According to NOAA's storm prediction center, more than 100 tornadoes developed across the central U.S. over the weekend. Some communities were leveled. Several injuries were reported, unfortunately along with at least two fatalities in Holdenville, Okla., where a very large "wedge" tornado touched down under the cover of darkness. Incredibly, radar imagery detected debris at nearly 25,000 feet, which typically only happens in strong tornadoes. My guess is that after the National Weather Service conducts its tornado damage surveys, some of the tornadoes will be rated EF4-plus.

May can be an active month for tornadoes in Minnesota, but June tends to be the most active, with an average of 14 twisters touching down across the state. The greatest number of tornadoes in any given month was 71 in June 2010, 48 of which occurred on June 17.

The week ahead looks somewhat active with more rain in the forecast. Thundery showers will be possible late Tuesday, with strong storms south.