List of tornado outbreaks by Outbreak Intensity Score


In late 2023, American meteorologist and tornado expert Thomas P. Grazulis created the Outbreak Intensity Score as a way to rank tornado outbreaks. For the score, only significant tornadoes are counted: F2/EF2 tornadoes receive 2 points each, F3/EF3 tornadoes receive 5 points each, F4/EF4 tornadoes receive 10 points each, and F5/EF5 tornadoes receive 15 points each. The number of total points determine the rating for the outbreak, which is broken up into seven categories.
Type of outbreakWeakMinorSignificantMajorDevastatingHistoricSuper
Number of
points
2–67–1011–2930–7980–119120–249250+

List

Super outbreaks

There have been three tornado outbreaks which scored more than 250 points on the OIS, reaching the status of "Super Outbreak".
OutbreakOIS score# of F2s# of F3s# of F4s# of F5sTotal tornadoesDeathsInjuriesReferences
1974 Super Outbreak5783435237148319
2011 Super Outbreak3834923114368324
Tornado outbreak sequence of May 25 – June 1, 1917296281714166+383+746+

Historic outbreaks

There have been 44 tornado outbreaks which scored at least 120 points, but less than 249 on the OIS, reaching the status of "Historic Outbreak".
OutbreakOIS score# of F2s# of F3s# of F4s# of F5sTotal tornadoesDeathsInjuriesReferences
1965 [Palm Sunday tornado outbreak]23814618055266
Tornado outbreak sequence of May 200323236206036342652
Tornado outbreak sequence of May 14–31, 19622094715401883168
Tornado outbreak sequence of May 189619917126338+501++
Tornado outbreak sequence of May 6–27, 199518839144027913500+
Tornado outbreak of November 21–23, 19921872615609526641
Tornado outbreak of June 14–18, 19921863315311701110
Tornado outbreak of April 2–3, 1956185258815539790
1932 Deep South tornado outbreak182161010038330
Tornado outbreak sequence of May 19821744216103291418+
Tornado outbreak sequence of May 22–31, 197317241104014524820
Tornado outbreak sequence of May 20191723118204028288
Tornado outbreak of May 19271691788134+217++
Tornado outbreak of March 21–22, 195216971110030204
Early May 1965 tornado outbreak169226817217770
1985 United States–Canada tornado outbreak169712814490875
Tornado outbreak sequence of May 21–26, 201116231832239178
Tornado outbreak of April 20–22, 19121591299032+56+410+
May 1960 [tornado outbreak sequence]1572610417133302
Tornado outbreak of March 16–17, 19421568136130+149+
Tornado outbreak sequence of April 25 – May 3, 19541543710301004167
Tornado outbreak sequence of March 18–27, 19481531911603680896
1920 Palm Sunday tornado outbreak1501588037+153++
Tornado outbreak of March 13–16, 20251473111301172365+
Tornado outbreak sequence of May 198314633160015762+
1999 Oklahoma tornado outbreak14520104115250895
Tornado outbreak of April 29 – May 1, 19091403084043+181+770+
Tornado outbreak sequence of April 18–27, 195714030840117233
Tornado outbreak sequence of May 4–8, 1964140357217315383
Enigma tornado outbreak1352594051+180++
2020 Easter tornado outbreak13319133014132257
Tornado outbreak of April 27–29, 1912130106802647+175+
Tornado outbreak of March 31 – April 1, 202312932111014726218+
Tornado outbreak of April 14–16, 201112932130017838588
June 1990 Lower Ohio Valley tornado outbreak12917570669253
Tornado outbreak of April 2–3, 19821281411316330433
Tornado outbreak sequence of April 19–21, 197312726930682106
Flint–Worcester tornado outbreak sequence1261375150251
March 1990 [Central United States tornado outbreak]12613102264289
1991 Great Plains tornado outbreak126187415521313
1908 Dixie tornado outbreak1242235131+324++
Tornado outbreak sequence of May 3–9, 1961123299207323126
Tornado outbreak sequence of December 18–20, 1957122169313719291
May 1957 Central Plains tornado outbreak sequence120207315759341

