Progression of a well-anticipated high risk event across the Central Plains on April 14, 2012. This event ultimately produced 85 tornadoes that day, one of which killed six people.

A high risk severe weather event is the greatest threat level issued by the Storm Prediction Center (SPC) for convective weather events in the United States. On the scale from one to five, a high risk is a level five; thus, high risks are issued only when forecasters at the SPC are confident of a major severe weather outbreak. This is usually for major tornado outbreaks with numerous strong to violent tornadoes expected, and occasionally derechos with widespread destructive wind gusts, and these outlooks are typically reserved for the most extreme events.[1] They are generally only issued on the day of the event. However, there have been two occurrences (April 7, 2006, and April 14, 2012) of a high risk being issued for Day 2 of the outlook period (with the event occurring the following day). Under the official protocol, a high risk cannot be issued for Day 3 of the outlook period.[2]

High risk days

1982–1989

Thirty-four high risks were issued in the 1980s.

Storm Prediction Center High Risk Events – 1982–1989[nb 1]
Date Year Region Tornadoes Max rating Peak gust Fatalities Outlook Notes
April 2 1982 Midwest, Southern U.S.[3][4] 63
F5
 27 Tornado outbreak of April 2–3, 1982 – Sixty-three tornadoes were confirmed; one was rated F5. The first ever PDS Tornado Watch was issued on this date.
December 24 1982 Southern U.S. 26
F4
 3 Twenty-six tornadoes were confirmed; one was rated F4.
April 1 1983 Midwest, Southern U.S. 13
F4
 2 Thirteen tornadoes were confirmed; one was rated F4.
July 2 1983 Midwest[5] 3
F1
 0 Only three weak tornadoes were confirmed; one was rated F1
March 27 1984 Southern U.S.[6] 11
F1
 0 Eleven weak tornadoes were confirmed; six were rated F1.[7]
March 28 1984 Southern U.S.[8][9] 24
F4
 57 1984 Carolinas tornado outbreak – Twenty-four tornadoes were confirmed; seven were rated F4. In addition to the 57 tornadic deaths, 1,249 people were injured.[10]
April 26 1984 Great Plains[11] 33
F4
 12 Thirty-three tornadoes were confirmed; one was rated F4.[12]
April 29 1984 Midwest, Southern U.S.[13] 42
F4
 1 Forty-two tornadoes were confirmed; one was rated F4.[14]
May 3 1984 Southern U.S.[15][16] 38
F3
 5 Thirty-eight tornadoes were confirmed; one was rated F3.[17]
October 18 1984 Midwest, Southern U.S.[18] 8
F3
 2 Eight tornadoes were confirmed; one was rated F3.[19]
April 21 1985 Upper Midwest[20] 22
F3
 3 Twenty-two tornadoes were confirmed; one was rated F3.[21]
April 22 1985 Southern U.S.[22] 11
F2
 0 Eleven tornadoes were confirmed; two were rated F2.
May 11 1985 Midwest, Southern U.S.[23] 24
F1
 0 Twenty-four weak tornadoes were confirmed; three were rated F1.[24]
May 13 1985 Midwest, Southern U.S.[25] 14
F2
 0 Fourteen tornadoes were confirmed; three were rated F2.[26]
May 30 1985 Midwest[27] 17
F3
 2 Seventeen tornadoes were confirmed; one was rated F3.[28]
July 4 1985 Midwest[29] 3
F1
 0 Mainly a wind and hail event.[30] Three weak tornadoes were confirmed; two were rated F1.[31]
March 11 1986 Southern U.S.[32] 4
F2
 0 Tornado outbreak of March 10–12, 1986 – Four tornadoes were confirmed; one was rated F2.[33]
April 19 1986 Southern U.S.[34] 13
F3
 1 Fourteen tornadoes were confirmed; one was rated F3.[35]
March 22 1987 Oklahoma, Texas[36] 9
F3
 0 Nine tornadoes were confirmed; one was rated F3.[37]
May 28 1987 Texas[38] 7
F2
 0 Seven tornadoes were confirmed; one was rated F2.[39]
July 20 1987 Michigan[40] 4
F0
 0 Produced a derecho with damaging downburst winds.[41] Four weak tornadoes were confirmed.[42]
November 16 1987 Alabama, Louisiana, Mississippi[43] 28
F2
 0 Twenty-eight tornadoes were confirmed; six were rated F2.[44]
December 14 1987 Southern U.S.[45] 5
F3
 6 Five tornadoes were confirmed; one was rated F3. The F3 tornado struck the northern portions of the Memphis metropolitan area.[46]
January 19 1988 Alabama, Louisiana, Mississippi, Tennessee[47] 14
F4
 5 Earliest date that a high risk was issued. Fourteen tornadoes were confirmed; one was rated F4.[48]
March 24 1988 Midwest, Southern U.S.[49] 10
F2
 0 Damaging squall line with tornadoes.[50] Ten tornadoes were confirmed; three were rated F2.[51]
November 4 1988 Southern U.S.[52] 18
F3
 0 Eighteen tornadoes were confirmed; four were rated F3.[53]
November 15 1988 Midwest[54] 44
F3
 7 Late season tornado outbreak. Forty-four tornadoes were confirmed; three were rated F3.[55]
November 26 1988 Southern U.S.[56] 8
F2
 0 Nine tornadoes were confirmed; two were rated F2.[57]
March 5 1989 Alabama, Georgia, Tennessee[58] 9
F3
 1 Nine tornadoes were confirmed; one was rated F3.[59]
May 16 1989 Oklahoma, Texas, New Mexico[60][61] 20
F4
 1 Only high risk ever issued for New Mexico. Twenty tornadoes were confirmed; one was rated F4.[62]
May 17 1989 Louisiana, Texas[63] 19
F3
 1 Nineteen tornadoes were confirmed; one was rated F3.[64]
May 24 1989 Midwest[65] 31
F4
 0 Thirty-one tornadoes were confirmed; two were rated F4.[66]
June 13 1989 Louisiana, Texas[67] 1
F1
 0 Only one tornado were confirmed.[68] The high risk was issued in the 1300 UTC outlook and removed from all subsequent outlooks.
November 15 1989 Southern U.S.[69] 17
F4
 21 November 1989 tornado outbreak – Seventeen tornadoes were confirmed; one was rated F4.[70]

1990–1999

Sixty high risks were issued in the 1990s.

