United States

	Hurricane
	Earthquake
	Winterstorm
	Severe Convective Storm
	Workers Comp Earthquake
	Terrorism
	Account Fire

U.S. Hurricane

Since 1992 the RMS® U.S. Hurricane Model has set the standard for analyzing hurricane risk in the United States. The technology is utilized by clients representing all aspects of hurricane risk transfer, including the U.S.-based insurance industry and regulators, multi-national insurers writing business in the United States, the global reinsurance community, and capital markets constituents.

The U.S. Hurricane model incorporates unique and innovative techniques for developing and validating hurricane models that have lead the state-of-the-art in modeling. The model is the first to fully represent the physical processes of hurricanes that impact the United States, simulating realistic behavior throughout a hurricane's life cycle. RMS has addressed the challenges of modeling the unique features of the United States coastlines through a combination of innovative modeling methodologies, insightful interpretations of historical and meteorological information, and extensive high resolution geophysical data. Furthermore, through its relationships with the leading property insurers in the U.S., RMS has accessed the wealth of knowledge embedded in claims files for numerous hurricanes to validate its models.

Model Highlights

	Acknowledged as the industry standard-setting technology since 1992
	Validated using over $13 billion in insurer claims data from all recent major hurricanes
	Incorporates detailed building inventory data, regional building characteristics, and key secondary modifiers
	Approved for rate-making purposes by several state Departments of Insurance, including the Florida Commission on Hurricane Loss Projection Methodology (FCHLPM) and serves as an official model for the Florida Hurricane Catastrophe Fund (FHCF)
	High resolution modeling of storm surge
	Models windfields of hurricanes undergoing extra-tropical transition

Geographic Scope

The RMS® U.S. Hurricane Model covers the entire U.S. Eastern Seaboard, Gulf Coast, and Hawaii. Specifically, the states included in the model are:

Alabama, Connecticut, Delaware, District of Columbia, Florida, Georgia, Hawaii, Louisiana, Maine, Maryland, Massachusetts, Mississippi, New Hampshire, New Jersey, New York, North Carolina, Pennsylvania, Rhode Island, South Carolina, Texas, Vermont, Virginia, and West Virginia.

Exposure Data Resolution

The Hurricane model supports analyses at each of the following levels of geographic resolution: Latitude/Longitude, Street Address, ZIP Code, City, and County.

U.S. Earthquake

Since 1989 the RMS® U.S. Earthquake Model has set the standard for analyzing earthquake risk in the United States. The technology is utilized by clients representing all aspects of earthquake risk transfer, including the U.S.-based insurance industry and regulators, multi-national insurers writing business in the United States, the global reinsurance community, and capital markets constituents.

Earthquakes can occur throughout the United States, as demonstrated by historical records and geological research. As such the RMS Earthquake Model covers all 50 United States, including high-risk regions such as California and the New Madrid Seismic Zone. In 2003 the western U.S. earthquake model was updated with source modeling representing the latest research, high resolution geotechnical data, and underwriting capabilities using the most advanced approach available for modeling building damage.

Model Highlights Included in 2003 Western U.S. Update

	Reflects the latest hazard components of the 2002 USGS National Seismic Hazard maps and the latest findings of the Working Group on California Earthquake Probabilities
	Models that full three-dimensional character of faults and subduction zones
	Performs time dependent modeling on key faults in California
	Incorporates the potential for cascading events on major California faults and the Cascadia Subduction Zone
	Models site-specific building damage using the RMS spectral response methodology, the most advanced approach available for modeling building damage
	Features high resolution geotechnical data coverage in all major population centers, including ZIP Code and site-specific soil and liquefaction data for high risk areas
	Models fire following earthquakes and earthquake sprinkler leakage

Geographic Scope

The U.S. Earthquake model is discretized into 11 distinct regions which are comprised of individual states or groups of states. Each region reflects the unique characteristics of seismic hazard in different parts of the U.S. The regions are Alaska, California, Great Basin, Hawaii, Midwest, Central U.S., Northeast U.S., Northern Rockies, Southeast U.S., Southern Rockies, and Pacific Northwest.

Exposure Data Resolution

The RMS Earthquake model supports analyses at each of the following levels of geographic resolution: Latitude/Longitude, Street Address, ZIP Code, City, and County.

U.S. Winterstorm

Winter storms in the U.S. are complex, extra-tropical weather systems that can produce various types and combinations of damage from the perils of snow, ice, freezing temperatures, and extra-tropical winds. The combination and intensity of the winter storm perils at a particular location are governed by the location of the storm origin, the region impacted, and the large-scale weather pattern. Winter storms that impact the U.S. can be generally characterized as follows:

 

 

	Storms that produce high wind speeds along North America’s West Coast and cause interior snowfall at higher elevations
	Alberta-clipper storms that develop over the Canadian Rocky Mountains and bring a combination of winter storm perils to Canada’s central and eastern provinces, the Great Lakes region, and the northeast U.S. Typically, these storm systems are followed by cold arctic air that is responsible for freeze-related losses
	Storms that develop east of the U.S. Rockies and bring a combination of winter storm perils to the eastern half of the U.S. and Canada
	Nor’easter storm systems that rapidly intensify over the warm Gulf Stream in the Atlantic Ocean and cause extensive snowfall, high winds, and occasional ice along North America’s East Coast
	Lake-effect snowstorms generally caused in the wake of a storm system as cold air from Canada travels over the relatively warm waters of the Great Lakes. Clouds and snowstorms can occur on windward side of the Great Lakes.

