Largest hail now
Hail size
Latest
The largest hail each storm is holding now, in inches across, every ten minutes: which storms carry hail, and how large.
.255 in
Storm analysis / Largest hail, last hour
Hail track, live radar analysis
Over Evergreen, Texas, where the map opens. The whole country
The largest hail of the last hour at each place, in inches across: the path each hail storm has cut. How to read it.
The rings are the storms the radars detect, the larger ring a severe one; each line runs to where its storm will be in an hour if it keeps its present speed and heading. Rotation and hail are what the radars detect and the analysis measures, not warnings: the official watches and warnings in force are drawn on the map in their own colours and set out in full under Alerts.
What the hail track map shows
The largest hail at each place in the hour to each frame, in inches across: the swath each hail storm has cut across the ground. Played, the tracks draw out behind the storms as they move, the widest and longest under the strongest storms.
How to read it
- Under 0.75 in
- Small hail.
- 0.75 to 1 in
- Penny to quarter.
- 1 to 1.75 in
- Severe hail.
- 1.75 to 2.75 in
- Golf ball to baseball.
- Over 2.75 in
- Giant hail.
What it is for
- Find where hail has fallen, street by street, after a storm passes.
- Check a car, a roof or a crop for damage, and when it was likely done.
- Follow a hail storm’s path and the direction it is moving.
How it is made
The storm analysis joins every radar in the national network every two minutes into one picture of the country on a grid about two thirds of a mile across, cleaned of ground clutter, birds and insects, and measures from it what no single radar shows: the largest hail, the turning of the wind, how high a storm’s heavy echo reaches above the freezing level, and what is falling, read with the temperature of the air. Storm Station keeps it every ten minutes for a day, the gauged rain and the radars’ view each hour, and draws it at every zoom from the analysis’s own grid.
A frame every 10 minutes, played as a loop of 1 to 24 hours. As data: /radar/now.json?show=meshtrack, the times of its frames.
In the Field Book
- SupercellFB-EVT-007
- ThunderstormFB-EVT-001
Over a state
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With it
Severe AlertsWeather by stateForecast accuracyInstrument atlas
Beside it
Turning wind, last hour
Rotation track
Latest
The sharpest turning of the wind near the ground in the last hour, in mph across a mile: the path each rotating storm took.
10150 mph a mile
Heavy echo above freezing
Hail core
Latest
How far above the freezing level each storm holds its heaviest echo, in thousands of feet: the taller the core, the larger the hail it can grow.
035,000 ft