| Wind force |
|
Terminology |
|
Wind* Speed
(Km/h) |
|
Wind* Speed (knots) |
|
Minimum Height (Max) waves (m) |
|
Effects observed at sea |
Effect observed on earth |
| 0 |
|
Calm |
|
less than 1 |
|
less than 1 |
|
0 |
|
The sea is like a mirror |
Calm, smoke rises vertically. |
| 1 |
|
Very light breeze |
|
1 to 5 |
|
1 to 3 |
|
0,1 |
|
Rather it is resembling wrinkles chips poissions.
No foam |
The wind direction is revealed by the training of the smoke, but not by wind. |
| 2 |
|
Light breeze |
|
6 to 11 |
|
4 to 6 |
|
0,2 (0,3) |
|
Ripples, still short but more extreme. Their crest is a glassy appearance but do not break. |
The wind is seen in the face. The leaves shiver. |
| 3 |
|
Gentle breeze |
|
12 to 19 |
|
7 to 10 |
|
0,6 (1) |
|
Very small waves. Crests begin to break. Foam of glassy appearance. Sometimes a few scattered sheep. |
Leaves and twigs are constantly agitated. Wind extends light flags. |
| 4 |
|
Nice breeze |
|
20 to 28 |
|
11 to 16 |
|
1 (1,5) |
|
Small waves becoming longer. Frankly many sheep. |
Wind raises dust and paper. Small branches are rough. |
| 5 |
|
Fresh breeze |
|
29 to 38 |
|
17 to 21 |
|
2 (2,5) |
|
Moderate waves taking a much more elongated. Birth of many sheep. Possibly spray. |
Shrubs leaf begin to sway. Small waves with peak form on inland waters. |
| 6 |
|
Fresh wind |
|
39 to 49 |
|
22 to 27 |
|
3 (4) |
|
Tears begin to form. The white foam crests are more extensive everywhere. |
The main branches are agitated. The son telegraph hear a hiss. The use of umbrellas is made difficult. |
| 7 |
|
Costly |
|
50 to 61 |
|
28 to 33 |
|
4 (5,5) |
|
Some trails tears waves of foam that is moving in the wind. |
The trees are shaken in full. Walking against the wind is difficult. |
| 8 |
|
Gale |
|
62 to 74 |
|
34 to 40 |
|
5,5 (7,5) |
|
Blades of average height and elongated. Clear trails scum oriented in the wind. Eddies of mist begins to form. |
The wind breaks branches. Walking against the wind is usually impossible. |
| 9 |
|
Strong gale |
|
75 to 88 |
|
41 to 47 |
|
7 (10) |
|
Large waves. Thick streaks of froth in the wind. The wave crest begins to crumble and break rolls. |
The wind caused minor damage to homes. |
| 10 |
|
Storm |
|
89 to 102 |
|
48 to 55 |
|
9 (12,5) |
|
Very large waves with long ridges panache. The foam produced in large agglomerates benches. The foam is blown in the wind into thick streaks. The surface water seems white. The wave rolls became intense and brutal. The spray can reduce visibility. |
Rare inland. Trees uprooted. Extensive damage to homes. |
| 11 |
|
Violent storm |
|
103 to 117 |
|
56 to 63 |
|
11,5 (16) |
|
The blades are exceptionally high. The sea is completely covered with white foam benches cross-tree in the wind. The edge of the wave crest is blown and gives the foam. Small and medium-sized vessels may by now be lost. The visibility is reduced. |
Very rarely observed. Accompanied by widespread devastation. |
| 12 |
|
Hurricane |
|
118 and more |
|
64 and more |
|
14 and more |
|
The air is full of foam and spray. The sea is completely white because of scum floating rigs. The visibility is drastically reduced. |
Mainly observed in the cyclone. Exceptionally under our lalitudes. |
| |
| * The speeds are related to mean wind and not to gusts. The gusting wind may exceed the average of 50% |
