Hurricane Laura

Post Landfall 2 | Summary
Posting Date: August 31, 2020, 2:45:00 AM

AIR estimates that industry insured losses to onshore property resulting from Hurricane Laura’s winds and storm surge will range from USD 4 billion to USD 8 billion. After evaluation, AIR has determined that the inland flood potential loss related to this event is low. 

ALERT™ subscribers can now download Touchstone^®, Touchstone Re™, and CATRADER^® event sets, loss-based SSEs, and wind and surge shapefiles of the median event for Hurricane Laura from the Downloads tab. The SSEs are recommended for exposures in Louisiana, Texas, and Arkansas.

Included in the estimates are losses to onshore residential, commercial, and industrial properties and automobiles for their building, contents, and time element coverage . See below for additional information:

AIR’s modeled insured loss estimates include:

• Insured physical damage to property (residential, commercial, industrial, auto), both structures and their contents from winds, wind-borne debris and storm surge
• Additional living expenses (ALE) for residential lines and business interruption losses for commercial lines
• A 5% leakage is assumed to estimate the amount of damage/losses caused by storm surge attributed to wind for residential lines
• The loss estimates for commercial lines reflect insured estimates of storm surge, which is a combination of leakage and take-up depending on the market segment
• For the automobile line, estimates reflect AIR’s view that insurers will pay for all of the storm surge damage in addition to damage from wind

AIR’s modeled insured loss estimates do not include:

• Losses paid out by the National Flood Insurance Program
• Losses to inland marine, ocean-going marine cargo and hull, and pleasure boats
• Losses to uninsured properties
• Losses to infrastructure
• Losses from extra-contractual obligations
• Losses from hazardous waste cleanup, vandalism, or civil commotion, whether directly or indirectly caused by the event
• Losses resulting from the compromise of existing defenses (e.g., natural and man-made levees)
• Loss adjustment expenses
• Other non-modeled losses, including those resulting from tornadoes spawned by the storm
• Losses for U.S. offshore assets and non-U.S. property

How Do Hurricane Rita (2005) and Hurricane Laura Compare?

Although comparisons between Laura and Hurricane Rita (2005) have been made, they differ in two important ways: Rita was a larger storm and hit a more populous area than Laura did. Rita made landfall west of where Laura did, impacting population centers of Texas; Laura made landfall well east of Houston and west of New Orleans, keeping losses lower.

Hurricane Laura Recap

Fueled by high sea surface temperatures in the Gulf of Mexico, Hurricane Laura made landfall near Cameron, Louisiana, close to the Texas border, at 1 a.m. CDT (6:00 UTC) on August 27 as a strong Category 4 storm, bringing catastrophic winds, around 15 feet of storm surge, and widespread heavy rain across the Gulf region, with wind and rain continuing north into Arkansas. Twelve deaths in Louisiana and four in Texas have been attributed to the storm. In the following sections we describe the impacts of each sub-peril as reported in more detail. The full extent of the damage may not be known for days, as the hardest-hit areas remain inaccessible; however, we expect the combination of Laura’s track through relatively lower populated areas and its Rmax on the smaller side to keep insured losses down somewhat, despite its major hurricane status at landfall.

Wind
Laura struck the Louisiana coast with sustained winds of nearly 150 mph (241 km/h), tying it with the 1856 Last Island hurricane in terms of the strongest recorded tropical cyclone to make landfall in Louisiana. Laura's rapid intensification over abnormally warm Gulf waters was similar to Hurricane Harvey (2017) and Hurricane Michael (2018), the other two most recent Category 4 or stronger storms to hit the U.S.