Storm Prediction Center High Risk Events – 1990–1999[nb 1]
Date Year Region Tornadoes Max rating Peak gust Fatalities Outlook Notes
February 1 1990 Arkansas, Louisiana, Oklahoma, Texas[71] 1
F1
 0 One weak tornado was confirmed.[72] Only the 1200 UTC outlook included a high risk.
March 14 1990 Southern U.S.[73] 11
F3
 1 Eleven tornadoes were confirmed; one was rated F3.[74]
May 9 1990 Midwest[75] 4
F2
 0 Four tornadoes were confirmed; two were rated F2.[76] Only the 1200 UTC outlook included a high risk.
May 15 1990 Arkansas, Illinois, Indiana, Kansas, Kentucky, Missouri, Tennessee, Oklahoma[77] 17
F3
 1 Seventeen tornadoes were confirmed; one was rated F3.[78]
May 20 1990 Arkansas, Kansas, Oklahoma[79] 10
F2
 0 Ten tornadoes were confirmed; one was rated F2.[80] Only the 1900 UTC outlook included a high risk.
May 29 1990 Kansas, Oklahoma, Texas[81] 9
F2
 0 Mainly a damaging wind threat.[82] Nine tornadoes were confirmed; one was rated F2.[83] Only the 1900 UTC outlook included a high risk.
June 1 1990 Great Plains[84] 21
F4
 2 Twenty-one tornadoes were confirmed; one was rated F4.[85]
June 2 1990 Ohio Valley[69] 68
F4
 9 June 1990 Lower Ohio Valley tornado outbreak – Sixty-eight tornadoes were confirmed; seven were rated F4.[86]
March 22 1991 Midwest, Southern U.S.[87] 23
F3
 6 Twenty-three tornadoes were confirmed; three were rated F3.[87]
March 26 1991 Kansas, Missouri, Oklahoma[88] 21
F4
 0 Twenty-one tornadoes were confirmed; one was rated F4.[89] Only the 1900 UTC outlook included a high risk.
March 27 1991 Midwest[90] 29
F3
 2 Twenty-nine tornadoes were confirmed; six were rated F3.[91]
March 28 1991 Indiana, Michigan, Ohio[92] 2
F0
 0 Two weak tornadoes were confirmed. Only the 0100 UTC outlook had a high risk.[93]
March 29 1991 Alabama, Florida, Georgia, North Carolina, South Carolina, Virginia[94] 21
F3
 0 First and only occurrence of four consecutive high risk days. Twenty-one tornadoes were confirmed; one was rated F3.[95]
April 11 1991 Oklahoma, Kansas, Texas[96] 7
F3
 0 Severe weather outbreak did not consolidate due to a lack of moisture and instability anticipated to develop.[69] Seven tornadoes were confirmed; one was rated F3.[97]
April 12 1991 Oklahoma, Kansas, Texas[69] 24
F3
 0 Twenty-four tornadoes were confirmed; two were rated F3.[98]
April 26 1991 Central U.S.[69] 55
F5
 21 Tornado outbreak of April 26, 1991 – Fifty-five tornadoes were confirmed; one was rated F5.[99]
April 28 1991 Eastern Oklahoma and Kansas[69] 13
F2
 0 Thunderstorm complex early in the day prevented significant moisture from moving into the region and ultimately limited severe weather activity.[100] Thirteen tornadoes were confirmed; two were rated F2.[101]
April 19 1992 Arkansas, Louisiana, Oklahoma, Texas[102] 4
F1
 0 Four weak tornadoes were confirmed; three were rated F1.[103]
June 16 1992 Midwest[104] 65
F5
 1 Mid-June 1992 tornado outbreak – Sixty-five tornadoes were confirmed; one was rated F5.[105]
June 17 1992 Great Lakes[106] 28
F3
 0 Mid-June 1992 tornado outbreak – Twenty-eight tornadoes were confirmed; one was rated F3.[107]
June 19 1992 Arkansas, Kansas, Louisiana, Oklahoma, Texas[108] 17
F1
 0 Seventeen tornadoes were confirmed; three were rated F1.[109] Only the 1900 UTC outlook included a high risk.
July 2 1992 Arkansas, Illinois, Iowa, Kansas, Missouri, Oklahoma, Wisconsin[110] 16
F3
 0 Sixteen tornadoes were confirmed; one was rated F3.[111]
September 9 1992 Illinois, Indiana, Kansas, Missouri[112] 4
F1
 0 Only high risk ever issued in September. Squall line with damaging winds and some large hail.[113] Four weak tornadoes were confirmed; one was rated F1.[114]
April 19 1993 Arkansas, Illinois, Kentucky, Missouri, Tennessee[115] 6
F2
 0 Six tornadoes were confirmed; one was rated F2.[116]
June 3 1993 Arkansas, Illinois, Kansas, Kentucky, Missouri, Oklahoma, Tennessee[117] 0 — 0 A high risk was issued for a derecho. No tornadoes were confirmed. Day 1 of 2 for the derecho.
June 4 1993 Kentucky, North Carolina, Tennessee, Virginia, West Virginia[118] 13
F1
 80 mph (130 km/h) 0 Major derecho event.[119] The Lynchburg, Virginia area was hit the hardest. The city had a wind gust to 80 mph, with significant damage reported. Power was cut to 95% of the city.[120] Thirteen tornadoes were confirmed; six were rated F1.[121] Only the 1900 UTC outlook had a high risk.
June 7 1993 Upper Midwest[122] 40
F4
 0 Forty tornadoes were confirmed; two were rated F4.[123]
June 8 1993 Great Plains, Upper Midwest[124] 58
F3
 0 Fifty-eight tornadoes were confirmed; one was rated F3.[125]
June 23 1993 Kansas, Nebraska[126] 3
F2
 0 Only three tornadoes were confirmed; one was rated F2.[127]
July 3 1993 Iowa, Minnesota, Nebraska, North Dakota, South Dakota[128] 13
F1
 0 Thirteen weak tornadoes were confirmed; four were rated F1.[129]
March 27 1994 Southern U.S.[130] 29
F4
 40 1994 Palm Sunday tornado outbreak – Twenty-nine tornadoes were confirmed; two were rated F4.[131] Only the 1900 UTC outlook included a high risk.
