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List of Storm Prediction Center high risk days

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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

[edit]

1982–1989

[edit]

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. This was and remained the deadliest official High Risk day (since SELS/SPC High Risk outlooks began) for over 27 years, surpassed by the Super Outbreak of April 27, 2011.[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] 9
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.[citation needed] 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

[edit]

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 29 1991 Alabama, Florida, Georgia, North Carolina, South Carolina, Virginia[92] 21
F3
0 Twenty-one tornadoes were confirmed; one was rated F3.[93]
April 11 1991 Oklahoma, Kansas, Texas[94] 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.[95]
April 12 1991 Oklahoma, Kansas, Texas[69] 24
F3
0 Twenty-four tornadoes were confirmed; two were rated F3.[96]
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.[97]
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.[98] Thirteen tornadoes were confirmed; two were rated F2.[99]
April 19 1992 Arkansas, Louisiana, Oklahoma, Texas[100] 4
F1
0 Four weak tornadoes were confirmed; three were rated F1.[101]
June 16 1992 Midwest[102] 65
F5
1 Mid-June 1992 tornado outbreak – Sixty-five tornadoes were confirmed; one was rated F5.[103]
June 17 1992 Great Lakes[104] 28
F3
0 Mid-June 1992 tornado outbreak – Twenty-eight tornadoes were confirmed; one was rated F3.[105]
June 19 1992 Arkansas, Kansas, Louisiana, Oklahoma, Texas[106] 17
F1
0 Seventeen tornadoes were confirmed; three were rated F1.[107] Only the 1900 UTC outlook included a high risk.
July 2 1992 Arkansas, Illinois, Iowa, Kansas, Missouri, Oklahoma, Wisconsin[108] 16
F3
0 Sixteen tornadoes were confirmed; one was rated F3.[109]
September 9 1992 Illinois, Indiana, Kansas, Missouri[110] 4
F1
0 Only high risk ever issued in September. Squall line with damaging winds and some large hail.[111] Four weak tornadoes were confirmed; one was rated F1.[112]
April 19 1993 Arkansas, Illinois, Kentucky, Missouri, Tennessee[113] 6
F2
0 Six tornadoes were confirmed; one was rated F2.[114]
June 3 1993 Arkansas, Illinois, Kansas, Kentucky, Missouri, Oklahoma, Tennessee[115] 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[116] 13
F1
80 mph (130 km/h) 0 Major derecho event.[117] 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.[118] Thirteen tornadoes were confirmed; six were rated F1.[119] Only the 1900 UTC outlook had a high risk.
June 7 1993 Upper Midwest[120] 40
F4
0 Forty tornadoes were confirmed; two were rated F4.[121]
June 8 1993 Great Plains, Upper Midwest[122] 58
F3
0 Fifty-eight tornadoes were confirmed; one was rated F3.[123]
June 23 1993 Kansas, Nebraska[124] 3
F2
0 Only three tornadoes were confirmed; one was rated F2.[125]
July 3 1993 Iowa, Minnesota, Nebraska, North Dakota, South Dakota[126] 13
F1
0 Thirteen weak tornadoes were confirmed; four were rated F1.[127]
March 27 1994 Southern U.S.[128] 29
F4
40 1994 Palm Sunday tornado outbreak – Twenty-nine tornadoes were confirmed; two were rated F4.[129] Only the 1900 UTC outlook included a high risk.
April 25 1994 Central U.S.[130] 28
F4
3 Tornado outbreak of April 25–27, 1994 – Twenty-eight tornadoes were confirmed; one was rated F4.[131] In addition, there were numerous large hail reports, with hail reaching 4.50".[132]
June 14 1994 Michigan, Minnesota, Wisconsin[133] 3
F1
0 Three weak tornadoes were confirmed; one was rated F1.[134] Only the 1200 UTC outlook included a high risk.
August 27 1994 Iowa, Michigan, Minnesota, Nebraska, South Dakota, Wisconsin[135] 12
F3
4 Only high risk ever issued in August.[citation needed] Twelve tornadoes were confirmed; two were rated F3.[136] The same system also produced an F4 in Turtle Mountain, Manitoba in Canada.
November 27 1994 Southern U.S.[137] 18
F3
6 Eighteen tornadoes were confirmed; four were rated F3.[138]
April 17 1995 Oklahoma, Texas 21
F2
0 Primarily a derecho event. Twenty-one tornadoes were confirmed; two were rated F2.[139]
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.[140]
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.[141]
May 13 1995 Ohio Valley 26
F4
