The severe thunderstorm that passed through the area the morning of July 27 “tested the limits” of the atmosphere, leaving behind significant debris and tree damage due to the high winds.

At about 8:30 a.m., skies abruptly turned dark as night, winds picked up, and quarter-sized hail fell from the sky.

Some communities to the south of here reported 4-inch baseball-sized hail, while the Fox Valley was hit hard by a rare EF-3 tornado.

Geoff Weller, Newswatch 12’s head meteorologist, shared his knowledge of how a storm of this magnitude developed.

“Monday’s severe weather certainly tested the limits of what the atmosphere is capable of in July in Wisconsin,” he said.

Weller explained that through much of Sunday, July 26, into Monday, an atmospheric cap was in place over northern Wisconsin, the U.P. of Michigan, and back into Minnesota.

“In a normal atmosphere, the atmosphere gets colder as you go up in height. Heat likes to rise through cold air, but when a cap is in place, a layer of air above the surface is warmer than the air below it. This shuts down the rising air needed for thunderstorms and effectively prohibits a thunderstorm from developing. Many forecasted severe weather events have busted because the cap held and thunderstorms never developed,” Weller said.

“As meteorologists, Sunday night into Monday we were waiting on pins and needles for the cap to break. It just takes one developing thunderstorm with a strong updraft to break the cap. When it goes, it tends to go explosively.”

That was the case in northern Wisconsin, and although Weller expected the cap to bust Sunday night, it didn’t actually happen until Monday morning.

“All the elements for severe thunderstorms to develop were in place. We had energy dropping down from Canada over Lake Superior,” he said. “Intense changes in wind direction with height and a very buoyant (unstable) atmosphere. When the initial thunderstorm broke the cap, it quickly rose to over 50,000 feet into the atmosphere just over the U.P. border. This thunderstorm gradually drifted into eastern Vilas, Forest and Florence counties before turning almost directly south into eastern Oneida and Langlade counties.”

What resulted was a high-altitude thunderstorm that quickly turned day into night by blocking out the sun.

“Initially, this thunderstorm produced large hail and damaging wind gusts as it developed over Star Lake back to Eagle River,” Weller said. “Numerous trees came down in this area along with reports of quarter-size hail.”

The storm increased in coverage and intensity as it moved toward Crandon, where golf ball- to baseball-sized hail reports started flooding into WJFW’s station from Crandon, over to Wabeno and down to Wittenburg as the storm traveled south at a speed of about 35-40 mph.

“At some point, as the storm was about to move into Crandon, I measured, using radar, 96 mph winds about 5,000 feet above the surface, knowing that if that wind energy was transferred down to the surface it would be devastating in this heavily forested part of the state,” Weller said.

The storm was still growing as it got east of Antigo, with more reports of baseball- to softball-sized hail coming in “left and right,” he said.

“We have computers that can estimate how big the hail is within the storm. They were giving us measurements around 3 inches,” Weller said. “To actually start getting viewer photos and trained spotter reports of 4-inch hail gave us pause. It’s just so rare. Hail needs strong updrafts in the thunderstorm to grow. The forces it takes to suspend a baseball- to softball-sized piece of ice are incredible.”

Rare EF-3 tornado hits Green Bay area

Weller said that soon after those reports, the most intense part of the thunderstorm left our viewing area into the Green Bay market.

“They had a monster on their hands. The thunderstorm continued to grow as it approached Appleton,” Weller said. “There, a rare (Wisconsin has seen three this year) EF-3 tornado was produced. This tornado was almost 1,500 yards wide and traveled 12.1 miles through a densely populated area before dissipating over Lake Winnebago.”

He explained that EF-3 tornadoes have wind speeds of 136 to 165 mph; similar to a Category 4 hurricane. EF status is determined by the damage, and there is a chance this tornado could be upgraded to EF-4 as the National Weather Service continues its surveying of the area.

Weller said that for the Northwoods, EF-3 tornadoes are exceptionally rare.

“I can think of two. The fall of 1971 produced one from near Antigo to White Lake,” he said. “To this day, you can still see the scar on the Earth from this tornado on visible satellite pictures. The other one was the summer of 1985 with a general track from Park Falls to the Rhinelander area.”

Weller expects this thunderstorm will be remembered for its explosive development turning day into night, damaging wind gusts, and long duration.

Localized damage

With such high winds, many communities saw multiple trees come down, causing power outages and some property damage.

In Eagle River, city Administrator Robin Ginner said Silver Lake Road near the beach bore the most significant damage to infrastructure with five electrical poles either snapped or damaged, and a large tree down near Hirzel Road.

A large spruce tree also snapped at Riverview Park, falling onto the roof of the bathroom facility and damaging several fencing panels at the pickleball courts. The golf course also saw some significant tree damage.

Mike Sanborn, director of Eagle River Light and Water Utility, said the utility started getting reports of power outages by about 8:50 a.m., clocking 322 customers out of power when the storm ended, which included both residential and commercial.

“A big portion were out south of the river between the river and Wall Street, from Maple/Walnut and Ninth Street to Willow Street,” Sanborn said. “Mckinley Boulevard was also out, and Sherburn and Michigan streets also had outages.”

Light and Water was able to restore power to approximately half of its customers before the decision to call in mutual aid was made. Crews came from New London, Clintonville, Medford, Marshfield and Wisconsin Rapids. Crews worked until about 1:30 a.m. to restore power where they could.

Sanborn thanked Brad Adamovich at Public Works and the street department for their assistance.

Three Lakes Public Works Superintendent Josh Paetow said the north half of the town had damage, with some areas hit harder than others. Crews and residents turned out in force to help mitigate the damage and blocked roadways.

“Our hardest hit areas are the Clearwater area and Wheeler Island, with most centralized damage being Meta Lake Road, Green Bass Road, Braeger Road, Wheeler Island Road, and Bonkowski Road,” Paetow said. “Our crews were out opening roads up just after the storm had passed about 9:30 a.m. Monday morning. As of late afternoon on Monday, all roads were passable (maybe one lane) with the exception of a few roads that had power lines in the trees. We also had many residents cutting trees off the roads where they live.”

He indicated that Wisconsin Public Service (WPS) also called in many crews, including subcontractors, to restore power in the many affected areas.

Paetow was pleased with the efforts of all involved in the clean-up. “I’d like to personally thank our town crew, police department, fire department, WPS, and many residents for their assistance in the clean-up efforts and dealing with the downed power lines,” he said.

According to WPS’s communications director Matthew Cullen, WPS crews restored power to more than 20,000 customers affected by the storms across northeast and north-central Wisconsin.

“The storms caused more than 150 power outages for WPS customers across the Northwoods, with Vilas and Oneida counties among the areas most affected by the damage,” Cullen said. “Our crews, as well as extra contract lineworkers, encountered significant damage, including broken utility poles, downed wires and trees and branches that fell onto our equipment. All available staff worked around the clock to make repairs and restore power to our customers.”

WPS finished restoring power to all affected customers in the evening on July 28.