A historical and monumental severe thunderstorm rolled through the panhandle on the evening of Saturday, June 6th. A severe thunderstorm watch is categorized as winds 58 miles per hour or greater and/or a tornado and/or hail one inch in diameter or larger.
We sure could have used the rain that typically goes along with what we know to be a thunderstorm but I know everyone is thankful that there was no hail with this storm.
Trees were uprooted around the area, some landing on houses and causing damage but in most cases residents saw a lot of sticks and branches in their yards and on the streets in both Hemingford and Alliance.
“Over a course of seven hours that we were watching the radar that day we issued warnings for every single county that we cover,” said Aviva Braun, Lead Meteorologist at the National Weather Service in Cheyenne, WY.
“That is something that none of us here have done so it was a huge event for us,” Braun noted. “We didn’t get much for rain at all, if anything it was a trace, primarily this was a wind event.
That line of storms that produce that kind of winds is called a derecho.
“By definition, this is a line of storms with damaging winds (58 mph+) with a swath of at least 250 miles,” Braun said. “The swath on this one I estimated to be around 400+ miles wide and traveled from Utah all the way up to Minnesota/North Dakota in a little over 13 hours. At points, cells were moving at 80 mph. This lead to hurricane like damage with some areas.”
“Usually we see storms like this starting to form over the western side of the Nebraska panhandle and then it wreaks havoc towards east. This time it formed over Colorado and it wreaked havoc for all 15 counties that we cover in Wyoming and Nebraska. It was something that we had not seen here in at least 10 years.”
“The Colorado station said that they have not gotten a call from the Storm Prediction Center to even be included in a storm like this in over a decade. We more frequently speak to the Storm Prediction Center because we get quite a bit of severe weather here but never the kind of coverage that we saw on Saturday.”
The Cheyenne Weather Station did issued one tornado warning over the snowy mountains as it moved off of the mountains into Arlington along I80.
“It’s incredibly rare to have a tornado in the mountains like that. We have done some preliminary surveys and it looks like it was a tornado but we have to go out one more time to do some last recognizant before we can confirm that. We will post the results on our webpage within the next few days. That was the only thing reported that was not a wind threat,” Braun said.
The highest MPH wind speed was recorded as 79 MPH in Coleman, WY and 75 MPH on the Nebraska side in Chadron and Melbeta.
The Storm Prediction Center is a national office that forecasts severe weather across the country.
We do a lot of things with them when we have the more severe weather. They stated that this was the most significant, which means 75 MPH in a day, wind gusts that they have seen since 2004,” Braun said.
“It was crazy being a part of it and crazy seeing it form,” she added.
There is no wind recorded in Hemingford but the Alliance airport reported 73 MPH at 6:21 p.m. on Saturday and at 6:16 p.m. it read 62 MPH wind.
There were a total of seven trees that were uprooted around the Box Butte Dam.
Nebraska Game and Parks employee/Box Butte Dam Superintendent II Robert Hughes said, “There was no other damage reported other than the trees.”
Hughes reported that it was a very busy weekend for camping and lake recreation. He expects this weekend to be even busier.
Dam elevation has dropped a half of a percent over these past couple of weeks with the higher temperatures. It’s sitting at 95.5 percent full with an elevation of 4006.16 feet as of the Wednesday, June 10th.
The City of Alliance has asked that tree branches be moved to the parkade and crews will come by and pick them up through noon on Friday, June 12.