Hail Map: See Where Significant Hail Fell
HailLeads maps where large hail most likely reached the ground. A radar hail estimate only makes the map if the storm itself backs it up.
Not every radar blob makes the map.
A radar hail estimate is only the starting point. HailLeads keeps it only if the storm supports it, and hail that doesn’t pass is left off.
Radar finds it
NOAA’s MRMS radar analysis flags hail estimated at 1.75 inches (golf ball) or larger.
The storm has to back it up
The radar reading at the -10°C level and the wet-bulb-zero height both have to fit. If either one doesn’t, the hail isn’t mapped.
We trace it to the ground
A launch height is chosen carefully for each hail core. Descent and wind drift then move it to where it probably landed.
Chase our hail map to its coordinates. You’ll have more than radar.
Follow a radar blob and you’re trusting one reading. Follow a point on the HailLeads map and you’re following hail that passed the checks, and was traced from where it formed to where it landed.
Six steps from radar to ground.
Each step either confirms the hail or moves it closer to where it landed.
MRMS hail size
Hail estimated at 1.75 inches or larger is the starting population.
Reflectivity at -10°C
The radar reading at the -10°C level has to meet a required value. Hail without that support is dropped.
Wet-bulb-zero height
The atmosphere’s wet-bulb-zero level has to fit the storm, or the hail is dropped.
The right starting point
The height of the hail-producing core is chosen with care, because a wrong starting height puts the landing spot in the wrong place.
Falling through the storm
The model follows the hail down instead of assuming it landed where the radar saw it.
Wind carries it sideways
Storm winds are applied along the fall to estimate how far the hail moved before reaching the ground.
What hail sizes look like.
Hail sizes are usually described by everyday objects. Larger hail generally means a greater chance of damage to roofs and vehicles.
| Size (inches) | Common comparison |
|---|---|
| 1.00 | Quarter |
| 1.25 | Half dollar |
| 1.50 | Ping-pong ball |
| 1.75 | Golf ball (where HailLeads analysis begins) |
| 2.00 | Hen egg |
| 2.50 | Tennis ball |
| 2.75 | Baseball |
| 3.00 | Teacup |
| 4.00 | Softball |
Sizes on the map are radar-derived estimates, not ground measurements.
Hail map questions.
What is a hail map?
A hail map shows where hail fell and how large it was estimated to be. HailLeads builds its map from radar-derived hail estimates, keeps only the ones the storm structure supports, and adjusts them for wind drift, so the mapped area reflects where the hail probably landed.
Where does the hail data come from?
The starting point is NOAA’s MRMS (Multi-Radar/Multi-Sensor) system, which estimates hail size from weather radar data. HailLeads then adds reflectivity structure, atmospheric conditions, and modeled hail descent and drift.
How accurate is the hail map?
The map is an estimate. Radar-derived hail sizes are not ground measurements, and the impact footprints are modeled, so treat the data as directional. Verify with a field inspection before making decisions about a specific property or vehicle.
How is this different from a radar image?
A radar image shows where a storm was and what it detected. On the HailLeads hail map, a radar hail estimate is kept only if the radar reading at the -10°C level and the wet-bulb-zero height both support it. It is then traced from a carefully chosen launch height down to where it probably landed, including wind drift.
What do the hail sizes mean?
They are estimated hail sizes in inches, from NOAA’s radar-based analysis. HailLeads focuses on significant hail, which starts at 1.75 inches (golf-ball size).
Who is the hail map for?
Roofing contractors, restoration teams, and auto hail repair professionals use it to decide where to send people after a storm. Storm chasers, researchers, and anyone curious about a hail event can also explore it.
Can I try it?
Yes. The live map has a 3-day trial. You can start it from the button below.
Open the hail map and see where the hail fell.
Explore radar-derived hail estimates, storm structure, hail-core analysis, and drift-adjusted impact areas on the live map, for roofing, restoration, auto hail repair, or plain curiosity about the weather.