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BEAUFORT SCALE
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WIND SPEED (km/h)
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DESCRIPTION
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WAVE HEIGHT (mt)
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SEA CONDITIONS
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LAND CONDITION
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0
|
<1
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Calm
|
0
|
Flat.
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Calm. Smoke rises vertically.
|
|
1
|
1-5
|
Light air
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0.1
|
Ripples without crests.
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Wind motion visible in smoke.
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|
2
|
6-11
|
Light breeze
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0.2
|
Small wavelets. Crests of glassy appearance, not breaking.
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Wind felt on exposed skin. Leaves rustle.
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|
3
|
12-19
|
Gentle breeze
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0.6
|
Large wavelets. Crests begin to break; scattered whitecaps.
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Leaves and smaller twigs in constant motion.
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|
4
|
20-28
|
Moderate breeze
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1
|
Small waves.
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Dust and loose paper raised. Small branches begin to move.
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|
5
|
29-38
|
Fresh breeze
|
2
|
Moderate (1.2 m) longer waves. Some foam and spray.
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Branches of a moderate size move. Small trees begin to sway.
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|
6
|
39-49
|
Strong breeze
|
3
|
Large waves with foam crests and some spray.
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Large branches in motion. Whistling heard in overhead wires. Umbrella use becomes difficult. Empty plastic garbage cans tip over.
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|
7
|
50-61
|
High wind, Moderate Gale, Near Gale
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4
|
Sea heaps up and foam begins to be blown in streaks in wind direction.
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Whole trees in motion. Effort needed to walk against the wind. Swaying of skyscrapers may be felt, especially by people on upper floors.
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|
8
|
62-74
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Fresh Gale
|
5.5
|
Moderately high waves with breaking crests forming spindrift. Streaks of foam.
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Twigs broken from trees. Cars veer on road.
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|
9
|
75-88
|
Strong Gale
|
7
|
High waves (6-7 m) with dense foam. Wave crests start to roll over. Considerable spray.
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Larger branches break off trees, and some small trees blow over. Construction/temporary signs and barricades blow over. Damage to circus tents and canopies.
|
|
10
|
89-102
|
Whole Gale/Storm
|
9
|
Very high waves. Large patches of foam from wave crests give the sea a white appearance. Considerable tumbling of waves with heavy impact. Large amounts of airborne spray reduce visibility.
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Trees are broken off or uprooted, saplings bent and deformed, poorly attached asphalt shingles and shingles in poor condition peel off roofs.
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|
11
|
103-117
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Violent storm
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11.5
|
Exceptionally high waves. Very large patches of foam, driven before the wind, cover much of the sea surface. Very large amounts of airborne spray severely reduce visibility.
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Widespread vegetation damage. More damage to most roofing surfaces, asphalt tiles that have curled up and/or fractured due to age may break away completely.
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|
12
|
≥118
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Hurricane-force
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≥14
|
Huge waves. Sea is completely white with foam and spray. Air is filled with driving spray, greatly reducing visibility. |
Considerable and widespread damage to vegetation, a few windows broken, structural damage to mobile homes and poorly constructed sheds and barns. Debris may be hurled about.
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