Significant changes in the atmospheric pattern showed up in the Midwest just in time for Father's Day and the formal start of astronomical summer.

Severe thunderstorm
(Photo : Getty Images)

Severe Thunderstorms 

AccuWeather forecasters say that the coolest conditions of the month will come after a round of intense thunderstorms. Severe thunderstorms began on Sunday afternoon across portions of Minnesota, Iowa, and Missouri. According to the National Weather Service's Storm Prediction Center, intensive hail and wind reports were made across the region during the day.

Severe thunderstorms pushed through Illinois, Indiana and into Michigan, by the evening hours. Late Sunday evening into early Monday morning, tornado warnings also began across portions of the Midwest. At least one verified tornado touched down in a suburb of Chicago.

In the wake of severe weather, another disturbance to the system will move into the Midwest as the cold front moves eastward into Monday. AccuWeather Senior Meteorologist Dan Pydynowski said: "Ironically, the first full day of summer will bring a remarkable cooldown to much of the Midwest in the wake of a powerful cold front."

Also Read: Powerful Thunderstorms in the Mid-West Can Cause Winds as Strong as Category 2 Hurricane, Forecasters Warn

Astronomical Summer Sets in

On Sunday, astronomical summer officially started at 10:32 p.m. CDT, but some residents may see themselves in the middle of springlike weather. Pydynowski added, saying on Monday it'll feel more like mid-May rather than the first full day of summer across much of the area. For some places, it'll be the coolest weather felt this June so far.

Most cities across the Midwest and even into the northern Plains are running much hotter than normal from June 1 to now. Temperature departures from Rapid City, South Dakota, to Minneapolis to Chicago have increased upwards of 7 degrees Fahrenheit above average since the beginning of June.

Although its normal high temperature increases from the middle 70s to the low 80s all through June, Minneapolis this June has recorded a whopping 11 days of temperatures above 90 degrees. Nine of these extremely hot days took place consecutively from June 3 to June 11. With a prolonged heat like that, it is no wonder the city is over 12 degrees above average thus far in June.

Effect of severe thunderstorm
(Photo : Getty Images)

Springlike High Temperatures 

On Sunday, as cooler air filters into the northern United States, Minneapolis struggled to get to even 74 for a high temperature. A high temperature in the upper 60s is forecast by Monday. High temperatures in the 60s and lower 70s on Monday will be usual from the Dakotas to Minnesota, Missouri and Iowa.

These springlike high temperatures will also stretch into parts of Indiana, Illinois, and Michigan. On Monday, high temperatures in parts of northern Wisconsin, Michigan's Upper Peninsula and  in the 50s northern Minnesota will even be stuck. June 1 was the last time Chicago underwent a low temperature in the low 50s. 

Related Article: Ohio Valley Experience Threats of Severe Weather Hazards Through End of Week

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