North Dakota almost outdid their yearly tornado average in one day. What caused this?

North Dakota’s severe weather on Sunday, September 14th was truly unprecedented – eighteen tornadoes struck North Dakota in a single day according to reports from the NOAA, which almost eclipsed the amount of tornadoes North Dakota gets in a single year, on average. What makes this even more remarkable is that only 15 September tornadoes had been reported in North Dakota over the past 30 years combined, as first reported by Bryce Anderson, DTN’s ag meteorologist.

What caused this?

The outbreak was fueled by record warmth, with overnight lows in the mid-sixties breaking temperature records, plus exceptional atmospheric moisture. Bismarck also set a September 14th rainfall record with 2.44 inches, per NWS data.

According to Anderson, meteorologists are now examining whether unusually warm North Pacific Ocean temperatures, running up to seven degrees above average, may have contributed to this rare late-season tornado activity.