Bowman County Courthouse
104 1st St NW
Bowman, ND 58623
RIDING OUT THE STORM: Southwest region pummeled by high winds, heavy rain, baseball-size hail
June 26, 2015
“Bowman could have been a lot worse,” Bowman CountyEmergency Manager Dean Pearson says. It was supposed to be, but why wasn’t it? Pearson explains that the city of Bowman is uniquely situated in both a radar shadow and a ‘cone of silence,’ which prevents highly-accurate weather forecasts of severe weather happening on the ground in Bowman.
As the old adage goes, “no weather is ill, if the wind be still.”
But North Dakota’s wind is rarely still which, according to proverb, means we should constantly expect severe weather.
Southwest North Dakota received its first severe storm of the season last weekend. While it somewhat waned once it reached the city of Bowman, its havoc was still felt in the region.
With the storm came heavy rainfall, gusty winds, frequent lightning and ominous thunder, along with damaging hail in some areas.
Bowman County joined most of the counties in western North Dakota as it skated in and out of one severe warning after the next on Friday and Sunday.
Areas as far north as Killdeer, east to Bismarck and south to Bison, S.D., got what Bowman County for the most part dodged.
Michael Matthews, forecaster with the National Weather Service in Bismarck, summed it up: “It’s summertime so certainly it is the time of year when we get weather events like this.”
While Matthews considered the range of storms as nothing too unordinary—even with the storms forming so quickly and closely together—Bowman County still felt a jolt.
Reports of large hail came out of Marmarth on Friday evening. Not just ordinary hail, but the size of baseballs; about 2.75 inches in diameter. Two reports suggested the large hail fell west of Sunset Butte in southwest Bowman County, south of Marmarth, according to the NWS.
That area also received a large amount of rainfall, totaling about 1-1/6 inches on Sunday, Matthews said.
The hail was smaller as it reached Bowman, but just as furious.
Further south, near Bison and into the Black Hills, the hail came down in the size of grapefruits. Bison also saw a tornado touch down but managed to avoid disaster with no reported damage.
A similar eerie tornado sighting was made to the east of Bowman near the Adams and Hettinger County line.
Matthews said there was no confirmation that that tornadic activity had reached the ground and it vanished as quickly as it formed.
While Friday and Sunday disturbed peoples’ plans for grilling and spending time outdoors, last weekend’s forecast and the multiple severe weather watches and warnings spelled out far more gloom than what actually happened.
Bowman County Emergency Manager Dean Pearson said Bowman County was lucky.
“ […] For the most part we lucked out considering what the possibilities were and what could have happened,” Pearson said on Tuesday.
Much of the energy that powered Friday’s storm headed north and joined the storm cell that was approaching from the north. That system scooted across Slope County and nailed Bismarck with flooding and damaging winds later in the evening.
Pearson said the county blew its emergency sirens at Bowman Haley Dam because of the hail that was approaching, but it mostly fizzled out before it got there.
That’s quite common, according to Pearson.
A storm’s intensity will move from one end of the storm to another depending upon where it is positioned and where it gets its moisture source.
Most of the heavy rain has been to the east of Bowman County so far this year. The storms typically build above the county but accelerate as they move further east because that’s where more of the moisture is, Pearson explained.
Last year the average rainfall in Bowman County showed that the area was about 3 to 4 inches ahead of Bismarck in the center of the state. Pearson said that is normally the opposite, as it is so far this year.
“When that happens, you usually have more severe storms build and move east than build west and move into us,” he explained.
More moisture on the ground provides a great build to a storm. Dry conditions are the converse. It all depends upon what happens from the Missouri River west to the Rocky Mountains, Pearson said.
But anything’s a possibility when it comes to Mother Nature.
When there’s a severe thunderstorm, the Bowman County Emergency Operations Center (EOC) goes active.
Either Pearson, Assistant Emergency Manager Karla Germann, or one of the department’s volunteers gather in the EOC—a partially underground, windowless room at the Bowman County Courthouse—to provide eyes and ears when weather becomes severe. The EOC serves an important role for the community as it assists with weather-related school closures, alerts law enforcement to blow emergency sirens, notifies local health care providers to move their patients when weather gets rough and more.
The EOC also monitors storms as they come through the area.
Pearson said rather than blaming the poor predictability of severe storms on the weather modification program—the mission of which is to deter and suppress hail—it’s because of Bowman’s location to weather radars.
Bowman is at the edge of the NWS’s radar in Bismarck—it can’t see any weather activity happening below 8,000 feet.
If there’s lightning or tornadic activity under the base of a storm system in Bowman County, and that base is lower than 8,000 feet, it can’t be seen on radar.
“All they can see is that we have a severe thunderstorm down here but they have no idea what it’s doing,” Pearson said.
That’s a big problem, but it’s where the EOC comes in, along with the NWS’s system of regional storm spotters.
But there’s another force working against radar use for Bowman, what Pearson called the “cone of silence.”
A live radar image of Bowman County and the surrounding area is available via the North Dakota State Water Commission’s website—www.swc.state.nd.us—but sometimes shows a small circle around the city of Bowman.
What is it? It’s the “cone of silence.”
When watching a storm system move into the area from Montana, once it reaches the cone of silence around Bowman, it seems to disappear from the radar only to later reemerge to the east around Scranton.
The storm hasn’t really died down, according to Pearson, as the cone of silence is affecting what the radar shows. That cone sticks out 10 miles around the city.
A radar—Bowman’s currently sits at the old airport—would need to be placed 10 miles away from the city to provide an accurate image.
Because of this, Pearson said Bowman technically has no radar coverage.
Once the radar is transferred to the new airport east of the city it will make a difference, but only a small one, giving about three extra miles of radar coverage on the west of the city but subtracting three miles from the east.
If the radar were ever moved outside of Bowman, it would be difficult to immediately fix when necessary, Pearson said.
Because of the radar absence, Pearson’s duty with the EOC is crucial.
It’s the EOC that is responsible for estimating what is occurring overhead during a storm.
If a storm is tracking towards Bowman and it’s severe, the emergency operations center makes its decision to sound emergency sirens at about 10 miles out.
Depending upon the situation, that 10-mile warning could either mean ample time or not enough.