Rain total, 1 hour
Last hour
Latest
All the rain of the last hour, in inches: the quickest way to see where the downpours are falling now.
.0112 in
Storm analysis / Rain, checked by gauges
Rain in the last hour, checked by gauges
Over Citizen station DW9278, California, where the map opens. The whole country
The rain of each hour, in inches, checked against the rain gauges: the truest measure of an hour’s rain, posted about an hour after it ends. 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 gauged hour map shows
The rain of each hour, in inches, the radars’ estimate checked and corrected against the rain gauges that reported that hour. The truest measure of an hour’s rain across the country; each hour is posted about an hour after it ends, and the time shown is the hour’s end.
How to read it
- Under 0.1 in
- A passing shower.
- 0.1 to 0.5 in
- Steady rain.
- 0.5 to 1 in
- Heavy rain; water ponds on roads.
- Over 1 in
- Flash flooding possible, above all in cities and steep ground.
What it is for
- Check how much rain really fell in an hour, gauge by gauge across the country.
- Compare with the radar’s own hourly total: where they differ, the gauges corrected it.
- Follow a slow storm hour by hour.
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 each hour, played as a loop of 6 to 24 hours. As data: /radar/now.json?show=qpe1, the times of its frames.
In the Field Book
- Flash floodFB-EVT-100
- WSR-88D radarFB-INS-005
Over a state
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With it
Severe AlertsWeather by stateForecast accuracyInstrument atlas
Beside it
Rain total, 24 hours
Last day
Latest
The rain of the last 24 hours, in inches: where the heaviest totals of the day fell, and which ground is soaked.
.0112 in
Falling now
Rain rate
Latest
How hard rain and snow are falling at this moment, in inches of water an hour, a new picture every two minutes.
.014 in an hour