What Is NEXRAD?
NEXRAD (Next-Generation Radar) is the United States' national network of 160+ high-resolution Doppler weather radars, operated jointly by NOAA, the National Weather Service, and the FAA. It detects rain, snow, wind, and hail in real time and is the primary radar source behind severe-weather warnings — and behind HailScore's hail records.
What does NEXRAD stand for?
NEXRAD stands for Next-Generation Radar. It is the official name for the WSR-88D (Weather Surveillance Radar, 1988, Doppler) network — the array of Doppler weather radars that blanket the United States. The network has been operational since the early 1990s and was upgraded to dual-polarization in 2011–2013.
How does NEXRAD detect hail?
A NEXRAD radar sends out pulses of microwave energy and measures what bounces back. Larger, denser objects like hailstones reflect more energy, producing higher reflectivity values. Dual-polarization radar adds a second, vertical pulse, which lets meteorologists distinguish hail from heavy rain by comparing the horizontal and vertical returns.
These radar returns are processed into hail-size estimates and archived. HailScore draws on NOAA's archive of these radar-derived hail signatures to determine where significant hail has fallen.
How HailScore uses NEXRAD data
NOAA NEXRAD radar is HailScore's primary data source: 5.9M+ radar hail records, all filtered to hail at least 0.75 inches in diameter (the National Weather Service's "severe" threshold), covering 2015 to present. These records come from NOAA's Severe Weather Data Inventory.
NEXRAD covers the entire continental US, which is why HailScore can score any US address — not just locations where someone happened to file a report.
Frequently asked questions
Who operates NEXRAD?
NEXRAD is operated jointly by three federal agencies: NOAA's National Weather Service, the Department of Defense, and the FAA. The data is public.
How many NEXRAD radars are there?
There are roughly 160 NEXRAD (WSR-88D) radar sites across the United States and select overseas locations, providing near-continuous coverage of the continental US.
Is NEXRAD the same as the radar on the news?
Yes. The radar imagery you see on TV and weather apps is largely derived from the NEXRAD network — the same network that supplies HailScore's historical hail records.
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