Hurricane Ian Overview

Origin and Formation 

In mid-September a weak and disorganized tropical wave slowly traveled westward across the tropical Atlantic, with little overall development as it experienced conditions unfavorable for development in the form of Saharan Dust and strong wind shear. Although the wave remained weak and disorganized, the system was first highlighted in the Tropical Weather Outlook (TWO) by the National Hurricane Center on September 19th while the system was still several hundred miles east of the Windward Islands. This was in large part due to increasing numerical model support of potential tropical development downstream as the system was expected to enter atmospheric conditions more conducive for development in the western Caribbean Sea. As the system entered the eastern Caribbean Sea on September 21st, the system remained disrupted by strong wind shear caused by the sprawling upper-level outflow of a departing Hurricane Fiona which was now moving northward across the southwestern Atlantic away from the greater Antilles. The strong wind shear acted to remove convection away from the developing surface circulation and thus hinder development over the next day or so. However, by the early morning hours of September 23rd, the tropical wave was located just to the northwest of the ABC Islands and atmospheric conditions became more conducive for development. As a result, a better defined low level circulation developed with sustained thunderstorm activity around the center. The system was officially designated as Tropical Depression Nine by the National Hurricane Center as of the 5am advisory on September 23rd, and the first advisory on what would eventually become Hurricane Ian was fresh off of the press. 

Although a tropical depression at the time of the initial forecast, National Hurricane Center forecasters were calling for significant intensification over the next five days based on intensity model guidance and atmospheric conditions that would be conducive for rapid intensification of the system over the western Caribbean and Gulf of Mexico. The initial 5-day intensity forecast was for Tropical Depression 9 to become a hurricane before approaching the Cayman islands and western Cuba. The forecast also called for the potential of continued strengthening of the system in the southeastern Gulf of Mexico after a brief passage over western Cuba. The National Hurricane Center stressed uncertainty about the future of the system and reminded all interests in “Cuba and those along the Eastern Gulf Coast of the United States should closely monitor this system, though at this juncture forecast uncertainty remains fairly high”.

The precursor to Hurricane Ian, Tropical Depression Nine was officially here. 

Meteorological Track History 

While the designation of Tropical Depression Nine occurred during the early morning of September 23rd, atmospheric conditions initially remained only marginally favorable and intensification was gradual to occur throughout the day. As the day progressed, thunderstorm activity began to build over the center and by nightfall, satellite estimations showed increasing surface winds to tropical storm force in portions of the system.  Given the trends on satellite imagery and surface wind speed estimations, the National Hurricane Center upgraded the system to Tropical Storm Ian at 11 PM on September 23rd. 

As Tropical Storm Ian continued to move westward over the central Caribbean Sea on the 24th of September, slight intensification occurred through the overnight as atmospheric conditions remain marginally conducive. Increased data from extra weather balloon launches across the United States and an increased number of aircraft reconnaissance flights allowed for a better understanding of the atmospheric conditions ahead of the storm, resulting in a better picture of the potential intensity of the system as it reached the western Caribbean and southeastern Gulf of Mexico. 

Conditions became more conducive for strenghtening in the western Caribbean on the 25th of September, and Ian began to exhibit better structure with a large area of thunderstorms developing around the center of the storm and sprawling rainbands developing well away from the center. Maximum sustained winds increased from 50 mph during the 11am advisory to 65 mph by the 11pm advisory with aircraft reconnaissance flights investigating the storm noting the development of a well-defined central core. These trends would continue into the overnight hours of September 26th, as hurricane hunter aircraft and satellite estimates indicated the continued development of a central core. Ian was officially designated a hurricane as of the 5am advisory on September 26th with maximum sustained winds of 75 mph. 