Devastating outbreaks

There have been several tornado outbreaks which scored at least 80 points, but less than 120 on the OIS, reaching the status of "Devastating Outbreak".
OutbreakOIS score# of F2s# of F3s# of F4s# of F5sTotal tornadoesDeathsInjuriesReferences
Tornado outbreak of June 5–6, 191611520131035+143+756+
Tornado outbreak of March 27, 18901141266024+187+846+
Tornado outbreak sequence of May 19–27, 202411221121024721243
1984 Carolinas tornado outbreak10975702457
2008 Super Tuesday tornado outbreak107165508757425
Tornado outbreak sequence of May 2004106238203897123
Tornado outbreak of May 1968105107224672
Tornado outbreak of March 20–21, 197610417830663189
Tornado outbreak sequence of May 4–10, 19331021683033+128644+
Tornado outbreak sequence of April 2–5, 1957102266207321341
March 1875 Southeast tornado outbreak101357019+96+377+
April 1924 tornado outbreak10113112028+114+
Tornado outbreak of April 30 – May 2, 196710121440381390
Tornado outbreak of November 17, 201310123720778190+
Tornado outbreak of April 15–16, 1998100107316312120
1967 Oak Lawn tornado outbreak99173504558
Tornado outbreak of May 22–27, 2008981491117313215
Tornado outbreak of April 1880971635025+166+516+
Tornado outbreak sequence of March 9–13, 2006971611109910183
Tornado outbreak of April 27–30, 201497169208235447
Tornado outbreak and floods of April 2–7, 20259633600145+1047+
Tornado outbreak sequence of May 8–12, 1959952072060734
Tornado outbreak of April 12, 194594754117128
Tornado outbreak sequence of May 19719422810766242
Tornado outbreak sequence of June 21–26, 1969931473063765+
Tornado outbreak sequence of April 1996931911001186200+
Tornado outbreak of March 2–3, 201293149207041300+
1953 Waco tornado outbreak91844133144895
Tornado outbreak of June 7–8, 198491234114613322
Tornado outbreak sequence of May 7–11, 2008912352012025419
1979 [Red River Valley tornado outbreak]90254206158
2002 Veterans Day weekend tornado outbreak90208107636303
Tornado outbreak of June 16–18, 2014891235076228
Tornado outbreak of April 21–23, 1883871154029+122+771+
Tornado outbreak sequence of June 9–14, 19678726320103515+
Tornado outbreak of April 25–28, 202487167201626156+
Tornado outbreak sequence of March 26–31, 19618618100047380
1913 Easter tornado outbreak85536015+192853+
Tornado outbreak of March 13–14, 1913841263023+76+301+
1936 Tupelo–Gainesville tornado outbreak84273114+454++
Tornado outbreak of November 23–24, 200183193306913219
April 1920 tornado outbreak82626017+243++
Tornado outbreak of December 10–11, 202182166207189676
1955 Great Plains tornado outbreak811331248102554
Tornado outbreak sequence of June 196681182215718543
Tornado outbreak sequence of June 10–16, 1970811871082373
Tornado outbreak of June 8, 19748189203622477
Tornado outbreak of January 21–23, 199981139101289162
1886 St. Cloud–Sauk Rapids tornado outbreak801044018+87+324+
1967 St. Louis tornado outbreak8015620307268
Tornado outbreak sequence of April 17–19, 19708010250332668

