Wind Velocidade Scales
De Gentle Breeze to Hurricane Força
Understand Wind CategoriesWeather reports mention "25 mph winds" ou "Category 3 hurricane" ou "gale force conditions." Understanding wind speed scales helps you interpret forecasts, prepare for storms, e appreciate o power of moving air—from o gentlest breeze to devastating hurricanes.
O Beaufort Wind Scale
Developed in 1805 by Sir Francis Beaufort for naval use, este scale correlates wind speed com observed sea e land conditions.
| Força | Name | MPH | KM/H | Knots | Effects |
|---|---|---|---|---|---|
| 0 | Calm | 0-1 | 0-2 | 0-1 | Smoke rises vertically |
| 1 | Light air | 1-3 | 2-6 | 1-3 | Smoke drifts |
| 2 | Light breeze | 4-7 | 7-11 | 4-6 | Leaves rustle |
| 3 | Gentle breeze | 8-12 | 12-19 | 7-10 | Flags extend |
| 4 | Moderate breeze | 13-18 | 20-29 | 11-16 | Small branches move |
| 5 | Fresh breeze | 19-24 | 30-39 | 17-21 | Small trees sway |
| 6 | Strong breeze | 25-31 | 40-50 | 22-27 | Umbrellas difficult |
| 7 | Near gale | 32-38 | 51-61 | 28-33 | Walking hindered |
| 8 | Gale | 39-46 | 62-74 | 34-40 | Twigs break |
| 9 | Strong gale | 47-54 | 75-87 | 41-47 | Minor structural damage |
| 10 | Storm | 55-63 | 88-102 | 48-55 | Trees uprooted |
| 11 | Violent storm | 64-72 | 103-117 | 56-63 | Widespread damage |
| 12 | Hurricane | 73+ | 118+ | 64+ | Devastating damage |
Saffir-Simpson Hurricane Scale
Usado for Atlantic e Eastern Pacific hurricanes. Based on sustained wind speed.
| Category | MPH | KM/H | Knots | Damage Potential |
|---|---|---|---|---|
| 1 | 74-95 | 119-153 | 64-82 | Minimal: alguns roof/siding damage |
| 2 | 96-110 | 154-177 | 83-95 | Moderate: major roof damage, trees uprooted |
| 3 | 111-129 | 178-208 | 96-112 | Extensive: devastating damage, electricity out for days |
| 4 | 130-156 | 209-251 | 113-136 | Extreme: severe damage, areas uninhabitable for weeks |
| 5 | 157+ | 252+ | 137+ | Catastrophic: total destruction of muitos buildings |
Category 3-5 são considered "major hurricanes."
Tornado Scales
Enhanced Fujita (EF) Scale
| Rating | MPH | KM/H | Damage Descrição |
|---|---|---|---|
| EF0 | 65-85 | 105-137 | Light: branches broken, shingles damaged |
| EF1 | 86-110 | 138-177 | Moderate: mobile homes overturned, roofs stripped |
| EF2 | 111-135 | 178-217 | Significant: roofs torn off, large trees uprooted |
| EF3 | 136-165 | 218-266 | Severe: entire stories destroyed, heavy cars thrown |
| EF4 | 166-200 | 267-322 | Devastating: bem-built homes leveled |
| EF5 | 200+ | 322+ | Incredible: strong buildings destroyed, cars missiles |
Outro Wind Classifications
National Weather Service Terms
| Term | Wind Velocidade |
|---|---|
| Wind Advisory | Sustained 31-39 mph ou gusts 46-57 mph |
| High Wind Aviso | Sustained 40+ mph ou gusts 58+ mph |
| Extreme Wind Aviso | Sustained 115+ mph |
| Tropical Storm | 39-73 mph |
| Hurricane | 74+ mph |
Marine Terms
| Term | Knots | MPH |
|---|---|---|
| Small Craft Advisory | 18-33 | 21-38 |
| Gale Aviso | 34-47 | 39-54 |
| Storm Aviso | 48-63 | 55-73 |
| Hurricane Força Aviso | 64+ | 74+ |
Measuring Wind Velocidade
Instruments
- Anemometer: Rotating cups measure wind speed
- Wind vane: Points into o wind for direction
- Doppler radar: Measures wind remotely
- Weather balloon: Upper atmosphere medições
Sustained vs Gusts
- Sustained wind: Average over 1-2 minutes
- Gusts: Brief increases lasting seconds
Gusts typically exceed sustained winds by 30-50%.
Conclusão
Wind speed scales translate abstract numbers into meaningful descriptions of conditions e hazards. O Beaufort scale covers cotidiano winds from calm to hurricane force. O Saffir-Simpson scale categorizes tropical storms by damage potential. Understanding estes scales helps you prepare for weather events e interpret forecasts precisamente.