The National Weather Service has completed upgrades to its Doppler radar northeast of Minot to better detect severe weather at lower altitudes, following a tornado in Watford City last summer that killed a baby.
The agency installed software upgrades to reduce the minimum angle the radar scans above the horizon from 0.5 degrees to 0.3, said Jeff Savadel, meteorologist in charge of the weather service’s Bismarck office.
The farther away from the Doppler site, the higher the radar beam scans above the ground. Before the upgrades, the lowest a radar beam could reach over Watford City from the site near Minot was 13,000 feet, meaning it could not gather detailed information about storms below that level. Now, the radar can reach 10,000 feet.
The change came about after a tornado hit a Watford City RV park last year, displacing 200 people in addition to causing one fatality. Given the unique circumstances of that tornado -- rather than spinning down from the middle of a thunderstorm, it formed quickly upward -- it’s unlikely the radar upgrade would have made a difference in detection, Savadel said.
Still, he said, the changes mean the weather service will have improved radar coverage in western North Dakota and other regions surrounding the Doppler site. It will enable meteorologists to better determine the rotation and strength of storms, as well as the likelihood of tornadoes, among other severe weather events.
“Even a few thousand feet will be helpful,” Savadel said.
Officials from the National Oceanic and Atmospheric Administration visited Watford City after the tornado and committed to upgrading the radar system near Minot, according to the office of U.S. Sen. John Hoeven, R-N.D. The senator also requested that western North Dakota be included in a study of gaps in Doppler radar coverage across the United States.
Savadel said the upgrades came with a $65,000 cost, funded by the weather service, and stemmed from an environmental survey. The assessment helped determine how far the weather service could lower the radar’s minimum scan angle without interference from hills, buildings and other structures.
The weather service operates other Doppler radar sites in North Dakota, including in Bismarck and Mayville.