3 Tornado outbreak sequence of May 6–27, 1995 – Included a major derecho.[citation needed] Twenty-six tornadoes were confirmed; two were rated F4.[142]
May 17 1995 Oklahoma 9
F3
0 Tornado outbreak sequence of May 6–27, 1995. Nine tornadoes were confirmed; one was rated F3.[143]
March 18 1996 Alabama, Florida, Georgia, Mississippi, South Carolina[144] 21
F3
0 Twenty-one tornadoes were confirmed; one was rated F3.[145]
April 19 1996 Illinois, Indiana, Missouri, Kentucky[146][147] 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.[148]
March 2 1997 Alabama, Louisiana, Mississippi[149] 2
F0
0 Two weak and short lived tornadoes were confirmed.[150] 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.[citation needed] Eight tornadoes were confirmed; two were rated F3.[151]
July 1 1997 Upper Mississippi Valley 20
F3
109 mph (175 km/h) 0 Moderate tornado outbreak reorganized into a progressive derecho.[citation needed] Twenty tornadoes were confirmed; one was rated F3. High Risk was discontinued at 02Z.[152]
October 25 1997 Arkansas, Louisiana, Mississippi, Oklahoma, Texas[153] 9
F1
0 Nine tornadoes were confirmed; four were rated F1.[154] Only the 1900 UTC outlook included a high risk.
February 10 1998 Alabama, Louisiana, Mississippi, Texas 11
F1
135 mph (217 km/h) 0 High Risk issued 15Z and discontinued 02Z. Rare winter serial derecho.[citation needed] Eleven tornadoes were confirmed; five were rated F1.[155]
April 8 1998 Alabama[156] 14
F5
92 mph (148 km/h) 35 Tornado outbreak of April 6–9, 1998 – High Risk lasted the entire outlook cycle. F5 damage in suburban Birmingham. Fourteen tornadoes were confirmed; one was rated F5.[157]
April 15 1998 Middle Mississippi Valley 21
F4
75 mph (121 km/h) 2 Tornado outbreak of April 15–16, 1998 – High Risk issued 12Z and discontinued 02Z. Day 1 of outbreak. Twenty-one tornadoes were confirmed; one was rated F4.[citation needed]
April 16 1998 Tennessee 41
F5
98 mph (158 km/h) 10 Tornado outbreak of April 15–16, 1998 – High Risk issued 15Z and subsequently maintained. Day 2 of outbreak. Forty-one tornadoes were confirmed; one was rated F5.[158]
May 9 1998 Arkansas, Mississippi, Tennessee[159] 5
F1
0 Five weak tornadoes were confirmed; one was rated F1.[160] Only the 1930 UTC outlook included a high risk.
May 31 1998 Northeastern U.S.[161][162][163][164] 42
F3
128 mph (206 km/h) 1 Late-May 1998 tornado outbreak and derecho – Only high risk ever issued in the Northeast (although it was discontinued and reduced to Moderate Risk at 1930Z, following a morning remnant derecho but prior to/concurrent with occurrence of afternoon into overnight severe weather outbreak).[citation needed] Forty-two tornadoes were confirmed; six were rated F3.[165]
June 14 1998 Ohio Valley 22
F1
92 mph (148 km/h) 0 High Risk was issued 15Z and discontinued 02Z. Followed by a progressive derecho.[citation needed] Twenty-two tornadoes were confirmed; six were rated F1.[166]
January 21 1999 Arkansas[167][168] 82
F4
8 Tornado outbreak of January 21–23, 1999 – High Risk was maintained through the day. Second earliest date that a high risk was issued.[citation needed] Eighty-two tornadoes were confirmed; one was rated F4.[169]
March 8 1999 Arkansas, Louisiana, Texas 10
F2
0 High Risk was issued 13Z and discontnued 01Z. Few tornadoes with some scattered hail and wind[citation needed]
April 8 1999 Iowa, Missouri, Illinois 47
F4
2 Tornado outbreak of April 8–9, 1999 – High Risk was maintained through the day. Fifty-four tornadoes were confirmed; three were rated F4. Some occurred overnight, outside the 01Z High Risk area.
May 3 1999 Oklahoma, Kansas[170] 73
F5
46 1999 Oklahoma tornado outbreak – High Risk was issued at 20Z and maintained thereafter. Highest winds ever recorded in a tornado, 301 mph (484 km/h);[171] seventy-three tornadoes were confirmed, including three F4s and one F5.
May 4 1999 Oklahoma, Arkansas, Texas[170] 43
F3
1 1999 Oklahoma tornado outbreak – High Risk was issued 06Z and discontinud at 01Z. Day 2 of outbreak
May 5 1999 Southern U.S. 15
F4
3 1999 Oklahoma tornado outbreak – High Risk was issued 13Z and discontinued 01Z. Only streak of three consecutive High Risk days continuing to-date (2024). Major derecho event.[citation needed]
June 5 1999 South Dakota, Nebraska[172] 21
F1
0 High Risk was maintained throughout the day; however, event failed to consolidate with only isolated tornadoes and scattered severe wind reported. A shortwave ridge maintained a capping inversion.[173]

