F5 tornado Elie Manitoba 2007.jpg
A tornado approaching Elie, Manitoba.
SeasonPrimarily spring and summer, but can be at any time of year
EffectWind damage

A tornado is a rapidly rotating column of air that is in contact with both the surface of the Earth and a cumulonimbus cloud or, in rare cases, the base of a cumulus cloud. The windstorm is often referred to as a twister, whirlwind or cyclone,[1] although the word cyclone is used in meteorology to name a weather system with a low-pressure area in the center around which, from an observer looking down toward the surface of the earth, winds blow counterclockwise in the Northern Hemisphere and clockwise in the Southern.[2] Tornadoes come in many shapes and sizes, and they are often visible in the form of a condensation funnel originating from the base of a cumulonimbus cloud, with a cloud of rotating debris and dust beneath it. Most tornadoes have wind speeds less than 110 miles per hour (180 km/h), are about 250 feet (80 m) across, and travel a few miles (several kilometers) before dissipating. The most extreme tornadoes can attain wind speeds of more than 300 miles per hour (480 km/h), are more than two miles (3 km) in diameter, and stay on the ground for dozens of miles (more than 100 km).[3][4][5]

Various types of tornadoes include the multiple vortex tornado, landspout, and waterspout. Waterspouts are characterized by a spiraling funnel-shaped wind current, connecting to a large cumulus or cumulonimbus cloud. They are generally classified as non-supercellular tornadoes that develop over bodies of water, but there is disagreement over whether to classify them as true tornadoes. These spiraling columns of air frequently develop in tropical areas close to the equator and are less common at high latitudes.[6] Other tornado-like phenomena that exist in nature include the gustnado, dust devil, fire whirl, and steam devil.

Tornadoes occur most frequently in North America (particularly in central and southeastern regions of the United States colloquially known as tornado alley),[7]Southern Africa, northwestern and southeast Europe, western and southeastern Australia, New Zealand, Bangladesh and adjacent eastern India, and southeastern South America.[8] Tornadoes can be detected before or as they occur through the use of Pulse-Doppler radar by recognizing patterns in velocity and reflectivity data, such as hook echoes or debris balls, as well as through the efforts of storm spotters.

Tornado rating scales

There are several scales for rating the strength of tornadoes. The Fujita scale rates tornadoes by damage caused and has been replaced in some countries by the updated Enhanced Fujita Scale. An F0 or EF0 tornado, the weakest category, damages trees, but not substantial structures. An F5 or EF5 tornado, the strongest category, rips buildings off their foundations and can deform large skyscrapers. The similar TORRO scale ranges from T0 for extremely weak tornadoes to T11 for the most powerful known tornadoes.[9] Doppler radar data, photogrammetry, and ground swirl patterns (trochoidal marks) may also be analyzed to determine intensity and assign a rating.[10][11]

A tornado near Anadarko, Oklahoma, 1999. The funnel is the thin tube reaching from the cloud to the ground. The lower part of this tornado is surrounded by a translucent dust cloud, kicked up by the tornado's strong winds at the surface. The wind of the tornado has a much wider radius than the funnel itself.
All tornadoes in the Contiguous United States, 1950–2013, plotted by midpoint, highest F-scale on top, Alaska and Hawaii negligible, source NOAA Storm Prediction Center.
Other Languages
Адыгэбзэ: Гъуэжькуий
Afrikaans: Tornado
Alemannisch: Tornado
العربية: إعصار قمعي
aragonés: Tornado
asturianu: Tornáu
azərbaycanca: Tornado
বাংলা: টর্নেডো
Banjar: Angin tutus
Bân-lâm-gú: Kńg-lê-á-hong
башҡортса: Ҡойон
беларуская: Тарнада
беларуская (тарашкевіца)‎: Тарнада
български: Торнадо
Boarisch: Windhosn
bosanski: Tornado
буряад: Хуй һалхин
català: Tornado
čeština: Tornádo
Cymraeg: Trowynt
dansk: Tornado
Deutsch: Tornado
Diné bizaad: Níyoltsoh
eesti: Tromb
Ελληνικά: Σίφωνας
español: Tornado
euskara: Tornado
فارسی: پیچند
français: Tornade
Frysk: Tornado
Gaeilge: Tornádó
Gàidhlig: Cuairt-ghaoth
galego: Tornado
ГӀалгӀай: Йилбазмух
客家語/Hak-kâ-ngî: Pô-lò-chiu-fûng
хальмг: Хү
한국어: 토네이도
Hausa: Guguwa
հայերեն: Տորնադո
हिन्दी: बवंडर
hrvatski: Tornado
Bahasa Indonesia: Tornado
interlingua: Tornado
ᐃᓄᒃᑎᑐᑦ/inuktitut: ᐅᓚᔪᔭᖅ
isiXhosa: Inkanyamba
íslenska: Skýstrokkur
italiano: Tromba d'aria
עברית: טורנדו
Jawa: Tornado
ქართული: ტორნადო
kaszëbsczi: Krãcëszk
қазақша: Торнадо
Kiswahili: Tufani
Kreyòl ayisyen: Tònad
kurdî: Bablîsok
Кыргызча: Куюн
latviešu: Virpuļviesulis
Lëtzebuergesch: Tornado
lietuvių: Viesulas
Limburgs: Tornado
Lingua Franca Nova: Tornado
magyar: Tornádó
македонски: Торнадо
മലയാളം: ടൊർണേഡോ
मराठी: घूर्णवात
მარგალური: ტორნადო
Bahasa Melayu: Puting beliung
Mìng-dĕ̤ng-ngṳ̄: Guōng-lòi-hŭng
မြန်မာဘာသာ: လေဆင်နှာမောင်း
Na Vosa Vakaviti: Covulaca
Nedersaksies: Wervelstörm
नेपाली: भूमरी
नेपाल भाषा: तःफय्
日本語: 竜巻
norsk: Tornado
norsk nynorsk: Tornado
oʻzbekcha/ўзбекча: Tornado
ਪੰਜਾਬੀ: ਟੋਰਨੈਡੋ
پنجابی: ٹورنیڈو
Papiamentu: Warwaru
Patois: Taaniedo
Picard: Tornade
Plattdüütsch: Warvelwind
polski: Tornado
português: Tornado
română: Tornadă
русский: Смерч
संस्कृतम्: चक्रवातः
shqip: Tornado
sicilianu: Turnatu
සිංහල: ටෝනාඩෝ
Simple English: Tornado
slovenčina: Tornádo
slovenščina: Tornado
کوردی: تۆرنادۆ
српски / srpski: Торнадо
srpskohrvatski / српскохрватски: Tornado
svenska: Tromb
Tagalog: Buhawi
татарча/tatarça: Өермә
Tsetsêhestâhese: Ma'xêhevovetäso
українська: Смерч
اردو: بگولا
vèneto: Tornado
Tiếng Việt: Lốc xoáy
文言: 龍掛
Winaray: Buhawi
吴语: 龙卷风
ייִדיש: טארנאדא
粵語: 龍捲風
žemaitėška: Viesols
中文: 龍捲風
kriyòl gwiyannen: Tòrnad