Wind Scale after Beaufort - Sea

Beaufort 0: Calm (Stille)

Wind velocity: 0 - 1 knot (0.0 - 0.52 m/s)

Sea like a mirror.

Beaufort 1: Light Airs (Flau vind)

Wind velocity: 1 - 3 knots (0.52 - 1.80 m/s)

Ripples with the appearence of scales are formed, but without

foam crests.

Beaufort 2: Light Breeze (Svak vind)

Wind velocity: 4 - 6 knots (1.80 - 3.35 m/s)

Small wavelets, short but pronounced; crests have a glossy

appearance, but do not break.

Beaufort 3: Gentle Breeze (Lett bris)

Wind velocity: 7 - 10 knots (3.35 - 5.41 m/s)

Large wavelets, crests begin to break. Foam of glossy

appearance. Perhaps scattered white horses.

Beaufort 4: Moderate Breeze (Laber bris)

Wind velocity: 11 - 16 knots (5.41 - 8.50 m/s)

Small waves, becoming longer; fairly frequent white horses.

Beaufort 5: Fresh Breeze (Frisk bris)

Wind velocity: 17 - 21 knots (8.50 - 11.07 m/s)

Moderate waves, taking a more pronounced long form; many

white horses are formed. Chance of some spray.

Beaufort 6: Strong Breeze (Liten kuling)

Wind velocity: 22 - 27 knots (10.07 - 14.16 m/s)

Large waves begin to form; the white foam crests are more

extensive everywhere. Probably some spray.

Beaufort 7: Near Gale (Stiv kuling)

Wind velocity: 28 - 33 knots (14.16 - 17.25 m/s)

Sea keeps up and white foam from breaking waves begins to

be blown in streaks along the direction of the wind.

Spindrift begins to be seen.

Beaufort 8: Gale (Sterk kuling)

Wind velocity: 34 - 40 knots (17.25 - 20.86 m/s)

Moderately high waves of greater length; edges of crests

break into spindrift. The foam is blown in well marked

streaks along the direction of the wind. Spray affects visibility.

Beaufort 9: Strong Gale (Liten storm)

Wind velocity: 41 - 47 knots (20.86 - 24.46 m/s)

High waves. Dense streaks of foam along the direction of the

wind. Sea begins to roll. Visibility affected.

Beaufort 10: Storm (Full storm)

Wind velocity: 48 - 55 knots ( 24.46 - 28.58 m/s )

Very high waves with long overhanging crests. The resulting

foam is in great patches and is blown in dense white streaks

along the direction of the wind. On the whole of the surface

the sea takes a white appearence. The rolling of the sea

becomes heavy and shock-like. Visibility is affected.

Beaufort 11: Violent Storm (Sterk storm)

Wind velocity: 56 - 63 knots (28.58 - 32.70 m/s)

Exceptionally high waves. Sea completely covered with long

white patches of foam lying in direction of wind. Everywhere

edges of wave crests are blown into fret. Visibility affected.

Beaufort 12: Hurricane (Orkan)

Wind velocity: more than 64 knots (more than 32.70 m/s)

Air filled with foam and spray. Sea white with driving spray;

visibility very seriously affected.