Beaufort Scale

Beaufort Wind speed Description Wave
knots m/s English Norsk metres
0 Under 1 Under 0.3 Calm Stille 0
Sea conditions: Flat.
1 1 to 2 0.3-1.5 Light air Flau vind 0.1
Sea conditions: Ripples without crests.
2 3 to 5 1.5-3.3 Light breeze Svak vind 0.2
Sea conditions: Small wavelets. Crests of glassy appearance, not breaking
3 7 to 10 3.3-5.5 Gentle breeze Lett bris 0.6
Sea conditions: Large wavelets. Crests begin to break; scattered whitecaps
4 11 to 15 5.5-8.0 Moderate breeze Laber bris 1
Sea conditions: Small waves.
5 16 to 20 8.0-10.8 Fresh breeze Frisk bris 2
Sea conditions: Moderate (1.2 m) longer waves. Some foam and spray.
6 21 to 26 10.8-13.9 Strong breeze Liten Kuling 3
Sea conditions: Large waves with foam crests and some spray.
7 27 to 33 13.9-17.2 Moderate gale Stiv kuling 4
Sea conditions: Sea heaps up and foam begins to be blown in streaks in wind direction.
8 34 to 40 17.2-20.7 Fresh gale Stark kuling 5.5
Sea conditions: Moderately high waves with breaking crests forming spindrift. Streaks of foam.
9 41 to 47 20.7-24.5 Strong gale Liten storm 7
Sea conditions: High waves (6-7 m) with dense foam. Wave crests start to roll over. Considerable spray.
10 48 to 55 24.5-28.4 Storm Full storm 9
Sea conditions: Very high waves. Large patches of foam from wave crests give the sea a white appearance.
11 56 to 63 28.4-32.6 Violent storm Sterk storm Sea conditions:11.5
Sea conditions: Exceptionally high waves. Very large patches of foam, driven before the wind, cover much of the sea surface.
12 Over 63 Over 32.5 Hurricane-force Orkan Over 14
Sea conditions: Huge waves. Sea is completely white with foam and spray. Air is filled with driving spray, greatly reducing visibility.

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