The slow start to the 2023 hurricane season quickly ramped up with a rare visit from Tropical Storm Hilary that caused severe weather in California and Nevada. This was followed by activity in the Atlantic with Hurricane Idalia causing damage in many parts of the Southeast, and Hurricane Lee affecting parts of New England. These three storms brought a plethora of wind damage, flood, roof leak, and storm surge claims.
Each of these storms has its own unique qualities, and now adjusters and attorneys are tasked with determining and proving what caused damage to occur.
Damaging Winds, Flash Floods, and Roof Leaks
Before Tropical Storm Hilary, the last named storm to affect Southern California was Hurricane Nora in 1997. Hilary made landfall in northern Baja California on Aug. 20, 2023, and moved north across southern California and Nevada, bringing the types of severe weather expected in more storm-prone areas like the Gulf coastal states and Florida. Hilary caused wind damage, roof leaks, flash floods, mudslides, and debris flows that damaged bridges and railways in many parts of southern California.
Some interstates were forced to close due to flooding and washouts. Torrential rainfall occurred over both the mountainous areas and the deserts. Widespread wind gusts between 50-70 miles per hour (MPH) affected parts of San Diego County, gusts of 40-50 MPH occurred in the Los Angeles valley area, and gusts reached 60-70 MPH in the San Gabriel Mountains. Wind speeds can be much higher in the mountainous areas of Los Angeles and San Diego Counties; a wind gust of 87 MPH was even recorded at the Magic Mountain Truck Trail.
Roof leaks could have occurred from wind-created openings, or perhaps from the wear and tear of the strong sun that beats down on rooftops so many days of the year. Downtown Los Angeles recorded 2.99 inches of rain, the most rain on record dating back to 1877 for this station. Meanwhile, 4.74 inches of rain accumulated at UCLA, 8.56 inches accumulated at Mount Wilson, and 13.07 inches fell at Upper Mission Creek. Hilary brought the first rainfall event of the month to many areas of Southern California.
Many homeowners and commercial policyholders did not have flood insurance, while others were not familiar with their insurance policy language, what was covered, and what was not. California State Insurance Commissioner Ricardo Lara said, “This once in a lifetime storm brought rainfall and wind damage, so it is crucial consumers understand their insurance coverage and know they have options and support.” Lara continued, “I have alerted insurance companies to follow California law requiring they cover any mudslide, debris flow, or other damage that is caused by our recent wildfires so that people can recover quickly.”
Idalia Causes Damage from Florida to the Carolinas
Hurricane Idalia was a major hurricane that brought damaging winds, heavy rain, and storm-surge flooding to a large part of the southeastern U.S. The extremely dangerous hurricane moved over record-warm ocean water temperatures in the eastern Gulf of Mexico that allowed the hurricane to explosively develop. Miraculously, the intense hurricane underwent a last-minute “eyewall replacement cycle” shortly before making landfall across the Big Bend area of Florida. As the eyewall reformed, the wind speeds decreased substantially just before Idalia made landfall.
While the damage could have been much worse, Idalia was still a powerful hurricane. Storm surge affected many areas from the Big Bend region of Florida to the Carolinas. In an interview with CLM Magazine, Mark Friedlander, director, corporate communications for the Insurance Information Institute, said, “Losses for Idalia will likely run between $2 billion and $5 billion.”
Since so many tropical storms and hurricanes have affected the Gulf Coast and Carolinas over the past 10 years, it is important to determine if storm surge occurred at a loss location, how high the water rose, how high the wind speeds were, and if the damage might have occurred from a prior event. Experienced forensic meteorologists have the tools and data to answer these questions. How high was the property above NAVD 88, a vertical datum for water levels? What were the highest water levels measured by USGS high water marks? What were the storm surge/storm tide water levels each hour according to area water sensors? Did the storm surge arrive before the high winds? As we continue to see with Hurricane Ian cases, the timing of the winds and “waves” at one property can differ significantly from the timing at neighboring properties because of their elevation above sea level.
A Close Brush in New England
Hurricane Lee was the first major tropical cyclone to develop over the open tropical Atlantic Ocean east of the Windward Islands. Lee was long-lived and moved over warm ocean waters, which helped the system become a major hurricane. Lee moved toward the northeastern U.S. and eventually moved over cooler ocean temperatures, which caused the storm to weaken.
The most intense winds and storm surge remained offshore, but the western fringes of the storm brought strong, gusty winds; flash flooding; and some storm surge to Cape Cod and portions of eastern Maine. High winds and storm surge are known to occur in these regions, so determining the historical wind speeds and storm surge heights during past events may be important.
Questions To Answer
There are undoubtedly going to be many disputes and lawsuits that arise from these storms. To make informed Hilary claims coverage and litigation decisions, for instance, adjusters and attorneys are going to want to know how high the winds were and how much rain fell at a specific loss location, not only from Hilary but also from past weather events such as the powerful Pineapple Express coastal storms or Santa Ana wind events.
Each claim or lawsuit is unique, and some require more complex research than others. For instance, does a named-storm deductible apply? Was Hilary still a named storm when it affected specific homes or businesses in California and Nevada? How much rain accumulated at the property as opposed to the closest airport or weather station? When was the last time rain fell? What is the recurrence interval of the rainfall that accumulated—was it a 50-, 100-, 1000-year storm? Did rainfall of this magnitude ever occur at this property before? Did a flash flood occur? Did flooding occur in a previous burn area, thus exacerbating the runoff and flooding? It is important to plot the property location on Doppler radar Digital Storm Total Precipitation images that are processed every one-to-five minutes. Incorporating this information along with a ground-truth rainfall analysis is crucial.
During Hurricane Idalia, did an isolated tornado or microburst occur at the property? How strong were the winds at the property itself? How high above sea level was the property and what were the winds at that elevation? A weather station at the airport near Camarillo, California, located 63 feet above sea level, reported a peak wind gust of 44 MPH during Hilary. Just 10 miles southeast of the airport, a weather station at Boney Mountain near western Malibu recorded peak wind gusts of 57 MPH at around 1,200 feet above sea level. The Santa Monica mountains, San Gabriel mountains, Santa Ana mountains, San Jacinto mountains, and Santa Rosa mountains are just some of the ranges in fairly close proximity where elevations increase dramatically. This is a very important consideration when you need to know how high the winds were at a specific property location.
How high were the winds at different floors of a high-rise? Were there higher winds or rainfall events outside the policy period, or when the policy was with another carrier? Did a tree fall on a home because so much rain fell that the soil was saturated?
Because getting it right is so important, the use of forensic meteorologists has expanded to not only litigation, but also the pre-litigation stage. Without having accurate weather information to know what the weather conditions were at the loss location, disputes or litigation may soon follow. Insurance carriers and attorneys are seeing firsthand the value of having reliable, site-specific data.
Engineers are retaining forensic meteorologists to provide the weather conditions at a specific location. The weather information and expert reports they provide are used by the engineer to do their calculations and are included in their reports so no Daubert standard issues arise. This information helps adjusters and attorneys make informed claims coverage and litigation decisions.
Carriers want to pay a claim if it is owed, and hurricanes, floods, hail, and windstorms are becoming more common. This makes the ability to get accurate weather information more important than ever.