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HURRICANES: NORTHEAST

SINCE 1900, NINE HURRICANES HAVE directly impacted the northeast including and New England. Most of these were relatively weak storms that did not cause a lot of damage. Recent examples are in 1985 and in 1991 – both less than $1 billion events. The landmark event for this region is the Great New England Hurricane of 1938. This storm destroyed tens of thousands of buildings, downed 20 million trees, left over 60,000 people homeless and caused over 600 deaths and 4,500 injuries. Scientists do not know the exact inten- sity of this storm and speeds are estimated at just 120mph (200 kph), but it was not its Saffir-Simpson category that made this storm so deadly and destructive. The 1938 hurricane began as a Cape Verde tropical storm on 10 September. The storm was forecast to make in south before it suddenly changed direction and began moving north. By the time it reached , the hurricane was traveling at over 60mph. , and coastal residents had no warning as they went about their business on what started out as a beautiful, sunny September afternoon. There was no advanced meteorological tech- Why the Next Big nology, such as radar, radio buoys or satellite imagery at that time. Apparently, Charlie Pierce, a junior forecaster at the US Weather Service predicted that the hurricane was heading for Northeast Hurricane the North East, but the chief forecaster over- ruled him, believing that the storm would die out when it encountered the colder waters of the North Atlantic. By the time the Weather Will Surprise Service learned the storm was headed directly for Long Island, it was too late. A repeat of the 1938 New England Hurricane could cause Too late losses as large as in 2005. When the storm arrived at 3:30 pm, it was high By Karen Clark , and the tide was even higher than usual because of the autumnal equinox. Fifteen to 20 foot waves on top of a 16 foot created a 35 foot wall of water that destroyed virtually everything in its path. Because the storm track cut through eastern Long Island, the worst of the storm surge was in . Downtown Providence, Rhode Island was flooded with 14 feet of water. Coastal destruction from the storm surge was experienced from New Haven, Connecticut to New Bedford, , as well as on Long Island. After landfall, the storm continued its fast track north and into . The hurricane was big, with an radius estimated at over 50 miles – more than twice the average size of storms in the Gulf and southeast regions. It was over in eight hours, but the entire northeast region felt the effects of the Great New England Hurricane. It caused more damage than the 1906 San Francisco earthquake and remained the most costly US disaster on record until NOAA in 1954. Images:

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HURRICANES: NORTHEAST

Moving quickly The KC Wind Damage Scale, shown in Figure While scientists are much better able to predict 2 for a repeat of the 1938 hurricane, provides storm tracks today, hurricanes can change insurers with information on the likely damage direction suddenly and unpredictably. The footprint. chances are that a Northeast hurricane will be In a repeat of the 1938 Great New England moving at over 40mph – more than twice the Hurricane, eastern Long Island and portions of speed of a typical hurricane in other coastal Connecticut and Rhode Island are likely to regions. This means the storm will travel from experience wind speeds in excess of 100 mph. to Long Island in less than 10 The KC-4 area (orange swath), will suffer wide- hours. That is very little time, particularly spread structural damage to wood frame, unre- considering that the number of New York resi- inforced masonry and light metal buildings. dents who live in vulnerable coastal areas and, Even mid and high rise commercial structures therefore, would need to evacuate, has been will suffer significant roof, cladding, signage, estimated at up to 2.5 million. window and contents damage. The yellow There is also the question of how people will swath, indicating KC-3 damage levels, extends get out. The Office of Emergency all the way into Vermont where there will be Management advises residents to use public localised areas of roof, window and cladding transportation to reduce the volume of traffic damage along with extensive tree damage. and roadway congestion. But there could be a Every New England state except would problem with this plan, because of the unique Figure 2 Damage footprint of the Great New experience at least KC-2 damage levels. There features of the New York coastline and, in England Storm 1938 using the KC would be extensive power outages throughout particular, what is known as the New York Wind Damage Scale. the region. It would take several weeks for Bight. This is where the shore and power to be restored in the hardest hit areas. the Long Island south shore converge almost Northeast hurricane would not only cause The insured losses could exceed $30 billion. perpendicularly to one another. If a hurricane billions of dollars of property damage along This same storm with the track shifted 50 miles traveling in a northwest direction made land- the coast, but is likely to cause multiples of that to the west could cause insured losses exceed- fall near New York City, the Bight would funnel damage in business interruption, infrastruc- ing $50 billion. tremendous storm surge into Lower ture, clean-up and recovery costs. Few, if any, of as well as across Long Island, block- these impacts are explicitly incorporated into Impacts of climate change? ing many of the exit routes. catastrophe models. Insurers and reinsurers For northeast hurricanes, the biggest risk posed According to an Army Corps of Engineers can only use their own imaginations and by climate change is sea level rise. The most study, even before such a storm made landfall, scenario testing to estimate what their losses recent report from the Intergovernmental floodwaters could rapidly fill many subway and could be from this type of event. Panel on Climate Change (IPCC) gives a best roadway tunnels. In 1992, a nor’easter that While the insured wind damages are a bit estimate range of sea level rise of four inches to followed this track flooded parts of Coney easier to quantify, there is still a high degree of 2.9 feet by the year 2100. A study conducted by Island, the FDR Drive and the suburban train uncertainty. Because they tend to be so big and researchers from NASA and Columbia PATH station at Hoboken. fast moving, Northeast hurricanes travel far University projects a sea level rise of 15 to 19 The study found that a Category 3 hurricane inland, causing widespread localised damage. inches by the 2050s in New York City. in New York could generate a storm surge of 24 A major Northeast hurricane is likely to affect According to one of the study’s authors: feet at Tunnel, 21 feet at the Lincoln tens of thousands of square miles and cause “With sea levels at these higher levels, flooding Tunnel, 25 feet at JFK Airport, and 16 feet at between $15 and $50 billion of insured wind by major storms would inundate many low LaGuardia Airport. Figure 1 shows that even a damage. lying neighborhoods and shut down the entire Category 2 hurricane could inundate signifi- The range is wide because the insured losses metropolitan transportation system with cant areas of Long Island and New York City, depend more on the size of the storm and the much greater frequency.” With that level of sea including Manhattan. storm track than on the maximum wind level rise, a Category 3 hurricane would likely The problems caused by this massive inunda- speeds. As with the storm surge, the further the put most of , southern tion would dwarf those caused by Hurricane track is to the west and the closer to New York Brooklyn and Queens under water. Katrina in 2005. The storm surge from a major City, the higher the losses will be, because of the The IPCC report does not project an increase higher number of properties on in hurricane frequency, but does project that Figure 1 the more powerful right hand side maximum wind speeds in hurricanes could of the storm. increase by 2% to 5% over the next 20 years. So Saffir-Simpson category Even with climate change, it is unlikely there alone does not capture the will be a Category 4 or 5 hurricane in the damage-producing potential of Northeast, but this does not mean there will northeast hurricanes. We have not be a devastating storm. We cannot be introduced our own tool for complacent because typical hurricane intensity quickly assessing the likely insured scales really do not apply in this region. Even a damage from tropical cyclones, large Category 2 storm with the right track the KC Wind Damage Scale. It could result in a $50 billion loss. ranges from KC-0, for a storm with WEBLINKS visit: www.cat-risk.com winds of less than 40mph in which US P&C capital cushion could shrink by $80bn negligible insured damage is likely, to KC-7, denoting a hurri- Karen Clark is president and CEO, Karen Clark & cane with winds in excess of Company. 160mph. www.karenclarkandco.com

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