An early morning phone call on October 19, 2005 informed National Hurricane Center (NHC) director Max Mayfield that Hurricane Wilma had not only intensified into a Category 5 hurricane, but that it was also the most intense Atlantic Basin storm ever measured.

“The night the bottom dropped out, I left the NHC around 1 a.m. knowing it was strengthening,” Mayfield recalled in an email. “Sometime around 4:00 a.m. the duty Hurricane Specialist, Dr. Lixion Avila, called me at home.  Excitedly, he yelled ‘882 millibars’ into the phone.”

An Air Force Reserve hurricane hunter WC-130 had measured the record-low surface pressure and reported  “the dreaded pinhole eye” as forecaster Jack Beven referred to it in his forecaster’s storm discussion bulletin. In general, the stronger a hurricane, the smaller its eye. At the time Wilma’s eye was roughly 2.3 miles across. Its peak wind speed was 184 mph.

“Unfortunately,” Mayfield said, “the phone in my bedroom is on my wife’s side of the bed. Fortunately, my wife, Linda, was more than used to the late night phone calls especially by the end of the 2005 season. In addition, Linda’s dad (Vaughn Carmichael) used to work as a forecaster at NHC—that’s how I met Linda—and she knew very well how significant it was for Wilma to go from a tropical storm to a Category 5 Hurricane within 24 hours. ”

Mayfield adds: With Wilma stalled for several days over some of the warmest seawater in the Caribbean south of Cuba, “we knew there was a good possibility of rapid intensification, but the bottom really did drop out on this storm.”

“Wilma’s pressure fell from 982 millibars to 882 in 24 hours, a rate of 4.2 millibars an hour. By contrast, the previous low-pressure record-holder in the Atlantic, Hurricane Gilbert, dropped 3 millibars an hour to a low of 888 mb in 1988. The lowest pressure ever recorded for a tropical cyclone anywhere was 870 mb inside Typhoon Tip in the northwest Pacific in 1979,” Mayfield said.

Fortunately, for the thousands of residents and tourists on Mexico’s Yucatan Peninsula, where Wilma was heading, the inner eye dissipated as the hurricane went though an eyewall replacement cycle.  Wilma had weakened to a Category 4 storm on October 21 when it crossed the island of Cozumel and then hit the mainland with 150 mph winds.

After hitting Mexico, Wilma turned toward the northeast to cross the Gulf of Mexico and hit southwestern Florida as a category 3 hurricane with 120 mph winds. It continued across southern Florida before moving over the Atlantic Ocean where it caused heavy rain and floods in the Bahamas before heading north over the ocean to die.

Wilma’s strength isn’t its only claim to fame; it was the 2005 season’s fourth Category 5 hurricane, the most on record.

In fact, records going back to 1924 show only five years with two category 5 hurricanes—1932, 1933, 1960, 1961, and 2007—and none with three.

The 2005 season’s run of Category 5 storms began on July 16 with Emily becoming a Category 5 on July 16, the earliest on record. Like Wilma, it hit Mexico’s Yucatan Peninsula as a Category 4 storm.

The year’s other two Category 5 hurricanes were Katrina and Rita, neither of which hit as Category 5 storms.

The only Category 5 storms on record as hitting the U.S. were the 1935 Labor Day hurricane that hit the Florida Keys, killing an estimated 600 people; Camille in 1969, which came ashore in Mississippi, killing 259 people, and Andrew in 1992, which hit Dade County, Fla., and Louisiana killing 65 people.

In the AMS Weather Book: I write that the Category 5 hurricane that hit the Florida Keys on Labor Day 1938 with no warning strengthened from a tropical story to a Category 5 storm in 30 hours.

The two days between Wilma reaching Category 5 and its landfall gave Mexican authorities time to move thousands of residents and tourists to safety. In wreaking havoc on Cancun, Wilma could have killed many more than the four people who died in the storm.

We can only imagine the toll if it had rapidly intensified into a Category 5 storm less than two days before hitting places such as the Florida Keys, the Tampa Bay area, New Orleans, the Galveston-Houston area, or one of the many other heavily populated locations on the Atlantic Ocean or Gulf of Mexico coasts.

More on the 2005 hurricane season: