April and May were historically active months across the central and eastern U.S. for severe weather. There have been 915+ confirmed tornadoes since the start of the year - the fourth most active year to date since 1950 following 2011, 2019, and 2008. In the April-May period alone we have seen over 700 confirmed tornadoes and that number is rising as more tornadoes are confirmed from "report" status to "official tornado" with a ranking. This is the second most active April-May period ever, after 2011.
Tornado reports are any public report of a potential tornado or tornado damage, usually reported on the day of a storm. Reports do not directly correlate to tornadoes at a 1:1 ratio - the same tornado can have multiple damage or sightings. The National Weather Service must individually confirm each potential tornado and rank it on the EF scale of EF-0 to EF-5. According to the SPC, "Historically, for every 100 preliminary tornado reports, at least 65 tornadoes are confirmed.".
As of June 4, 2024 there are 915+ confirmed tornadoes YTD and the number is rising as additional tornadoes are confirmed. There have been 402 confirmed tornadoes in May, but a total of 560+ tornado reports. Still, even after tornado confirmation and "data cleaning", we are looking at a historically active year.
The graph below compares tornado reports to an average number of tornadoes year to date. We had a relatively average start to the severe season - in January, February and March our year-to-date tornado reports were sitting at 163 and typically we see around 155 by the end of March. Things really took off in April though with 200 more tornado reports than typical by the year to date. In May, a similar situation with year-to-date tornado reports sitting at 1114 on May 31st, nearly double the average of 606 tornadoes. According to NOAA, "during April, there were 384 preliminary tornado reports. This was more than double the 1991-2020 average of 182.4 tornadoes for the month of April, the second-highest April count on record, and the most tornadoes reported since April 2011."
Some of the more impactful tornadoes included two EF-4 tornadoes in Oklahoma and one EF-4 in Greenfield, IA. The first EF-4 to hit Oklahoma was on the evening of April 28th in Marietta. It was one of 33 tornadoes that occurred that evening. The second occurred on the evening of May 6th ripping a 39-mile path northwest of Tulsa, OK through the town of Barnsdall during a "High Risk" day. The "high risk" is the highest level of severe weather outlook the storm prediction center can issue. They typically occur 1-2x/year and we have had two High-Risk days in 2024 and one in 2023. Every single day in May, there was a level 2 or higher severe weather risk, with most days seeing a level 3 or higher threat.