“The scale was developed 1 to 5,” Joel Myers, the founder and president of AccuWeather, said in an interview Tuesday evening. “When you develop a scale 1 to 5, there can’t be any Category 6.”

The purpose of the categories, known as the Saffir-Simpson scale, is to quantify a hurricane’s destructive power, and the destructive power of a Category 5 hurricane — one with sustained winds of at least 157 miles per hour — is virtually total. “A high percentage of framed homes will be destroyed, with total roof failure and wall collapse,” Dennis Feltgen, a spokesman for the National Hurricane Center, wrote in an email. “Fallen trees and power poles will isolate residential areas. Power outages will last for weeks to possibly months. Most of the area will be uninhabitable for weeks or months.”

The scale classifies this level of damage as “catastrophic,” Mr. Feltgen said, and “what is left after ‘catastrophic’ damage?”

This is not to say there is no difference between a storm that brings 160-mile-per-hour winds and one that reaches 190. Dr. Myers noted that “the force of the winds goes up with the square of the velocity.” In layman’s terms, that means a hurricane with 200-mile-per-hour winds has four times — not just double — the force of one with 100-mile-per-hour winds. And wind is not the only factor; barometric pressure and other characteristics also affect how destructive it will be.

But practically, once a storm has leveled a city, there is little more it can do.

Just three Category 5 Atlantic hurricanes have made landfall in the United States since 1924. The most recent one, Hurricane Andrew, hit in August 1992, and the destruction it wrought in South Florida was so complete, The Miami Herald reported the next morning, that it “changed the very nature of the region.”

Thirty miles south of Miami, a state official told The Herald at the time, Homestead Air Force Base “no longer exists.”