A tornado emergency is an enhanced version of a tornado warning, which is used by the National Weather Service (NWS) in the United States during imminent, significant tornado occurrences in highly populated areas. Although it is not a new warning type from the NWS, issued instead within a severe weather statement or in the initial tornado warning, a tornado emergency generally means that significant, widespread damage is expected to occur and a high likelihood of numerous fatalities is expected with a large, strong to violent tornado.[1][2]
These enhanced warnings are intended to convey the urgency of the weather situation to the general public, who are advised to take safety precautions immediately if they are in or near the projected path of a large tornado or its accompanying thunderstorm; tornado emergencies are usually identified following the preceding storm summary in the tornado warning product, which itself will denote visual or radar confirmation of "a large and extremely dangerous [or destructive] tornado" that is ongoing; precautionary action statements in the product also recommend that people in the storm's path find shelter in an underground shelter or safe room to protect themselves from the storm, if available.
While many tornadoes observed to be at or larger than ¼-mile in width have been documented to have produced catastrophic damage falling under the "strong" or "violent" categories (EF2–EF5) of the Enhanced Fujita Scale, there have been instances in which tornadoes of this intensity have resulted in very few to no fatalities and, occasionally, have produced damage corresponding to the Enhanced Fujita Scale's "weak" category (EF0–EF1).
The term was first used during the May 3, 1999 tornado outbreak that spawned an F5 tornado which struck the municipalities of Bridge Creek and Moore, located just south of Oklahoma City, followed by southern and eastern parts of the city itself, Del City, and Midwest City. On that day, between 5:30 and 6:30p.m., David Andra, the Science and Operations Officer at the National Weather ServiceWeather Forecast Office in Norman watched as the large, destructive tornado approached Oklahoma City. This led to the issuance of the first tornado emergency, which in this instance was released as a standalone weather statement issued separately from the original tornado warning.[3]
As the large tornado approached western sections of the OKC metro area, we asked ourselves more than once, 'Are we doing all we can do to provide the best warnings and information?' It became apparent that unique and eye-catching phrases needed to be included in the products. At one point we used the phrase 'Tornado Emergency' to paint the picture that a rare and deadly tornado was imminent in the metro area. We hoped that such dire phrases would prompt action from anyone that still had any questions about what was about to happen.[4]
Text of the Moore, Oklahoma Tornado Emergency from May 20, 2013
BULLETIN - EAS ACTIVATION REQUESTED TORNADO WARNING NATIONAL WEATHER SERVICE NORMAN OK 301 PM CDT MON MAY 20 2013 THE NATIONAL WEATHER SERVICE IN NORMAN HAS ISSUED A * TORNADO WARNING FOR... NORTHWESTERN MCCLAIN COUNTY IN CENTRAL OKLAHOMA... SOUTHERN OKLAHOMA COUNTY IN CENTRAL OKLAHOMA... NORTHERN CLEVELAND COUNTY IN CENTRAL OKLAHOMA... * UNTIL 345 PM CDT * AT 259 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS AND STORM SPOTTERS WERE TRACKING A LARGE AND EXTREMELY DANGEROUS TORNADO NEAR NEWCASTLE. DOPPLER RADAR SHOWED THIS TORNADO MOVING NORTHEAST AT 20 MPH. THIS IS A TORNADO EMERGENCY FOR MOORE AND SOUTH OKLAHOMA CITY. IN ADDITION TO A TORNADO...LARGE DESTRUCTIVE HAIL UP TO TENNIS BALL SIZE IS EXPECTED WITH THIS STORM. * LOCATIONS IMPACTED INCLUDE... MIDWEST CITY...MOORE...NEWCASTLE...STANLEY DRAPER LAKE...TINKER AIR FORCE BASE AND VALLEY BROOK. PRECAUTIONARY/PREPAREDNESS ACTIONS... THIS IS AN EXTREMELY DANGEROUS AND LIFE THREATENING SITUATION. IF YOU CANNOT GET UNDERGROUND GO TO A STORM SHELTER OR AN INTERIOR ROOM OF A STURDY BUILDING NOW. TAKE COVER NOW IN A STORM SHELTER OR AN INTERIOR ROOM OF A STURDY BUILDING. STAY AWAY FROM DOORS AND WINDOWS. && LAT...LON 3524 9763 3532 9766 3547 9738 3527 9728 TIME...MOT...LOC 2000Z 236DEG 16KT 3530 9760 $$
After the original usage for the May 3, 1999, F5 tornado, the term Tornado Emergency was used by other National Weather Service Weather Forecast Offices (WFOs), although no uniform criteria existed and the issuance was entirely at the discretion of the forecaster issuing the warnings. Usage of the term varied from simply confirmed tornadoes in populated areas to significant, rare tornadoes causing severe damage and injuries. Some NWS forecast offices, such as the one serving the Des Moines, Iowa, metropolitan area, have created standardized criteria and purpose for the usages of the heightened wording. Because data about the tornado and its exact path are often ascertained after the initial tornado warning is issued, this designation is usually added to the Severe Weather Statement (SAME code: SVS) that is used to follow up a tornado warning.