At landfall, Laura's hurricane-force winds extended outward up to 60 miles (95 km) from the center and tropical storm–force winds extended up to 205 miles (335 km); the radius of maximum winds (Rmax) was equal to about 17 miles, which is on the smaller side, although certainly not the smallest. Wind damage was greatest in Louisiana, particularly in areas closer to the eyewall near landfall. Preliminary maximum wind reports from the National Weather Service (NWS) reported 133 mph gusts at Lake Charles in Calcasieu Parish. Reports show damage from torn off roofs and façades to structures that were destroyed, along with upended vehicles, damage to power lines, roads, railways, and other infrastructure (see “Reported Damage and Disruption” section for more).

Laura's winds diminished after landfall but remained at hurricane strength for nearly half the day, pummeling the region for hours as the storm’s center traversed north through Louisiana. By Thursday at noon, tropical storm–force winds extended outward up to 105 miles (165 km) from the center and a tropical storm warning was issued as far north as Little Rock, the state capital of Arkansas. Laura finally weakened to a tropical storm by early afternoon on Thursday as the center passed Shreveport, Louisiana, then crossed into Arkansas late Thursday as a tropical depression with maximum sustained winds of 35 mph recorded, according to the NHC’s 10 p.m. CDT report, when Laura was centered about 30 miles north-northeast of Little Rock. The storm continued traversing the state later that night, when it is suspected that the storm spawned a tornado in Craighead County. Major roof damage was reported in Goobertown, 10 miles northeast of Jonesboro and a gas line was ruptured in Lake City, 15 miles east of Jonesboro; no injuries have been reported. The storm's remnants passed east across the mid-Atlantic states on Saturday before moving offshore.

Storm Surge
Prior to landfall, NHC had forecast the possibility of storm surge up to 20 feet (6 meters) for some areas of Louisiana; however, Laura’s storm surge was not as severe as expected, as the storm tracked a bit east of the Calcasieu Ship Channel, a waterway that connects the town of Lake Charles with the Gulf of Mexico, and pushed less water forward. The highest storm surge recorded thus far was around 15 feet above NAVD88 (around 17 feet above MLG), measured at a USACE river gauge on the Mermentau River at Grand Chenier (70900) in Cameron Parish County, Louisiana; the previous record high stage at that gauge was 11 feet above NAVD88 (around 13 feet above MLG) on June 27, 1957. The next highest storm surge measured thus far was 9.82 feet above NAVD88, recorded at Calcasieu Pass near Cameron, Louisiana, just west of where the storm made landfall. Video footage of Cameron shows the entire downtown inundated. Reports for storm surge elsewhere in Louisiana are still being assessed and verified, and higher totals may have occurred near where the eastern eyewall came ashore. Surge near Sabine Lake on the Texas side of the Texas/Louisiana border has been measured at 2.63 feet (at Rainbow Bridge) and 4.79 feet (at Texas Point, Sabine Pass) above NAVD88. Wide portions of Crystal Beach on the Bolivar Peninsula east of Galveston received some storm surge flooding from Laura, according to reports; this area received devastating storm surge from Hurricane Ike in 2008.

New Orleans' levees and flood mitigation systems were prepared in advance of Laura, but the storm made landfall far enough to the west that New Orleans was not affected by significant storm surge.


Reported Damage and Disruption

More than 580,000 coastal residents were ordered to evacuate in advance of the dangerous winds and what NHC had termed “unsurvivable” storm surge. A high concentration of oil platforms, refineries, petrochemical plants, and natural gas processing plants were in Laura's path; many were shut down and evacuated in advance of the storm and appear to have escaped major damage, but AIR will continue to study offshore impacts.

More than 900,000 homes and businesses across Texas, Louisiana, Arkansas, and Mississippi were without power Thursday evening in the storm's aftermath, with most in Louisiana and Texas; on the weekend about 350,000 remained without power in Louisiana, 88,000 in Texas, and 13,000 in Arkansas. In addition, about 200,000 homes in Louisiana still did not have access to water, as water systems were damaged; it could be weeks before it is restored, according to the mayor of Lake Charles. Texas appears to have escaped widespread damage—southeast Texas was hardest hit, particularly the cities of Orange and Port Arthur. Winds in Texas Point may have reached 90 mph. Texas Governor Greg Abbott declared a disaster in 62 counties, stressing that power, water, evacuees, and assessment were priorities. Arkansas experienced minor damage to roofs and toppled trees and power lines.

