NOAA's National Centers for Environmental Information
Visit:NCEI U.S. Tornadoes
July 2021 Tornado Occurrences
Source: SPC
According to data from NOAA's Storm Prediction Center, during July, there were 149 preliminary tornado reports. This is slightly above the 1991-2010 average of 134 tornadoes for the month of July. Historically, the month of July represents the fourth-highest average number of U.S. tornadoes based on the 1991-2010 reference period, following the most active months of April, May and June. This July was a relatively active month for tornadoes with persistent days of tornado activity including a pair of days with several dozen tornadoes. The days with the highest count of tornadoes and their impacts are noted below in chronological order.
On July 7-8, there were 19 tornadoes that impacted coastal areas of Florida, Georgia, South Carolina, North Carolina, Virginia and New Jersey. These were all EF-1 and EF-0 tornadoes that were produced from Tropical Storm Elsa. However, these tornadoes did cause damage to homes, RV camps, industrial buildings and other infrastructure. In particular, an EF-1 tornado caused damage to many homes and apartment complexes, as well as industrial parks in Jacksonville, Florida. There was one tornado-related fatality reported in Florida.
On July 14, there was an outbreak of 38 tornadoes that occurred across Iowa. This outbreak produced a combination of EF-2, EF-1 and EF-0 tornadoes, as well as one EF-3 tornado. The EF-3 tornado passed through Lake City and produced damage to homes, farmsteads, vegetation and other infrastructure. This one-day outbreak across Iowa was one of Iowa's most prolific tornado-producing days in decades. There were no tornado-related fatalities.
The highest tornado count for any two-day period was on July 28-29, as 50 tornadoes were reported across Wisconsin, Illinois, Indiana, Ohio, Pennsylvania and New Jersey. A majority were EF-1 and EF-0 tornadoes, but there were also at least four EF-2 and one EF-3 tornado. The EF-3 tornado caused major damage across the northeastern suburbs of Philadelphia, as homes, businesses, vehicles and other infrastructure were damaged. In particular, several automotive dealerships sustained extensive damage to the many vehicles and surrounding buildings. Other large retail complexes also sustained minor to moderate levels of damage. This was the first EF-3 tornado in Pennsylvania since 2004. There were at least 5 injuries but no tornado-related fatalities.
Did You Know?
Tornado Count
Final monthly tornado counts are typically less than the preliminary count. This can be due to some phenomena being inaccurately reported as tornadic activity or a single tornado being reported multiple times. Tornado accounts are reported to the local National Weather Service forecast offices who are responsible for going into the field and verifying each tornado reported. This process often takes several months to complete. Once all reports have been investigated, the final count is published by the Storm Prediction Center (SPC).
The Tornado Monthly Climate Reports are written using the preliminary numbers because the final data is not available at the time of production. Historically, for every 100 preliminary tornado reports, at least 65 tornadoes are confirmed. An error bar is depicted on the tornado count graphic representing this uncertainty in the preliminary tornado count.
The following U.S. studies performed by SPC meteorologists offer deeper context and discussion regarding the frequency and distribution of tornado intensity climatologies:
-
Edwards, R., H. E. Brooks, and H. Cohn, 2021: Changes in tornado climatology accompanying the Enhanced
Fujita scale. J. Appl. Meteor. Climatol., 60, 1465-1482
DOI: 10.1175/JAMC-D-21-0058.1. - Mccarthy, Daniel & Schaefer, Joseph. (2004). Tornado trends over the past thirty years. paper presented at 14th Conference on Applied Meteorology.