The prolific 2011 Super Outbreak set the all-time record for the most tornado emergencies issued by the National Weather Service during a 24-hour period. During the afternoon and early evening of April 27, 2011, which saw a record-breaking 216 tornadoes reported across the southeastern U.S., local NWS offices in Birmingham and Huntsville, Alabama, Memphis, Tennessee, and Jackson, Mississippi, issued a combined total of 16 tornado emergencies during the regional outbreak for multiple long-track tornadoes; among others, the emergency declarations covered the EF4 Tuscaloosa–Birmingham, Alabama tornado, and the EF5-rated Philadelphia and Smithville, Mississippi, and Hackleburg–Phil Campbell and Rainsville, Alabama, tornadoes. (The previous single-day record, 11, was set on May 7, 2003, during an outbreak of 18 tornadoes—among 30 reported that day across the central and southern United States that occurred as part of a broader nine-day outbreak sequence—that struck much of the same region affected by the 2011 outbreak.)
On April 2, 2012, the National Weather Service began an experimental program within its Wichita, Topeka, Springfield, St. Louis and Kansas City/Pleasant Hill offices in Kansas and Missouri called Impact Based Warning (IBW), which allows the respective offices to enhance warning information, such as adding tags to the warning messages which signify the potential damage severity. In regards to tornadoes, the creation of this multi-tiered system resulted in the implementation of an intermediate tornado warning product, a Particularly Dangerous Situation Tornado Warning.[6][7]
On April 1, 2013, the IBW experiment expanded to include all National Weather Service WFOs within the Central Region;[8] the IBW experiment was expanded again to include eight additional offices within the Eastern, Southern and Western Regions in the spring of 2014.[9] Within the span of eleven days, the National Weather Service WFO in Norman issued tornado emergencies for parts of the Oklahoma City metropolitan area and central Oklahoma: first on May 20, 2013, for the EF5 tornado that struck Moore and portions of southern Oklahoma City,[10] and again on May 31, for portions of eastern Canadian County and western sections of the immediate Oklahoma City area for another tornado.
In 2016, Impact-Based Tornado Warnings were implemented nationwide and all offices began standardized training and practice for tornado emergencies.[11] National directive allows for the use of tornado emergency products when a severe threat to human life exists and catastrophic damage is imminent or occurring.[12]
A tornado emergency was issued in the late-night hours of Memorial Day on May 27, 2019 for Montgomery County, Ohio, including the cities of Dayton, Ohio, and Trotwood, Ohio. The tornado was rated EF4.
On very rare occasions, tornado emergencies have been issued by local NWS offices that either do not verify a tornado touchdown in subsequent surveys or are based on false reports. One notable instance occurred on April 15, 2022, when the National Weather Service office in Little Rock, Arkansas, issued tornado emergencies for several communities across seven counties in north-central and northeastern parts of the state.[17][18][19][lower-alpha 1] Although strong rotation was detected in the storm as it crossed from south-central Missouri into north-central Arkansas, prompting tornado warnings for the supercell, surveys conducted that weekend by NWS Little Rock—which issued the initial emergency around 7:30p.m. CDT, based on an emergency management report of a wedge tornado and damage to structures and trees near Hardy—indicated a tornado had not touched down and that damage produced by the storm was caused by straight-line winds and hail.[20]
The area where the emergencies were issued were within coverage “dead zones” in the radii of NEXRAD radars based in Little Rock, Springfield, Missouri, and Memphis, Tennessee; the supercell was within the highest beam tilt of each radar (ranging roughly 6,000–10,000 feet above ground level), impairing the ability of the radars to provide accurate wind velocity and correlation coefficient data, with large hail being produced by the storm contaminating the correlation coefficient data, producing lower values often indicative of lofted debris. The storm occurring at nightfall in a mostly rural area also complicated matters, with video taken by residents and posted on social media erroneously confusing a tube cloud that extended to near surface level for a tornado. Five days earlier, on April 11, NWS Little Rock issued a tornado emergency for Jacksonville and Cabot, based in part on reports of a large tornado on the ground in Jacksonville; although the storm—which was within 15 miles (24km) of the Little Rock NEXRAD site—did produce an EF1 tornado, the report of a large tornado that prompted the emergency, along with several additional damage reports associated with the storm filed with the NWS’s Little Rock and Tulsa, Oklahoma, offices associated with that day’s convection, were later attributed to an Ohio woman who used a Spotter Network account with spoofed coordinates.[20][21]
On May 7th, 2024, a tornado emergency was issued by the National Weather Service office in Northern Indiana for Branch County, Michigan.[23] It was the first tornado emergency ever issued for the state of Michigan.
