Hurricane 101
Weather Systems
- Tropical Depression: an organized system of clouds and thunderstorms with a defined surface circulation and maximum sustained winds of 38 mph (33 knots) or less. Sustained winds are defined as one-minute average wind measured at about 33 ft. (10 meters) above the surface.
- Tropical Storm: an organized system of strong thunderstorms with a defined surface circulation and maximum sustained winds of 39-73 mph (34-64 knots)
- Hurricane: an intense tropical weather system of strong thunderstorms with a well-defined surface circulation and maximum sustained winds of 74 mph (64 knots) or highe
Warning Types and Levels
- Gale Warning: a warning that is given within a range of 39-54 mph (34-47 knots) which may precede or accompany a hurricane watch.
- Hurricane/ Tropical Storm Watch: Hurricane/ tropical storm conditions are possible in the specified area, usually within 48 hours.
- Hurricane/ Tropical Storm Warning: Hurricane/ tropical storm conditions are expected in the specified area, usually within 36 hours.
- Short Term Watches and Warnings: Warnings intended to provide detailed information on specific hurricane threats, such as flash floods and tornadoes.
- Hurricane Category: Classification given to a hurricane by the National Hurricane Center based on the Saffir-Simpson Scale, in order to provide a continuing assessment of the potential for wind and storm surge damage. The classifications are revised regularly by the National Hurricane Center.
Source: National Oceanic and Atmospheric Administration, National Weather Service
Saffir-Simpson Hurricane Scale
| Storm Category | Wind Speed | Damage |
|---|---|---|
| 1 | 74-95 MPH | Very dangerous winds will produce some damage: Well-constructed frame homes could have damage to roof, shingles, vinyl siding and gutters. Large branches of trees will snap and shallowly rooted trees may be toppled. Extensive damage to power lines and poles likely will result in power outages that could last a few to several days. |
| 2 | 96-110 MPH | Extremely dangerous winds will cause extensive damage: Well-constructed frame homes could sustain major roof and siding damage. Many shallowly rooted trees will be snapped or uprooted and block numerous roads. Near-total power loss is expected with outages that could last from several days to weeks. |
| 3 | 111-129 MPH | Devastating damage will occur: Well-built framed homes may incur major damage or removal of roof decking and gable ends. Many trees will be snapped or uprooted, blocking numerous roads. Electricity and water will be unavailable for several days to weeks after the storm passes. |
| 4 | 133-156 MPH | Catastrophic damage will occur: Well-built framed homes can sustain severe damage with loss of most of the roof structure and/or some exterior walls. Most trees will be snapped or uprooted and power poles downed. Fallen trees and power poles will isolate residential areas. Power outages will last weeks to possibly months. Most of the area will be uninhabitable for weeks or months. |
| 5 | 157 MPH and higher | Catastrophic damage will occur: A high percentage of framed homes will be destroyed, with total roof failure and wall collapse. Fallen trees and power poles will isolate residential areas. Power outages will last for weeks to possibly months. Most of the area will be uninhabitable for weeks or months. |
Watch Vs. Warning
- Hurricane Watch: hurricane conditions are expected within 48 hours. Residents are urged to enact their disaster plans and secure their homes.
- Hurricane Warning: hurricane conditions may be experienced within 364 hours. Residents are urged to finalize disaster action plans and seek shelter in a safe location.
Watch the video below for information about what to do when a watch has been issued and when a warning has been issued.