April 25 1994 Central U.S.[132] 28
F4
 3 Tornado outbreak of April 25–27, 1994 – Twenty-eight tornadoes were confirmed; one was rated F4.[133] In addition, there were numerous large hail reports, with hail reaching 4.50".[134]
June 14 1994 Michigan, Minnesota, Wisconsin[135] 3
F1
 0 Three weak tornadoes were confirmed; one was rated F1.[136] Only the 1200 UTC outlook included a high risk.
August 27 1994 Iowa, Michigan, Minnesota, Nebraska, South Dakota, Wisconsin[137] 12
F3
 4 Only high risk ever issued in August. Twelve tornadoes were confirmed; two were rated F3.[138] The same system also produced an F4 in Turtle Mountain, Manitoba in Canada.
November 27 1994 Southern U.S.[139] 18
F3
 6 Eighteen tornadoes were confirmed; four were rated F3.[140]
April 17 1995 Oklahoma, Texas 21
F2
 0 Primarily a derecho event. Twenty-one tornadoes were confirmed; two were rated F2.[141]
May 7 1995 Kansas, Oklahoma, Texas 33
F3
 6 Tornado outbreak sequence of May 6–27, 1995 – Day one of a 5-day event. Thirty-three tornadoes were confirmed; two were rated F3.[142]
May 12 1995 Arkansas, Iowa, Kansas, Missouri, Nebraska, Oklahoma 14
F2
 0 Tornado outbreak sequence of May 6–27, 1995. Twelve tornadoes were confirmed; two were rated F2.[143]
May 13 1995 Ohio Valley 26
F4
 3 Tornado outbreak sequence of May 6–27, 1995 – Included a major derecho. Twenty-six tornadoes were confirmed; two were rated F4.[144]
May 17 1995 Oklahoma 9
F3
 0 Tornado outbreak sequence of May 6–27, 1995. Nine tornadoes were confirmed; one was rated F3.[145]
March 18 1996 Alabama, Florida, Georgia, Mississippi, South Carolina[146] 21
F3
 0 Twenty-one tornadoes were confirmed; one was rated F3.[147]
April 19 1996 Illinois, Indiana, Missouri, Kentucky[148][149] 60
F3
 104 mph (167 km/h) 1 Tornado outbreak sequence of April 1996. A total of 60 tornadoes were confirmed; six were rated F3.[150]
March 2 1997 Alabama, Louisiana, Mississippi[151] 2
F0
 0 Two weak and short lived tornadoes were confirmed.[152] Only the 1900 UTC outlook included a high risk.
May 2 1997 Alabama, Mississippi 8
F3
 92 mph (148 km/h) 1 Also a derecho event. Eight tornadoes were confirmed; two were rated F3.[153]
July 1 1997 Upper Mississippi Valley 20
F3
 109 mph (175 km/h) 0 Moderate tornado outbreak reorganized into a progressive derecho. Twenty tornadoes were confirmed; one was rated F3.[154]
October 25 1997 Arkansas, Louisiana, Mississippi, Oklahoma, Texas[155] 9
F1
 0 Nine tornadoes were confirmed; four were rated F1.[156] Only the 1900 UTC outlook included a high risk.
February 10 1998 Alabama, Louisiana, Mississippi, Texas 11
F1
 135 mph (217 km/h) 0 Rare winter serial derecho. Eleven tornadoes were confirmed; five were rated F1.[157]
April 8 1998 Alabama[158] 14
F5
 92 mph (148 km/h) 35 Tornado outbreak of April 6–9, 1998 – F5 damage in suburban Birmingham. Fourteen tornadoes were confirmed; one was rated F5.[159]
April 15 1998 Middle Mississippi Valley 21
F4
 75 mph (121 km/h) 2 Tornado outbreak of April 15–16, 1998 – Day 1 of outbreak. Twenty-one tornadoes were confirmed; one was rated F4.
April 16 1998 Tennessee 41
F5
 98 mph (158 km/h) 10 Tornado outbreak of April 15–16, 1998 – Day 2 of outbreak. Forty-one tornadoes were confirmed; one was rated F5.[160]
May 9 1998 Arkansas, Mississippi, Tennessee[161] 5
F1
 0 Five weak tornadoes were confirmed; one was rated F1.[162] Only the 1930 UTC outlook included a high risk.
May 31 1998 Northeastern U.S.[163][164][165][166] 42
F3
 128 mph (206 km/h) 7 Late-May 1998 tornado outbreak and derecho – Only high risk ever issued in the Northeast. Forty-two tornadoes were confirmed; six were rated F3.[167]
June 14 1998 Ohio Valley 22
F1
 92 mph (148 km/h) 0 Followed by a progressive derecho. Twenty-two tornadoes were confirmed; six were rated F1.[168]
January 21 1999 Arkansas[169][170] 82
F4
 8 Tornado outbreak of January 21–23, 1999 – Second earliest date that a high risk was issued. Eighty-two tornadoes were confirmed; one was rated F4.[171]
March 8 1999 Arkansas, Louisiana, Texas 10
F2
 0 Few tornadoes with some scattered hail and wind
April 8 1999 Iowa, Missouri, Illinois 47
F4
 2 Tornado outbreak of April 8–9, 1999 – Fifty-four tornadoes were confirmed; three were rated F4.
May 3 1999 Oklahoma, Kansas[172] 73
F5
 46 1999 Oklahoma tornado outbreak – Highest winds ever recorded in a tornado, 301 mph (484 km/h);[173] seventy-three tornadoes were confirmed, including three F4s and one F5.
May 4 1999 Oklahoma, Arkansas, Texas[172] 43
F3
 1 1999 Oklahoma tornado outbreak – Day 2 of outbreak
May 5 1999 Southern U.S. 15
F4
 3 1999 Oklahoma tornado outbreak – Second longest streak of consecutive high risk days. Major derecho event.
June 5 1999 South Dakota, Nebraska[174] 21
F1
 0 Event failed to consolidate with only isolated tornadoes and scattered severe wind reported. A shortwave ridge maintained a capping inversion.[175]