The usage of tornado emergencies to alert major population centers to the imminent threat of a catastrophic tornado impact has also led to the development of the flash flood emergency which is similarly employed when severe flash floods threaten populated areas.
Criteria
With the national implementation of Impact-Based tornado warnings in 2016, common criteria were established for the use of tornado emergency.[12] National guidance requires the confirmation of a tornado via radar or spotter confirmation, with evidence the ongoing tornado is strong to violent.[24]
Local offices established criteria for tornado emergencies prior to this nationalization, such as:
The National Weather Service Weather Forecast Office in Des Moines, Iowa, is one of the forecast offices to have created a set purpose and criteria for the usage of "tornado emergencies" in tornado warning products, which were made effective on March 12, 2010. According to the Des Moines office, the purpose of the tornado emergency wording is as follows:
To motivate and provide a sense of urgency to persons in the path of this storm to take immediate shelter in a reinforced structure that offers maximum protection from destructive winds
To communicate to state, local, and county officials and emergency responders that they should prepare for immediate search and rescue operations
To communicate the need to prepare for immediate medical emergencies, evacuation measures, and emergency sheltering.
Before usage, the following criteria must be met:
A large and catastrophic tornado has been confirmed and will continue
The tornado will have a high impact
The tornado is expected to cause numerous fatalities.[citation needed]
The National Weather Service Weather Forecast Office in Jackson, Mississippi, defines a tornado emergency as "an enhanced Tornado Warning that will be issued by NWS Jackson when there is a heightened risk for a killer or violent tornado of EF3 rating or greater."[25] Their criteria for issuing a tornado emergency are:
Radar indication of a strong tornado
Reliable reports of significant damage or a large tornado
The National Weather Service office in Nashville, Tennessee, also created criteria to declare a tornado emergency within a tornado warning statement effective January 1, 2011. It states, "Tornado Emergency can be inserted in the third bulletin of the initial tornado warning (TOR) or in a severe weather statement (SVS)." Before the phrase can be used:
A confirmed large tornado doing significant damage must be going through a highly populated area
Radar must indicate tornadic debris
The tornado must be expected to cause significant, widespread damage and loss of life.[citation needed]
It is recommended that people in the path of a large and violent tornado, whether referenced in a tornado warning or a tornado emergency, seek shelter in a basement, cellar or safe room, as stronger tornadoes (particularly those significant enough to warrant the inclusion of a tornado emergency declaration within a tornado warning) pose a significant risk of major injury or death for people above ground level. Those who do not have below-ground shelter are still advised to take cover in a room in the center of the home on the lowest floor, and cover themselves with some type of thick padding (such as mattresses or blankets), to protect against falling debris in the event that the roof and ceiling collapse.[26]
A tornado warning is a public warning that is issued by weather forecasting agencies to an area in the direct path of a tornado, or a thunderstorm capable of producing one, and advises individuals in that area to take cover. Modern weather surveillance technology such as Doppler weather radar can detect rotation in a thunderstorm, allowing for early warning before a tornado develops. They are also commonly issued based on reported visual sighting of a tornado, funnel cloud, or wall cloud, typically from weather spotters or the public, but also law enforcement or local emergency management. When radar is unavailable or insufficient, such ground truth is crucial. In particular, a tornado can develop in a gap of radar coverage, of which there are several known in the United States.
A tornado watch is a statement issued by weather forecasting agencies to advise the public that atmospheric conditions in a given region may lead to the development of tornadoes within the region over several hours. In addition to the potential for tornado development, thunderstorms that develop within the watch area may contain large hail, straight-line winds, intense rainfall and/or flooding that pose a similar damage risk as the attendant tornado threat. A tornado watch does not mean a tornado is active or will appear, just that favorable conditions increases the likelihood of such happening. A watch must not be confused with a tornado warning.