Throughout the morning and early afternoon of September 26th, aircraft reconnaissance flights continued to observe continued intensification as Hurricane Ian approached the southern coast-line of western Cuba. By 5pm, maximum sustained winds had increased to 100 mph as the system had now achieve Category 2 strength on the Saffir-Simpson Hurricane Wind Scale. Hurricane Ian would continue to strengthen during the overnight and early morning of September 27th before the National Hurricane Center issued a 4:30am special update to confirm that the center of Ian has made landfall just southwest of the town of La Coloma in the Pinar Del Rio Province of Cuba at 4:30am. Maximum sustained winds at landfall were estimated to be 125 MPH and thus Ian reached category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale at landfall in Cuba.

Although Ian spent much of the morning of the 27th traversing western Cuba, the narrow width of the western portion of Cuba and the large circulation of the storm prevented any significant weakening during the system’s passage over land. Significant damage was reported in western Cuba with the destruction of the local power grid across much of the western portion of the island nation. By noon, the center of Hurricane Ian re-emerged over open water in the southeastern Gulf of Mexico. As the storm continued to move northward over the southeastern Gulf of Mexico, a large mid/upper level trough moving eastward across the United States influenced the system by steering it to the north-northeastward, as well as providing atmospheric conditions more conducive for strengthening over the warm waters of the Gulf. Throughout the rest of the afternoon and the evening of September 27th, Ian largely remained at a constant level of intensity, however internal structure changes such as an eyewall replacement cycle expanded the size of the storm and the extent of tropical storm and hurricane force winds. During the late evening, the eye of Hurricane Ian passed directly over the Dry Tortugas as a Category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale bringing surge and wind impacts to the lower and middle Keys during the late evening and early morning. 

Radar and reconnaissance aircraft investigating the storm during the early morning of September 28th indicated that the eyewall replacement cycle of Ian had come to completion and that the system had resumed strengthening. In fact, aircraft reconnaissance investigating the storm during the early morning hours experienced several turbulence and graupel in the eyewall. Maximum winds increased from 120 mph at the 2am intermediate advisory to 155 mph at the 7am advisory, a jump in intensity of 35mph in a time period of 5 hours. Ian had now become a very intense Category 4 hurricane on the Saffir-Simpson Hurricane Wind Scale as it approached the coastline of Southwest Florida. The forward motion of the storm also began to slow on its approach to the Florida coast. Lightning sensor arrays indicated significant lightning in the eyewall of Ian during this time period, indicative of powerful updrafts within the eyewall that allowed for ice crystals to form in the tall convective towers of the storm. Water levels and wind speeds along the Southwest Florida coast steadily increased during the morning as the center of the storm and the eyewall inched closer to the coast. 

By 305pm EDT on September 28th, the National Hurricane Center announced that radar imagery indicated that the eye of Ian made landfall along the southwestern coast of Florida near Cayo Costa. Data from an Air Force Reserve reconnaissance aircraft indicated that Ian's maximum sustained winds at landfall were estimated to be near 150 mph (240 km/h) with an estimated minimum central pressure of 940 mb (27.75 inches). As the system moved onshore across Southwest Florida, significant impacts were experienced across much of the area. These impacts will be covered in detail in various tabs ahead, examining the storm surge, flooding, tornado, and wind impacts that were observed across southern Florida.

Conclusion 

The aftermath of Hurricane Ian varied across the region, with varying impacts experienced across southern Florida. Daylight on September 29th revealed significant damage across most of southern and western Collier County from Everglades City all the way up the coast to Naples and points north, where storm surge and wave action caused major inundation and damage. Wind gusts of hurricane force created widespread power outages resulting from downed power lines and trees across the region with many households remaining without power for an extended period of time. On the eastern side of South Florida, the primary impact was the damage left behind by at least 11 tornadoes spawned by individual storm cells in the outer rain bands of Ian. Significant damage was reported in Kings Point near Delray Beach in Palm Beach County, as well as damage to 20 aircraft at the North Perry Airport in Pembroke Pines. Gusts to tropical storm force were widespread across the eastern portion of South Florida which resulted in intermittent power outages and tree damage.