Louisiana
The vast majority of impacts were in Louisiana, as Hurricane Laura slammed the coastal town of Cameron, in Cameron Parish, and the town of Lake Charles, Calcasieu Parish, 30 miles from the coast, causing widespread destruction to buildings of all types. Extensive damage has been reported to residential and commercial buildings, automobiles and pleasure boats, industrial facilities and infrastructure. Laura is credited with causing a BioLab chemical plant in Lake Charles that makes chlorine for swimming pools to catch fire Thursday morning. Residents within a 1-mile radius of the plant were given shelter-in-place orders Thursday because of a chlorine leak caused by the fire. The fire burned into that evening and was declared under control on Friday by a spokesperson from BioLab’s parent company.
Communities close to the Texas-Louisiana border experienced minor roof damage and uprooted trees.

Residential buildings in and around Lake Charles saw significant damage to roofs of all geometries and with various roof cover types. Residential building envelopes were breached due to debris impacts and the damage was further exacerbated in many cases due to the impacts of storm surge. Residential homes in Louisiana are founded primarily on crawlspace and slab foundations, both of which are vulnerable when it comes to flood damage. Similar to residential buildings, commercial buildings—including hotels, offices, restaurants, retail and wholesale stores, gas stations, and hospitals—saw varying degrees of damage. These included tearing of built roofs to entire roofs lifting off and dislodging from the buildings, significant damage to the envelope elements such as cladding, openings, and interior damage due to penetration of wind-driven rain.

Louisiana Building Codes and Their Enforcement

Louisiana has a statewide adoption of the Louisiana State Uniform Construction Code. This code is an adaptation of the 2015 editions of the International Building Code (IBC) and International Residential Code (IRC) with amendments. These codes were adopted and have been effective since early 2018. According to these standards, residential and commercial buildings in and around Lake Charles and Cameron are required to be designed for wind gusts of 130 mph as per the American Society of Civil Engineers ASCE 7-10 load standards. Commercial buildings are typically subject to a touch more stringent requirements per the IBC, given the risk category in which individual commercial buildings fall. Given these design wind speeds and the wind speeds that Laura produced in these areas, however, it is conclusive that Laura equaled if not exceeded the design levels in some of these areas. Buildings that are older and predate the adoption of some of these standards can be expected to perform worse. While adoption of building codes is one aspect, an equally important aspect is their enforcement. While enforcement is good for coastal counties, the same is not true for inland counties. Therefore, as Laura trekked through the state and continued to produce damaging winds, damage can be expected to buildings across the entire state.

Potential Impacts of COVID-19 on Hurricane Laura

While the impact of Laura is still being felt across many states and will be so for weeks and months to come in the affected areas, the fact that a Category 4 storm struck in the middle of a global pandemic will yield lessons for the future. While Laura spared the major metropolitan areas of Houston and New Orleans, hundreds of thousands of customers are experiencing power cuts in the affected states and 200,000 in Louisiana do not have access to water. Hundreds of thousands of evacuees were directed to thousands of hotel rooms in addition to shelters to maintain social distancing norms. To read about potential insurance impacts, please go to our In Focus blog: https://www.air-worldwide.com/blog/posts/2020/8/how-covid-19-may-impact-loss-inflation-in-florida-construction-if-a-hurricane-makes-landfall/. In time lessons and the extent of impacts from Hurricane Laura will be revealed.

Post Landfall 2 | Downloads
Posting Date: August 31, 2020, 2:45:00 AM

Simulated Event Set

Note: The "All simulated scenarios" set consists of all the events simulated by AIR using the event's actual parameters. The "Select simulated scenarios" set consists of a subset of the full distribution that is most representative of the range of potential industry losses.

Similar Stochastic Event IDs

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