Wind Force Scale
See also: Tropical cyclone scales and Surface weather analysisHistorically, the Beaufort wind force scale provides an empirical description of wind speed based on observed sea conditions. Originally it was a 13-level scale, but during the 1940s, the scale was expanded to 17 levels. There are general terms that differentiate winds of different average speeds such as a breeze, a gale, a storm, tornado, or a hurricane. Within the Beaufort scale, gale-force winds lie between 28 knots (52 km/h) and 55 knots (102 km/h) with preceding adjectives such as moderate, fresh, strong, and whole used to differentiate the wind's strength within the gale category. A storm has winds of 56 knots (104 km/h) to 63 knots (117 km/h). The terminology for tropical cyclones differs from one region to another globally. Most ocean basins use the average wind speed to determine the tropical cyclone's category. Below is a summary of the classifications used by Regional Specialized Meteorological Centers worldwide:
General wind classifications | Tropical cyclone classifications (all winds are 10-minute averages) | |||||||
---|---|---|---|---|---|---|---|---|
Beaufort scale | 10-minute sustained winds (knots) | General term | N Indian Ocean IMD |
SW Indian Ocean MF |
Australian region South Pacific BoM, BMKG, FMS, MSNZ |
NW Pacific JMA |
NW Pacific JTWC |
NE Pacific & N Atlantic NHC & CPHC |
0 | <1 | Calm | Low Pressure Area | Tropical disturbance | Tropical low Tropical Depression |
Tropical depression | Tropical depression | Tropical depression |
1 | 1–3 | Light air | ||||||
2 | 4–6 | Light breeze | ||||||
3 | 7–10 | Gentle breeze | ||||||
4 | 11–16 | Moderate breeze | ||||||
5 | 17–21 | Fresh breeze | Depression | |||||
6 | 22–27 | Strong breeze | ||||||
7 | 28–29 | Moderate gale | Deep depression | Tropical depression | ||||
30–33 | ||||||||
8 | 34–40 | Fresh gale | Cyclonic storm | Moderate tropical storm | Tropical cyclone (1) | Tropical storm | Tropical storm | Tropical storm |
9 | 41–47 | Strong gale | ||||||
10 | 48–55 | Whole gale | Severe cyclonic storm | Severe tropical storm | Tropical cyclone (2) | Severe tropical storm | ||
11 | 56–63 | Storm | ||||||
12 | 64–72 | Hurricane | Very severe cyclonic storm | Tropical cyclone | Severe tropical cyclone (3) | Typhoon | Typhoon | Hurricane (1) |
13 | 73–85 | Hurricane (2) | ||||||
14 | 86–89 | Severe tropical cyclone (4) | Major hurricane (3) | |||||
15 | 90–99 | Intense tropical cyclone | ||||||
16 | 100–106 | Major hurricane (4) | ||||||
17 | 107–114 | Severe tropical cyclone (5) | ||||||
115–119 | Very intense tropical cyclone | Super typhoon | ||||||
>120 | Super cyclonic storm | Major hurricane (5) |
Read more about this topic: Gust (wind)
Famous quotes containing the words wind, force and/or scale:
“I have hardly begun to live on Staten Island yet; but, like the man who, when forbidden to tread on English ground, carried Scottish ground in his boots, I carry Concord ground in my boots and in my hat,and am I not made of Concord dust? I cannot realize that it is the roar of the sea I hear now, and not the wind in Walden woods. I find more of Concord, after all, in the prospect of the sea, beyond Sandy Hook, than in the fields and woods.”
—Henry David Thoreau (18171862)
“America is a model of force and freedom & moderationwith all the coarseness and rudeness of its people.”
—George Gordon Noel Byron (17881824)
“I by no means rank poetry high in the scale of intelligencethis may look like affectation but it is my real opinion. It is the lava of the imagination whose eruption prevents an earthquake.”
—George Gordon Noel Byron (17881824)