Breakdown: Why hurricanes aren’t just a coastal problem
MEMPHIS, Tenn. (WMC) - The 2021 Atlantic Hurricane Season is officially under way, and with the forecast for another above-normal year, now is the time to prepare.
Those who live in hurricane prone areas understand how intense these storms can be, and these tropical systems have multiple threats. While many of us picture wind and storm surge at the coast, the risk from hurricanes extends inland.
Specifically in the Southeast, where river flooding linked to hurricanes and heavy storms is common. Some of the worst damage in the past several decades has come from inland flooding along rivers after hurricanes move ashore.
According to the National Oceanic and Atmospheric Administration (NOAA), approximately 25% of tropical cyclone-related deaths in the United States don’t occur along the coast.
In fact, the impacts from tropical storms and hurricanes can be felt hundreds of miles inland.
Between 2016 and 2018, the National Hurricane Center estimates that most of the deaths from hurricanes were from inland flooding.
Contrary to popular belief, significant impacts still occur without it being a major hurricane. The category of a hurricane does not tell you how much rain might fall. The size of a tropical storm or hurricane can give a little bit of an idea, but the largest clue comes from how slowly a tropical system is moving. That’s why even tropical depressions can leave record and lethal flooding.
Hurricane Sandy was once the second-costliest hurricane in United States history (after Hurricane Katrina), yet was barely a Category 1 when it made landfall. Whereas Hurricane Andrew was a Category 5.
The Reason? Flooding.
As warmer ocean temperatures contribute to heavier rainfalls and slower moving hurricanes, inland flooding is likely to increase. Torrential rains from a tropical system can cause rivers to flood their banks and mudslides to form.
In addition to the amount of rain that falls from a tropical storm or hurricane, other factors that control inland flooding are the locations of rivers and valleys, the slope of terrain, the amount of development, and how saturated soil may be from recent rain.
Tropical Storm Allison in 2001 was an example of a storm without extreme wind, producing extreme rain of over 3 feet. More than 20 people lost their lives from flooding from Allison.
And in 2017, Hurricane Harvey dropped at least 52 inches of rain on Houston in 6 days, an amount NASA described as “unfathomable.” Dozens and dozens of people drowned and there were tens and tens of billions of dollars of flood damage.
Hurricanes that strike the central Gulf Coast frequently continue northward to the Ohio Valley or Northeastern region. Hurricane Ivan left flooding rain in West Virginia in 2004.
Even though these powerful storms lose wind strength as they move over land, they continue to dump massive amounts of tropical rain into streams, lakes, and rivers — posing a serious threat of inland flooding.
These floods account for more than 50% of hurricane-related deaths each year.
Damage from inland flooding caused by these storms can often time run well into the billions of dollars — especially when a major metropolitan area is impacted.
Around 70% of all hurricanes that make landfall are a major contributor to the total number of significant floods in the Southeast U.S.
Adding to the destructive power of the storm, landfalling tropical systems also produce tornadoes. Tornadoes associated with tropical systems are generally less intense than those produced by supercell thunderstorms, but when added to hurricane-force winds, these tornadoes can still produce substantial damage and potentially be deadly. (Note: Tornadoes are most likely to occur in the northeast quadrant of a hurricane).
While cities and communities away from the coast may not expect large impact from tropical weather, it’s important to remember the threat of inland flooding. Click here to see if you live in a flood zone.
Atlantic Hurricane Season lasts through November 30th. However, the Atlantic has produced early-season cyclones over the last 7 consecutive years. The time to prepare is now, before the formation of a storm.
For information on how to prepare for a hurricane and stay safe during a storm, head to www.ready.gov/
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