Winter Storm Risk

Winter storm losses are a key component of the total natural catastrophe risk in the U.S. contributing an estimated 10% of the overall average annual loss in the U.S. Winter storms are the key driver of risk to regions such as the Pacific Northwest and the northeast U.S.

Several historical winter storms have highlighted the potential winter storm risk across the U.S. with events such as the 1962 Pacific Northwest Windstorm, the 1983 Freeze Outbreak, and the 1993 Superstorm, which was arguably the costliest winter storm to impact the U.S. with insured loss estimates of $US1.75 billion at the time of the event. From March 12-14, 1993, a powerful extra-tropical storm descended upon the eastern half of the United States, causing widespread damage from the Gulf Coast to Maine. The storm spawned tornadoes in Florida, caused record snowfalls across the Appalachian Mountains and Mid-Atlantic states, hurricane-force wind speeds along the coast, and extremely low temperatures throughout the region.

Model Highlights

	Comprehensive winter storm modeling solution explicitly capturing losses from the perils of snow, ice, wind, and freezing temperatures
	Developed through an innovative hybrid modeling solution that combines numerical weather prediction models and statistical techniques to create a fully representative stochastic event set, simulating common to severe winter storms, representing 30,000 years of winter storm activity
	High-resolution numerical weather prediction modeling of winter storms in 4-dimensions captures the complex spatial patterns of the winter storm perils and the interdependency upon atmospheric conditions
	Winter storm hazard evaluated on RMS’ high-resolution variable resolution grid (VRG) specific to winter storms
	Unique vulnerability functions developed for each winter storm peril to capture the different damage modes between perils to drive an accurate assessment of winter storm risk
	Broad suite of secondary modifiers to refine building damage assessment

Geographic Scope
The RMS® U.S. Winterstorm Model covers the United States, excluding Alaska and Hawaii

Exposure Data Resolution
The RMS® U.S. Winterstorm Model supports analyses at the following geographic resolution: Latitude/longitude, Street Address, Zip Code, City, or County
 

 

U.S. Severe Convective Storm

The unique geography of the United States contributes to the highest annual frequency of severe convective storm occurrence in the world. The risk associated with severe convective storms—destructive storms including thunderstorms, tornadoes, and hailstorms—results in average annual insured losses of approximately $11 billion in the U.S., comparable to insured losses from hurricanes and about three times that of insured losses from earthquakes. Since 1994 the RMS® U.S. Severe Convective Storm Model (formerly the Tornado/Hail Model), has been utilized by the insurance and reinsurance industry to evaluate and transfer risk associated with these types of severe convective storms. The model considers risk from tornadoes, hailstorms, damaging straight-line winds, and lightning for the contiguous 48 states.

The U.S. is located within the mid-latitudes (35-65° N), a region where strong horizontal variations in temperature accompanied by large vertical variations in wind speed create a volatile mix of ingredients for storm formation. Two primary mechanisms spawn severe local storms. The first, common throughout the Central Plains, the Midwest, and much of the South, occurs when abundant moisture originating from the Gulf of Mexico meets cool, dry air from the north along boundaries such as cold fronts. Severe storms develop along these boundaries with highest frequency during the spring and summer months. A second type of storm formation is more common on the eastern slopes of the Rocky Mountains and in the southern Plains, where warm, dry air originating in the higher elevations descends atop moist air at the surface. Storm initiation occurs as the moist air is forced upward through the mass of dry air, particularly in areas of rapidly increasing elevation.

Tornadoes, hail, and straight-line winds have been observed in each of the contiguous 48 states and can occur at any time of year, most frequently from March to September. The annual frequency of tornadoes, hail, and straight-line winds is highest in the Central Plains, Midwest, and southern U.S. Risk decreases gradually to the north and east and there is a sharp decrease in risk in the western U.S.

Some recent notable hail and tornado events are summarized below.

Historical Event Date	Location	Estimated Inusurance Loss in Billions (2007 USD)*
July 11, 1990	Colorado	$1.3
May 15, 1998	Minnesota	$2.6
May 3-7, 1999	Central Plains	$2.6
April 6-12, 2001	Central Plains, Midwest	$3.4
April 27-May 3, 2002	Northeast, Southeast, Midwest	$2.4
May 2-11, 2003	Central Plains, Southeast, Midwest	$4.1
April 13-15, 2006	Midwest	$1.8
February 5-6, 2008	Southeast	$0.9
May 22-26, 2008	Midwest	$0.8

*Values are for property damage only. Source: Property Claims Services
 

Model Highlights

	Stochastic event set with robust representation of the spectrum of potential outbreaks based on the latest advancements in meteorological and statistical modeling
	Comprehensive loss estimation for tornado, hail, and straight-line wind events including losses due to lightning, tornadic damage outside of immediate path, rain-related building content damages, and high-frequency/low-severity events
	Model results validated using expert review, insurer and industry losses for individual events, return periods for extreme historical events, and comparisons of state-level average annual loss estimates

Geographic Scope

The U.S. Severe Convective Storm Model covers the 48 contiguous states, comprising all areas of the United States with significant tornado, hail, and straight-line wind risk.

Exposure Data Resolution

Exposure data may be entered at county, ZIP Code, street address, or latitude/longitude level of resolution. Model analysis is performed based on a variable resolution grid, with greatest resolution in metropolitan areas with high exposure to severe convective storm hazard.