By The Federal Emergency Management Agency
As Hurricane Irene demonstrated last year, New Jersey is susceptible to significant damage from hurricanes and other severe storms. The Federal Emergency Management Agency (FEMA) is urging all New Jersey residents on the occasion of National Hurricane Preparedness Week (May 27 – June 2) to take action and be ready for any serious storms and flooding to come.
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.
The ingredients for a hurricane include a pre-existing weather disturbance, warm tropical oceans, moisture, and relatively light winds aloft. If the right conditions persist long enough, they can combine to produce the violent winds, huge waves, torrential rains, and floods we associate with this phenomenon.
Each year, an average of 11 tropical storms develop over the Atlantic Ocean, Caribbean Sea, and Gulf of Mexico. Many of these remain over the ocean and never impact the U.S. coastline. Six of these storms become hurricanes each year. In an average three-year period, roughly five hurricanes strike the U.S. coastline, killing approximately 50 to 100 people from Texas to Maine. Of these, two are typically “major” or “intense” hurricanes (a category 3 or higher storm on the Saffir-Simpson Hurricane Scale).
Tropical cyclones are classified as:
Tropical depressions, an organized system of clouds and thunderstorms with a defined surface circulation and maximum sustained winds of 38 mph or less.
Tropical storms, an organized system of strong thunderstorms with a defined surface circulation and maximum sustained winds of 39-73 mph.
Hurricanes, an intense tropical weather system of strong thunderstorms with a well-defined surface circulation and maximum sustained winds of 74 mph or higher. 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 also can produce significant damage and loss of life, mainly due to flooding.
When the winds from storms reach 39 mph (34 kts), the cyclones are given names. Years ago, an international committee developed names for Atlantic cyclones. In 1979 a six-year rotating list of Atlantic storm names was adopted – alternating between male and female hurricane names. Storm names are used to facilitate geographic referencing, for warning services, for legal issues, and to reduce confusion when two or more tropical cyclones occur at the same time. Through a vote of the World Meteorological Organization Region IV Subcommittee, Atlantic cyclone names are retired usually when hurricanes result in substantial damage or death or for other special circumstances.
Basic Hurricane Safety Actions
Know if you live in an evacuation area. Know your home’s vulnerability to storm surge, flooding and wind. Have a written plan based on this knowledge.
At the beginning of hurricane season (June 1), check the supplies for your disaster supply kit, replace batteries and use food stocks on a rotating basis.
During hurricane season, monitor the tropics.
Monitor NOAA Weather Radio. It is an official source for real-time weather information and warnings.
If a storm threatens, heed the advice from local authorities. Evacuate if ordered.
Execute your family plan.
Warning vs. Watch: Know the Difference
A tropical storm watch is an announcement that tropical storm conditions (sustained winds of 39 to 73 mph) are possible within the specified coastal area within 48 hours.
A tropical storm warning is an announcement that tropical storm conditions (sustained winds of 39 to 73 mph) are expected somewhere within the specified coastal area within 36 hours.
A hurricane watch is an announcement that hurricane conditions (sustained winds of 74 mph or higher) are possible within the specified coastal area. Because hurricane preparedness activities become difficult once winds reach tropical storm force, the hurricane watch is issued 48 hours in advance of the anticipated onset of tropical-storm-force winds.
A hurricane warning is an announcement that hurricane conditions (sustained winds of 74 mph or higher) are expected somewhere within the specified coastal area. Because hurricane preparedness activities become difficult once winds reach tropical storm force, the hurricane warning is issued 36 hours in advance of the anticipated onset of tropical-storm-force winds.
The Federal Emergency Management Agency is part of the U.S. Department of Homeland Security.