Be Ready: Weather Alert Definitions
The National Weather Service defines a severe thunderstorm as any storm that produces one or more of the following elements:
- A tornado.
- Damaging winds or speeds of 58 mph (50 knots) or greater.
- Hail 1 inch in diameter or larger.
Know these definitions so you are prepared for any storm:
- Hurricane Watch
Winds greater than 74 mph may hit the area within 36 hours.
- Hurricane Warning
Winds greater than 74 mph probably will to hit the area within 24 hours.
- Tropical Storm Watch
Winds from 39 to 73 mph may hit the area within 36 hours.
- Tropical Storm Warning
Winds from 39 to 73 mph probably will to hit the area within 24 hours. Usually issued for areas to either side of the Hurricane Warning area.
- Tornado Watch
Conditions are ripe for tornadoes within the watch area. Tornadoes associated with hurricanes and tropical storms are typically a very significant cause of death and damage.
- Tornado Warning
A tornado has actually been spotted visually or on radar. Usually issued for a county. If a tornado WARNING is issued where you live, GET TO THE MIDDLE OF THE LOWEST FLOOR OF A STRONG BUILDING IMMEDIATELY!!!
- Severe Thunderstorm Watch
Conditions are ripe for severe thunderstorms within the watch area.
- Severe Thunderstorm Warning
There is a severe thunderstorm in or heading for the warned area. Treat this like a tornado warning!!
- Flash Flood Watch
Flash floods are likely to occur in the near future. Be alert for rising water and be prepared to have to move to high ground.
- Flash Flood Warning
Flash floods are occurring or expected to occur in the near future. If this happens, get to high ground immediately, and GET AWAY FROM VEHICLES... it only takes 18 inches of water to sweep a car or truck away!
- High Wind Advisory
Windy conditions may occur in the advisory area. This usually makes for unsafe conditions while driving, especially in (but not limited to) large vehicles. Also, avoid boating anywhere in the advisory area.
- High Wind Warning
Very strong winds are expected or already are occurring that present a significant danger while driving, boating and other outdoor activities. Often issued near tropical storms and hurricanes.
- Special Marine Warning
Warnings of interest to boaters, usually because of rough conditions, squall lines, waterspouts,
- Hurricane or Tropical Storm Statement
Statements issued periodically by the National Hurricane Center with an overview of the current situation.