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How warnings and the tornado unfolded in Joplin on 22 May 2011
The National Weather Service reconstructed the Joplin tornado from warnings, local sirens, radar and damage surveys. An NWS warning covering Joplin was issued at 5:17 p.m. local time, about 17 minutes before estimated touchdown. The tornado intensified rapidly as it reached the western side of the city.
Sources checked
- 5:17 p.m.NWS warning polygon 31 covered Joplin and nearby areas.
- About 5:34 p.m.The survey estimated touchdown southwest of city limits.
- 5:38 p.m.The second local siren alert sounded as EF4 damage began in western Joplin.
- About 6:12 p.m.The tornado dissipated southeast of Joplin.
The times are local. Sirens and tornado warnings were recorded as separate events.
A watch, a warning and a local siren are different records
The afternoon watch covered southwest Missouri. NWS Springfield issued geographically bounded tornado warnings, while local officials sounded sirens. Warning 31 preceded the estimated 5:34 p.m. touchdown by 17 minutes. The sequence helps compare the lead time with the storm’s development. Source 1
The tornado intensified before crossing western Joplin
The survey estimated touchdown southwest of the city, arrival in the western suburbs at about 5:36 p.m. and the onset of EF4 damage around 5:38 p.m. NWS estimated the entire path at 22.1 miles, with roughly six miles of EF4 or EF5 damage. Source 1
The spotter time and the statement time refer to different moments
The first statement reporting a confirmed tornado went out at 5:39 p.m. and cited a sighting from 5:34 p.m. The assessment also describes radar evidence and the survey reconstruction. Each record has its own timestamp and observation basis. Source 1
The rating came from damage indicators
The NWS rated the tornado EF5 with maximum winds estimated above 200 mph. Its service assessment recorded 158 direct deaths and separately noted indirect fatalities. The assessment examined both warning operations and how residents received and responded to warnings. Source 1 Source 2