2000–2009

There were no high risk days in 2000.

Storm Prediction Center High Risk Events – 2000–2009[nb 1][nb 2]
Date Year Region Tornadoes Max rating Peak gust Fatalities Outlook Notes
April 6 2001 Texas Panhandle, Western Oklahoma, much of Kansas, and extreme southern Nebraska[176] 6
F2
 124 mph (200 km/h)† 1 A serial derecho formed, producing widespread wind damage. One person was killed by lightning in Ohio. Six tornadoes were confirmed; two were rated F2.[177]
April 11 2001 Eastern Iowa, Southern Wisconsin, and northwest Illinois[178] 40
F3
 92 mph (148 km/h) 3 Tornado outbreak of April 10–11, 2001 – Three people were killed by tornadoes. The event also featured the costly Tri-State hailstorm on the prior day. Forty tornadoes were confirmed; one was rated F3.[179]
June 11 2001 Southern Minnesota, Northeastern Iowa, and West-Central Wisconsin[180] 29
F2
 120 mph (190 km/h) 2 A progressive derecho produced widespread wind damage, including a measured thunderstorm wind gust of 120 miles per hour (193 km/h) near Atwater, Minnesota. Twenty-nine tornadoes were confirmed; one was rated F2. However, some of the tornadoes were associated with landfalling Tropical Storm Allison, not the system that triggered the high risk.[181]
October 13 2001 U.S. Gulf Coast[182] 32
F3
 112 mph (180 km/h)† 1 One person was killed by straight-line winds in Illinois. Thirty-two tornadoes were confirmed; one was rated F3.[183]
October 24 2001 Midwest[184] 25
F3
 104 mph (167 km/h)† 3 A significant tornado event that included a major serial derecho. One person was killed by straight-line winds in Michigan while another person was also killed in Tennessee. Twenty-five tornadoes were confirmed; two were rated F3.[185] Over 400 damaging wind gusts were reported across 18 states.[186]
April 16 2002 Upper Midwest[187] 14
F3
 85 mph (137 km/h)† 1 Widespread hail damage occurred and one person was killed by straight-line winds in Kansas. Fourteen tornadoes were confirmed; one was rated F3. The high risk was removed at 2000 UTC outlook update, although the initiation of the most intense severe weather occurred after that time.[188]
July 31 2002 Minnesota, Wisconsin[189] 3
F0
 75 mph (121 km/h)† 0 No fatalities took place.[190] Three weak tornadoes were confirmed.[191] Only the 0600 UTC outlook included a high risk.
November 10 2002 Midwest and Southern U.S.[192] 61
F4
 100 mph (160 km/h)† 34 Tornado outbreak of November 9–11, 2002 – No non-tornadic death took place.[193] Sixty-one tornadoes were confirmed; one was rated F4 (in Northwest Ohio, outside the high risk area – the strongest tornadoes within the high risk were rated F3). Thirty-four people were killed by the outbreak. Part of a three-day outbreak that resulted in 76 tornadoes and 36 deaths.[194]
December 23 2002 Texas, Louisiana[195] 15
F1
 70 mph (110 km/h)† 0 One of only two high risk ever issued in December and second latest in the year (first was December 24, 1982). No fatalities took place.[196] Fifteen tornadoes were confirmed; three were rated F1.[197]
April 6 2003 Texas, Louisiana, Mississippi[198] 18
F3
 83 mph (134 km/h) 0 Eighteen tornadoes were confirmed; one was rated F3.[199]
May 4 2003 Central U.S.[200] 79
F4
 89 mph (143 km/h)† 38 May 2003 tornado outbreak sequence – Seventy-nine tornadoes were confirmed; four were rated F4.[201]
May 5 2003 Southern U.S.[202] 28
F3
 104 mph (167 km/h)† 0 May 2003 tornado outbreak sequence – Twenty-eight tornadoes were confirmed; one was rated F3.[203]
May 8 2003 Kansas, Oklahoma[204] 45
F4
 104 mph (167 km/h) 0 May 2003 tornado outbreak sequence – Forty-five tornadoes were confirmed; one was rated F4.[205]
May 10 2003 Central U.S.[206] 49
F3
 92 mph (148 km/h)† 0 May 2003 tornado outbreak sequence – Forty-nine tornadoes were confirmed; three were rated F3.[207] Also included 35% tornado probability area, above the 25% minimum threshold for a high risk.
May 15 2003 Texas, Oklahoma[208] 47
F2
 92 mph (148 km/h)† 0 Forty-seven tornadoes were confirmed; seven were rated F2.[209]
March 4 2004 Texas, Oklahoma[210] 25
F2
 91 mph (146 km/h) 0 Reorganized into a large serial derecho Twenty-five tornadoes were confirmed; two were rated F2.[211]
May 22 2004 Nebraska, Iowa[212] 68
F4
 106 mph (171 km/h) 1 May 2004 tornado outbreak sequence/2004 Hallam tornado – Sixty-eight tornadoes were confirmed; one was rated F4. The F4 tornado was the largest tornado on record at the time with a peak width of 2.5 miles (4.0 km) as it struck Hallam, Nebraska.[213] Second of only three known times a high risk was not issued until 0100 UTC (the other two being March 28, 1991, and April 30, 2010).