2000–2009

[edit]

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[174] 6
F2
124 mph (200 km/h) 1 Tornadoes of 2001#April 6–7 – The high risk was issued at 0600Z and discontinued at 0100Z. A serial derecho formed, producing widespread wind damage. 162 damaging wind gusts were reported, including 12 hurricane force.[175] One person was killed by lightning in Ohio. Six tornadoes were also confirmed; two were rated F2.[176]
April 11 2001 Eastern Iowa, Southern Wisconsin, and northwest Illinois[177] 33
F3
92 mph (148 km/h) 3 Tornado outbreak of April 10–11, 2001 – The high risk was issued at 1630Z and discontinued at 0000Z. Three people were killed by tornadoes. The event also featured the costly Tri-State hailstorm on the prior day. Thirty-three tornadoes were confirmed; one was rated F3.[178]
June 11 2001 Southern Minnesota, Northeastern Iowa, and West-Central Wisconsin[179] 29
F2
120 mph (190 km/h) 2 Tornadoes of 2001#June 11–13 – The high risk was issued at 2000Z. A progressive derecho produced widespread wind damage, including a measured thunderstorm wind gust of 120 miles per hour (193 km/h) near Atwater, Minnesota. 194 damaging wind gusts were reported, including 5 hurricane force.[180] Twenty-nine tornadoes were also 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. One of the tornadoes in Florida killed one person.[181]
October 13 2001 U.S. Gulf Coast[182] 32
F3
112 mph (180 km/h) 1 The high risk was issued for only the 2000Z update. Thirty-two tornadoes were confirmed; one was rated F3. One person was killed by straight-line winds in Illinois.[183]
October 24 2001 Midwest[184] 25
F3
104 mph (167 km/h) 3 Tornadoes of 2001#October 24 – The high risk was maintained throughout the entire day. A significant tornado event was concentrated mostly in northern portions of the High Risk area, with nearly the entire High Risk area also experiencing 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 446 damaging wind gusts were reported across 18 states, including 2 hurricane force.[186]
April 16 2002 Upper Midwest[187] 14
F3
85 mph (137 km/h) 1 The high risk was issued at 0600Z update; it was removed at 2000Z outlook update due to concern over the extent of how favorable conditions would be for severe weather. However, the initiation of the most intense severe weather occurred after that time. Fourteen tornadoes were confirmed; one was rated F3. Widespread hail damage occurred and one person was killed by straight-line winds in Kansas.[188]
July 31 2002 Minnesota, Wisconsin[189] 3
F0
75 mph (121 km/h) 0 Only the 0600Z outlook included a high risk, which was for a significant wind event instead of tornadoes. This is the second consecutive High Risk issuance to be downgraded to a Moderate Risk before the expected onset of the highest severe weather potential; such a downgrade remains rare as of 2024. It is also the most recent use of a High Risk during the July through September period (typically a mid and late summer into very early fall minimum for such outlooks). No fatalities took place.[190] Three weak tornadoes were confirmed.[191]
November 10 2002 Midwest and Southern U.S.[192] 67
F4
100 mph (160 km/h) 31 Tornado outbreak of November 9–11, 2002 – This was the second and most intense day of a late fall tornado outbreak. The high risk was maintained throughout the entire day and is the only time since 1990 in which a fall High Risk was issued in back to back years (see October 24, 2001). The issuance of a High Risk at the initial 06Z Day 1 Outlook notably followed a Day 2 Outlook for the same period that did not contain a Moderate Risk area, as both Day 2 outlooks issued the day before included only an enhanced Slight Risk. This is the last time such an event has occurred as of 2024. Sixty-one tornadoes were confirmed; one was rated F4 (in Northwest Ohio, outside the high-risk area, where an concentrated outbreak of tornadoes also materialized – however a slightly separated tornado outbreak also occurred within the High Risk area, with the strongest tornadoes within the high-risk tornado outbreak area being rated F3). Thirty-one people were killed during the outlook period.[193] [194]
