Preparing for Hurricanes
June marks the beginning of the hurricane season on the Atlantic coast. A significant portion of the premiums we pay for homeowner's insurance relates to the risks associated with hurricanes and tropical storms. Much of the information used in this article has been provided by the Loss Control people at The Hartford Insurance Company. The Hartford and Belmont intend for this information to be general and advisory. Readers seeking to resolve specific safety, legal or business issues or concerns related to this information should consult with an appropriate safety, legal or business advisor.
What is a Hurricane?
A hurricane is a tropical storm that has rotating winds of at least 73 mph, but rarely exceeding 150 mph. Hurricanes are usually accompanied by rain, thunder and lightning. These severe storms, which are spawned by low-pressure depressions moving over warm, tropical waters, originate in the Atlantic Ocean from June to October. In an average year, approximately six Atlantic tropical storms mature into hurricanes. (Hurricanes that originate in the Pacific Ocean are referred to as typhoons.)
As the warming air rises and gains moisture, it begins to spin and gain speed near the calm center, known as the eye of the hurricane. Surrounding the eye is a towering wall of moisture laden clouds whirled by strong winds.
At the center of the hurricane, the low pressure allows the surface of the ocean to be drawn up into the eye, forming a mound of water one to three feet higher than the surrounding surface. Driven by winds, this mound of water becomes the storm surge; as the storm makes landfall, the storm surge can tower up to twenty feet higher than the normal high tide.
What Happens When a Hurricane Makes Landfall?
Once a hurricane hits land, it loses contact with its primary source of energy, the warm ocean waters, and begins to slow down. As the hurricane passes over land, increased friction contributes to the break-up of the storm.
The greatest threat posed from a hurricane is from the heavy rainfall and from flooding caused by the storm surge. However, hurricane-force winds and flying debris can cause extensive damage until they dissipate. Hurricanes can also spawn tornadoes that are extremely dangerous and that contribute to the overall damage.
Hurricanes can cause catastrophic damage and potentially large losses of life. In recent years, the death toll from hurricanes has been greatly diminished by timely warnings of approaching storms and by improved programs of public awareness. At the same time, losses from hurricane-related property damage in the United States continue to climb; this is primarily due to an increase in population and construction.
The National Oceanic and Atmospheric Administration's (NOAA) National Hurricane Center in Miami, Florida uses satellite imagery, radar and weather balloons to spot conditions that could trigger a hurricane.
As the storm nears land, NOAA and the Air Force use special aircraft to fly through the hurricane, measuring wind speed and barometric pressure and gathering other data. The information gathered is analyzed by computer models that estimate the storm's strength, rate of development, path, and estimated storm surge. Based on this information, NOAA issues a tropical storm warning, a hurricane watch, or a hurricane warning.
A tropical storm warning may be issued if winds of 39 to 73 mph are expected in an area. Such a warning will not be issued first if a hurricane is expected to strike.
A hurricane watch is issued for coastal areas when a tropical storm or hurricane conditions threaten within 24 to 36 hours.
A hurricane warning is issued for specific coastal areas when hurricane-force winds are expected to strike within 24 hours or less.
Usually, warnings allow sufficient time to prepare against hurricane damage and to make decisions for evacuation of personnel, if proper preparation had been taken at the beginning of the hurricane season.