A severe thunderstorm watch is a statement issued by weather forecasting agencies to advise the public that atmospheric conditions in a given region may lead to the development of severe thunderstorms within the region over several hours. The criteria for issuing a watch varies from country to country and may also include torrential rainfall and tornadoes. A watch may also be issued several hours ahead of the arrival of a mature and organized complex of storms, such as a mesoscale convective system.
A severe thunderstorm warning is a type of public warning for severe weather that is issued by weather forecasting agencies worldwide when one or more severe thunderstorms have been detected by Doppler weather radar, observed by weather spotters, or reported by an emergency management agency, law enforcement, or the general public. Unlike a watch, a warning is issued to areas in the direct path of active severe thunderstorms, that are expecting a direct impact typically within an hour. Severe thunderstorms can cause property damage and injury due to large hail, high winds, and flooding due to torrential rainfall. The exact criteria to issue a warning varies from country to country.
A winter storm warning is a hazardous weather statement issued by Weather Forecast Offices (WFO) of the National Weather Service (NWS) in the United States to alert the public that a winter storm is occurring or is about to occur in the area, usually within 36 hours of the storm's onset.
This article describes severe weather terminology used by the National Weather Service (NWS) in the United States. The NWS is a government agency operating as an arm of the National Oceanic and Atmospheric Administration (NOAA) branch. It defines precise meanings for nearly all of its weather terms.
A flash flood warning is a severe weather warning product of the National Weather Service that is issued by national weather forecasting agencies throughout the world to alert the public that a flash flood is imminent or occurring in the warned area. A flash flood is a sudden, violent flood after a heavy rain, or occasionally after a dam break. Rainfall intensity and duration, topography, soil conditions, and ground cover contribute to flash flooding.
In weather forecasting in the United States, "particularly dangerous situation" (PDS) is enhanced wording used by the National Weather Service to convey special urgency in some watch or warning messages for unusually extreme and life-threatening severe weather events, above and beyond the average severity for the type of event. It is used in the format "This is a particularly dangerous situation..." at the discretion of the issuing forecaster. A watch or warning bearing the phrase is referred to as a PDS watch or PDS warning as shorthand jargon.
From May 3 to May 11, 2003, a prolonged and destructive series of tornado outbreaks affected much of the Great Plains and Eastern United States. Most of the severe activity was concentrated between May 4 and May 10, which saw more tornadoes than any other week-long span in recorded history; 335 tornadoes occurred during this period, concentrated in the Ozarks and central Mississippi River Valley. Additional tornadoes were produced by the same storm systems from May 3 to May 11, producing 363 tornadoes overall, of which 62 were significant. Six of the tornadoes were rated F4, and of these four occurred on May 4, the most prolific day of the tornado outbreak sequence; these were the outbreak's strongest tornadoes. Damage caused by the severe weather and associated flooding amounted to US$4.1 billion, making it the costliest U.S. tornado outbreak of the 2000s. A total of 50 deaths and 713 injuries were caused by the severe weather, with a majority caused by tornadoes; the deadliest tornado was an F4 that struck Madison and Henderson counties in Tennessee, killing 11. In 2023, tornado expert Thomas P. Grazulis created the outbreak intensity score (OIS) as a way to rank various tornado outbreaks. The tornado outbreak sequence of May 2003 received an OIS of 232, making it the fourth worst tornado outbreak in recorded history.
From May 10–13, 2010, a major tornado outbreak affected large areas of Oklahoma, Kansas, Missouri, and Arkansas, with the bulk of the activity in central and eastern Oklahoma. Over 60 tornadoes, some large and multiple-vortex in nature, affected large parts of Oklahoma and adjacent parts of southern Kansas and Missouri, with the most destructive tornadoes causing severe damage in southern suburbs of the Oklahoma City metropolitan area and just east of Norman, Oklahoma, where the fatalities were reported from both tornado tracks. The outbreak was responsible for three fatalities, all of which occurred in Oklahoma. Damage was estimated to be over $595 million in central Oklahoma alone.