December 23 2002 Texas, Louisiana[195] 15
F1
70 mph (110 km/h) 0 Tornadoes of 2002#December 23–24 – One of only two high-risk ever issued in December and second latest in the year (first was December 24, 1982). The high risk was maintained throughout the entire day for both widespread wind damage and isolated strong tornadoes, but the day busted as a whole.[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 Tornadoes of 2003#April 4–7 – The High Risk was issued at 1630Z and subsequently maintained. 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 – The High Risk was issued at 13Z and subsequently maintained. 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 – The High Risk was issued at 1630Z and discontinued at 01Z. 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 – The High Risk was issued at 1630Z and expanded southward at 20Z, then fully discontinued at 01Z. Forty-five tornadoes were confirmed; one was rated F4 (occurring in the area not upgraded to a High Risk until 20Z).[205]
May 10 2003 Central U.S.[206] 49
F3
92 mph (148 km/h) 0 May 2003 tornado outbreak sequence – The High Risk was issued at 13Z and subsequently maintained. 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 The High Risk spanned the entire Day 1 Outlook cycle. This day capped the only occurrence since 1994 of five High Risk days in a calendar month. Forty-seven tornadoes were confirmed; seven were rated F2.[209]
March 4 2004 Texas, Oklahoma[210] 25
F2
91 mph (146 km/h) 0 The High Risk was issued at 1630Z and discontinued at 01Z. Reorganized into a large serial derecho[citation needed] 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] This is the first time a High Risk did not appear until the 01Z outlook within an outlook cycle, which has occurred one additional time since (on April 30, 2010).
May 24 2004 Nebraska, Iowa[214] 54
F2
104 mph (167 km/h) 1 May 2004 tornado outbreak sequence – The High Risk lasted the entire Day 1 Outlook cycle. Also a major derecho event.[citation needed] Included a 45% sig risk for damaging winds, meeting High Risk criteria (for the time). Fifty-four tornadoes were confirmed; two were rated F2.[215] 128 damaging wind gusts were reported, including 3 hurricane force.[216]
May 29 2004 Central U.S.[217] 80
F4
90 mph (140 km/h) 3 May 2004 tornado outbreak sequence – The High Risk lasted the entire Day 1 Outlook cycle. Eighty tornadoes were confirmed; one was rated F4.[218]
May 30 2004 Central U.S.[219] 86
F3
120 mph (190 km/h) 2 May 2004 tornado outbreak sequence – For the second consecutive May and the last occurrence to-date (2024), a fourth High Risk day was issued in an eight-day period. The High Risk lasted the entire Day 1 Outlook cycle. Eighty-six tornadoes were confirmed; two were rated F3.[220] Included 35% tornado risk area above minimum threshold of 25%.
April 11 2005 Louisiana, Mississippi[221] 3
F0
86 mph (138 km/h) 0 Only the 1630Z outlook had a High Risk. Three weak tornadoes were confirmed.[222]
June 4 2005 Central U.S.[223] 44
F2
81 mph (130 km/h) 0 The High Risk was issued at 13Z and discontinued at 01Z. Forty-four tornadoes were confirmed; one was rated F2.[224]
November 15 2005 Midwest and Southern U.S.[225] 49
F4
98 mph (158 km/h) 1 Mid-November 2005 tornado outbreak – The High Risk lasted the entire outlook cycle. Forty-nine tornadoes were confirmed; one was rated F4. This was the only violent tornado to be recorded in 2005.[226]
March 12 2006 Midwest[227] 59
F4
107 mph (172 km/h) 8 Tornado outbreak sequence of March 9–13, 2006 – The High Risk lasted the entire outlook cycle. Fifty-nine tornadoes were confirmed; one was rated F4.[228] One supercell storm tracked nearly 800 miles from Oklahoma to Michigan, producing many tornadoes along its path.
April 6 2006 Nebraska, Kansas[229] 12
