GRANITE CITY - After a year-long review of new ground survey data and aerial imagery, the National Weather Service office in St. Louis has updated its damage assessment of the May 16, 2025, tornado event in the St. Louis metropolitan area, concluding that two tornadoes occurred and that the primary tornado’s path was wider than previously reported.
The NWS increased the reported width of the St. Louis tornado to 3,168 yards, or 1.8 miles, calling it the widest tornado in the region since 1950, when reliable records began. The agency said that, including non-tornadic wind south and east of the tornado’s path, the swath of damage exceeds 2 miles. The second tornado had a path width of 525 yards, or 0.3 miles.
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In its updated findings, the NWS said an EF-3 tornado tracked through St. Louis County, St. Louis City, and far-western Madison County, Ill., and dissipated outside of Granite City. The NWS also found a second tornado, rated EF-1 with a maximum wind speed of 107 mph, that tracked through western Madison County and dissipated just east of SIU Edwardsville.
The NWS St. Louis said the updated assessment is based on the addition of more than 10,000 damage points from various sources, with most stemming from the Missouri Structural Assessment and Visual Evaluation, or SAVE, Coalition. The agency said the high-resolution, high-density dataset allowed for a more comprehensive damage assessment.
The NWS said the assessment was updated because while it is among the agency’s highest priorities to provide a timely and accurate assessment following a tornado, the availability of new ground survey data and high-resolution aerial imagery provided an opportunity to refine the official survey.
