Some storms, instead of producing large hail, instead produce copious amounts of small hail. Storms like these have produced hail drifts that, when captured in clogged drainage channels, …

Dual-polarization radar can distinguish between rain, hail, snow, or ice pellets inside the clouds. NSSL scientists are developing algorithms that will produce estimates of whether the …

Hail can cause billions of dollars of damage to structures, crops and livestock. NSSL focuses research efforts towards the prediction and detection of hail and hailstorms to give those in the …

Information about hail forecasting, models and methodology, from the NOAA National Severe Storms Laboratory.

Information about radar systems and algorithms used to detect severe hail, from the NOAA National Severe Storms Laboratory.

Frequently asked questions about severe thunderstorm forecasting, models and methodology, from the NOAA National Severe Storms Laboratory.

A thunderstorm is classified as “severe” when it contains one or more of the following: hail one inch or greater, winds gusting in excess of 50 knots (57.5 mph), or a tornado.

Step into the wild world of weather! What is a wall cloud? What's the difference between a watch and a warning? Is it ever “too cold to snow”? Learn all about thunderstorms, tornadoes, hail, …

Multicell storms may produce hail, strong winds, brief tornadoes, and/or flooding. A squall line is a group of storms arranged in a line, often accompanied by “squalls” of high wind and heavy rain.

Most thunderstorms have hail, but not all thunderstorms produce hail at the ground. Temperatures at the upper levels of a thunderstorm are well below freezing, allowing for the development of …