F2
82 mph (132 km/h) 0 Tornado outbreak of April 6–8, 2006 – The High Risk was issued at 13Z and subsequently maintained. Twelve tornadoes were confirmed; one was rated F2.[230]
April 7 2006 Southern U.S.[231] 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.[232] 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 the High Risk persisted for the entire Day 1 Outlook cycle. This aforementioned Day 2 High Risk produced the first/only instance to date (2024) where a high risk was simultaneously in effect for both Day 1 (April 6) and Day 2. Forty-seven tornadoes were confirmed; two were rated F3.[233]
March 1 2007 Southern U.S.[234] 36
EF4
81 mph (130 km/h) 20 Tornado outbreak of February 28 – March 2, 2007 – The High Risk was issued 06Z and discontinued 01Z. Thirty-six tornadoes were confirmed; two were rated EF4.[235]
April 13 2007 Texas[236] 7
EF1
81 mph (130 km/h) 1 April 2007 nor'easter – The High Risk was issued at 20Z and subsequently maintained. However, only seven tornadoes were confirmed; one was rated EF1.[237]
April 24 2007 Texas[238] 23
EF3
90 mph (140 km/h) 7 Tornado outbreak sequence of April 20–27, 2007 – The High Risk was issued at 20Z and subsequently maintained. 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.[239]
May 5 2007 Nebraska, Kansas[240] 90
EF3
100 mph (160 km/h) 1 Tornado outbreak of May 4–6, 2007 – The High Risk was issued at 13Z and subsequently maintained. Ninety tornadoes were confirmed; two were rated EF3. Notably, an EF5 tornado related to the same system also occurred the day before, which was a Moderate Risk day. [241]
June 7 2007 Upper Midwest[242] 12
EF3
81 mph (130 km/h) 0 The High Risk was issued at 06Z and discontinued at 01Z. Reorganized into a moderate wind event.[citation needed] Included a 60% sig risk for damaging winds for the 1200z outlook before being switched back to a 30% sig tornado risk in the 1300z outlook. Twelve tornadoes were confirmed; one was rated EF3.[243] 135 damaging gusts were reported. However, the 3 hurricane force wind gusts occurred in Missouri, outside the High Risk.[244]
February 5 2008 Middle Mississippi Valley[245] 63
EF4
100 mph (160 km/h) 48 2008 Super Tuesday tornado outbreak – The High Risk was issued at 13Z and subsequently maintained. Sixty-three tornadoes were confirmed; three were rated EF4. [246] 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[247] 44
EF3
100 mph (160 km/h) 2 2008 Atlanta tornado outbreak – Only the 20Z outlook had a High Risk area. Forty-four tornadoes were confirmed; three were rated EF3.[248]
May 22 2008 Kansas[249] 28
EF3
100 mph (160 km/h) 1 Tornado outbreak of May 22–27, 2008 – The High Risk was issued at 20Z and subsequently maintained. Twenty-eight tornadoes were confirmed; one was rated EF3.[250]
May 29 2008 Nebraska, Iowa, South Dakota[251] 37
EF3
85 mph (137 km/h) 0 List of United States tornadoes in May 2008#May 29 event – The High Risk was issued at 1630Z and discontinued at 01Z. Thirty-seven tornadoes were confirmed; two were rated EF3.[252]
June 5 2008 Midwest[253] 40
EF2
100 mph (160 km/h) 0 Tornado outbreak sequence of June 3–11, 2008 – The High Risk was issued at 13Z and subsequently maintained. Also including a 60% significant severe wind probability which meets high risk standards. Forty tornadoes were confirmed; three were rated EF2.[254] 261 damaging wind gusts were reported including 10 hurricane-force which were up to 100 mph, though many occurred south of the high risk.[255]
April 10 2009 Alabama, Georgia, Tennessee[256] 62
EF4
96 mph (154 km/h) 2 Tornado outbreak of April 9–11, 2009 – Only the 20Z outlook had a High Risk. Sixty-two tornadoes were confirmed; one was rated EF4.[257]
April 26 2009 Oklahoma, Kansas, Texas[258] 11
EF2
81 mph (130 km/h) 0 Eleven tornadoes were confirmed; one was rated EF2.[259] The High Risk was issued at 1630Z and, despite the maintenance of the high risk through the rest of the day, the outbreak busted as a whole.
† – Value is estimated

