The Perfect Storm

Posted Sept. 13, 2013 By BRYCE MARTIN


With temperatures in Bowman County reaching the 90s for most of last week, residents were looking forward to a weekend cool-down, but with it brought severe storms and damaging hail.


A frontal system moving in from the west coast surprised the area throughout the weekend. It was responsible for damaging crops to the east and west of Bowman and minor flooding in outlying areas. 


After the hail Friday morning, hot temperatures spread across the state, nearing a record high for September.


But the bad weather only was beginning for the county. 


A low-pressure system came from off the west coast and tracked across the Northern Rockies. 


“It was pretty slow moving,” said Todd Hamilton, a meteorologist with the National Weather Service in Bismarck. “It took its time moving across the Northern Rockies and across Montana.” 


Because of its slow movement, the storm cell allowed a lot of moist air from the Gulf of Mexico to be drawn into the area. 


The National Weather Service has a parameter that they look at when determining storm activity called precipitable water, which represented the amount of water vapor in the atmosphere.


Water vapor is only a small component of the composition of the atmosphere, but the NWS can track the amount of water it contains. 


“We were looking at an amount of water vapor, that, for this time of year, was very high – probably some of the highest we’ve seen in September,” Hamilton said. “(It) doesn’t get much higher than that.” 


Over Bowman County stood a system of high pressure, responsible for the 90-degree temperatures ahead of the storm. 


Warm air can hold a lot more moisture than cold air, so the area was warm and had the capability to hold more moisture, Hamilton said. 


“It setup perfectly to have the potential for very heavy rains,” he said. 


The NWS spotted the storm days in advance, which is why they issued a flash flood warning for Bowman County. 


Typically in September, the area starts to get into the time of the year that precipitation amounts are going down and air temperature is getting cooler. 


“It’s probably something we don’t see very often around here,” he said. 


Bowman and Adams counties had a few areas with 5-1/2 to 6-1/2 inches. 


“Those were probably something that you don’t see in quite some time,” Hamilton said. 


The rainfall amounts were enough to set daily rainfall records in Bowman County, adding to rainfall records from the same storm in Bismarck, Minot, Jamestown and Dickinson. 


For the month of September, 2.5 inches was the previous record daily total rainfall in Bowman County, which fell on Sept. 2, 1950. That was until Sept. 8 when 2.69 inches of rain fell. The previous record for total monthly precipitation was 4.65 in 1941. So far this month, Bowman has received 5.59 inches, which already is a record that only will increase with any additional precipitation this month. 


For the year, the record precipitation for Bowman is 28.01, which was set in 1982. So far this year, the total is 26.34, which places 2013 in second place, only 1.67 inches away from the all time record. 


Larger amounts of rainfall were captured further south in the county, Bowman County Emergency Manager Dean Pearson said. 


“Some areas probably got the largest amounts that they’ve gotten,” Pearson said. “But not everybody got a record.” 


Several local businesses reported leaking from their roofs, including ALCO in Bowman and a hail-damaged roof on the Pioneer and Finder’s office downtown. Sweetwater Golf Course in Bowman was shut down Tuesday and was undetermined for Wednesday due to flooding. 


Late summer storms do not occur on a regular basis in the area. 


“It’s usually that we don’t get this much this late in the season because the temperatures usually are cooling down and we’re in a dry spell and it’s hard to get moisture to generate,” Pearson said. 


Crops, too, were reported damaged. 


Corn and sunflowers are the two main crops left out standing because they’re not going to be ready yet until after frost, Pearson said. Most of the small grain was done, however, but some areas were either late or some larger operators still had some standing. 


“But the majority was done,” he said. 


As the Bowman weather modification project ended Sept. 8 at midnight, the storms still had the ability to be seeded to reduce hail. 


Planes took off from Bowman Regional Airport to seed the clouds, but found the job a difficult one.


On a large weather cell system, such as the one that affected Bowman, the actual core is embedded and found behind a significant rain shaft. 


When the rain is occurring, the cloud is dropping precipitation out and not actively sucking and building. In order to get the seeding in it, pilots have to get it in the updraft side of the cloud. 


“So they have to get there when the cloud is forming,” Pearson said. “If they can’t get close enough to the core because of the rain shaft, then a lot of times they can’t get anything into the clouds. 


“Just because you spray, doesn’t mean you’ll get it all.” 


Hail ultimately rained down upon Bowman County despite the efforts of the seeding project. 


“It’s been sort of abnormal all year because it’s been wet,” Pearson said.