Storm Impacts Across Southern Florida

Note: data in this section includes the following counties: Collier, Hendry, Glades, Palm Beach, Broward, and Miami-Dade. Death and damage information received from Florida Department of Law Enforcement (FDLE), county and city emergency management officials, and news reports.

As of late October, the death toll from Hurricane Ian in Florida was 118. Almost half (57) occurred in Lee County, with 8 in Collier County and 2 in Hendry County.

Storm Impacts

Collier County

Significant to major storm surge flooding covered almost all of Collier County south/west of Tamiami Trail/US 41 from Everglades City to the Lee County line. Major storm surge flooding occurred within a mile of the coast, both at the beachfront as well as the intracoastal waterways. Farther inland, there was significant to major storm surge flooding south and west of Naples Municipal Airport along the Gordon River and Rock Creek, as well as along the Cocohatchee River and Palm River areas. Wind gusts of 100- 110 mph were measured at about 100-150 feet above ground level over western Collier County, with peak near-surface wind gusts likely in the 80-90 mph range. Wind damage was mainly confined to trees/fences/screens, with minor wind damage to vulnerable structures. Estimated highest number of customers without power was 201,095 as of 3 PM on September 29th. Reported damage estimates for the entire county are $2.2 billion. Of that, $1.7 billion is to residential properties and $492 million to commercial. A total of 33 buildings were destroyed, with 3,515 residential and commercial buildings suffering major damage. Breakdown of damage amount by City/area: unincorporated Collier $948 million, city of Naples $989 million, Marco Island $256 million, Everglades City $7.1 million.

Hendry County

Highest winds occurred in western Hendry county in the LaBelle area where gusts likely reached hurricane force. Maximum wind gusts in the 70 mph over eastern sections of the county. Estimated highest number of people without power is 10,588 as of 3 PM on September 29th. Estimated damage total is $419,000. A total of 112 structures were damaged, most in the western part of the county. One death to a 72-year old male was from a heart attack while outside during the storm. No details on the second reported death.

Glades County

Highest winds occurred over western and northern sections of the county where winds likely gusted to hurricane force. Maximum wind gusts were in the 70 mph range over eastern sections of the county. Estimated highest number of people without power is 5,696 as of 3 PM on September 29th. Damage assessment: 3 structures destroyed, 14 with major damage, and 25 with minor damage. An EF-0 tornado in Moore Haven caused 2 homes to be severely damaged.

Palm Beach County

Four (4) confirmed tornadoes, the strongest in Kings Point/Delray Beach of EF-2 intensity. Two EF-1 tornadoes in Wellington and Loxahatchee areas, respectively, and 1 EF-0 in Boynton Beach. Otherwise, tropical storm force wind gusts produced very minor wind damage confined to trees. Maximum wind gusts were in the 50-60 mph range. Estimated highest number of people without power is 8,110 as of 3 PM September 29th. Minor tidal flooding was noted near the times of high tide at the coast.

Broward County

Four (4) confirmed tornadoes, the strongest in Pembroke Pines/North Perry Airport of EF-1 intensity which caused an estimated $2 million in damage. EF-0 tornadoes were reported in parts of Hollywood and Davie, with a fourth tornado in the Everglades of far western portions of the county confirmed by radar. Otherwise, tropical storm force wind gusts caused very minor wind damage confined to trees. Maximum wind gusts were in the 40-55 mph range, highest at the coast. Number of customers without power is 1,572 as of 3 PM September 29th. Minor tidal flooding occurred during high tide times at the coast.

Miami-Dade County

Two (2) confirmed tornadoes. One EF-0 tornado was in the Fountainbleau/Doral area, and an un-rated tornado in the Everglades of far NW Miami-Dade County which was confirmed by radar. Otherwise, tropical storm force wind gusts produced very minor wind damage confined to trees. Maximum wind gusts were in the 40-55 mph range, highest at the coast. Number of customers without power is 5,950 as of 3 PM September 29th. Minor tidal flooding was observed during high tide times at the coast.