As the hurricane season makes its grand opening in June, all eyes turn to the Gulf of Mexico and Atlantic Ocean to see just what the is in store for coastal residents this year. The National Hurricane Center released its annual outlook for the Atlantic hurricane season, and information is the most important tool anyone can use to survive through a disaster. This terminology guide for the Hurricane Season can help make sense of the watches, warnings and advisories. The full National Hurricane Center glossary can be found here.
Advisories
The National Hurricane Center (NHC) issues advisories that include all information pertaining to tropical cyclone watches and warnings, as well as the storm's location, intensity and other pertinent information. This is different than other storm advisories which, according to NOAA's glossary, usually identify weather phenomenon that are less severe forms of weather, like flood advisories, but can still cause damage or loss of life if not treated with caution.
Tropical Storm Watch
This is a weather notice that identifies that tropical storm force winds (sustained winds 39 to 73 mph) are possible in a given area within the next 48 hours.
Tropical Storm Warning
This is a weather notice that identifies that tropical storm force winds are expected in a given area over the next 36 hours. It is important to note that the likelihood of the storm occurring in an area with a tropical storm warning is significantly higher than an area with just a tropical storm watch.
Hurricane Watch
This is a weather announcement that identifies that hurricane conditions (sustained winds above 74 mph) are possible at a given location. This notice is issued when it is expected that the tropical storm force winds will reach an area within 48 hours. In theory, a hurricane watch could be issued for an area before a hurricane has officially developed. This would happen if a storm was a tropical storm force, but conditions are right for it to gain strength and make landfall at an area within the 48 hour window.
Hurricane Warning
This is a weather announcement that hurricane conditions are expected in a given area. Again, these notices are going to be issued in advance of the tropical storm force winds reaching the area, usually when those winds are expected within the next 36 hours.
Knots
This is a speed representation of nautical miles per hour. One nautical mile, according to an international agreement detailed by the agency formerly known as the National Bureau of Standards, is equal to approximately 6,076 feet, as opposed to a statute mile which is 5,280 feet. Wind speeds in hurricanes and speed of storm movement are typically reported in knots (kt) and also converted to statute miles per hour (mph).
Tropical Disturbance
This is the beginning of a hurricane. These storms begin showing development and may, or may not, have sustained winds. Their size is usually 100 to 300 nautical miles wide, but are not organized enough to be classed as a tropical depression.
Tropical Depression
A tropical cyclone that has sustained winds of 33kt or less (38 mph or less). Depressions normally represent the first phase of a storm that shows strong development, including a central core that the storm rotates around.
Tropical Storm
A tropical cyclone that has sustained winds between 34kt and 63kt (39 mph and 73 mph). Tropical storms normally are given a name, which stays with the storm until it loses enough energy to return to tropical depression status.
Hurricane
A tropical cyclone that has sustained winds greater than 64kts (74 mph). The term hurricane is used for storms north of the equator and east of the International Date Line and west the Prime Meridian. Pacific tropical cyclones west of the International Date Line are known as typhoons.
Donald is an instructor in military command and control as well as emergency management. He has supported disaster response in a wide range of situations, including hurricanes, forest fires, volcano eruptions and aircraft accidents.
