A record rainfall Monday for Yankton — with some parts of the region receiving nearly 4 inches of precipitation — could be followed by more storm systems the rest of this week.
After a second rainfall moved through the area, Yankton recorded a total of 2.23 inches at Chan Gurney Airport during a 24-hour period, while the WNAX radio station officially recorded a total of 2.11 inches. Both figures surpassed the previous July 6 record of 2.05 inches of rainfall in 1989.
Douglas County recorded flash flooding, with the Corsica area receiving 3.88 inches of rain. In Yankton County, Gayville led the way with 3.49 inches.
The region received multiple rain events. However, the greatest one came late Monday afternoon when a storm rolled through the area. Wind gusts of 69 miles per hour and hail created crop damage in a number of areas.
The storm also created problems with power lines, leading to major outages in Yankton and the surrounding area, said NorthWestern Energy spokesman Tom Glanzer.
“It was a really active system, and we did have some obvious trouble with the storm. We had 1,093 customers affected, which is a very significant outage. It also covered quite a territory,” he said.
“Most of the problems came during the strong cell that went through (the area) around 5 p.m. It did open up a few breakers, and we had some problems with Yankton, Lesterville and Utica. Most of the power was restored around 7 p.m.”
NorthWestern crews were working with downed trees and power lines, along with six broken poles, Glanzer said. Most of those issues are associated with high winds and lightning, he added.
“When you see a storm like this (that hit Monday night), you never know what to expect,” he said. “You may have a pole that looks and operates normally, but it may be a broken pole that could break all the way.”
The general public should stay away from potentially live wires and other danger areas, Glanzer said.
“Our focus is on safety and paying attention to overhead power lines and trees,” he said. “If it doesn’t look normal, it could be a broken or damaged line. Give us a call we’ll take care of it for you.”
Monday’s storm arrived suddenly and passed quickly through the area, Glanzer said. The loss of power may have affected people in a number of ways, he added.
“We totally understand people are frustrated. We rely on electricity and the system so much. We’re seeing more electricity usage now because of air conditioning and sump pumps,” he said.
“People really miss the electricity when things go bad. Unfortunately, no matter where you live, there are usually outages due to weather. In South Dakota, it’s not only winter outages but definitely also summertime.”
The 69 mph gusts placed tremendous stress on the system, Glanzer said. “(During) a strong wind event, that’s when stuff breaks and starts flying,” he said.
NorthWestern crews were taking COVID precautions while restoring power Monday in the Yankton area, Glanzer said.
“Our crews are working as pods and pretty much stay with each other,” he said. “Even (Monday) night, they kept the groups together as much as possible so things didn’t become cross contaminated with each other.”
During Monday’s storm, Southeastern Electric Cooperative of Marion reported 27 members without power. At 6:35 p.m. Tuesday, the co-op reported two customers — one in McCook County and one in Turner County — still without power.
During Monday’s storm, the NWS reported hail up to 3 inches in diameter. The hail ranged from the size of tennis balls near Volin and the size of ping-pong balls in northern Knox County, Nebraska, to the size of quarters in southern Knox County and in neighboring Cedar County.
The NWS reported the following 24-hour precipitation totals:
• Corsica area 3.88 inches
• Gayville 3.49 inches
• Tripp 3.27 inches
• Dimock and Armour areas 3.16 inches
• Avon area 2.28 inches
• Yankton Municipal Airport 2.23 inches
• North Sioux City 2.22 inches
• Tyndall 2.14 inches
• Yankton area 2.11 inches
• Newcastle, Nebraska 1.93 inches
• Ponca, Nebraska area 1.75 inches
• Jefferson area 1.62 inches
• Parkston area 1.56 inches
• Springfield area 1.32 inches
In addition, Sioux City television station KTIV reported 2.2 inches near Newcastle, Nebraska; 1.24 inches in Vermillion; 0.48 inches near Elk Point; 0.23 inches near Centerville; and 0.19 inches at Beresford.
The Yankton region has recorded below-average rainfall amounts in recent weeks, with the U.S. Drought Monitor classifying the area as abnormally dry. This week’s rain will ease the dry conditions, but it has also created localized flooding.
The NWS issued a flood warning for the James River near Scotland until late Thursday night. At 8 a.m. Tuesday, the stage was 13.47 feet with minor flooding both occurring and forecast. The river should fall below flood stage by Thursday.
At stages near 14.0 feet, approximately 4,400 acres of farmland are flooded between Mitchell and Yankton.
The NWS outlook calls for the threat of strong to severe thunderstorms returning today (Wednesday). For the rest of the week, the heat index will average 95-100 degrees nearly every afternoon. Some areas could see a heat index of 102 degrees or more.
Looking ahead to mid-month, the outlook calls for continued high risk of extreme heat July 15-17 with some chances for precipitation. The conditions will be “tough on many crops and people/livestock,” the outlook concludes.
To report outages, NorthWestern Energy customers should call (800) 245-6977. They can also check the outage map at northwesternenergy.com.
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