Atornado emergency is an enhanced version of atornado warning, which is used by theNational Weather Service (NWS) in theUnited States during imminent, significanttornado occurrences. 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 catastrophic, 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 orsafe 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 theEnhanced 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 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 theflash flood emergency which is similarly employed when severeflash floods threaten populated areas.
The term was first used during theMay 3, 1999 tornado outbreak that spawnedan F5 tornado which struck the municipalities ofBridge Creek andMoore, located just south ofOklahoma City, followed by southern and eastern parts of the city itself,Del City, andMidwest City. On that day, between 5:30 and 6:30 p.m., David Andra, the Science and Operations Officer at theNational Weather ServiceWeather Forecast Office inNorman 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]
SEVERE WEATHER STATEMENT NATIONAL WEATHER SERVICE NORMAN OK 657 PM CDT MON MAY 3 1999 ...TORNADO EMERGENCY IN SOUTH OKLAHOMA CITY METRO AREA... AT 657 PM CDT...A LARGE TORNADO WAS MOVING ALONG INTERSTATE 44 WEST OF NEWCASTLE. ON ITS PRESENT PATH...THIS LARGE...DAMAGING TORNADO WILL ENTER SOUTHWEST SECTIONS OF THE OKLAHOMA CITY METRO AREA BETWEEN 715 PM AND 730 PM. PERSONS IN MOORE AND SOUTH OKLAHOMA CITY SHOULD TAKE IMMEDIATE TORNADO PRECAUTIONS. THIS IS AN EXTREMELY DANGEROUS AND LIFE THREATENING SITUATION. IF YOU ARE IN THE PATH OF THIS LARGE AND DESTRUCTIVE TORNADO...TAKE COVER IMMEDIATELY. DOPPLER RADAR HAS INDICATED THIS STORM MAY CONTAIN DESTRUCTIVE HAIL TO THE SIZE OF BASEBALLS...OR LARGER.
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]
The prolific2011 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 inBirmingham andHuntsville, Alabama,Memphis, Tennessee, andJackson, Mississippi, issued a combined total of 16 tornado emergencies during the regional outbreak for multiple long-track tornadoes; among others, the emergency declarations covered theEF4 Tuscaloosa–Birmingham, Alabama tornado, and the EF5-ratedPhiladelphia andSmithville, Mississippi, andHackleburg–Phil Campbell andRainsville, 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 abroader 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 itsWichita,Topeka,Springfield,St. Louis andKansas 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, aParticularly Dangerous Situation Tornado Warning.[5][6]
On April 1, 2013, the IBW experiment expanded to include all National Weather Service WFOs within the Central Region;[7] the IBW experiment was expanded again to include eight additional offices within the Eastern, Southern and Western Regions in the spring of 2014.[8]
In 2016, Impact-Based Tornado Warnings were implemented nationwide and all offices began standardized training and practice for tornado emergencies.[9] 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.[10]
The first tornado emergency ever issued in theNortheastern United States was issued by the National Weather Service inMount Holly, New Jersey, on September 1, 2021, at 7:04 pm forBristol,Croydon andBurlington when a confirmed large and destructive tornado was observed overBeverly heading towards the highly populated areas ofLevittown,Trenton, andHamilton Square. The alert for areas inPennsylvania andNew Jersey occurred as the remnants ofHurricane Ida passed through the region.[11] The tornado was rated EF1.[12]
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 theNational Weather Service office inLittle Rock, Arkansas, issued tornado emergencies for several communities across seven counties in north-central and northeastern parts of the state.[13][14][15][a] 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 7:30 p.m. CDT, based on an emergency management report of a wedge tornado and damage to structures and trees nearHardy—indicated a tornado had not touched down and that damage produced by the storm was caused by straight-line winds and hail.[16] The area where the emergencies were issued were within coverage “dead zones” in the radii ofNEXRAD radars based in Little Rock,Springfield, Missouri, andMemphis, 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 atube cloud that extended to near surface level for a tornado. Five days earlier, on April 11, NWS Little Rock issued a tornado emergency forJacksonville andCabot, based in part on reports of a large tornado on the ground in Jacksonville; although the storm—which was within 15 miles (24 km) 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 andTulsa, Oklahoma, offices associated with that day’s convection, were later attributed to an Ohio woman who used aSpotter Network account withspoofed coordinates.[16][17]
A similar situation occurred on May 24, 2024, when theNWS office inShreveport, Louisiana issued a tornado emergency forBowie County, Texas, where no tornado threat materialized. A brief EF1 tornado occurred to the north ofNew Boston, Texas, which had lifted before the upgrade to a tornado emergency occurred.[18][19]
With the national implementation of Impact-Based tornado warnings in 2016, common criteria were established for the use of tornado emergency.[10] National guidance requires the confirmation of a tornado via radar or spotter confirmation, with evidence the ongoing tornado is strong to violent.[20]
Before usage, the following criteria must be met:
The National Weather Service Weather Forecast Office inJackson, 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."[23]
The National Weather Service office inNashville, 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:
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 abasement, cellar orsafe 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 asmattresses orblankets), to protect against falling debris in the event that the roof and ceiling collapse.[24]