2010–2019

[edit]

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.[260] 39
EF4
120 mph (190 km/h) 10[261] Tornado outbreak of April 22–25, 2010 – A high risk was issued at 06Z 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 strongest tornadoes were in/near the High Risk area. The high risk was discontinued at 0100Z.
April 30 2010 Arkansas[262] 27
EF3
75 mph (121 km/h) 1[263] 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 second known time a high risk was not issued until 0100 UTC (the other occurrence May 22, 2004). The eventual High Risk area was only in an enhanced slight risk prior to 20Z. This is the only day in which the entire 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[264] 30
EF3
83 mph (134 km/h) 4 Tornado outbreak of April 30 – May 2, 2010 – A high risk was issued at 13Z on the second day of the aforementioned outbreak for a 30% probability of significant tornadoes, and was subsequently maintained. Only 11 weak tornadoes were confirmed during the day, but several strong tornadoes, one of which was rated EF3, occurred overnight focused on the eastern portions of the High Risk area and into the bordering Moderate Risk. A major flood disaster also occurred from the same storm.
May 10 2010 Oklahoma, Kansas[265] 70
EF4
100 mph (160 km/h) 3 Tornado outbreak of May 10–13, 2010 – A high risk lasted the entire outlook cycle on the first day of the aforementioned outbreak for a 30% probability of significant tornadoes. There were 70 tornadoes confirmed; two were rated EF4, both of which occurred around the west edge of the High Risk in the southern suburbs of the Oklahoma City metropolitan area and were responsible for the three fatalities during the outbreak.
May 19 2010 Oklahoma[266] 13
EF1
70 mph (110 km/h) 0 Tornadoes of 2010#May 18–21 – A high risk was issued at 1630Z on the second day of the aforementioned outbreak for a 30% probability of significant tornadoes. Overall, the event busted, only 13 weak tornadoes, seven of which were rated EF1, were confirmed in the area, although significant flooding occurred from the same storm system. The High Risk was discontinued at 01Z.
October 26 2010 Ohio, Indiana, Illinois, Michigan[267] 43
EF2
85 mph (137 km/h) 0 October 2010 North American storm complex – This was a major derecho event.[citation needed] The high risk was issued at 06Z 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 (many inside the High Risk) up to 85 mph (137 km/h).[268] The high risk was discontinued at 2000Z as the squall line was most intense in the morning and early afternoon.
April 16 2011 North Carolina, Virginia[269] 53
EF3
81 mph (130 km/h) 26 Tornado outbreak of April 14–16, 2011 – A high risk was issued at 1630Z 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.[270] 55
EF3
110 mph (180 km/h) 0 2011 Super Outbreak – A high risk was issued at 13Z and subsequently maintained on the second day of the record-setting aforementioned outbreak for a 30% probability of significant tornadoes. In the 1630z outlook, the wind risk was also upgraded to 60%, which meets high risk criteria.[271] There were 55 tornado touch downs during the day; one was rated EF3. 390 damaging wind gusts were also reported, including 5 hurricane gusts. Despite the abundance of tornadoes and wind reports, most of the severe 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. Additionally, on the previous day (April 25, the first day of this sequence), a Moderate Risk was in effect simultaneously for that day (the 25th), in anticipation for this day (the 26th; Day 2 outlook), and also in anticipation for the following day (April 27; Day 3 outlook; which turned into an extremely destructive and record setting High Risk day - see below). This is the only known simultaneous occurrence of Day 1, 2, and 3 Moderate Risk outlooks.
