There was a brief tornado in the afternoon of March 21 near Maxwell, California. The same system produced more severe weather across eastern Nebraska. Later, a group of supercells began producing tornadoes in south-central Iowa. On March 23, more tornadoes and severe weather developed. The strongest tornadoes formed in eastern Tennessee, where major damage was reported.
On March 29, a warm front over the Gulf of Mexico moved northward into the Gulf Coast States. It brought some severe weather. Three tornadoes formed in Louisiana. One person was killed in Mississippi after lightning caused a house fire. The worst weather shifted into central Florida on March 30. Ten tornadoes formed over the next two days. Damage totalled more than $5 million. Seven people were injured when one of the tornadoes hit a local festival.
There were 768 tornadoes were confirmed in the United States in April. That set a new record for the most tornadoes in the country over a one-month period. The previous record was 552 in May 2003.
Two tornadoes were reported in Kentucky during the early afternoon on April 4. Both were rated EF2 and caused several injuries. Many buildings were reported to be destroyed, trapping people under the wreckage. One person was killed by an EF2 tornado in Dodge County, Georgia. Nearly 100,000 and 147,000 residences lost power in Tennessee and Georgia respectively.
Two tornadoes formed on April 8, one of which was an EF2 that caused very bad damage in Pulaski, Virginia. Many houses were damaged and eight people were injured. During the afternoon of April 9, supercells moved through parts of Kentucky, Tennessee and North Carolina. At least four tornadoes were formed.
During the evening of April 9, several severe thunderstorms developed across Nebraska, South Dakota and Iowa. Over the far west of Iowa, a single supercell formed a group of ten tornadoes. The first was wide and struck Mapleton, Iowa. It destroyed about 100 homes. Nobody was killed, but about 14 to 16 people were injured.
During the afternoon of April 14, a warning was issued for much of eastern Oklahoma. Supercells developed over central Oklahoma. Several tornadoes were confirmed. A large and very strong tornado caused major damage in the towns of Atoka and Tushka. Many houses in these towns were destroyed. Two people were killed and 25 more injured in Tushka. Another two people were killed in Arkansas.
Thunderstorms developed again over parts of Mississippi, and tornadoes began to form again. An emergency was declared for the northern Jackson area shortly after 11:00 am CDT (1600 UTC). A destructive tornado moved across the area causing very bad damage and several injuries. A large tornado formed in east-central Mississippi and west-central Alabama and another tornado emergency was issued. At least eight people were killed between the two states.
On April 16, a massive outbreak of tornadoes formed in North Carolina. It became the state's worst tornado outbreak in 25 years. At least 24 died and 135 were badly injured. Tornadoes also struck South Carolina, Virginia, Maryland and Pennsylvania. Twelve supercells produced at least 25 tornadoes. At least 32 counties were affected. A total of 21 businesses and 440 homes were destroyed. Another 92 businesses and 6,189 homes suffered very bad damage. The worst damage was in Raleigh County.
More severe weather developed across the Midwest and southern Great Plains on April 19. Thunderstorms began in the late afternoon and early evening. They brought large hail and several tornadoes. A large tornado was reported near Octavia, Oklahoma. The supercells then merged into a very large squall line. Overnight, the squall line moved eastward and caused major wind damage. It formed several tornadoes across several states. A few were as strong as EF2, but most were brief and weak. In the early hours of April 20, a tornado moved through Oregon, Ohio. It caused some damage but nobody was injured. Three tornadoes hit New Albany, Indiana and Jeffersonville, Indiana. On April 22, several more tornadoes caused damage across the area. The strongest was rated EF4 and struck St. Louis. It caused extensive damage to the city. A few more tornadoes were reported on April 23–24, but most did not cause any severe damage.
Severe weather returned across parts of the Midwest on April 22. St. Louis was the hardest-hit area. The airport was badly damaged. There were several tornadoes reported in other areas. These included an EF2 tornado which moved through Henderson, Webster and Union County in Kentucky.
Between April 25 and 28, a huge outbreak of tornadoes happened across much of the Southern United States, as well as parts of the Midwest and Northeast. There were over 300 confirmed tornadoes. A total of 325 people were killed. It was one of the worst outbreaks in the history of the United States. More than 40 tornadoes were confirmed each day of the event: 46 on April 25, 55 on April 26, 206 on April 27 and 51 on April 28. In terms of violent tornadoes, the event ranks third (having a total of 15 EF4/5 storms), behind the 1974 Super Outbreak and 1965 Palm Sunday outbreak.
During May, there were 326 tornadoes confirmed in the United States. There was also one tornado in Taiwan, and another in the Philippines. The one in the Philippines caused very bad damage and killed one person.
On May 3, a series of thunderstorms hit the far north of New Zealand. Around 3:00 pm NZST, a tornado formed in the suburb Albany in Auckland. Winds were estimated at . The tornado ranked as a high-end EF2. It caused bad damage to much of the area. A total of 50 homes were damaged along the tornado's path. One person was killed and at least 20 others were injured.
On May 9, two tornadoes formed in South Dakota. They were rated EF1 and EF2. Continuing into May 10, the system slowly moved eastward to Minnesota. Thunderstorms in the state produced large hail. One EF1 tornado formed.
On May 21, several tornadoes formed in Kansas. One person was killed in Topeka, several others were injured and at least 20 houses were destroyed. After hitting Topeka, it hit several other towns. Several other tornadoes formed in the region that evening.
On May 22, a tornadic supercell formed over Minnesota. It caused major damage in and around Minneapolis. A strong tornado also moved towards Harmony that afternoon and a tornado emergency was issued. Late that afternoon, a very large and strong tornado resulted in serious damage in Joplin. Entire communities were destroyed. Many people were reported to have been trapped in destroyed houses. A total of 158 were killed, and more than 1,000 others were injured.
There were 156 tornadoes confirmed in the United States in June. A tornado watch was issued on June 1 for parts of Connecticut, Massachusetts, Maine, New Hampshire, New Jersey, New York, Pennsylvania and Rhode Island. That afternoon, an EF3 tornado formed in downtown Springfield, Massachusetts and continued east for 39 miles. It caused major damage to many towns, and many injuries were reported. The tornado in Springfield was the first tornado in Massachusetts to kill somebody since 1995.
A large EF3 tornado formed north of Hill City, Kansas on June 19. Another formed later that afternoon near Elm Creek, Nebraska. Several other tornadoes were reported across the region including near Ravenna and in York County. Some were reported to have been very large and strong, but were mostly over open country. On June 21, tornadoes were reported in Anoka County, Minnesota, and Green Lake and Fond du Lac Counties in Wisconsin. A series of tornadoes moved across the area around Louisville, Kentucky late on June 22. A total of five tornadoes were confirmed in the area, including two that were rated EF2. One of the tornadoes hit Churchill Downs and badly damaged several buildings. Tornadoes were also confirmed in Mississippi, Tennessee, Michigan, and Indiana.