Storm data guides

IndependentNot affiliated with NOAA or the National Weather Service.

Plain explanations of the storm data on this site: what NOAA radar estimates and storm reports show, how to read them for one address, and where they fall short. Each guide uses our own numbers from public NOAA data and cites its sources.

• How to check if it hailed at your addressHow to find out whether hail fell near an address on a given day: the address lookup, storm-day pages, and what NOAA radar estimates and storm reports each show.
• Hail size chart and roof damageHail sizes from pea to softball, the sizes at which research finds hail can damage common roof coverings, impact ratings, and how often each size is reported.
• Hail vs wind damageHow hail and damaging wind differ in NOAA storm reports, how often they come on the same storm day, and the signs each one can leave.
• What radar-estimated hail (MESH) is and isn'tWhat NOAA's radar hail estimate (MRMS MESH) measures, where it is wrong, and how often radar-estimated hail near a city came with a hail report on the ground.
• Storm reports: preliminary vs finalWhy this year's NOAA storm reports are preliminary, how they are filtered, how the final Storm Data record differs, and what that means for counts and dates.

For reporters: data for journalists. For every source and method: methodology & sources.