It was a familiar pattern.
“It looks like the most significant rainfalls fell outside the areas that need it most,” said meteorologist Mike McClure of the National Weather Service in La Crosse, Wis.
While that pattern of near-miss rain doesn’t help area farmers and Rochester lawns and gardens, it does provide enough moisture to keep restrictions on water use at bay and has kept crops in this region of the state viable so far.
The Southeast corner of the state along the Mississippi River is abnormally dry but is so far the least-affected part of the state in the grips of its worst drought in a decade. However, state and local officials are monitoring the situation and weighing whether to impose restrictions on outdoor water use.
Rochester Public Utility water staff have been in regular correspondence with the Minnesota Department of Natural Resources to prepare initiating water restrictions that would focus on non-essential outdoor water use, said Todd Osweiler, RPU environmental and regulatory affairs coordinator.
Other cities have already implemented water use restrictions where the DNR has issued a drought warning. According to the U.S. Drought Monitor report as of Aug. 3, more than 97% of the state is in a drought. About 79% of Minnesota is in “severe drought” and 35% is in “extreme drought” conditions, up from 22% the week before.
This map from the National Weather Service shows the precipitation deficit in Southeast Minnesota since Oct 1, 2020 through Aug. 4, 2021. Contributed / National Weather Service
The Rochester area is part of the Upper Mississippi Root-Black major watershed which is not yet part of the drought warning that much of the state is currently in, Osweiler said.
The recent rains do help, but the area continues to fall behind on seasonal rainfall.
“This recent rain will definitely help, but we are prepared to work with our customers to reduce water use if we become part of the drought warning phase,” Osweiler said.
The rains have kept things in Southeast Minnesota from getting much worse but have done little to improve current conditions. Long-term forecasts don’t predict much relief any time soon.
Farms seeing sparse rain
In Mower County, where a portion of the county is under “severe drought,” the DNR isn’t yet restricting farmers from irrigating their fields, said Justin Hanson of the Mower County Soil and Water Conservation District and Cedar River Water District.
“Mower County is fortunate to have a healthy groundwater supply,” Hanson said. “Our farmers have been fortunate to get key rains that are propping up crops.”
U.S. Drought Monitor as of Aug. 3, 2021
However, that rain has been sparse and inconsistent.
“Unfortunately, we’re hearing about rain events that drop out a good rainfall in one field and completely miss the neighbor,” Hanson said. “If this trend continues, we’ll have farms that get impacted.”
The drought had been building since last fall, said Kenny Blumenfeld, the state’s senior climatologist. Climatologists and meteorologists measure Oct. 1 through Sept. 30 as “water years.” That’s because precipitation that falls in autumn generally doesn’t get used by plants or evaporate before the following summer. Precipitation either soaks into soils or runs off.
Scant snowfall in winter 2020-2021 started much of Minnesota in a water deficit to start the growing season, Blumenfeld said.
Through Aug. 4, precipitation in Rochester has fallen short of normal by 4 to 8 inches since Oct. 1.
Worst since 2012
Blumenfeld said this drought is the worst wide-spread dry spell in about a decade when a drought and unusually warm summer and fall struck the state in 2012.
“All the moisture just got sucked out of the system,” he said.
Blumenfeld said that although Minnesota’s climate is generally becoming wetter, the state was due for a dry spell.
People ask him whether this drought defies or confirms climate change trends, he added.
“I think the more appropriate question is how is climate change influencing the weather now,” he said.
The drought itself, while significant and severe, isn’t out of the realm of historic weather events.
“We’re seeing a normal variation of dry conditions overlaid with a warm period,” he said. “It’s hard to make the case that there’s something unusual about it itself.”