Hurricane Matthew 2016
Status: Closed
Pre-Landfall 6 | Summary
Posting Date: October 8, 2016, 6:30:00 AM
More than 800 people have been killed by Hurricane Matthew in the Caribbean, the majority in Haiti, and the death toll is expected to rise there. In the Bahamas, winds reaching 140 mph buffeted Nassau yesterday, as flooding throughout the populous island damaged buildings and downed trees and power lines. The extent of the damage throughout the Bahamas is yet to be known.
President Obama declared a state of emergency for Florida, Georgia, and South Carolina last night. Matthew was downgraded to a Category 3 hurricane overnight, packing 120 mph winds. Although Matthew has not made landfall and may not until tonight—if it ever does—the storm’s eye has come as close as 25 miles east of Cape Canaveral this morning at 6, where wind gusts up to 107 mph have been recorded, leading to a rare extreme wind warning to be issued from the National Weather Service (NWS) for Brevard County. Near Cape Canaveral, storm surge has peaked at 4 feet at Trident Pier, according to NOAA. Matthew is then skirted the coast about 30 miles east-southeast of Daytona Beach, Florida, where a wind gust of 71 mph was recorded.
In addition to bringing strong winds, Matthew is expected to cause major flooding due to heavy precipitation and storm surge. North-northeast of Matthew, bands of locally heavy rains have spread more than 500 miles into South Carolina. As of this morning, 6 to 7 inches of rainfall was recorded in Orlando, where Disney World closed yesterday for only the fourth time in its history; the other closures were also for hurricanes. According to the National Hurricane Center, storm surge could peak at 7 to 11 feet above ground level from Sebastian Inlet, Florida, to Edisto Beach, South Carolina. By comparison, Sandy’s highest storm surge values in October 2012 were 4 to 9 feet above ground level in New York and New Jersey. It is feared that barrier islands will be breached and new inlets will be cut off, according to NWS Jacksonville. And NWS Charleston has warned that tide levels have already been raised and that they could make the top 5 or 10 highest ever.
Matthew has been affecting the Caribbean and the U.S. now for more than one week and it will continue to do so for another one to two days and perhaps even longer if it recurves and swings back toward Florida. One reason for Matthew’s longevity has to do with its hard turn northward from deep in the tropics at the beginning of the month. Typically tropical cyclones that form so far south will continue moving westward into the Gulf of Mexico. Another reason was exactly where Matthew turned north, allowing it almost clean passage toward the U.S. between Haiti and Cuba. As Matthew threaded the needle between these two mountainous land masses, its circulation was only minimally disrupted and it was able to quickly regain strength to a Category 4 as it has tracked parallel and very close to much of Florida’s eastern coastline.
Hurricane David took a very similar track along the east coast of Florida in 1979, eventually making landfall in southeast Georgia as a minimal Category 1. However, David is far better known as the only Category 5 hurricane to have struck the Dominican Republic, killing more than 2,000 people. This is an important point, because typically, strong hurricanes of Caribbean origin traveling north will necessarily cross the large islands, which can provide an effective “wall,” protecting the U.S. East Coast by severely weakening them. Unlike Matthew, David never fully recovered after emerging north of Hispaniola.
Another unique aspect of the track has to do with the orientation of the coastline and the location and strength of the subtropical high that is steering Matthew. While it is normal for storms to move northeastward at those latitudes, the motion typically happens either farther to the east, so there is little threat to land, or some change in direction will ultimately steer the storm onshore as a landfalling hurricane, although this is also rare. In fact, since the mid-1800s, when reliable records were first kept, no major hurricanes have ever made landfall along the upper Atlantic coast of Florida. The many unique aspects of Matthew limit the historical and even stochastic analogs that can faithfully represent its features.
Reported U.S. Impacts
It is early, but Matthew has already made serious U.S. impacts. One person in St. Lucie County, Florida, has died, and more than 600,000 people across Florida have lost power. Schools across Florida are closed. Thousands of flights to and from the state’s airports have been canceled, and Amtrak has suspended services in the southeast. More than 3 million have been ordered to evacuate in Florida, Georgia, and South Carolina.
Exposure at risk
As Hurricane Matthew’s eyewall continues to brush parts of Florida’s east coast with high winds and storm surge-related flooding, significant wind and surge damage can be expected to the building inventory in the path of the storm. The majority of wind damage tends to be caused by the insufficient wind resistance of building envelope systems, which in turn lead to the intrusion of wind-driven rain, thereby leading to significant damage to contents and loss of use. Furthermore, wind-induced damage and the failure of building structures and components tend to occur where there is a break or discontinuity in the load path.
The surge performance of residential and commercial buildings is primarily dictated by the underlying foundation type. Slab foundations tend to be the predominant foundation type in Florida, thereby leading to the potential for significant surge damage in areas impacted by surge. These foundations tend to have the first floor located closer to the ground surface in comparison to several other foundation types, thereby providing an easy channel for water to flow into them and cause widespread building, contents, and time element losses.
Building codes and standards, and floodplain regulations are adopted and enforced to regulate construction in at-risk areas. AIR’s analysis of damage data over time has indicated that building vulnerability can change significantly due to changes in building codes and code enforcement, changes in material and construction practices, and structural aging. Florida has a long history of evolving building codes. The state’s codes since 2002 have been based on the International Building and Residential Code. Building structural capacities appeared to have improved since Hurricane Andrew (1992) because of stronger building codes and better enforcement, resulting in less structural damage overall even from intense hurricanes during the 2004-2005 hurricane season. AIR expects newer structures in the region will perform better than older structures.
Forecast and Intensity
Matthew is expected to remain a Category 3 hurricane as it continues to parallel Florida’s coast. As it travels up the Southeast coast for the next 24-36 hours it is expected to weaken, with the potential to move either or closer or farther from shore all along the way and possibly make landfall at some point. It is then expected to move southeastward and south as a much weaker storm. A great deal of uncertainty surrounds the forecast track and intensity of Hurricane Matthew.