October 13th, 2018

Hurricane Michael

Posted at 11:11 AM ET

michael-smallHurricane Michael made landfall on October 10 as a high-end Category-4 hurricane on the Florida Panhandle, with maximum sustained winds of 155 mph. The storm rendered severe to complete damage to areas from Panama City to Port Saint Joe, with especially severe damage in Mexico Beach due to severe wind and storm surge. Damage due to wind has caused roof and wall collapse, especially for cinderblock construction and even commercial properties. Some coastal areas of Mexico Beach have been scoured to the foundation by storm surge and wave battering. At least twelve fatalities have been reported by media, although this number could rise as damage survey and search and rescue efforts continue. Our thoughts and concerns are with those lost and directly affected by this event. Hurricane Michael is the strongest hurricane to affect the Continental U.S. since Hurricane Andrew (1992).

Meteorological Discussion

According to advisories of the National Hurricane Center (NHC), Michael originated from an area of showers and thunderstorms over the western Caribbean Sea, near a broad area of low pressure. The NHC began issuing advisories at 5 PM EDT (21 UTC) on Saturday October 6, at which time tropical storm watches and warnings were issued for areas of western Cuba and the Yucatan Peninsula. The shower and thunderstorm activity eventually consolidated and organized, and once a closed area of low pressure was evident the NHC classified the feature as a tropical depression at 5 AM EDT (09 UTC) October 7. The feature then gained intensity while moving slowly to the north and was soon upgraded by the NHC to tropical storm status at 12:55 PM EDT (1655 UTC) October 7. Given the forecast track and potential impacts, a hurricane watch was issued by the NHC for areas of the northeastern Gulf Coast at 5 AM EDT (09 UTC) October 8, along with a hurricane warning for western Cuba. Michael continued to strengthen with warm waters and reduced wind shear and reached hurricane status at 11 AM EDT (15 UTC) October 8, just before passing the western tip of Cuba and rendering hurricane conditions and heavy rainfall to the area. Hurricane watches were upgraded to warnings for the northeastern Gulf Coast at 5 PM EDT (21 UTC) October 8.

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Hazard data illustrated in the CAT-i map was taken from GC AdvantagePoint®, Guy Carpenter’s web-based risk management platform. GC AdvantagePoint users can view impacted areas on any map as well as see how their portfolios were affected. Please contact your broker or cat modeling analyst for further information.

Michael continued moving to the north in a steering flow between a large trough to the northwest, and a large ridge to the northeast. This took Michael into the Gulf of Mexico and into an environment of high ocean heat content (warm waters of considerable depth), diminishing wind shear and good storm ventilation. With these enabling conditions in place, Michael underwent rapid intensification. By 5 PM EDT (21 UTC) October 9, Michael was located 295 miles south of Panama City, Florida, and had gained maximum sustained winds of 120 mph, a Category-3 hurricane on the Saffir-Simpson Scale. Michael then strengthened further to Category-4 status with maximum sustained winds of 130 mph by 2 AM EDT (06 UTC) October 10, while 180 miles south-southwest of Panama City, Florida. The outer rain bands began to move over the Florida Panhandle just a few hours later, and tropical storm conditions moved onshore in the Florida Panhandle around 8 AM EDT (12 UTC) October 10.

As the center of Michael made final approach to the coast it continued to move through an environment of very warm waters, reduced wind shear and good storm ventilation, allowing further strengthening even while approaching land. Michael had gained maximum sustained winds of 150 mph with a central pressure of 923 mb while 150 miles south-southwest of Panama City, Florida, and continued to gain intensity until the center moved onshore. In the meantime, the storm strength, diameter, wind direction and the shape of the coastline produced a significant storm surge, especially along and to the east of the core of the storm.

