Reflectivity
Radar
Latest
Rain, snow and hail across the country now, from every radar in the national network, a new picture every five minutes.
1070 dBZ
Live radar / Falling now
Rain rate, live radar
Over Chalco, Nebraska, where the map opens. The whole country
How hard rain and snow are falling at this moment, in inches of water an hour, a new picture every two minutes. 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 rain rate map shows
How hard it is raining or snowing at this moment, in inches of water an hour. Under 0.1 inch an hour is light rain; over 0.3 is heavy; an inch an hour is a downpour that can flood streets.
How to read it
- Under 0.1 in an hour
- Light rain or snow.
- 0.1 to 0.3 in
- Moderate rain.
- 0.3 to 1 in
- Heavy rain; gutters and ditches fill.
- Over 1 in an hour
- A downpour that floods streets and underpasses.
- Over 2 in an hour
- Flash flooding likely, above all in cities and on burn scars.
What it is for
- Time the heaviest rain at a place, to the minute.
- See where streets and creeks may flood before the water rises.
- Read the water in falling snow, which decides how heavy and wet it lies.
How it is made
Every radar in the national network, more than 150 of them, sweeps the sky every few minutes, tilting up through a set of angles. The sweeps are joined into one picture of the country on a grid about a third of a mile across, each place taking the lowest beam that sees it clearly. Each picture is checked against the national analysis before it is drawn, and echo it does not confirm (birds, insects, ground clutter, the beam bent back to the ground) is left out.
A picture every 2 minutes, played as a loop of 1 to 24 hours. As data: /radar/now.json?show=rate, the times of its frames.
In the Field Book
- ThunderstormFB-EVT-001
- WSR-88D radarFB-INS-005
Over a state
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With it
Severe AlertsWeather by stateForecast accuracyInstrument atlas
Beside it
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
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
Forecast amount
Rain, 6 hours
For
How much rain will fall in each 6 hours, in inches, snow as its water: the bands of rain crossing storm by storm.
.0112 in