HURRICANES & WINDSTORMS
Hurricanes are unique forces of nature
Hurricanes, or tropical cyclones, are unique forces of nature that start out as streams of low-pressure air that move through the moisture-rich tropics before emerging as fierce storms that bring massive rainfall and high-speed winds that leaving flooding storm surges in their wake.
The category of a hurricane (on a 1-5 scale) is determined by its sustained wind speeds, with Category 4 and 5 storms capable of catastrophic damage. A Category 1 hurricane starts at 74 mph, while a Category 5 hurricane has wind speeds greater than 157 mph. While Category 1 and 2 storms are weaker, they present the threat of stalling over a populated area, dumping excessive amounts rain, and causing rivers and low-lying areas to flood.
According to the National Ocean and Atmospheric Administration, during just one hurricane, raging winds can churn out about half as much energy as the electrical-generating capacity of the entire world. Hurricanes occur most often from June to November, threatening the Caribbean, the Gulf of Mexico, and the eastern seaboard of the United States.
Windstorms1, which are classified separately from hurricanes, are strong enough to cause light-to-severe damage to trees and buildings, and may be accompanied by rain, snow or hail. Windstorms take the form of wind gusts (short bursts of high-speed winds) or long periods of strong, sustained winds. They can last for just a few minutes, as when caused by downbursts from thunderstorms, or go on for hours and even days when part of large-scale weather systems.
A windstorm that travels in a straight line and is caused by the gust front (the boundary between descending cold air and warm air at the surface) of an approaching thunderstorm is called a derecho —a Spanish word that means “straight” or “right.” Derechos are capable of causing widespread damage to developed and undeveloped areas. For example, a July 4, 1999 derecho in Minnesota clocked wind speeds of 100 miles per hour and knocked down millions of trees.
With such force at their disposal, the damage these storms can cause is massive. When Hurricane Dorian — one of the two largest hurricanes ever to make landfall in recorded history — hit the Bahamas in 2019, it was a Category 5 hurricane with wind speeds of 185 mph and 25-foot storm surges. The storm caused $3.4 billion in damages in the Bahamas, and left 29,500 people with damage to homes and assets.
While hurricane winds are dangerous, the rain and flooding they often produce can be just as perilous. The majority of the damage caused by Hurricane Harvey in 2017 wasn’t produced by winds, but by extreme flooding after it stalled over Texas, engulfing the area in an estimated 33 trillion gallons of flood waters, according to the Washington Post2.
Research from the National Climate Assessment (NCA) shows the number of storms and their severity are increasing every year. Since the 1980s, the number of Category 4 and 5 hurricanes has risen by 80 percent as a result of higher sea temperatures in the Atlantic region. NCA models also predict wetter hurricanes in the future, with greater rainfall rates for hurricanes in warmer climates and increased rainfall near the center of hurricanes.
How Hurricanes Damage Roofs
If you live in a coastal area like the Gulf of Mexico or the Atlantic coast, making sure your roof can withstand extreme storms is vitally important. Not only can extreme winds can tear or blow off shingles, but gutters, satellite dishes, roof vents and other objects attached to your roof can rip off and become airborne hazards. Objects attached to your roof should be inspected and firmly secured prior to a high wind event.
Water damage is also a major concern with hurricanes, as wind damage to roofing components can provide rain with easy access to the inside of a home. This is why modern roof systems include roofing underlayments – weatherproofing membranes installed on the roof deck before the shingles are attached – as a vital secondary barrier against leaks.
How to Prepare for and Recover from a Hurricane
There’s no such thing as a hurricane-proof home, so it’s important to fortify your roof in advance of an approaching storm. Look for any previous storm damage and, if possible, have a professional make repairs. Trimming overhanging trees near your home is also important. With 100+ mph winds, even healthy trees are at risk of storm damage, so check in the early spring before hurricane season starts. In general, tree branches should not be within six feet of your home. If your roof is badly damaged and needs support before it can be repaired, FEMA may be able to provide a tarp to protect you from the elements. You can reach them at 1-888-766-3258.
In addition to your roof, there are important steps you can take to protect the rest of your property and family. Park your car in a covered area and stay in a safe area of your home (i.e. away from windows) until the storm passes. Also, be prepared for storm surges – rapid sea level rise that can accompany hurricanes that hit areas close to coastlines and rivers. Even six inches of storm surge can be difficult to stand in and one foot of storm is enough to send a car sailing, so don’t unnecessary risk3. Prior to any major hurricane, be sure to purchase adequate flood insurance based on the location of your property.
Don’t forget emergency essentials such as a weather radio, flashlight with batteries, copies of important documents, medicine, a first-aid kit and plenty of food and water. Also stayed tuned for weather updates and evacuation orders. If an evacuation order is issued, getting out of the area should be your first priority.