Hurricane Wilma was the 21st named storm of the infamous 2005 Atlantic hurricane season. From her formation on October 15th to her demise on the 26th, Wilma would become one of the most memorable hurricanes in Atlantic basin history. As the 4th category 5 hurricane of the year, Wilma would become a monstrous bookend to an incredible, record-setting season.
Hurricane Wilma’s origin was relatively atypical for an Atlantic tropical cyclone. Instead of originating from a tropical wave from the African coast or the remnants of a mid-latitude frontal system, Wilma began as a large low-level circulation over the western Caribbean. This monsoon trough is often present in the area especially southward toward Colombia, but it rarely spawns intense tropical cyclones. 2005 was not a typical year, however, and this broad low eventually became the most intense hurricane ever observed in the Atlantic basin.
Conditions across the western Caribbean were primed for an intense hurricane the week of October 13th as the monsoon low began to organize. The area had been cyclone free since early that summer when category 5 Hurricane Emily moved south of Jamaica and into the Yucatan. This span between systems allowed waters to become much warmer than normal and environmental wind shear remained quite low.
Wilma took its time organizing. The system was not classified as a tropical depression until the 15th, and from there it tracked slowly westward under weak steering currents. An initial forecast complication was that since the circulation for Wilma was so large, it was hard to determine the location of the center of the storm. Several southward adjustments were made over the next 24 hours to account for this. Due to the large size of the system, Wilma struggled to develop tropical storm force winds for quite some time.
The system continued to develop intense convective activity south of the center of circulation, and Wilma was finally classified as a tropical storm early on the 17th. The storm continued its slow development into the morning of the 18th when it turned to the west and northwest. Over the next 24 hours, Wilma underwent one of the most incredible rapid intensification processes that has ever been observed in a tropical cyclone. At 7 am CDT, the system had just reached hurricane strength with 75 mph winds and a central pressure of 979 mb. On the morning of the 19th, the storm had wind speeds of 185 mph and a central pressure of 882 mb.
Wind speeds of this magnitude in an Atlantic hurricane are incredibly rare, and Wilma was able to attain them in part because she had the smallest recorded eye ever in a tropical cyclone in that basin. At 2 nm in diameter, winds in the eyewall were able to rotate at incredible speeds. To put something like this in perspective, the widest tornado on record was around as large as the eye of Hurricane Wilma at its peak. Although the processes that create intense winds in strong tornadoes and major hurricanes are vastly different, similar wind speeds can become possible.
Thankfully for people in the path of Wilma, hurricanes have a difficult time remaining this intense for long. After its peak, Wilma began to gradually weaken upon approach to Cozumel, Mexico. Part of this weakening was caused by an eyewall replacement cycle, where the incredibly compact eye was replaced by a much larger center. Despite this weakening, Wilma made its first landfall on the 21st as a high end category 4 storm with wind speeds of 150 mph over Cozumel. Incredibly, the death toll in Mexico was limited to 4 people. This may have been because the storm struck an area populated mostly by tourists, which were able to evacuate well in advance of the storm. The damage to the region was severe, however, estimated to be near seven and a half billion dollars.
After making landfall across the Yucatan, Wilma set her sights on Florida. Although emerging in the southeastern Gulf of Mexico significantly weaker, conditions downstream remained favorable for intensification. Wilma strengthened back to a major hurricane on the morning of the 24th, making landfall near Cape Romano as a category hurricane with 120 mph winds. Impacts in Florida were severe, with over 3 million people losing power. Total damage estimates were near 17 billion dollars.
Wilma then moved into the Atlantic, causing more damage in the Bahamas before finally dissipating on the 26th. When all was said and done, Hurricane Wilma held the record for the most intense hurricane ever recorded in the Atlantic basin. Although overshadowed by Katrina and its impact to a relatively small area of the United States, Hurricane Wilma will be remembered for ages.