Forecast wind map

What the wind map shows

The wind ahead, 33 ft above the ground, in miles an hour, with lines that flow the way it blows and as fast. Strong wind turns the map amber and red; the lines show where it comes from and where it goes.

How to read it

Under 10 mph

Light wind.

10 to 20 mph

Breezy.

20 to 30 mph

Windy.

30 to 40 mph

Strong wind; hard to drive a high truck.

Over 40 mph

Damaging wind, what a high wind warning names.

What it is for

• Plan a drive, a flight or a day on the water around the wind.
• See where dry wind spreads fire.
• Watch the wind turn as a front passes.

How it is made

The forecast maps are drawn from the national blend of the forecast models: the models joined into one forecast and corrected against what each place has measured, on a grid 1.6 miles across, the forecast the country’s forecasters start from. Each of its main runs, four a day, is read whole, laid onto the same grid of latitude and longitude as the radar at 2.8 miles a cell, and played forward from now.

A frame every 3 hours to 3 days, then every 6 hours to 7 days, played from now as a loop of 1 to 7 days. As data: /radar/now.json?show=fwind, the times of its frames.