0
|
Calm |
< 1 kt 0-0.2 m/s < 1 km/h < 1 mph
|
- Calm
- Smoke rises vertically
|
|
|
0 m 0 ft
|
1
|
Light air |
1-3 kt 0.3-1.5 m/s 1-5 km/h 1-3 mph
|
- Direction of wind shown by smoke drift but not by wind vanes
|
- Ripples with the appearance of scales are formed, but without foam crests
|
- Fishing smack just has steerage way
|
0.1 (0.1) m 0.25 (0.25) ft
|
2
|
Light breeze |
4-6 kt 1.6-3.3 m/s 6-11 km/h 4-7 mph
|
- Wind felt on face
- Leaves rustle
- Ordinary vanes moved by wind
|
- Small wavelets, still short but more pronounced
- Crests have a glassy appearance and do not break
|
- Wind fills the sails of smacks which then travel at about 1-2 kt
|
0.2 (0.3) m 0.5 (1) ft
|
3
|
Gentle breeze |
7-10 kt 3.4-5.4 m/s 12-19 km/h 8-12 mph
|
- Leaves and small twigs in constant motion
- Wind extends light flag
|
- Large wavelets
- Crests begin to break
- Foam of glassy appearance
- Perhaps scattered white horses
|
- Smacks begin to careen and travel about 3-4 kt
|
0.6 (1) m 2 (3) ft
|
4
|
Moderate breeze |
11-16 kt 5.5-7.9 m/s 20-28 km/h 13-18 mph
|
- Raises dust and loose paper
- Small branches are moved
|
- Small waves, becoming longer
- Fairly frequent white horses
|
- Good working breeze
- Smacks carry all canvas with good list
|
1 (1.5) m 3.5 (5) ft
|
5
|
Fresh breeze |
17-21 kt 8.0-10.7 m/s 29-38 km/h 19-24 mph
|
- Small trees in leaf begin to sway
- Crested wavelets form on inland waters
|
- Moderate waves, taking a more pronounced long form
- Many white horses are formed (chance of some spray)
|
|
2 (2.5) m 6 (8.5) ft
|
6
|
Strong breeze |
22-27 kt 10.8-13.8 m/s 39-49 km/h 25-31 mph
|
- Large branches in motion
- Whistling heard in telegraph wires
- Umbrellas used with difficulty
|
- Large waves begin to form
- White foam crests are more extensive everywhere (probably some spray)
|
- Smacks have double reef in mainsail
- Care required when fishing
|
3 (4) m 9.5 (13) ft
|
7
|
Near gale |
28-33 kt 13.9-17.1 m/s 50-61 km/h 32-38 mph
|
- Whole trees in motion
- Inconvenience felt when walking against wind
|
- Sea heaps up and white foam from breaking waves begins to be blown in streaks along the direction of the wind
|
- Smacks remain in harbor and those at sea lie to
|
4 (5.5) m 13.5 (19) ft
|
8
|
Gale |
34-40 kt 17.2-20.7 m/s 62-74 km/h 39-46 mph
|
- Breaks twigs off trees
- Generally impedes progress
|
- Moderately high waves of greater length
- Edges of crests begin to break into the spindrift
- Foam is blown in well-marked streaks along the direction of the wind
|
- All smacks make for harbor, if near
|
5.5 (7.5) m 18 (25) ft
|
9
|
Strong gale |
41-47 kt 20.8-24.4 m/s 75-88 km/h 47-54 mph
|
- Slight structural damage occurs (chimney pots and states removed)
|
- High waves
- Dense streaks of foam along the direction of the wind
- Crests of waves begin to topple, tumble and roll over
- Spray may affect visibility
|
-
|
7 (10) m 23 (32) ft
|
10
|
Storm |
48-55 kt 24.5-28.4 m/s 89-102 km/h 55-63 mph
|
- Seldom experienced inland
- Trees uprooted
- Considerable structural damage occurs
|
- Very high waves with long overhanging crests
- Resulting foam, in great patches, is blown in dense white streaks along the directionof the wind
- On the whole, the surface of the sea takes on a white appearance
- Tumbling of the sea becomes heavy and shock-like
- Visibility affected
|
-
|
9 (12.5) m 29 (41) ft
|
11
|
Violent storm |
56-63 kt 28.5-32.6 m/s 103-117 km/h 64-72 mph
|
- Very rarely experienced
- Accompanied by widespread damage
|
- Exceptionally high waves (small and medium-sized ships might be for a time lost to view behind waves)
- Sea is completely covered with long white patches of foam lying along the direction of the wind
- Everywhere the edges of the wave crests are blown into froth
- Visibility affected
|
-
|
11.5 (16) m 37 (52) ft
|
12
|
Hurricane |
> 64 kt > 32.7 m/s > 118 km/h > 73 mph
|
-
|
- Air is filled with foam and spray
- Sea completely white with driving spray
- Visibility very seriously affected
|
-
|
14 (-) m 45 (-) ft
|