|
Force
|
Description
|
Appearance
|
Wind (knots)
|
Wave Ht (ft)
|
Max ht (ft)
|
|
0
|
Calm
|
Sea like a mirror
|
<1
|
—
|
—
|
|
1
|
Light air
|
Ripples
|
1-3
|
0.25
|
0.25
|
|
2
|
Light breeze
|
Small wavelets; crests have a glassy appearance
|
4-6
|
0.5
|
1
|
|
3
|
Gentle breeze
|
Large wavelets, foam of glassy appearance, scattered white caps
|
7-10
|
2
|
3
|
|
4
|
Moderate breeze
|
Small waves, fairly frequent white caps
|
11-16
|
3.5
|
5
|
|
5
|
Fresh breeze
|
Moderate waves, many white caps, chance of spray
|
17-21
|
6
|
8.5
|
|
6
|
Strong breeze
|
Large waves, Foam crests everywhere, Probable spray
|
22-27
|
9.5
|
13
|
|
7
|
Near gale
|
Sea heaps up, foam begins to be blown in direction of wind
|
28-33
|
13.5
|
19
|
|
8
|
Gale
|
Moderately high waves, spindrift, foam is blown in streaks
|
34-40
|
18
|
25
|
|
9
|
Strong gale
|
High waves, dense foam, crests of waves begin to topple
|
41-47
|
23
|
32
|
|
10
|
Storm
|
Very high waves, visibility affected by spray
|
48-55
|
29
|
41
|
|
11
|
Violent storm
|
Exceptionally high waves, sea covered in foam
|
56-63
|
37
|
52
|
|
12
|
Hurricane
|
Air is filled with spray and foam, visibility seriously affected
|
>64
|
45
|
—
|
