Severe weather labels

Two datasets supply severe weather reports that can label other data. They overlap heavily and differ in shape, and both need care before they become a training set.

name: oklahoma-2024
sources:
  - dataset: noaa:storm-events
    start: 2024-01-01
    end: 2024-12-31
  - dataset: noaa:spc-tornado-reports
    start: 2024-01-01
    end: 2024-12-31

Storm Events or SPC

Storm Events (noaa:storm-events) is NCEI's database of about fifty event types, one gzipped CSV per year. Tornado, hail, and thunderstorm-wind rows each carry a magnitude, timing, location, casualties, damage, and a narrative. A tornado appears once per county it crossed, linked by EPISODE_ID; EVENT_ID identifies the row.

SPC tornado reports (noaa:spc-tornado-reports) is the Storm Prediction Center's tornado database: one row per tornado segment with a single straight-line path, an F or EF rating, and casualties, from 1950. It has no hail or wind rows and no narrative, but its columns are consistent across seventy-five years.

For tornado-versus-not labels, Storm Events supplies all three classes and SPC cross-checks the tornado rows.

Local time

Storm Events rows are stamped in local time with a CZ_TIMEZONE column such as CST-6. Convert before joining to radar, satellite, or model data, which are all UTC. SPC rows carry a tz code where 3 means Central Standard Time regardless of daylight saving. Never assume a timezone from the state.

Several rows per storm

One storm can produce a tornado row, a hail row, and several wind rows minutes apart, and one tornado can produce several county rows. Count events, not rows, and decide whether your unit is the report, the episode, or the storm before you aggregate.

Absence is not evidence

A missing report does not establish that nothing happened. Reports depend on population, spotters, and survey resources, and historical reporting practice changed over the decades. Negative examples should come from hail and wind rows, not from silence, and any climatology should state the reporting era it covers.

The tornado classification example builds a twelve-row labeled table this way and lists the caveats it could not resolve; the SPC tornadoes example counts one year by rating.