Wednesday’s storm passage came just a week after the Miami Valley experienced its first consecutive 90-degree days — on May 27 and 28 — since September of 2016, Zontini said. Just a month earlier, temperatures were dramatically lower.
April was the fourth coldest on record, while May is on track to be one of the warmest since 1944.
“It was kind of a complete turnaround,” Zontini said.
The bizarre and extreme weather shifts are part of an ever-changing weather pattern, Zontini said, with upper-level winds pushing cold air northward and allowing warm air into the Miami Valley.
The whiplash effect of the weather has affected the entire Midwest. In Minnesota, temperatures on Memorial Day soared to more than 100 degrees where ice had covered lakes just a month prior. It was the earliest 100 degree day on record in the state.
The chilly April was a far cry from last year. After a warm winter from 2016 to 2017, the winter of 2017 to 2018’s frigid temperatures extended well into spring. Zontini said the temperature difference between the two winters was due to El Niño and La Niña, complex weather patterns resulting from differences in water temperatures in the Pacific Ocean.
During El Niño, warmer-than-average water temperatures in the pacific result in warmer temperatures in the Ohio Valley. Conversely, winters are colder during La Niña.
Zontini said that as a building El Niño begins to affect the Ohio Valley this year, temperatures are expected to stay at or above average in May and June.
The Ohio Valley isn’t expected to see more tropical storm remnants than average, either. According to the National Hurricane Center, the 2018 storm season is expected to be at or slightly above average.