May 24 2004 Nebraska, Iowa[214] 54
F2
 104 mph (167 km/h)† 1 May 2004 tornado outbreak sequence – Also a major derecho event. Fifty-four tornadoes were confirmed; two were rated F2.[215]
May 29 2004Central U.S.[216] 80
F4
 90 mph (140 km/h) 3 May 2004 tornado outbreak sequence – Eighty tornadoes were confirmed; one was rated F4.[217]
May 30 2004 Central U.S.[218] 86
F3
 120 mph (190 km/h)† 2 May 2004 tornado outbreak sequence – Eighty-six tornadoes were confirmed; two were rated F3.[219] Included 35% tornado risk area above minimum threshold of 25%.
April 11 2005 Louisiana, Mississippi[220] 3
F0
 86 mph (138 km/h) 0 Three weak tornadoes were confirmed.[221]
June 4 2005 Central U.S.[222] 44
F2
 81 mph (130 km/h)† 0 Forty-four tornadoes were confirmed; one was rated F2.[223]
November 15 2005 Midwest and Southern U.S.[224] 49
F4
 98 mph (158 km/h)† 1 Mid-November 2005 tornado outbreak – Forty-nine tornadoes were confirmed; one was rated F4. This was the only violent tornado to be recorded in 2005.[225]
March 12 2006 Midwest[226] 59
F4
 107 mph (172 km/h)† 8 Tornado outbreak sequence of March 9–13, 2006 – Fifty-nine tornadoes were confirmed; one was rated F4.[227] One supercell storm tracked nearly 800 miles from Oklahoma to Michigan, producing many tornadoes along its path.
April 6 2006 Nebraska, Kansas[228] 12
F2
 82 mph (132 km/h) 0 Tornado outbreak of April 6–8, 2006 – Twelve tornadoes were confirmed; one was rated F2.[229]
April 7 2006 Southern U.S.[230] 47
F3
 92 mph (148 km/h)† 10 Tornado outbreak of April 6–8, 2006 – Only known high risk to include a 60% tornado contour, the highest level issued by the SPC.[231] It was also the first of only two known occurrences (the other being April 14, 2012) in which a Day 2 high risk outlook was issued, and is the first/only instance to date where a high risk was issued for both Day 1 (April 6th) and Day 2. Forty-seven tornadoes were confirmed; two were rated F3.[232]
March 1 2007 Southern U.S.[233] 36
EF4
 81 mph (130 km/h)† 20 Tornado outbreak of February 28 – March 2, 2007 – Thirty-six tornadoes were confirmed; two were rated EF4.[234]
April 13 2007 Texas[235] 7
EF1
 81 mph (130 km/h)† 1 April 2007 nor'easter – Only seven tornadoes were confirmed; one was rated EF1.[236]
April 24 2007 Texas[237] 23
EF3
 90 mph (140 km/h)† 7 Tornado outbreak sequence of April 20–27, 2007 – Twenty-three tornadoes were confirmed; one was rated EF3, although this all occurred outside the high risk area, which saw virtually no activity. The supercell that produced the EF3 tornado also produced an F4 tornado in Mexico before crossing the international border.[238]
May 5 2007 Nebraska, Kansas[239] 90
EF3
 100 mph (160 km/h) 1 Tornado outbreak of May 4–6, 2007 – Ninety tornadoes were confirmed; two were rated EF3.[240]
June 7 2007 Upper Midwest[241] 12
EF3
 81 mph (130 km/h)† 0 Reorganized into a moderate wind event Twelve tornadoes were confirmed; one was rated EF3.[242]
February 5 2008 Middle Mississippi Valley[243] 63
EF4
 100 mph (160 km/h)† 48 2008 Super Tuesday tornado outbreak – Sixty-three tornadoes were confirmed; three were rated EF4.[244] One EF4 tornado in Arkansas tracked over 120 miles. One of only two high risk issued in January or February since January 21, 1999, continuing to present, with the other being January 22, 2017.
March 15 2008 Georgia, South Carolina[245] 44
EF3
 100 mph (160 km/h)† 2 2008 Atlanta tornado outbreak – Forty-four tornadoes were confirmed; three were rated EF3.[246]
May 22 2008 Kansas[247] 28
EF3
 100 mph (160 km/h)† 1 Tornado outbreak of May 22–27, 2008 – Twenty-eight tornadoes were confirmed; one was rated EF3.[248]
May 29 2008 Nebraska, Iowa, South Dakota[249] 37
EF3
 85 mph (137 km/h)† 0 List of United States tornadoes in May 2008#May 29 event – Thirty-seven tornadoes were confirmed; two were rated EF3.[250]
June 5 2008 Midwest[251] 40
EF2
 100 mph (160 km/h)† 0 Tornado outbreak sequence of June 3–11, 2008 – Also including a 60% significant severe wind probability which meets high risk standards. Forty tornadoes were confirmed; three were rated EF2.[252] 261 damaging wind gusts were reported including 10 hurricane-force which were up to 100mph, though many occurred south of the high risk.[253]
April 10 2009 Alabama, Georgia, Tennessee[254] 62
EF4
 96 mph (154 km/h)† 2 Tornado outbreak of April 9–11, 2009 – Sixty-two tornadoes were confirmed; one was rated EF4.[255]
April 26 2009 Oklahoma, Kansas, Texas[256] 11
EF2
 81 mph (130 km/h)† 0 Eleven tornadoes were confirmed; one was rated EF2.[257] Despite the maintenance of the high risk through the day, the outbreak busted as a whole.
† – Value is estimated

