A hurricane’s deadly forces
The combination of water and wind can have catastrophic impacts on man and nature. Learn what these mortal features can do and how to survive them.
Storm surge is simply the rise in water which floods the coast as water is pushed onshore by powerful winds, and to a much lesser degree very low pressure. It is important that you know the tides of the coastal area where you’re located. For example, many places on the Gulf coast have very little tidal ranges, whereas places on the U.S. east coast have large tidal ranges. It makes a substantial difference on the consequences to the shore if a hurricane moves ashore during a low or high tide in a place where the tidal range is large. Today, inland flooding causes the largest loss of life. Before, when hurricane forecasting technology was not as complicated, storm surge was the motive for most deaths. It is best to leave a structure which could be impacted by the storm wave of a hurricane. The force from sea water is extremely powerful and can destroy a house easily. High waves take the debris from destroyed buildings which are on the shore that batter other structures further inland. Houses built on stilts have a much greater survivability from surge damage. Even so, it is best not to”ride out” a hurricane and evacuate to a safer location.
Hurricanes produce strong sustained winds that have the capability of destroying structures and toppling trees and power lines. The Saffir-Simpson hurricane scale gives an estimate on the type of wind damage which can be expected with different categories of hurricanes. A major hurricane is thought to be a category 3 or higher. Strong winds can blow off in garage doors, break windows, or lift roofs from homes. Make sure that you have shutters or plywood to cover windows correctly during a hurricane. Also, know how structurally sound your roof and garage doors are so that they won’t fail in case of high winds. If you’re in a flood zone, then evacuate to higher ground. If you don’t have a basement, find a small room on the lowest floor with no windows near the center of the house to stay.
Tornadoes are many times associated with land falling tropical cyclones. The majority of the tornadoes occur within a day of land fall, although it’s potential for tornadoes to still occur two or three days later still associated with the circulation. The most significant hurricane associated tornado outbreak on record happened with Hurricane Ivan in 2004 with 123 tornadoes. Other hurricanes that produced a significant tornado outbreak were: Hurricane Buelah (115), Hurricane Frances (103) and Hurricane Rita (101) tornadoes. Unlike their Midwest cousins, tornadoes on average are poorer in hurricanes. There is usually a weaker signature on radar and hail almost never accompanies them. Stronger land falling hurricanes have a greater potential to produce tornadoes than weaker ones. Tornadoes happen with land falling hurricanes as the hurricane moves over land and encounters greater low level friction from the property. This slows the wind at the surface more than higher aloft, adding to vertical wind shear. It’s this growth in wind shear that sets up an environment favorable for tornado development. Follow the same safety guidelines for high winds to safeguard you and your family from the harmful effects of tornadoes.
All hurricanes do not produce severe flooding. There are lots of factors that contribute to the flooding potential of a hurricane or poorer tropical cyclone. The most important factor is the rate of movement. If a tropical cyclone moves into a region where steering currents from the winds aloft are feeble, very heavy rain can result. It is possible for the tropical cyclone to be almost stationary for days resulting in very heavy rainfall amounts of 40 to 50 inches or longer. Rainfall amounts are also influenced by the terrain of a place. Mountains cause an additional lift to happen, enhancing rainfall rates on the windward slopes. The surrounding environment in which the hurricane forms is another thought. If a hurricane forms in the deep tropics, it usually can tap a deeper source of deep layered moisture. Hurricanes which form in higher latitudes have a greater prospect of entraining dry air from mid latitude weather systems limiting moisture. When a tropical cyclone is coming, understand the potential for heavy rainfall to make flooding or flash flooding in which you reside. If you live in a flood plain, evacuate to high ground before the hurricane’s effects arrive.
A hurricane has the potential to cause widespread damage and loss of life. The best way to survive the effects of a hurricane is by staying informed.