History of Tornado warning in Timeline

A tornado warning is a critical alert issued by weather agencies when a tornado is imminent or has been sighted, or when a severe thunderstorm capable of producing a tornado is detected. These warnings prompt individuals in the affected area to seek immediate shelter. Modern technology, like Doppler radar, plays a vital role in early detection by identifying rotation within thunderstorms. However, visual confirmation from weather spotters, the public, law enforcement, or emergency management is equally important, especially in areas with limited radar coverage. Timely warnings are crucial for public safety, enabling people to take necessary precautions and minimize the risk of injury or death.

April 1908: U.S. Weather Bureau Publishes Replies on Tornado Protection

In April 1908, the U.S. Weather Bureau addressed a question about how to protect against tornadoes by publishing several replies.

March 1925: Tri-State Tornado

In March 1925, the Tri-State Tornado, the deadliest tornado in U.S. history, occurred before warnings were common, resulting in a high death toll.

1925: Tornado Death Rate

In 1925, the tornado death rate was 1.8 deaths per million people per year.

1938: Weather Bureau Rescinds Ban on "Tornado" Usage

In 1938, the Weather Bureau lifted its ban on using the word "tornado" in weather products that were sent to emergency management personnel.

April 1947: Glazier–Higgins–Woodward Tornadoes

In April 1947, the Glazier–Higgins–Woodward tornadoes occurred before warnings were common, resulting in a high death toll.

March 20, 1948: Tornado Strikes Tinker Air Force Base

On March 20, 1948, a tornado struck Tinker Air Force Base after an erroneous forecast of dry conditions. The tornado caused an estimated $10 million in damage to military aircraft.

March 25, 1948: First Official Tornado Forecast

On March 25, 1948, United States Air Force Captain Robert C. Miller and Major Ernest Fawbush made the first official tornado forecast.

1948: USAF Pioneers Tornado Forecasting

In 1948, The USAF had pioneered tornado forecasting and tornado warnings.

March 25, 1949: Successful Tornado Prediction by Miller and Fawbush

On March 25, 1949, Miller and Fawbush successfully predicted tornadic activity in southeastern Oklahoma.

July 12, 1950: Ban on Tornado Warnings Lifted

On July 12, 1950, Chief of Bureau Francis W. Reichelderfer officially revoked the ban on issuing tornado warnings to the general public. This was communicated in a Circular Letter to all first order stations, instructing employees to avoid statements negating the Bureau's willingness or ability to make tornado forecasts, while emphasizing the need for a "good probability of verification" due to the difficulty in accurately predicting tornadic activity.

1951: Formation of Severe Weather Warning Center

In 1951, the Air Force began issuing severe weather forecasts relayed to Weather Bureau offices and emergency personnel in tornado-prone regions through the formation of the Severe Weather Warning Center.

March 1952: Weather Bureau Issues First Experimental Public Tornado Forecast

In March 1952, the Weather Bureau issued its first experimental public tornado forecast, which proved inaccurate and was released too late to become widely available for public consumption.

1954: First Televised Tornado Warning

In 1954, meteorologist Harry Volkman broadcast the first televised tornado warning over WKY-TV (now KFOR-TV) in Oklahoma City, defying the Federal Communications Commission's ban.

1974: Average Tornado Warning Times

In 1974, average tornado warning times were -10 to -15 minutes.

1974: Super Outbreak

The last tornado alert to be officially issued was discussed in earnest following the 1974 Super Outbreak.

1974: Tornado alert in use

Until the early 1980s, an intermediate type of tornado advisory known as a tornado alert was defined by the National Weather Service. In 1974, it was issued by the agency's local forecast offices, indicating that tornado formation was imminent.

May 3, 1999: First tornado emergency declared

On May 3, 1999, the first tornado emergency was declared when an F5 tornado struck southern portions of the Oklahoma City metropolitan area, causing major damage exceeding $1 billion.

2000: Tornado Death Rate Decreases

In 2000, the tornado death rate decreased to 0.11 per million people.

September 20, 2002: Tornado emergency declared in Indianapolis

On September 20, 2002, a tornado emergency was declared within the initial issuance of the tornado warning for an F3 tornado that struck the Indianapolis, Indiana metropolitan area.

October 2007: National Weather Service Issues Warnings on a Per-County Basis

Prior to October 2007, warnings were issued by the National Weather Service on a per-county basis.

2008: Emergency Management Ontario implements red alerts

In 2008, Emergency Management Ontario implemented a system that issues red alerts for sections of the province under an Environment Canada-issued tornado warning. This system can sometimes override the tornado warning if local government or media outlets participate in the program.

March 2012: Implementation of Impact Based Warning System

In March 2012, the NWS Weather Forecast Offices in Wichita and Topeka, Kansas, and Springfield, St. Louis and Kansas City/Pleasant Hill, Missouri, began incorporating categorical tornado and damage threat indicators as part of its implementation of a multi-tier Impact Based Warning (IBW) system.

March 2013: Expansion of Threat and Damage Indicators

In March 2013, the NWS expanded the threat and damage indicators to 33 additional Central Region WFOs.

2013: Increased Tornado Warning Times

As of 2013, average tornado warning times have increased to about 15 minutes, and sometimes more.

March 2014: IBW Indicators Used by Additional Offices

In March 2014, eight additional offices operating within the Eastern, Southern and Western Region divisions began using the IBW indicators.

2016: Agency-Wide Use of IBW Format

In 2016, the entire agency began using the IBW format.

August 15, 2020: First Tornado Warning for Pyrocumulonimbus

On August 15, 2020, the National Weather Service issued a tornado warning for a pyrocumulonimbus capable of producing a tornado in southeastern Lassen County, California, which was being affected by the Loyalton Fire. This event marked the first time in history that such a warning was issued.

July 2021: Full Implementation of IBW Formatting

In July 2021, IBW formatting was fully implemented for other individual warning bulletins, when all NWS offices incorporated damage threat indicators into severe thunderstorm warnings.

April 2023: Introduction of the TORNADO Act

In April 2023, U.S. Sen. Roger Wicker (R–MS) introduced the Tornado Observation Research Notification and Deployment to Operations (TORNADO) Act. The bill aims to improve NOAA's methods for predicting severe weather events and communicating weather alerts to the public.