2010–2019

There were no high risk days in 2015, 2016, or 2018.

Storm Prediction Center High Risk Events – 2010–2019[nb 1]
Date Year Region Tornadoes Max rating Peak gust Fatalities Outlook Notes
April 24 2010 Southern U.S.[258] 39
EF4
 120 mph (190 km/h)† 10[259] Tornado outbreak of April 22–25, 2010 – A high risk was issued for a 30% probability of significant tornadoes. There were 39 tornadoes confirmed; two were rated EF4. One of the EF4 tornado was the second (then-first) widest in Mississippi state history, and the fourth-longest tracked in the state. The high risk was discontinued at 0100Z.
April 30 2010 Arkansas[260] 27
EF3
 75 mph (121 km/h)† 1[261] Tornado outbreak of April 30 – May 2, 2010 – A high risk was issued on the first day of the aforementioned outbreak for a 30% probability of significant tornadoes. For only the third known time a high risk was not issued until 0100 UTC (the other two occurrences were March 28, 1991 and May 22, 2004) and was only a slight risk for most of the day. This is the only day in which the area to eventually be in a high risk was not even in a moderate risk until 2000Z. There were 28 tornadoes confirmed; two were rated EF3.
May 1 2010 Middle Mississippi Valley[262] 30
EF3
 83 mph (134 km/h)† 4 Tornado outbreak of April 30 – May 2, 2010 – A high risk was issued on the second day of the aforementioned outbreak for a 30% probability of significant tornadoes. Only 11 weak tornadoes were confirmed during the day, but several strong tornadoes, one of which was rated EF3, occurred overnight. A major flood disaster also occurred from the same storm.
May 10 2010 Oklahoma, Kansas[263] 70
EF4
 100 mph (160 km/h)† 3 Tornado outbreak of May 10–13, 2010 – A high risk was issued on the first day of the aforementioned outbreak for a 30% probability of significant tornadoes. 70 tornadoes were confirmed; two were rated EF4, both of which occurred in the southern suburbs of the Oklahoma City metropolitan area and were responsible for the three fatalities during the outbreak.
May 19 2010 Oklahoma[264] 13
EF1
 70 mph (110 km/h)† 0 Tornadoes of 2010#May 18–21 – A high risk was issued on the second day of the aforementioned outbreak for a 30% probability of significant tornadoes. Only thirteen weak tornadoes, seven of which were rated EF1, were confirmed in the area, but significant flooding occurred from the same storm system. The High Risk was discontinued at 01Z.
October 26 2010 Ohio, Indiana, Illinois, Michigan[265] 43
EF2
 85 mph (137 km/h)† 0 October 2010 North American storm complex – This was a major derecho event. The high risk was based on 60% significant severe wind probability, with a tornado probability of 15% falling short of high risk standards. There were 43 tornadoes confirmed; five were rated EF2. There were also 339 damaging wind reports including 7 hurricane-force gusts up to 85 mph (137 km/h).[266] The high risk was discontinued at 2000Z as the main activity was in the morning and early afternoon.
April 16 2011 North Carolina, Virginia[267] 53
EF3
 81 mph (130 km/h)† 26 Tornado outbreak of April 14–16, 2011 – A high risk was issued on the third day of the aforementioned outbreak for a 30% probability of significant tornadoes. A total of 58 tornadoes were confirmed; six were rated EF3, two of which had path lengths of over 50 miles (80 km) with the first striking Raleigh, North Carolina (albeit at EF1 strength). The high risk was discontinued at 0100Z as the storms had mostly moved off the East Coast.
April 26 2011 South-Central U.S.[268] 55
EF3
 110 mph (180 km/h)† 0 2011 Super Outbreak – A high risk was issued on the second day of the record-setting aforementioned outbreak for a 30% probability of significant tornadoes. There were 55 tornado touch downs during the day; one was rated EF3. Despite the abundance of tornadoes, most of the tornadic activity happened either along and south of the southern part of the high risk area or well to the east in the slight risk area over Alabama.
April 27 2011 Southern U.S.[269] 215
EF5
 100 mph (160 km/h)† 316 2011 Super Outbreak – This was day 3 of the record-setting aforementioned outbreak; this day alone set the record for most tornadoes in a 24-hour period. It was also the deadliest high-risk day on record as well as the deadliest single day outbreak in the United States since the Tri-State tornado outbreak on March 18, 1925. The outlook included a 45% significant tornado area, which is above the minimum threshold for a high risk. It also produced the first known watch (PDS tornado watch 235) with a >95% probability for all severe and significant severe hazards.[270] The tornadoes came in three rounds starting with two damaging morning squall lines followed by an outbreak of large tornadic supercells. The strongest tornadoes occurred in the high risk area while dozens of other tornadoes were confirmed throughout the other risk areas. Three of the tornadoes tracked over 100 miles (160 km), with one of them becoming the deadliest tornado ever recorded in Alabama. Several areas that had experienced tornadoes either from that morning or from other outbreaks earlier that year were struck again as well. There were 215 tornado touch downs; four were rated EF5. An additional F0 tornado was confirmed in Canada.
May 24 2011 Oklahoma, Kansas, Texas[271] 47
EF5
 92 mph (148 km/h)†* 14 Tornado outbreak sequence of May 21–26, 2011 – This was day 4 of the aforementioned outbreak sequence and included a 45% significant tornado area, above minimum high risk threshold. There were 47 tornado touch downs; one was rated EF5. The two EF4 tornadoes that were confirmed that day may have also reached EF5 intensity. The high risk was discontinued at 0100Z.
May 25 2011 Midwest[272] 94
EF4
 100 mph (160 km/h)† 4 Tornado outbreak sequence of May 21–26, 2011 – A high risk was issued on the fifth day of the aforementioned outbreak sequence for a 30% probability of significant tornadoes. A total of 94 tornadoes were confirmed; one was rated EF4; three of the tornadoes were in California, well to the west of the main risk area, although one of them was rated EF2 (the other two were rated EF1). The high risk was discontinued at 0100Z.
March 2 2012 Midwest and Southern U.S.[273] 64
EF4
 86 mph (138 km/h)† 41 Tornado outbreak of March 2–3, 2012 – A high risk was issued on the first day of the aforementioned outbreak for a 30% probability of significant tornadoes. A total of 64 tornadoes were confirmed; two were rated EF4, both of which were produced by the same supercell, which also produced an EF3 tornado. Another EF3 tornado tracked for over 80 miles (130 km) through eastern Kentucky and southwestern West Virginia. The high risk was discontinued at 0100Z.
April 14 2012 Central U.S.[274] 83
EF4
