KURV.COM - Tropical Coverage 2010 : Weather Terms

What is a Hurricane?

A hurricane is a type of tropical cyclone, which is a generic term for a low pressure system that generally forms in the tropics. The cyclone is accompanied by thunderstorms and, in the Northern Hemisphere, a counterclockwise circulation of winds near the earth's surface. Tropical cyclones are classified as follows:

Tropical Depression
An organized system of clouds and thunderstorms with a defined surface circulation and maximum sustained winds* of 38 mph (33 kt**) or less.

Tropical Storm
An organized system of strong thunderstorms with a defined surface circulation and maximum sustained winds of 39-73 mph (34-63 kt).

Hurricane
An intense tropical weather system of strong thunderstorms with a well-defined surface circulation and maximum sustained winds of 74 mph (64 kt) or higher.

* Sustained winds are defined as a 1-minute average wind measured at about 33 ft (10 meters) above the surface.
** 1 knot = 1 nautical mile per hour or 1.15 statute miles per hour. Abbreviated as "kt".

Hurricanes are categorized according to the strength of their winds using the SAFFIR-SIMPSON HURRICANE SCALE. A Category 1 storm has the lowest wind speeds, while a Category 5 hurricane has the strongest. These are relative terms, because lower category storms can sometimes inflict greater damage than higher category storms, depending on where they strike and the particular hazards they bring. In fact, tropical storms can also produce significant damage and loss of life, mainly due to flooding.

HURRICANE WATCHES AND WARNINGS

When a HURRICANE WATCH is issued for your part of the coast, it indicates the possibility that you could experience hurricane conditions within 36 hours. This watch should trigger your family's disaster plan, and proactive measures should be taken including actions that require extra time such as securing a boat, leaving a barrier island, etc.

When a HURRICANE WARNING is issued for your part of the coast, it indicates that sustained winds of at least 74 mph are expected within 24 hours. Once this warning has been issued, your family should be in the process of completing proactive actions and deciding the safest location to be during the storm.

STORM RESOURCES