According to NHC advisories, Hurricane Michael made landfall on the Florida Panhandle between Tyndall AFB and Mexico Beach, to the east of Panama City. Landfall occurred around 12:30 PM CDT (1730 UTC) October 10, at which time the NHC reported maximum sustained winds of 155 mph, a high-end Category-4 hurricane on the Saffir-Simpson Scale. The minimum central pressure at the time of landfall was 919 mb. This is the third-lowest pressure in recorded history, and the strongest hurricane since Hurricane Andrew (1992), for a landfalling hurricane in the continental U.S., according to NHC statements.

Prior to gauge failure a wind gust of 130 mph was reported at Tyndall Air Force Base. Wind gusts of 129 mph and 104 mph were reported at Panama City Airport and Mexico Beach, respectively. A gust of 71 mph was also reported at Tallahassee International Airport. A report of 7.7 feet of inundation above ground level due to storm surge was reported in Apalachicola. Higher storm surge severity was evident in Mexico Beach, Florida as apparent from the degree of damage, although gauge recovery from the area is still ongoing.

Michael weakened considerably following landfall and was downgraded to tropical storm status at 12 AM EDT (04 UTC) October 11, while moving into eastern Georgia. By this time, hurricane warnings had been discontinued for the northeastern Gulf Coast while tropical storm warnings remained active for areas of the Carolinas and Georgia. The storm then tracked through the Carolinas and southeastern Virginia while maintaining tropical storm strength. The storm was undergoing extratropical transition in the meantime. Heavy rainfall was an ongoing threat with the threat of flooding and flash-flooding extending from the Carolinas into Virginia, along with tropical-storm-force winds gusts.

Michael cleared the Atlantic coast well before 2 AM EDT (06 UTC) October 12, and by 5 AM EDT (09 UTC) Michael had completed its transition into a frontal system and was classified by the NHC as a post-tropical cyclone (with an asymmetric structure, expanded wind field, lack of a central dense overcast and the presence of fronts). In the meantime, the boundary between remaining tropical air, and colder air behind a frontal boundary clearing the mainland, had caused some gain in intensity. The storm continued to render hazards of gale-force winds and heavy rainfall for areas of the Mid-Atlantic and Northeast.

Impacts

Areas of the Florida Panhandle have suffered severe impacts, especially coastal areas between Panama City Beach and Apalachicola due to both catastrophic wind damage as well as storm surge. Media reports indicate at least 12 fatalities although this number may increase as survey efforts continue. In the meantime, downed trees and powerlines with variable property damage have affected a broader area from Florida to the Mid-Atlantic coast. Initial reports indicate that power outages have affected at least 1.5 million customers.

Florida

Initial media reports indicate severe to complete damage for near-coastal regions for areas including eastern Panama City and Panama City Beach, and Mexico Beach. Catastrophic wind damage has been reported including roof and wall failure for both residential and commercial properties, especially for cinder-block construction, with damage also reported for engineered structures. Several near-coastal areas of Mexico Beach have been scoured to the foundations due to storm surge and wave battering, with areas further inland showing severe to complete damage due to wind; most properties in the area have sustained severe to complete damage. The National Guard was able to rescue about twenty people, but many residents were still accounted for. Catastrophic damage was also reported in Port St. Joe. Meanwhile at Tyndall AFB, significant property damage was reported for every structure on the base; base personnel were evacuated on Monday and there were no fatalities or injuries reported.

Multiple hospitals were affected by the storm, yet some were able to remain functional with increased aid and emergency response. Bay Medical Sacred Heart and Gulf Coast Regional Medical Center suffered impacts and began to evacuate patients on Thursday. Reports indicate that both hospitals have been able to keep their emergency rooms open. The largest psychiatric hospital in the state, The Florida State Hospital with 975 residents and 325 staff was completely isolated following the storm. Ample supplies stored on site and helicopter airdrops of additional supplies allowed the hospital to remain functional and continue to supply care.