 97 mph (156 km/h) 6 Tornado outbreak of April 13–16, 2012 – This was day 2 of aforementioned outbreak; it was only the second high risk to be issued on Day 2 (the day before the event; first Day 2 high risk was for April 7, 2006) and the first/only to date ever issued on the initial (0600Z) Day 2 outlook.[274] It included 45% tornado probability above minimum threshold of 30%. A total of 83 tornadoes were confirmed; one was rated EF4. The high risk largely busted in most of Oklahoma (except far northern and western) as the brunt of outbreak was focused in Kansas. The high risk was maintained for the entire day in the regions where most of the tornadoes occurred (the southern end was trimmed at 01Z).
June 12 2013 Midwest[275] 19
EF3
 95 mph (153 km/h)† 0 June 12–13, 2013 derecho series – The high risk was driven by 60% significant severe wind probability as the maximum tornado probability was a hatched 15% area, just short of the high risk level. A total of 19 tornadoes were confirmed; one was rated EF3. 278 damaging wind gusts were reported, including 4 hurricane force gusts, though most occurred over Ohio and were outside the high risk.[276] The high risk was discontinued at 01Z.
November 17 2013 Midwest[277] 77
EF4
 100 mph (160 km/h)† 11[278] Tornado outbreak of November 17, 2013 – The high risk was initially issued for a 30% probability of significant tornadoes. This was an unusually far north tornado outbreak and one of only five high risk days during the month of November in recorded history.[279] It was the third latest date in the year a high risk has been issued since 2000 (the second latest was December 23, 2002, in the Deep South), and latest date a high risk has been issued in the Midwest, surpassing previous latest of November 15, 2005. It also included a high-risk level (60% significant severe) wind probability in the 2000Z outlook. In all, 77 tornadoes were confirmed; two were rated EF4. The high risk was discontinued at 0100Z as the storms had moved east of the areas that had been in that risk area.
April 27 2014 Southwestern Arkansas[280] 18
EF4
 90 mph (140 km/h)† 19 Tornado outbreak of April 27–30, 2014 – This was a first day of the aforementioned outbreak. A small high-risk area was issued at the 2000Z outlook that included the cities of Little Rock, Camden, and Danville for a 30% probability of significant tornadoes. An EF4 tornado were confirmed in the area before the high risk was discontinued in a special outlook update at 0230Z. The outlook period as a whole produced 18 tornadoes.[281]
April 28 2014 Alabama, Mississippi[282] 57
EF4
 70 mph (110 km/h)† 16 Tornado outbreak of April 27–30, 2014 – This was the second day of the aforementioned outbreak. A high risk was issued at the 2000Z outlook for a 30% probability of significant tornadoes. Numerous long-tracked and/or strong to violent tornadoes occurred across Mississippi, Alabama, and Tennessee. It was the largest tornado outbreak in central Alabama since April 27, 2011. A total of 57 tornadoes were confirmed during the outlook period; one was rated EF4. The high risk was discontinued at 0100Z.[283]
June 3 2014 Nebraska, Iowa, Missouri[284] 9
EF3
 100 mph (160 km/h)† 0 Tornadoes of 2014#June 3–4 – The high risk was issued at 2000Z for 60% wind probability and potential derecho; tornado probability was 10%, well short of high-risk level. Extreme hail/wind and some tornadoes were reported, although most of the activity remained along or south of the southern part of the high risk. Nine tornadoes were confirmed during the outlook period; one tornado was rated EF3. The high risk was discontinued at 0100Z.
January 22 2017 Georgia, Florida[285] 17
EF3
 75 mph (121 km/h) 7 Tornado outbreak of January 21–23, 2017 – This was the second day of the aforementioned outbreak.  The high risk was issued for a 30% probability of significant tornadoes, primarily in northern Florida and southern Georgia.[286] This was also the first high risk issued under the five-category system (which began in October 2014). There were 17 confirmed tornado touch downs during the outlook period; one tornado, which was rated EF3, traveled over 70 miles (110 km) and was over a 1 mile (1.6 km) wide. There were six fatalities from tornadoes along with one non-tornadic death. The high risk was discontinued at 0100Z.
April 2 2017 Texas, Louisiana[287] 30
EF2
 70 mph (110 km/h) 2 Tornadoes of 2017#April 2–3 – This was the first day of the aforementioned outbreak. The high risk was issued at 1630Z for a 30% probability of significant tornadoes. Although most of the tornado that touched down were relatively weak and short-lived, seven of them were more than 1⁄2 mi (0.80 km) wide, including one that reached a peak width of just over 1+1⁄4 mi (2.0 km) wide, and multiple tornado emergencies were issued. 30 tornadoes were confirmed during the outlook period; six of them were rated EF2. The high risk was discontinued at 0100Z.[288]
April 5 2017 Georgia, South Carolina[289] 26
EF2
 80 mph (130 km/h) 0 Tornadoes of 2017#April 4–6 – This was the second day of the aforementioned outbreak. The high risk was issued for a 30% probability of significant tornadoes. A total of 26 tornadoes were confirmed during the outlook period, four of which were rated EF2, although the tornadoes were mostly scattered throughout the risk areas rather than being concentrated within the high-risk area. One EF2 tornado in Georgia did prompt the issuance of a tornado emergency. The high risk was discontinued at around 0100Z.[290]
May 18 2017 Kansas, Oklahoma[291] 58
EF2
 104 mph (167 km/h) 0 Tornado outbreak sequence of May 15–20, 2017 – This was day 4 of the outbreak sequence. The high risk was issued for a 30% probability of significant tornadoes. The outbreak was widely anticipated with a Moderate risk originally being issued on Day 2. A total of 58 tornadoes were confirmed during the outlook period, three of which were rated EF2. However, only weak, scattered tornadoes were reported in the high-risk area, which saw a large plume of heavy convective rainfall when the most favorable tornado parameters arrived; the strongest tornadoes occurred to the east of that area. The high risk was discontinued at 01Z.[292]
May 20 2019 Oklahoma, Texas[293] 51
EF3
 94 mph (151 km/h) 0 Tornado outbreak sequence of May 2019 – This was day 4 of the outbreak sequence. The high risk was initially issued for a 30% probability of significant tornadoes; this risk area was subsequently expanded and upgraded at 1626Z to a 45% probability of significant tornadoes, exceeding the minimum high-risk criteria. This high risk produced the second known tornado watch with a >95% chance of all hazards (PDS Tornado Watch 199).[294] The event did not quite live up to the high parameters that were in place for the day due to the cap being stronger than anticipated over the warm sector, which was displaced from the upper-level jet. However, 50 tornadoes were confirmed during the outlook period, one of which was rated EF3 (one of the tornadoes was well outside of the risk area in Arizona). The high risk lasted for the entire outlook period, although it was only maintained in a very small region at 01Z, where parameters remained the most favorable.[295]
† – Value is estimated
* – Peak wind gust of 151 mph (243 km/h) measured during the EF5 El Reno tornado

