Force One - Light air (1-3 knots) |
Sea state: |
Ripples with the appearance of scales are formed but without foam crests. |
From land: |
Direction of wind shown by smoke drift but not by wind vanes. |
'Forces-of-Nature' sports: |
Climbing, gorge walking, downhill mountain-boarding, surfing or stay at home and mend broken kit. |
|
|
Force Two - Light breeze (4-6 knots) |
Sea state: |
Small wavelets, still short but more pronounced. Crests have a glassy appearance but do not break. |
From land: |
Wind felt on the face. Leaves rustle. Ordinary vane moved by wind. |
'Forces-of-Nature' sports: |
Climbing, gorge walking, downhill mountain-boarding, kite-flying, surfing or stay at home and mend broken kit. |
|
|
Force Three - Gentle breeze (7-10 knots) |
Sea state: |
Large wavelets. Crests begin to break. Foam of glassy appearance. Perhaps scattered white horses. |
From land: |
Leaves and small twigs in constant motion. Wind extends light flags. |
'Forces-of-Nature' sports |
Climbing, gorge walking, downhill mountain-boarding, surfing, kite-flying and kite-buggying. |
|
|
Force Four - Moderate breeze (11-16 knots) |
Sea state: |
Small waves becoming longer. Fairly frequent white horses. |
From land: |
Raises dust and loose paper. Small branches are moved. |
'Forces-of-Nature' sports |
Surfing, kite-buggying with medium sized kites, kite-surfing with big kites, windsurfing with big kit. |
|
|
Force Five - Fresh breeze (17-21 knots) |
Sea state: |
Moderate waves, taking a more pronounced long form. Many white horses are formed. Chance of some spray. |
From land: |
Small trees in leaf begin to sway. Crested wavelets form on inland water. |
'Forces-of-Nature' sports |
Surfing, kite-buggying with small kites, kite-surfing with medium sized kites, windsurfing with 5.0-6.0m sails |
|
|
Force Six - Strong breeze (22-27 knots) |
Sea state: |
Large waves begin to form. The white foam crests are more extensive everywhere. Probably some spray. |
From land: |
Large branches in motion. Whistling in telegraph wires. Umbrellas used with difficulty. |
'Forces-of-Nature' sports |
Kite-surfing with small kites, windsurfing with 5.0m sails and small boards. |
|
|
Force Seven - Near gale (28-33 knots) |
Sea state: |
Sea heaps up and white foam from breaking waves begins to be blown in streaks along the direction of the wind. |
From land: |
Whole trees in motion. Inconvenience felt when walking against the wind. |
'Forces-of-Nature' sports |
Windsurfing with 4.0-4.5m sails and small boards, kitesurfing for experts with small kites. |
|
|
Force Eight - Gale (34-40 knots) |
Sea state: |
Moderately high waves of greater length. Edges of crests begin to break into spindrift. The foam is blown in well-marked streaks along the direction of the wind. |
From land: |
Breaks twigs off trees. Generally impedes progress. |
'Forces-of-Nature' sports |
Windsurfing with 3.0-4.0m sails. |
|
|
Force Nine - Strong gale (41-47 knots) |
Sea state: |
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. |
From land: |
Slight structural damage occurs (chimney pots and slates removed). |
'Forces-of-Nature' sports |
Windsurfing with 3.0-4.0m sails in 'survival' conditions. |
|
|
Force Ten - Storm (48-55 knots) |
Sea state: |
Very high waves with long over-hanging crests. Foam in great patches is blown in dense white streaks along the direction of the wind. The surface takes on a white appearance. The tumbling of the sea becomes heavy and shock-like. Visibility affected. |
From land: |
Seldom experienced inland. Trees uprooted. Considerable structural damage occurs. |
'Forces-of-Nature' sports |
Find somewhere sheltered. |
|
|
Force Eleven - Violent Storm (56-63 knots) |
Sea state: |
Sea covered in foam patches, with waves high enough to hide medium-sized vessels and with crests blown into froth, visibility affected. |
From land: |
Very rare on land, causing widespread damage. |
'Forces-of-Nature' sports |
Forget it. |
|
|
Force Twelve - Hurricane (64+ knots) |
Sea state: |
Sea completely white, with driving spray, the air filled with foam and spray, visibility seriously impaired. |
From land: |
No description. |
'Forces-of-Nature' sports |
Yeah right...death on a stick mate!. |
|
|