Historic Midwest flooding prompts water rescues, evacuations across region

Thought bubble, via Axios' senior climate reporter Andrew Freedman: This is a "ring of fire" pattern where thunderstorms are erupting around the edges of the heat dome, where the temperature contrasts plus frontal zones and jet stream energy is present.

Threat level: South Dakota Gov. Kristi Noem declared a statewide emergency Sunday for communities affected by the storms and flooding that she said at a news conference had killed at least one person.

• Minnesota Gov. Tim Walz on Sunday declared a peacetime emergency, authorizing the state's National Guard to be available to provide support for emergency flood operations in areas of the state experiencing extreme flood conditions.
• Iowa Gov. Kim Reynolds declared a disaster in 21 counties in response to the extreme weather flooding the state's northwest and told reporters Sunday there had been at least 250 water rescues.
• Nebraska Gov. Jim Pillen announced in a statement he had authorized the deployment of a military helicopter and crew to assist with search and rescue operations in and around Sioux City in northwest Iowa.

Zoom in: "Major to historic flooding continues along portions of the Des Moines River above Saylorville Lake," per a Sunday forecast discussion by the National Weather Service's Des Moines office in Iowa.

• "River observations today have trended slightly higher than forecasts, which has resulted in an increase in expected crests at multiple sites."
• This included the West Fork Des Moines River at Estherville, Emmetsburg
  and Humboldt, which the NWS' Des Moines office noted were "either currently exceeding or forecasted to exceed their record crests."

The City of Rock Valley, Iowa, some 50 miles southeast of Sioux Falls, ordered residents north of Highway 18 to evacuate on Saturday, as the Rock River rose to record levels.

• The mayor of Spencer, Iowa, issued a weekend curfew after record flooding of the Little Sioux River.

In South Dakota, the Union County Emergency Management recommended that residents in the Dakota Dunes area evacuate on Sunday due to the threat of historic flooding.

In Minnesota, the NWS' Twin Cities office on Sunday issued flood warnings and watches for several parts of the state, with river flood warnings in place around the Minneapolis–Saint Paul area and central Minnesota.

Zoom out: There's a slight risk of severe thunderstorms (level 2/5) over parts of the Upper Midwest late Monday afternoon, per the NWS' Sunday forecast discussion.

• "There's a Slight Risk of Severe Thunderstorms for parts of Iowa/northern Missouri into northern Illinois, southern Wisconsin, southwest Lower Michigan, northern Indiana and northwestern Ohio," it added.
• "There's also a targeted Slight Risk of Excessive Rainfall over parts of eastern Iowa, southern Wisconsin and northern Illinois, where storms yielding high rain rates could cause flash flooding."
• Meanwhile, the NWS said the ongoing heat wave would continue across the Mid-Atlantic, with more record-high temperatures likely.

Context: Climate change is raising the frequency and severity of extreme weather events across the world, from heat waves to flooding, multiple studies show.

Go deeper: Attributing extreme weather to climate change

Editor's note: This article has been updated with new details throughout.