HaSDEx Project

The National Severe Storms Laboratory (NSSL) needs YOUR help with a research project!

If you live in the area shown on the map, the Hail Size Discrimination Experiment (HaSDEx) wants YOU to watch and report on hail.

HaSDEx is looking for young, old, and in-between volunteers to make observations - teachers, classes and families too! We have collected over 4,000 observations since 2006, and making HaSDEx successful because of your help.

HaSDEx volunteers can spend a little or a lot of time making observations. The basic idea is simple: NSSL will collect radar data from NEXRAD radars during thunderstorms, and compare it with YOUR observations.

Why? Because the radars cannot see close to the ground, we need YOU to tell us what is happening.

Are you getting bombarded with baseball-sized hail? Are pea-sized pellets pelting you? Tell us where you are and what is hitting the ground! NSSL scientists will compare your report with what the radar has detected, and develop new radar technologies and techniques to determine what size hail will fall where.

The report is easy! Click on the “I Want to Volunteer!” button (or the report form link to the left) to check it out. We only ask for the date, time, location, and hail size. If you would like to report temperature, wind speed and direction, we will take that too – but it is not required. There is no commitment, and no minimum amount of reports.

We need as many observations as we can get! Check us out on Facebook or follow us on Twitter!

Please note: While these data are important, safety is absolutely essential. Please read the safety tips here.