Hurricane Hazards
Hurricane hazards come in many forms: storm surge, high winds, tornadoes, and flooding. It is important to understand each of these hazards and consider them when creating a disaster plan.
Storm Surge
Storm Surge - The greatest potential for loss of life related to a hurricane is from storm surge. Storm surge is water that is pushed toward the shore by the force of winds swirling around the storm. When combined with normal tides and wind-driven rain, water levels can rise to heights that severely impact beaches, roads, homes, and other critical infrastructure. This rise in water can cause severe flooding in coastal areas, particularly when storm tide coincides with normal high tides. Because much of the United States’ densely populated Atlantic and Gulf Coast areas lie less than 10 feet above mean sea level, the danger from storm tides is tremendous.
Inland Flooding
Inland Flooding - In addition to storm surges, high winds, and tornadoes, hurricanes produce inland flooding, which can often be the most deadly of the storm’s hazards. Between 1970 and 2000, inland flooding accounted for more hurricane-related deaths than storm surge.
Intense rainfall is not directly related to the wind speed of a hurricane. In fact, some of the greatest rainfall amounts associated with tropical systems occur from weaker tropical storms that have a slow forward speed (1 to 10 mph) or that stall over an area. Due to the amount of rainfall a tropical storm can produce, they are capable of causing as much damage as a Category 2 hurricane.
Inland flooding can be a major threat to communities located hundreds of miles from where a hurricane or tropical storm makes landfall. These large tropical systems bring intense rainfall which can cause catastrophic flooding.
The National Flood Insurance Program is a pre-disaster flood mitigation and insurance protection program. The National Flood Insurance Program makes federally-backed flood insurance available to residents and business owners. For more information, call 1-888-2255-35663 (1-888-CALL-FLOOD) or for the hearing impaired call TTY 711 option 1 to receive assistance or visit the FEMA Flood Insurance page.
High Winds
High Winds - Hurricanes are categorized in terms of the strength of their winds. According to the Saffir–Simpson Hurricane Wind Scale, a Category 1 hurricane has lighter winds compared to storms in higher categories. A Category 4 hurricane would have winds between 131 and 155 mph and, on average, would usually be expected to cause substantially more damage than a Category 1 storm. Depending on circumstances, less intense storms may still be strong enough to produce damage, particularly in areas that have not prepared in advance.
Hurricane-force winds can easily destroy poorly constructed buildings and mobile homes. Debris such as signs, roofing material, and small items left outside can become flying missiles in hurricanes. Hurricanes can also cause extensive damage to trees, towers, poles, and water and underground utility lines (from uprooted trees).
Tornadoes
Tornadoes - Hurricanes can produce tornadoes that add to the storm’s destructive power. Tornadoes are most likely to occur in the right-front quadrant of the hurricane; however, they are also often found elsewhere embedded in the rainbands, well away from the center of the hurricane. Some hurricanes seem to produce no tornadoes, while others develop multiple ones. The effects of tornadoes, added to the larger area of hurricane-force winds, can produce substantial damage.
Currently, there is no way to predict exactly which storms will spawn tornadoes or where they will touch down. Doppler radar systems have greatly improved warning capability, but technology usually provides lead times from only a few minutes up to about 30 minutes. Consequently, preparedness is critical.
Fort Lauderdale – Broward County Hurricane Evacuation Map and Regional Shelters - Those persons located in low-lying areas or near tidal bodies of water should seek shelter elsewhere if conditions warrant. All mobile home residents must evacuate in Plan A and B and may be ordered to evacuate if tropical storm conditions warrant.