Glossary

The NOAA NCEI Storm Events Database is a publicly accessible source of National Weather Service (NWS) Storm Data, a collection of significant weather phenomena that have sufficient intensity to cause loss of life, injuries, significant property damage, and/or disruption to commerce in the United States and adjacent water bodies.

An Episode is an entire storm system and can contain many different types of events. An Event is an individual type of storm event.

Since 1996 to present, 55 event types (as defined in the NWS Directive 10-1605, event types derived from the 2007 version) are captured in the database.

Between 1950 and 1954, tornadoes were the only event type recorded by the NWS.

Between 1955 and 1992, tornado, thunderstorm wind, and hail events were captured by the NWS in the Storm Data Publications.

Magnitude for wind speeds (e.g., 81 kts, where 1 kt = 1.152 mph) can be estimated by damage caused or measured by official NWS-approved calibrated anemometers. Common measurement types include Measured Gust (MG), Measured Sustained (MS), Estimated Gust (EG), or Estimated Sustained (ES).

When listing hail size under Magnitude, e.g., 2.25 in., the hail size is given in inches and hundredths of inches. These values are assigned a size in inches from their appearance.

The Enhanced F-scale still is a set of wind estimates (not measurements) based on damage.

Tornadoes may contain multiple segments. A tornado that crosses a county line or state line is considered a separate segment.

Zone (NWS Forecast Zone): A zone is a geographic area defined by the NWS for issuing forecasts, watches, and warnings. While zones often align with counties, they can also represent smaller or subdivided areas within a county to account for differences in weather conditions, such as elevation or proximity to water. Larger-scale events—such as heat, cold, drought, and winter storms—are typically recorded by zone.

For events recorded by forecast zone, the system includes all zones that fall within or intersect the selected county.

As a distance (in miles) and direction on a 16-point compass scale from a known location (typically a city or town; e.g., 4.5 miles ESE Atlanta). The NWS uses a database of over 106,000 cities and towns as reference points.

The National Weather Service reports property and crop damage estimates using available data at the time of event reporting. These values should therefore be considered broad estimates. Damage amounts are not adjusted for inflation.

Direct fatalities and injuries are caused by the natural hazard itself, while indirect fatalities and injuries are caused by the aftermath of the event.

Two character code that defines if this is a major disaster, fire management, or emergency declaration.

The dataset includes declared recovery programs and geographic areas (county not available before 1964; Fire Management records are considered partial due to historical nature of the dataset).

which in the determination of the President causes damage of sufficient severity and magnitude to warrant major disaster assistance under this chapter to supplement the efforts and available resources of States, local governments, and disaster relief organizations in alleviating the damage, loss, hardship, or suffering caused thereby.

"Emergency" means any occasion or instance for which, in the determination of the President, Federal assistance is needed to supplement State and local efforts and capabilities to save lives and to protect property and public health and safety, or to lessen or avert the threat of a catastrophe in any part of the United States.

Fire Management Assistance Grant (FMAG) Program is available to states, local and tribal governments, for the mitigation, management, and control of fires on publicly or privately owned forests or grasslands, which threaten such destruction as would constitute a major disaster.

Agency standard method for uniquely identifying Stafford Act declarations - Concatenation of declaration type, disaster number and state code. Ex: DR-4393-NC

The name or phrase describing the geographic area that was included in the declaration

Congress passed the National Flood Insurance Act (NFIA), Title 42 United States Code 4001 in 1968, creating the National Flood Insurance Program (NFIP) in order to reduce future flood losses through flood hazard identification, floodplain management, and providing insurance protection.

It is derived from the National Flood Insurance Program system of record, staged in the program's reporting platform and redacted to protect policy holder personally identifiable information.

This dataset is not intended to be an official federal report, and should not be considered an official federal report.

Year in which the flood loss occurred

National Flood Insurance Program (NFIP) Insured Residential Policy Contracts in Force (CIF) in the county.

Policy Contracts in Force (CIF) is a good approximation of individual insured structures, as opposed to Policies in Force (PIF), which includes individual units within condominium structures.

This dataset provides information on structures that have had multiple National Flood Insurance (NFIP) claims across the history of the program.

The National Risk Index dataset leverages available source data for natural hazard and community risk factors to develop a baseline relative risk measurement for each United States county and Census tract.

The National Risk Index data are meant for planning purposes only.

Risk Index represents the average loss in dollars to buildings, population, and/or agriculture (consequence types) each year to a community due to natural hazards adjusted based on the community's Social Vulnerability and Community Resilience. Risk Index is provided through values, scores, and ratings.

Expected Annual Loss (EAL) is a natural hazards component of the National Risk Index data that represents the average loss in dollars to buildings, population, and/or agriculture (consequence types) each year due to natural hazards. Expected Annual Loss is provided through values, scores, and ratings.

Social vulnerability is a consequence enhancing risk component and community risk factor that represents the susceptibility of social groups to the adverse impacts of natural hazards, including disproportionate death, injury, loss, or disruption of livelihood. Social vulnerability is provided through values, scores, and ratings.

Community resilience is a consequence reduction risk component and community risk factor that represents the ability of a community to prepare for anticipated natural hazards, adapt to changing conditions, and withstand and recover rapidly from disruptions. Community resilience is provided through values, scores, and ratings.

Ratings are provided in one of five qualitative categories describing the community’s component Value in comparison to all other communities at the same level. Rating categories range from “Very Low” to “Very High.”

The rating is a qualitative categorization that describes the community in comparison to all other communities at the same level, ranging from “Very Low” to “Very High.”

Scores represent the national percentile ranking of the community’s component Value compared to all other communities at the same level (county or U.S. Census tract).

5-digit Postal Zip Code of the insured property as reported by WYO partners

Note, the County Code field may not reflect the individual county the property is located as projects can be associated with more than one county

ZIP Code Tabulation Areas or ZCTAs (pronounced zik-tahs) are a geographic product of the U.S. Census Bureau created to allow mapping, display, and geographic analyses of the United States Postal Service (USPS) Zone Improvement Plan (ZIP) Codes dataset.

This dataset (known as Atlantic HURDAT2) has a comma-delimited, text format with six-hourly information on the location, maximum winds, central pressure, and (beginning in 2004) size of all known tropical cyclones and subtropical cyclones.