Storm Records

The Storm Events Database is the National Weather Service’s official record of weather that killed, injured or did damage, and of weather rare enough to note. Each forecast office writes up its area every month in Storm Data; NOAA’s National Centers for Environmental Information compiles the months into this database and publishes each about 75 days after it ends.

An episode is one office’s account of one weather system, with a narrative of the whole. The events are its parts: each is one kind of weather in one county or forecast zone, with its own times, measurements, casualties, damage and, from 1996 on, a narrative. A storm that crossed three offices is three episodes.

From 1996 the record holds 48 kinds of event with each office’s narrative; before that, tornadoes, hail and thunderstorm wind only, and before 1955 tornadoes alone. Events filed by forecast zone rather than at a point, which is most heat, cold, winter, drought and many flood events, are drawn at the center of the zone’s counties and marked as such.

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.