We're rapidly approaching peak tornado season in Ohio, and we don't have to look far back in history for a stark reminder of this fact.
It was two years ago when a series of powerful tornadoes struck Ohio on Memorial Day in 2019.
With a warm front lifting north, temperatures were sent into the low 80s across western and central Ohio.
That same front also transported a lot of low-level moisture with it. The air mass was very unstable, and by the evening CAPE values, which measure basically how much energy there is to fuel any storms, were forecast to be 1500-2000 J/kg.
Those numbers are considered high. Wind shear was present in the low levels of the atmosphere. Helicity values of around 300 m^2/s^2.
Values of around 150 are typically high enough to cause mid-level rotation in storms.
With this environment conducive to tornadoes, a tornado watch was issued for western and central Ohio just after 8 p.m.
Just a few hours later, storms in Indiana with a history of tornadoes crossed into Ohio.
Around 10 p.m., an EF3-rated tornado moved through Celina. This tornado stayed on the ground for 11 miles and at its peak produced 150 mph winds. One person was killed when an automobile was launched through a home.
Before the tornado lifted, it damaged over a dozen homes and additional buildings.
Around 30 minutes after the Celina tornado, an even stronger tornado touched down in Montgomery County.
At the peak of this tornado's strength, 170 mph winds were estimated by damage surveys after the storm. The tornado was rated EF4 on the Enhanced Fujita Scale, which ranges from EF0 to EF5.
Well-built apartment buildings had their roofs completely removed and no exterior walls were left. The path of this tornado was 20 miles long, from just west of Brookville to just west of the Greene County line.
There were additional very strong tornadoes that night. Besides the Celina EF3 tornado, two additional EF3 tornadoes touched down in Ohio from this system, and three EF2 tornadoes.
In total, 21 tornadoes were reported across the state from the evening of May 27 into the early morning hours of May 28.
May 26 Editor’s note: A previous version of this story said “deadly tornadoes crossed the Ohio border on Memorial Day in 2019.” This version of the story has been updated to reflect that one tornado was deadly in Ohio on Memorial Day 2019.