2020–present

There were no high risk days in 2020 or 2022.

Storm Prediction Center High Risk Events – 2020–2023[nb 1]
Date Year Region Tornadoes[nb 3] Max rating Peak gust Fatalities Outlook Notes
March 17 2021 Mississippi, Alabama, Louisiana, Arkansas[296] 40
EF2
 64 mph (103 km/h) 0 Tornado outbreak of March 16–18, 2021 – This was day 2 of the outbreak. The high risk was initially issued for a 30% hatched area for tornadoes; this was upgraded to a 45% hatched area for tornadoes at 1606Z. A total of 40 tornadoes were confirmed during the outlook period, four of which were rated EF2, although little tornado activity occurred within the 45% risk area.[297]
March 25 2021 Mississippi, Alabama, Tennessee[298] 20
EF4
 105 mph (169 km/h) 7 Tornado outbreak sequence of March 24–28, 2021 – This was day 2 of the outbreak sequence. The high risk was issued for a 30% hatched area for tornadoes. A PDS tornado watch was issued, with a >95% chance for both tornadoes and strong tornadoes, and high probabilities for most other categories. Multiple tornado emergencies were issued for at least three different tornadoes. The high risk was discontinued at 01z and downgraded to an Enhanced risk as the storm system began weakening and the supercells began dying off, although the strongest tornado, which was rated EF4, took place a few hours after that time. A total of 20 tornadoes were confirmed during the outlook period.[299]
March 31 2023 Upper and Lower Mississippi Valleys[300] 136
EF4
 83 mph (134 km/h) 23 Tornado outbreak of March 31 – April 1, 2023 – Two high risk zones were issued at 1630Z with 30% hatched areas for tornadoes. The northern of the two zones was discontinued at 01Z. Multiple tornado emergencies and mass causality events were issued during the outbreak. A total of 136 tornadoes were confirmed the outlook period, one of which was rated EF4. This was the first instance of two separate high-risk areas since the initial 06Z outlook on April 14, 2012. This was also the deadliest high-risk day since March 2, 2012.

See also

Notes

  1. 1 2 3 4 5 All values include events that took place outside the high-risk area(s). Tornado and fatality totals only include incidents that occurred on the respective high risk days. Fatality totals only include direct tornadic deaths.
  2. ↑ Starting on February 1, 2007, the Fujita Scale was replaced with the Enhanced Fujita Scale for rating tornadoes.
  3. ↑ This number reflects the number of tornadoes during the outlook period between 12Z on the day of the high risk to 12Z the next day.

References

  1. ↑ Chris Hayes Novy (March 25, 2010). "SPC and its Products: Convective Outlooks". Storm Prediction Center. National Oceanic and Atmospheric Administration. Retrieved June 15, 2013.
  2. ↑ "SPC Products". www.spc.noaa.gov.
  3. ↑ "Notable Weather Events of 2022". National Weather Service. Retrieved 3 January 2023.
  4. ↑ Weiss, Steven; Wilson, Larry; Edwards, Roger (22 December 2020). "In Memoriam: Robert H. Johns 1942 – 2020". National Weather Association. Retrieved 3 January 2023.
  5. ↑ Herzmann, Daryl. "IEM :: SWO from NWS MKC". mesonet.agron.iastate.edu. Retrieved 2020-12-22.
  6. ↑ Herzmann, Daryl. "IEM :: SWO from NWS MKC". mesonet.agron.iastate.edu. Retrieved 2020-12-22.
  7. ↑ "Tornado History Project: March 27, 1984". www.tornadohistoryproject.com. Retrieved 2020-12-22.
  8. ↑ Badgett, Phillip; Smith, Barrett; Blaes, Jonathan; Gonski, Rod & Keeter, Kermit (March 18, 2009). "March 28, 1984 Carolina's Tornado Outbreak". National Weather Service Office in Raleigh, North Carolina. North Carolina State University. Retrieved June 18, 2013.
  9. ↑ Herzmann, Daryl. "IEM :: SWO from NWS MKC". mesonet.agron.iastate.edu. Retrieved 2020-12-22.
  10. ↑ "March 28, 1984 Tornado List". National Climatic Data Center. Tornado History Project. 2013. Retrieved June 17, 2013.
  11. ↑ Herzmann, Daryl. "IEM :: SWO from NWS MKC". mesonet.agron.iastate.edu. Retrieved 2020-12-22.
  12. ↑ "Tornado History Project: April 26, 1984". www.tornadohistoryproject.com. Retrieved 2020-12-22.
  13. ↑ Herzmann, Daryl. "IEM :: SWO from NWS MKC". mesonet.agron.iastate.edu. Retrieved 2020-12-22.
  14. ↑ "Tornado History Project: April 29, 1984". www.tornadohistoryproject.com. Retrieved 2020-12-22.
  15. ↑ Click, Terry; Figurskey, Darin; Hartfield, Gail; McLamb, Bradley; Orrock, Jeff; Sharp, Scott; Smith, Barrett; Vincent, Brandon; Blaes, Jonathan; Wrenn, Rachel & Andersen, Lindsey (February 3, 2012). "April 16, 2011 North Carolina Tornado Outbreak". National Weather Service Office in Raleigh, North Carolina. North Carolina State University. Retrieved June 18, 2013.
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