Away from the coast, downed trees and powerlines with variable wind damage were reported over widespread areas along with resulting power outages. About 110,000 power outages were reported in Tallahassee, and it could be weeks before power is restored to the most damaged areas. The state also saw significant transportation disruption including toppled railcars due to wind, airport closures and road closures. Areas of US-98 were washed out for immediate coastal areas due to storm surge. Wind-driven debris caused significant blockage to roadways including an 80 mile stretch of I-10, which was later reopened.

A presidential disaster declaration was made for the state, making federal air available for state and local response efforts. Florida Insurance Commissioner David Altmaier estimated that around 500,000 policyholders would be affected by the storm, according to media reports.

Georgia

As of Thursday morning, around 350,000 homes and businesses were without power, with greatest concentration in southwestern areas of the state. The amount of crops damaged by the storm was increased due to the timing of the storm with harvest season. Georgia Agriculture Commissioner Gary Black indicated that 84 chicken houses, estimated to have held more than 2 million chickens, were destroyed. The National Weather Service has confirmed three tornadoes, with an EF-0 just southwest of Atlanta, a high-end EF-1 in Crawford County and a brief tornado in Peach County. Reports indicate numerous reports of downed trees and powerlines, with several homes also damaged by falling trees. At least one fatality was reported where a girl was killed by a damaged carport in Seminole County, according to media reports.

Alabama

According to media reports, more than 60,000 homes and businesses in Southern Alabama were without power early Thursday. A tree fell on a home and injured three people in Dothan, Wednesday afternoon.

Carolinas

Heavy rainfall caused a significant threat for flooding and flash-flooding, including overwhelmed rivers and streams. According to media reports, flooding displaced people from their homes and caused at least twenty water rescues in Irmo. Severe flooding impacted areas of the North Carolina Outer Banks, where some had to be evacuated due to floodwaters. Several roads in Boone, North Carolina were closed due to floodwaters. Across North and South Carolina, many schools were closed for the day on Thursday. Schools in Henderson and Polk counties, south of Asheville, were closed due to the storm, with other schools in the area sending students home shortly after they arrived. Media reports indicate at least one fatality due to a downed tree in Iredell County, north of Charlotte.

Virginia

Heavy rainfall and strong winds affected many areas of southern and central Virginia. Media reports indicate that flooding affected homes, businesses and government buildings across the county. The Virginia Department of Emergency Management identified at least five fatalities in the state, including a firefighter killed while responding to an emergency. Flooding has caused road closures and led to water rescues in several counties including Roanoke, Danville, Southern Pittsylvania and Henry County. Downed trees and powerlines were reported along with some property damage, with a possible tornado reported in Williamsburg (causing a tree to fall through a house), and another confirmed in Amelia County near Scott’s Fork. Reports also indicate that a roof was blown off a structure in James City County.

Economic Impacts

Initial media reports indicate that CoreLogic estimates insured losses of around USD 2.0-4.5 billion (not including NFIP), with USD 1.5-3.0 billion in residential and USD 0.5-1.0 billion in commercial. Meanwhile Karen Clark & Company estimates insured losses of around USD 8 billion, with nearly half occurring in Bay and Gulf counties in Florida (not including NFIP losses), according to media reports. According to the U.S. Agriculture Department, up to 3.7 million crop acres (1.5 million hectares) containing cotton, timber, pecan and peanut crops were damaged causing an estimated loss of around USD 1.9 billion. Crude oil production and natural gas output were reduced by more than 40 percent and 33 percent respectively, causing major disruptions to the U.S. Gulf of Mexico energy operations.

Sources: U.S. National Hurricane Center, U.S. National Weather Service, Reuters, Associated Press, New York Times, Insurance Journal, The Weather Company, RMS

Guy Carpenter publishes CAT-i reports for major natural catastrophes worldwide. These reports cover catastrophes including worldwide tropical cyclones, earthquakes, major UK and European floods and any other natural event that is likely to incur a significant loss to the (re)insurance industry. Please email CAT.i@guycarp.com if you wish to be added to the free email distribution list.

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