The following table describes wind speed in terms of the Beaufort scale...
| Force | Name | Description | Wind Speed | Wave Height (m) | |||||
| Sea | Land | kts | mph | kph | m/s | AVG | MAX | ||
| 0 | Calm | Sea like a mirror | Tree leaves don't move; smoke rises vertically | 0 1 |
0 1 |
0 1 |
0 0.2 |
0 | 0 |
| 1 | Light air | Ripples with appearance of scales, no crests form | Tree leaves don't move; smoke drifts slowly | 1 3 |
1 3 |
1 5 |
0.3 1.5 |
0.1 | 0.1 |
| 2 | Light breeze | Wavelets, small but pronounced. Crests with glassy appearance, but do not break | Tree leaves rustle; flags wave slightly | 4 6 |
4 7 |
6 11 |
1.6 3.3 |
0.2 | 0.3 |
| 3 | Gentle breeze | Large wavelets, crests begin to break. Glassy looking foam, occasional white horses | Leaves and twigs in constant motion; small flags extended | 7 10 |
8 11 |
12 19 |
3.4 5.4 |
0.6 | 1.0 |
| 4 | Moderate breeze | Small waves becoming longer, frequent white horses | Small branches move; flags flap | 11 16 |
13 18 |
20 29 |
5.5 7.9 |
1.0 | 1.5 |
| 5 | Fresh breeze | Moderate waves of pronounced long form. Many white horses, some spray | Small trees sway; flags flap and ripple | 17 21 |
19 24 |
30 38 |
8.0 10.7 |
2.0 | 2.5 |
| 6 | Strong breeze | Some large waves, extensive white foam crests, some spray | Large branches sway; flags beat and pop | 22 27 |
25 31 |
39 50 |
10.8 13.8 |
3.0 | 4.0 |
| 7 | Near gale | Sea heaped up, white foam from breaking waves blowing in streaks with the wind | Whole trees sway | 28 33 |
32 38 |
51 61 |
13.9 17.1 |
4.0 | 5.5 |
| 8 | Gale | Moderately high and long waves. Crests break into spin drift, blowing foam in well marked streaks | Twigs break off trees | 34 40 |
39 46 |
62 74 |
17.2 20.7 |
6.0 | 7.5 |
| 9 | Severe gale | High waves, dense foam streaks in wind, wave crests topple, tumble and roll over. Spray reduces visibility | Branches break off trees; tiles blown from roofs | 41 47 |
47 54 |
75 86 |
20.8 24.4 |
7.0 | 10.0 |
| 10 | Storm | Very high waves with long overhanging crests. Dense blowing foam, sea surface appears white. Heavy tumbling of sea, shock-like, poor visibility | Some trees blown down; damage to buildings | 48 55 |
55 63 |
87 101 |
24.5 28.4 |
9.0 | 12.5 |
| 11 | Severe storm | Exceptionally high waves, sometimes concealing small and medium sized ships. Sea completely covered with long white patches of foam. Edges of wave crests blown into froth. Poor visibility | Widespread damage to trees and buildings | 56 63 |
64 74 |
102 120 |
28.5 32.6 |
11.5 | 16.0 |
| 12 | Hurricane | Air filled with foam and spray, sea white with driving spray, visibility poor | Severe and extensive damage | >63 | >74 | >120 | >32.6 | >11.5 | >16.0 |
The following table describes wind speed in terms of the Saffir-Simpson hurricane scale...
| Category | Name | Description | Wind Speed | Storm Surge | |||||
| Coastal | Inland | kts | mph | kph | m/s | ft | m | ||
| 1 | Minimal Hurricane | Low-lying coastal roads inundated, minor pier damage, some small craft in exposed anchorage torn from moorings | No real damage to building structures. Damage primarily to unanchored mobile homes, shrubbery, and trees. Some damage to poorly constructed signs | 64 82 |
75 95 |
121 153 |
33 42 |
4 5 |
1.2 1.5 |
| 2 | Moderate Hurricane | Coast roads and low-lying escape routes inland cut by rising water 2 to 4 hours before arrival of hurricane center. Considerable damage to piers. Marinas flooded. Small craft in unprotected anchorages torn from moorings. Evacuation of some shoreline residences and low-lying areas required | Some roofing material, door, and window damage of buildings. Considerable damage to shrubbery and trees with some trees blown down. Considerable damage to mobile homes, poorly constructed signs, and piers | 83 95 |
96 110 |
154 177 |
43 49 |
6 8 |
1.8 2.4 |
| 3 | Extensive Hurricane | Low-lying escape routes are cut by rising water 3-5 hours before arrival of the hurricane center. Flooding near the coast destroys smaller structures with larger structures damaged by battering of floating debris. Terrain continuously lower than 5 ft above mean sea level may be flooded inland 8 miles (13 km) or more. Evacuation of low-lying residences within several blocks of the shoreline may be required | Some structural damage to small residences and utility buildings with a minor amount of curtainwall failures. Damage to shrubbery and trees with foliage blown off trees and large tress blown down. Mobile homes and poorly constructed signs are destroyed | 96 113 |
111 130 |
178 209 |
50 58 |
9 12 |
2.7 3.7 |
| 4 | Extreme Hurricane | Low-lying escape routes may be cut by rising water 3-5 hours before arrival of the hurricane center. Major damage to lower floors of structures near the shore. Terrain lower than 10 ft above sea level may be flooded requiring massive evacuation of residential areas as far inland as 6 miles (10 km) | More extensive curtainwall failures with some complete roof structure failures on small residences. Shrubs, trees, and all signs are blown down. Complete destruction of mobile homes. Extensive damage to doors and windows | 114 135 |
131 155 |
210 249 |
59 69 |
13 18 |
4.0 5.5 |
| 5 | Catastrophic Hurricane | Low-lying escape routes are cut by rising water 3-5 hours before arrival of the hurricane center. Major damage to lower floors of all structures located less than 15 ft above sea level and within 500 yards of the shoreline. Massive evacuation of residential areas on low ground within 5-10 miles (8-16 km) of the shoreline may be required | Complete roof failure on many residences and industrial buildings. Some complete building failures with small utility buildings blown over or away. All shrubs, trees, and signs blown down. Complete destructon of mobile homes. Severe and extensive window and door damage | >135 | >155 | >249 | >70 | >19 | >5.5 |