Major outbreaks

There have been several tornado outbreaks which scored at least 30 points, but 79 or less on the OIS, reaching the status of "Major Outbreak".
OutbreakOIS score# of F2s# of F3s# of F4s# of F5sTotal tornadoesDeathsInjuriesReferences
Tornado outbreak sequence of April 28 – May 2, 19537973502436361
Tornado outbreak of April 9–11, 20097912910855112
June 2010 Northern Plains tornado outbreak78944093343
Tornado outbreak of April 28–30, 19637716710371372
Tornado outbreak of April 18–21, 197476186103621+
Tornado outbreak of May 18–21, 202576131000123010+
Tornado outbreak of June 188174245011+20+141+
Tornado outbreak of March 28–31, 1976731452035101+
Tornado outbreak of April 30 – May 1, 194971891024+10103
March 1997 tornado outbreak7185303927464
Tornado outbreak of May 4–6, 200770155011321489
Tornado outbreak of May 23–24, 194669753017+442
1980 Grand Island tornado outbreak689430296413
Tornado outbreak sequence of May 22–26, 201668981098011+
Tornado outbreak of May 2, 19426711608+31172+
Tornado outbreak of May 20–21, 194967634046+560+
Tornado outbreak of May 6–8, 1973662310147241
Late-May 1998 tornado outbreak and derecho6613610607233+
Tornado outbreak of April 8–9, 1999668430546100
Tornado outbreak of May 10–13, 20106613420913127
December 2021 Midwest derecho and tornado outbreak663300012053
Tornado outbreak of April 9, 19196553401292+412
Tornado outbreak sequence of November 13–17, 1958652050043037
Tornado outbreak of June 7–9, 1993651052010711+
Tornado outbreak of February 21–22, 197164732119+123
Tornado outbreak of April 27–28, 20026412610486256
Tornado outbreak of February 11–13, 195063145102441+228
1975 Omaha tornado outbreak6314320363137+
1994 Palm Sunday tornado outbreak6347202940491
Tornado outbreak of February 28 – March 2, 2007639330572098
Tornado outbreak sequence of June 3–11, 20086314510192784
Tornado outbreak of March 12–15, 19536211610232172
Tornado outbreak of April 23–27, 1970621161034326+
Tornado outbreak of December 23–25, 1982621641044111+
Tornado outbreak sequence of May 30 – June 3, 1954611831039965
Tornado outbreak of April 8, 1957618520187203
Tornado outbreak of December 17–21, 19676113510306110
Tornado outbreak of April 21–24, 19686182212614525
Tornado outbreak sequence of December 1–6, 195360103111949404
Tornado outbreak of April 2–4, 1968601522031120+
Tornado outbreak of April 19–22, 1972601061028842
Tri-State tornado outbreak59242112+751
Tornado outbreak sequence of April 23–30, 1961591251030338
Tornado outbreak sequence of June 17–23, 1964591251052037
Tornado outbreak of March 25–26, 194958942015+25+180+
Tornado outbreak sequence of April 26–30, 19715894203010187
Tornado outbreak of April 22–25, 20105894208810184
Tornado outbreak sequence of April 5–8, 1954571151025122
Hurricane Carla tornado outbreak5767102114337
Tornado outbreak of March 13–17, 198257117002341+
Tornado outbreak sequence of May 15–16, 20255711320552738-45
Tornado outbreak of February 5–6, 1942561840022+15114
Tornado outbreak of March 26, 197656332117489
Tornado outbreak sequence of April 12–18, 1960551070037460
Tornado outbreak of April 28–30, 194754742013+24+0+
Tornado outbreak sequence of July 1–10, 195554723028448
Tornado outbreak sequence of January 7–11, 200854780073462
Tornado outbreak of May 26–31, 201354126001349172
Tornado outbreak of November 7–8, 19575395102812213
Tornado outbreak sequence of March 4–8, 19615314500442152
Tornado outbreak sequence of April 29 – May 2, 197253471021012
Tornado outbreak of November 20–21, 190052642014+97+388+