The 1999 Bridge Creek–Moore tornado was a large, long-lived and exceptionally powerful F5 tornado in which the highest wind speeds ever measured globally were recorded at 135 metres per second by a Doppler on Wheels (DOW) radar. Considered the strongest tornado ever recorded to have affected the metropolitan area, the tornado while near peak intensity devastated southern portions of Oklahoma City, Oklahoma, United States, along with surrounding suburbs and towns to the south and southwest of the city during the early evening of Monday, May 3, 1999. Parts of Bridge Creek were rendered unrecognizable. The tornado covered 38 miles (61 km) during its 85-minute existence, destroying thousands of homes, killing 36 people, and leaving US$1 billion in damage, ranking it as the fifth-costliest on record not accounting for inflation. Its severity prompted the first-ever use of the tornado emergency statement by the National Weather Service.
From April 13 to 16, 2012, a major tornado outbreak occurred across a large portion of the Great Plains. The storms resulted in six tornado-related fatalities, all of which occurred as a result of a nighttime EF3 tornado that caused major damage in and around Woodward, Oklahoma. Numerous other tornadoes occurred, including a violent EF4 tornado that passed near Marquette, Kansas, and an EF3 that caused major damage in Wichita.
National Weather Service - Norman, Oklahoma is a Weather Forecast Office (WFO) of the National Weather Service based in Norman, Oklahoma, which is responsible for forecasts and the dissemination of weather warnings and advisories for central and most of western Oklahoma, and western portions of north Texas. It is located in the National Weather Center on the University of Oklahoma campus, where it acts as one of the NOAA Weather Partners, a group of close-together weather-related agencies of the National Oceanic and Atmospheric Administration. NWS Norman is currently overseen by Mark Fox, who serves as the Meteorologist In Charge of the office.
This page documents notable tornadoes and tornado outbreaks worldwide in 2020. Strong and destructive tornadoes form most frequently in the United States, Argentina, Brazil, Bangladesh, and eastern India, but can occur almost anywhere under the right conditions. Tornadoes also develop occasionally in southern Canada during the Northern Hemisphere's summer and somewhat regularly at other times of the year across Europe, Asia, Argentina, Australia and New Zealand. Tornadic events are often accompanied by other forms of severe weather, including strong thunderstorms, strong winds, and hail. There were 1,243 preliminary filtered reported tornadoes in 2020 in the United States in 2020, and 1,086 confirmed tornadoes in the United States in 2020. Worldwide, at least 93 tornado-related deaths were confirmed with 78 in the United States, eight in Vietnam, two each in Canada, Indonesia, and Mexico, and one in South Africa.
Hurricane Laura was a deadly and destructive Category 4 hurricane that is tied with the 1856 Last Island hurricane and 2021's Hurricane Ida as the strongest hurricane on record to make landfall in the U.S. state of Louisiana, as measured by maximum sustained winds. The twelfth named storm, fourth hurricane, and first major hurricane of the record-breaking 2020 Atlantic hurricane season, Laura originated from a large tropical wave that moved off the West African coast on August 16 and became a tropical depression on August 20. Laura intensified into a tropical storm a day later, becoming the earliest twelfth named storm on record in the North Atlantic basin, forming eight days earlier than 1995's Hurricane Luis.
This page documents notable tornadoes and tornado outbreaks worldwide in 2021. Strong and destructive tornadoes form most frequently in the United States, Argentina, Brazil, Bangladesh, and Eastern India, but can occur almost anywhere under the right conditions. Tornadoes also develop occasionally in southern Canada during the Northern Hemisphere's summer and somewhat regularly at other times of the year across Europe, Asia, Argentina, Australia and New Zealand. Tornadic events are often accompanied by other forms of severe weather, including strong thunderstorms, strong winds, and hail. Worldwide, 150 tornado-related deaths were confirmed with 103 in the United States, 28 in China, six in the Czech Republic, four in Russia, three in Italy, two in India, and one each in Canada, New Zealand, Indonesia, and Turkey.
From April 1 to 3, 2024, a significant tornado outbreak, which also included a derecho, affected much of the Midwestern and Southeastern United States. The National Weather Service issued dozens of severe thunderstorm and tornado warnings across West Virginia, Kentucky, Tennessee, Ohio, Oklahoma, Kansas, Illinois, Indiana, and Missouri during the event. A total of 32 million people were estimated to be under watches or warnings, and over 150,000 people were estimated to be without power. and 15 people were injured. The event was given an outbreak intensity score of 28 points, ranking it as a significant tornado outbreak, and five people were killed by non-tornadic events as well.
↑ September 1 2021 Tornadoes (Report). Iowa Environmental Mesonet. September 3, 2021. Archived from the original on September 3, 2021. Retrieved September 3, 2021.
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