The next time you hear hurricane -- think inland
flooding!
Inland Flooding Backgrounder
Freshwater Flooding 59%; Wind 12%; Surf
11%; Offshore 11%; Tornado 4%; Other 2%; Surge 1% |
While storm surge has been the number one cause of hurricane related
deaths in the past, more people have died from inland flooding associated
with tropical systems in the last 30 years. Since the 1970's, inland
flooding has been responsible for more than half of all deaths associated
with tropical cyclones in the United States. Flooding from hurricanes
can occur hundreds of miles from the coast placing communities,
which would not normally be affected by the strongest hurricane
winds, in great danger.
Some of the greatest rainfall amounts associated with tropical
systems occur from weaker Tropical Storms that have a slow forward
speed (1 to 10mph) or 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.
FACTS ABOUT INLAND FLOODING FROM HURRICANES
- Freshwater floods accounted for more than half
(59%) of U.S. tropical cyclone deaths over the past 30 years.
These floods are why 63% of U.S. tropical cyclone deaths during
that period occurred in inland counties.
- Over the past 30 years, 78% of children killed
by tropical cyclones drowned in freshwater floods.
- One cubic yard of water weighs 1700lbs. The
average automobile weighs 3400lbs. Many automobiles will float
in just 2 feet of water.
- The average person can be swept off their feet
in 6 inches of moving water.
- The average automobile can be swept off the
road in 12 inches of moving water.
- The average automobile can be swept off the
road in 12 inches of moving water. At least 23% of U.S. tropical
cyclone deaths occur to people who drown in, or attempting to
abandon, their cars.
- Rainfall is typically heavier with slower moving
storms.
- Rainfall Rule of Thumb: to estimate the total
amount of rainfall that can be expected from a tropical system,
divide 100 by the forward speed of the storm in miles per hour.
Example (100/Forward Speed = estimated inches of rain). Your local
NWS forecast office will have a more accurate estimation method
to predict rainfall.
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