60 -mile-per-hour wind gusts, prompting a severe thunderstorm warning for central Lyon, and north central Sioux counties. That cell traveled northeasterly at 35 miles per hour, arriving near Doon at about 9:20, and Alvord at around 9:25, before moving through the area, allowing the last warning to expire at 9:45 in the evening.
There were multiple hail reports from these cells as they moved through the area, including inch and a half hailstones near Cleghorn at 7:43. There were several reports of one-inch hail in Plymouth county. A trained spotter reported an estimated one-inch diameter hail near Rock Valley at 9:14, and this same cell dropped inch-and-a-half sized hailstones near Doon at 9:20. KIWA received a listener report of heavy rain and pea size hail between Hartley and Sanborn at 9:50. Although there was a severe thunderstorm that prompted a warning that went through that area, at 9:50 that area was not under a severe thunderstorm warning, but was getting heavy precipitation on the radar as well.
The National Weather Service reminds the public to always have multiple ways of receiving alerts for severe weather.
