Wild spring weather continues as roof blown off Conde bar, South Dakota braces for 100-degree heat

With the formal start of summer less than a week away, a spring filled with wild weather refuses to subside.

Storms with high winds caused damage and power outages across the region both Monday and Tuesday mornings.

Next up, brace for excessive heat.

A bar in Conde took one of the worst hits this week, at least in northeastern South Dakota.

A storm system that produced what are called "wake low winds" blew the roof off of Sandy's Bar & Grill in Conde early Monday morning.

More:National Weather Service has confirmed 16 tornadoes in May 12 derecho; total could still grow

The roof to Sandy's Bar & Grill in Conde was blown into the street following high winds early in the morning hours Monday.

Gusts reached 75 mph, according to the National Weather Service.

Wake low winds are severe, short-lived phenomena and are virtually impossible for forecasters to predict, according to the NWS.

The winds peaked around 4 a.m. Monday after a thunderstorm rolled through the area, per information from the weather service. That's about when the roof blew off the bar, said Sandy Hoops, owner of Sandy's Bar & Grill.

Residents also reported trees and powerlines down in the area. That led to a handful of temporary power outages.

Trees and branches in Conde were blown down during a Monday morning storm.

By Monday night, the bar had reopened and was serving customers. Hoops said that the bar is operable without the roof, which was put on top of another roof to prevent leaks.

In Aberdeen, gusts reached 63 mph at 3:18 a.m. Monday, said meteorologist Ryan Lueck, who works in the Aberdeen NWS office. There were reports of tree damage and branches down in and around town.

More:4 tornadoes confirmed in Memorial Day storm system as spring rain totals mount

Most of the storm's damage was earlier in the night along the Interstate 90 corridor to the south in Jones and Lyman counties. There were reports of blown over semi trailers on the interstate, Lueck said, and flooding in both Jones and Stanley counties.

A Sunday night tornado was was confirmed 4 miles northeast of Okaton in Jones County. It was rated EF1 with winds of up to 100 mph, according to the NWS. A couple of farms reported damage to buildings and vehicles.

Tuesday morning storm knocks out power, damages grain bin

It was more of the same Tuesday morning in the Aberdeen area when another storm knocked out power, knocked town trees and caused other damage in the Frederick, Roscoe, Leola and Ellendale, N.D., areas.

In Frederick, there were reports of building damage, including a grain bin that was pushed off of its base, according to the NWS.

In Roscoe, there were reports of "many tops of trees stripped and several whole trees uprooted and down" to go along with a power outage across town. A personal weather station recorded gusts of up to 120 mph.

More:Early 2022 appears to be one of the windiest in recent history for northeastern South Dakota

In Leola, a radio antenna pole snapped in half, according to the NWS. Peak winds of 79 mph were recorded. 

Monday morning, 0.14 inch of rain fell in Watertown, followed by 0.04 inch Tuesday morning. In Aberdeen, there was 0.09 inch of rain Monday morning and 0.01 inch Tuesday morning, according to the weather service. 

Next up, brace for 100-degree temperatures

While temperatures were mild for much of spring, at least until the past week or so, that's changing.

The NWS forecast calls for a high of 100 in Aberdeen on Saturday and 104 on Sunday. And Watertown is going to be nearly as hot with a projected high of 96 for Saturday followed by 100 on Sunday. The highs for Monday will be only slightly cooler, if the forecast holds.

More:South Dakota's wild spring weather continues with hail, tornado, high winds, blizzard

The normal high temperature for this time of year in Watertown is about 77. In Aberdeen, it's about 80, according to NWS historical data.

Could there be rolling blackouts in South Dakota?

South Dakota could see rolling blackouts this summer as warmer-than-normal temperatures across the Midwest increase the demand for electricity. But local power companies say they're hoping it doesn't come to that.

Much of South Dakota's power grid falls under the purview of two regional transmission organizations: the Midcontinent Independent System Operator and the Southwest Power Pool.

The organizations are in charge of balancing the power generation and transmission across their service areas. The Midcontinent Independent System Operator stretches as far east as Wisconsin and all the way down to Louisiana, while the Southwest Power Pool reaches into parts of Texas.

More:Temperatures in the 100s expected for southeastern South Dakota this weekend

That has benefits, said Chris Studer, the public relations officer for East River Electric, which largely operates under the the Southwest Power Pool. Extra power can be sold into the larger market, and power can be purchased if enough isn't being generated, he said.

But, Studer said, being part of a larger system works both ways. If demand begins to outpace supply, "we all sort of share in the pain."

While cutting off power to customers is a last resort, Studer said that not doing it can result in cascading effects that have "devastating impacts" on electrical infrastructure.

In terms of eastern South Dakota, where much of the Midcontinent Independent System Operator's presence in the state lies, Tim Hansen, associate professor at South Dakota State University's Department of Electrical Engineering and Computer Science, said he wouldn't "sound the alarm" about rolling blackouts.

As a state that exports a considerable amount of power, South Dakota is better prepared to deal with a situation like this than some others, he said.

More:Castlewood School badly damaged by tornado; Noem declares state of emergency

Still, there could be concerns.

While the Southwest Power Pool is forecasting that generation will exceed peak demand this summer, it's a different story for the the Midcontinent Independent System Operator.

An April report from the organization projected that June's peak demand on the grid would match available capacity, while July and August peak demands are likely to exceed capacity.

Hansen said it's possible that capacity issues could be addressed by next summer, as repairs on a major transmission line for the Midcontinent Independent System Operator are nearing completion.

“They have a chance now to try and make it up," he said. "There is time to prepare.”

Spring weather has included wind, hail, excess moisture and tornadoes

The wickedly hot weather seems an appropriate ending to a spring season that started chilly, featured lots of wind and rain, saw significant hail and included a May 12 storm system that had at least 16 confirmed tornadoes.

Castlewood was hardest hit the night of May 12 with dozens of buildings damaged, including the school. But there was plenty of other damage across the region, especially on farmsteads.

Through Wednesday morning, Aberdeen had received 12.71 inches of moisture so far this year compared to an average of 9.02 inches. In Watertown, there had been 10.13 inches of moisture compared to a normal of 9.06 inches.

If there's an upside to the short-term forecast, it's that no severe weather is expected in the Watertown and Aberdeen areas in the days to come, though extreme heat can sometimes spark thunderstorms.