Tornado outbreak of November 16–19, 19575211220321084
1967 Hurricane Beulah tornado outbreak526800120541
2009 South American tornado outbreak52642028151+
Tornado outbreak of January 4–6, 194651333010+47412+
Tornado outbreak of October 14–15, 19665113201236225
Tornado outbreak of May 6–10, 20245113310162387-91+
Tornado outbreak of January 29–30, 1947501041015+13+24+
Tornado outbreak sequence of May 12–17, 195750104105023105
Tornado outbreak of May 18–21, 20135051217826229
Tornado outbreak sequence of March 24–28, 2021501041043737+
Tornado outbreak sequence of September 26–29, 1959491212036247
2012 Leap Day tornado outbreak49171104215193
Tornado outbreak sequence of May 17–20, 1960489220631108
2003 South Dakota tornado outbreak489220125219
Tornado outbreak of January 3, 194947651014+60+504
Tornado outbreak of March 24–25, 1954471611028211
1944 Appalachians tornado outbreak4713307+154+
Tornado outbreak of March 10–12, 1963471112018638
Tornado outbreak of April 12–14, 196447632023775
1967 European tornado outbreak4714118+1780+
Tornado outbreak of December 1–3, 19824767003820+
2008 Atlanta tornado outbreak471630046353
Tornado outbreak of June 5–6, 2010471131053868
Tornado outbreak sequence of May 15–20, 19464632308+8+53+
Tornado outbreak of June 3–4, 19584631211328175
1997 Central Texas tornado outbreak463311202830
Tornado outbreak of April 2, 20064686006627348
Tornado outbreak of April 9–11, 201146841049021
Tornado outbreak sequence of May 5–10, 2015468600127567
Tornado outbreak of March 16–18, 1965455510242129
Tornado outbreak of June 13, 19764552111621+
Tornado outbreak of April 197745102012224158
May 1989 tornado outbreak455130167168
Tornado outbreak of November 22–24, 20044515300104439
Tornado outbreak of October 17–19, 2007451530063528
Tornado outbreak of March 28–31, 2007451050081526
Tornado outbreak sequence of April 19–24, 20114515110134014
Tornado outbreak of April 4–7, 2022451031089117+
Tornado outbreak of December 12–15, 2022452010077364
Tornado outbreak sequence of April 21–24, 1955441221027629
Tornado outbreak of December 14–15, 19714417200402119
Tornado outbreak of April 25–27, 198244760013+00+
Tornado outbreak of November 4–5, 202244722031234+
1929 Rye Cove tornado outbreak4395001742+323+
Great Storm of 197543141104512377
Tornado outbreak of April 23, 2000431430033012
Tornado outbreak of June 18–22, 20114395007804
Tornado outbreak of December 16–17, 201943950041314+
Tornado outbreak sequence of April 2–8, 19644211101337119
Tornado outbreak of November 25–27, 196542660018126
Tornado outbreak of February 22–24, 197542112102331+
Tornado outbreak of May 22–23, 1981421121043012
Tornado outbreak of May 7–10, 201642641057219
1947 Glazier–Higgins–Woodward tornado outbreak41801112+185+990+
Tornado outbreak of May 24–25, 195741831045410
Tornado outbreak of April 28–30, 196041850019379
Tornado outbreak of April 19, 197641820116011
Hurricane Ivan tornado outbreak4118100120724+
Tornado outbreak of April 13–16, 20124135101136101
Tornado outbreak of February 28 – March 1, 201741831071438
Tornado outbreak of March 21–23, 2022411330085368
1936 Cordele–Greensboro tornado outbreak40503013+49+149+
Tornado outbreak of April 18, 19694054101520+
Tornado outbreak of April 25–27, 1994401002010161+
Tornado outbreak of April 13–15, 2019401520075365
Tornado outbreak of March 12–13, 1961391230025284
Tornado outbreak of September 24–25, 19733925108366
Tornado outbreak of April 6–9, 19983972016241250+
Tornado outbreak of November 15, 2005397310491108
