Under the radar

Areas of low coverage in the state’s weather radar coverage could be putting central Minnesotans in danger should unexpected severe weather strike.

“(We wanted to) let people know (the gap) exists to begin with,” said Bob Brezinka, Stearns County emergency management specialist. “You can’t find the solution to the problem if you don’t know there is one. … If (residents) have a concern about it, they can certainly reach out to their local legislators.”

Stearns County is alerting its residents to the public safety risk coming from weather radar gaps, particularly in the central-western area of the state. The gaps are areas that are far from weather radar stations, making it difficult to detect tornadoes or other severe weather incidents and leaving people with little to no warning when they occur. In winter, the gaps make it harder to detect snowfall that happens farther away from weather stations.

The closest weather radar stations to west-central Minnesota are in Duluth and Chanhassen and eastern North Dakota and South Dakota. These are part of the National Weather Service’s Next Generation Weather Radar, but although they cover most of Minnesota, the state’s size means there remain areas where low-altitude radar coverage is lacking.

“The most impactful or severe portions of the storm that can cause issues for residents and for weather spotters … fall between that 2,000 to 8,000 feet above ground level,” Brezinka said. “Because of the curvature of the earth, and because the beam goes out at the same degree over the entire distance, the farther away (it travels), the more the ground curves so that’s why we’re missing some of that (low-altitude weather).”

The NWS S-band radar provides high-resolution coverage in a 60-100 mile radius, from about ground level to 3,000 feet. Only the southeastern tip of Stearns County is in the high-resolution area from the Chanhassen radar station. Otherwise, the eastern half of the county is in an area where the radar station can detect in the 3,000-6,000 foot altitude range, and the western half of the county is where the station can detect in the 6,000-10,000 foot altitude range.

Farther to the west, there is a diamond-shaped area along the southern border of Otter Tail County and the meeting point of Grant, Douglas, Stevens and Pope counties where there is no weather radar coverage below 10,000 feet.

“When the storms are coming from that direction – which is generally the case – we don’t have as much advanced warning on radar,” Brezinka said. “We need to rely more on weather spotters, volunteer firefighters, law enforcement (and) people who are interested in weather spotting who do the SKYWARN training.”

These weather gaps are especially dangerous in the summer when an influx of visitors come to the state’s lakes and recreation areas, many of which are located in the gaps. There have been instances of people getting injured or killed by tornadoes that occurred in the weather gaps, including a Kandiyohi County first responder who was killed while storm spotting in 2022.

A group of Minnesota emergency managers from Stearns, Kandiyohi, Grant, Beltrami, Otter Tail, Hennepin and Cook counties have teamed up to fix the lack of low-level weather radar. They are assisted by a former member of the NWS and current members of the University of Minnesota and the National Guard. They have been working with the private company Climavision to fill gaps as efficiently as possible. Their plan, so far, is to deploy two X-band, low-range radar units – reaching a 20-40 mile radius with high-resolution coverage – on the western side of the border between Otter Tail and Grant counties and another as-yet undetermined location in Kandiyohi County. Other mid-range commercial solutions are being discussed.

While these solutions are solidified, residents are reminded of the importance of being prepared for severe weather, most especially for people living in a weather gap, so one should be aware of where the gap areas are, spread the word to others in the gap, have plans for tornadoes or other severe weather and stay informed about the weather forecast. Severe weather can happen even when weather apps say the skies are clear. Regional forecasts can be more reliable than more general national weather apps.

Brezinka encourages concerned residents to reach out to their local legislators.

“Ultimately, (the project) is going to need to come with additional funding,” Brezinka said. “Make sure they’re aware of it also and to know it’s a concern of their constituents.”