The Enhanced Fujita Scale or EF Scale, which became operational on February 1, 2007, is used to assign a tornado a 'rating' based on estimated wind speeds and related damage. When tornado-related damage is surveyed, it is compared to a list of Damage Indicators (DIs) and Degrees of Damage (DoD) which help estimate better the range of wind speeds the tornado likely produced. From that, a rating (from EF0 to EF5) is assigned.
The Saffir–Simpson Hurricane Wind Scale (SSHWS), classifies hurricanes – Western Hemisphere tropical cyclones that exceed the intensities of tropical depressions and tropical storms – into five categories distinguished by the intensities of their sustained winds.
- Tropical depression: The first stage of a tropical weather event is called a tropical depression. Meteorologists sometimes refer to these formations as a tropical wave, disturbance, feature, system or disturbance. Tropical depressions are cyclones with winds that gust at 38 miles per hour (33 knots) or less. While cyclones aren’t as strong as tropical storms or hurricanes, they can bring significant amounts of rain, thunderstorms and devastating floods.
- Tropical storm: Meteorologists upgrade a tropical depression to a tropical storm when the cyclone’s circulation is more organized and has sustained wind speeds of 39 to 73 miles per hour (34 to 63 knots). Tropical storms produce large amounts of rain, and can cause enough wind and wave activity to damage boats and erode beaches. When a weather event qualifies as a tropical storm, meteorologists categorize it according to the Saffir-Simpson Scale.
The Beaufort scale is an empirical measure that relates wind speed to observed conditions at sea or on land.
Severe Thunderstorm Risk Categories - The NWS defines a severe thunderstorm as any storm that produces one or more of the following elements:
1. A tornado
2. Damaging winds or speeds of 58 mph (50 knots) or greater.
3. Hail 1 inch in diameter or larger.
Hurricane Watch Net
14.325 MHz Day / 7.268 MHz Night
Amateur Radio Station
at the National Hurricane Center
