What is storm surge, and what contributes to the deadly hurricane hazard?

One of the most dangerous and deadly hazards of a hurricane is the storm surge. As Hurricane Ian hits Florida's west coast, FEMA warned that it's expected to cause "life-threatening storm surge and widespread flooding."

Parts of the coast could see storm surge of up to 18 feet, according to Ken Graham, the director of the National Weather Service. The National Hurricane Center considers three feet of storm surge to be life-threatening.

"We have to talk about the water," Graham said in a briefing Wednesday. "Ninety percent of your fatalities in these tropical systems comes from the water," he added, noting that figure includes deaths from storm surge and rainfall flooding.