Tornado outbreak of November 27–28, 2005391230073215
Tornado outbreak of April 30 – May 2, 2010391230060531
Tornado outbreak of June 4–5, 19553842204600
Tornado outbreak sequence of May 12–14, 1956389020194162
Tornado outbreak of March 31 – April 2, 195938441017783
Tornado outbreak of July 1–3, 1997389400522100
Tornado outbreak of March 6–8, 1956371111017142
Tornado outbreak of February 13, 1952376310155102
Tornado outbreak sequence of April 1–6, 195837650032340
Tornado outbreak of May 10, 1985371320100+0+
Tornado outbreak of May 30 – June 1, 19993765005931+
Tornado outbreak of April 10–11, 2001371610079418
Tornado outbreak of January 21–23, 201737113008120204
Tornado outbreak of March 24–27, 20233763103523236
Tornado outbreak of March 20–21, 1913361301016+53156+
1944 South Dakota–Minnesota tornado outbreak3631116+13+560+
Tornado outbreak of February 12, 1945363410845427
Tornado outbreak of October 29–30, 19563634101607
Tornado outbreak of August 6, 19693682101415+109
March 1917 tornado outbreak3553109+47+300+
Tornado outbreak of November 15–16, 195535550018135
Tornado outbreak of April 1–2, 1974351030023472
1985 Hurricane Danny tornado outbreak35103004617+
Tornado outbreak of May 1–3, 2008351030060645
Tornado outbreak of March 9–11, 1973347210167132
Tornado outbreak of March 10–12, 19863412200416122
Tornado outbreak of June 2, 1998347210332277
2008 Poland tornado outbreak34241012255+
Tornado outbreak sequence of June 14–19, 20233412200934120
Tornado outbreak of May 17, 19493343108+1+0+
Tornado outbreak sequence of January 21–22, 1957339110161331
Tornado outbreak sequence of August 24–31, 196433911026212
Tornado outbreak of February 11, 196533930015028
Tornado outbreak of December 16, 20003391102412186
2010 [New Year's Eve tornado outbreak]33450037932
Tornado outbreak of March 29–31, 202233930090217
Great Blue Norther of November 11, 191132621013+16101+
Tornado outbreak of May 11, 19473214106122
Tornado outbreak sequence of May 27 – June 2, 195832112002303
Tornado outbreak of April 14–15, 196532640016158
Tornado outbreak sequence of September 20–23, 19653264002604
Tornado outbreak of April 12–13, 196732160003009
Tornado outbreak of January 12, 2023321120044853
Tornado outbreak and derecho of June 19–22, 20253261014172+
1881 Minnesota tornado outbreak3131206+24123+
Tornado outbreak of September 29, 19273183001582+620+
St. Louis tornado outbreak of February 19593133101721358
Tornado outbreak of June 22–24, 196031830018010
Tornado outbreak of March 4, 19643133108444
1984 Soviet Union tornado outbreak31312011403804
November 1989 tornado outbreak3181104030523
Tornado outbreak of September 21–23, 200631811048014+
October 2013 North American storm complex31312022317+
Tornado outbreak and floods of April 28 – May 1, 201731811075570
Tornado outbreak of February 24–25, 1956301001023647
Tornado outbreak of February 26–27, 1958305400161392
Tornado outbreak of March 26–27, 1950301020016152
Tornado outbreak sequence of June 20–23, 19573051012311105
Tornado outbreak of May 4–6, 195930150005002
Tornado outbreak of December 10–11, 19673010200222103
Tornado outbreak of March 12, 19713004101015
1978 Bossier City tornado outbreak305210115277
May 2009 Southern Midwest derecho30102003945+
Late-May 2010 tornado outbreak30100108000
Tornado outbreak of December 23–25, 2015305210381377
Tornado outbreak of February 23–24, 2016305400617136
August 2017 Chinese tornado family3000303558+
Tornado outbreak sequence of June 20–26, 202330102001145126