"The last time I recall this many tornado warnings was Labor Day 1997," he said. "It is not a normal event."
The first warning was issued by Stutsman County. The National Weather Service issued four more over the next hour.
"The tornado was on the ground according to a deputy and headed towards Jamestown," Bergquist said, referring to the warning issued by Stutsman County. "We sounded the sirens at 7:09 p.m."
Bill Abeling, meteorologist for the National Weather Service in Bismarck, said the storm systems moving through the Jamestown area were much lower in elevation or closer to the ground than normal thunderstorms.
"We had thunderstorms in the forecast and a lot of funnel clouds reported," he said. "There were a lot of low-level spinning winds. One storm in Stutsman County spun up a quick tornado."
The National Weather Service issued its first tornado warning at about 7:15 p.m. or about six minutes after the county-issued warning.
"It was very difficult to identify the storms that would generate the funnel clouds by radar," Abeling said. "Everything was low altitude and near the surface of the earth. When conditions were just right, you can pop up a tornado."
Tornadoes formed by low-altitude storms are normally lower in intensity than tornadoes formed from higher-level thunderstorms.
"That doesn't mean it couldn't cause damage," Abeling said. "It would have winds of 80 to 90 mph."
The county-issued tornado warning may have caused some confusion for the public.
"When we set off the sirens without a warning by the National Weather Servic, the links are not in place for radio," Bergquist said, referring to the Emergency Alert System, which electronic media such as radio stations and cable providers use to issue on-air alerts. "No watches, no warnings, it just happened. You do the best you can."
Those links would have enabled local radio stations and cable television providers to interrupt programming and broadcast the weather warning from the National Weather Service. Instead, many people called the Stutsman County Law Enforcement Center questioning what was happening.
Bergquist said no damage was reported from the tornado although the rain that accompanied the weather system contributed moisture to already wet soil.
"We're certainly getting over-saturated," he said. "The Doppler weather radar summary for this storm indicated the most rain occurred southeast of Jamestown in the Montpelier area with up to 4 inches."
A storm a little more than a week earlier had dumped up to 9 inches in the Spiritwood Lake area along with extensive rain in the Jamestown area.
Average annual precipitation for this time of year is normally 5.65 inches at Jamestown Regional Airport, which has reported 9.61 inches since Jan. 1.
Rain from the two systems is also delaying reductions in discharges from Jamestown Dam, according to Bob Martin, Pipestem Dam manager for the U.S. Army Corps of Engineers.
"We plan to do a reduction in releases from the Jamestown Dam by the end of the week," Martin said. "We would increase outflows at the Pipestem Dam at that time."
Currently, 500 cubic feet per second of water are being released from Jamestown Dam and 5 cubic feet from Pipestem Dam. Once the Jamestown Dam reaches its target of 1,431 feet above mean sea level (msl), the change will be made. The water level at Jamestown Dam was 1,431.85 feet msl as of noon Monday.
"We have to wait to see the effect of all this rain," Martin said.
Rainfall and thunderstorms are in the forecast from Wednesday through the coming weekend, which could continue to aggravate the situation.
©2014 The Jamestown Sun