April 27 2011 Southern U.S.[272] 215
EF5
100 mph (160 km/h) 316 2011 Super Outbreak – The High Risk lasted the entire Day 1 Outlook cycle. 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 that was introduced at 1630Z (the first instance of a 45% area being added prior to the 20Z outlook), 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.[273] The tornadoes came in three rounds starting with two damaging morning squall lines followed by an outbreak of large tornadic supercells. The strongest (violent EF4/EF5) tornadoes occurred in the high-risk area (many in/near the 45% probability) 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 touchdowns; four were rated EF5. An additional F0 tornado was confirmed in Canada.
May 24 2011 Oklahoma, Kansas, Texas[274] 47
EF5
92 mph (148 km/h)†* 14 Tornado outbreak sequence of May 21–26, 2011 – The High Risk was issued at 06Z and discontinued at 01Z. This was day 4 of the aforementioned outbreak sequence and included a 45% significant tornado area, above the minimum high-risk threshold. There were 47 tornado touchdowns; one (occurring within the High Risk over Oklahoma) was rated EF5. This EF5 occurred only two days after the devastating Joplin EF5 from the same overall storm sequence (which was on a Moderate Risk day). 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[275] 94
EF4
100 mph (160 km/h) 4 Tornado outbreak sequence of May 21–26, 2011 – A high risk was issued at 13Z on the fifth day of the aforementioned outbreak sequence for a 30% probability of significant tornadoes. A total of 94 tornadoes were confirmed; one (which occurred inside of the High Risk) was rated EF4; three of the tornadoes were in California, well to the west of the main risk area. The high-risk was discontinued at 0100Z.
March 2 2012 Midwest and Southern U.S.[276] 64
EF4
86 mph (138 km/h) 41 Tornado outbreak of March 2–3, 2012 – A high risk was issued at 13Z 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, all within the High Risk area. 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.[277] 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.[277] It included 45% tornado probability above minimum threshold of 30%. This was the only day to have a 45% tornado area in its 06Z Day 1 Outlook (although that 45% area was north of most of the tornadoes; by 20Z the 45% area had been shifted southward and covered the region that ultimately saw the most/densest tornado activity). 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 1 cycle (in addition to both Day 2 outlooks) in the regions where most of the tornadoes including the strongest tornadoes occurred (the southern end of the High Risk, which lacked storms due to capping until well into the night when a moderate squall line developed along the cold front as it overtook the dryline, was trimmed back to a Moderate Risk at 01Z).
June 12 2013 Midwest[278] 19
EF3
95 mph (153 km/h) 0 June 12–13, 2013 derecho series – This is the latest date of a 'spring season' High Risk in the 21st century to date. The high risk was issued at 1630Z 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 east of the high risk and near or after its 01Z discontinuation.[279] The high risk was discontinued at 01Z.
November 17 2013 Midwest[280] 77
EF4
100 mph (160 km/h) 11[281] Tornado outbreak of November 17, 2013 – The high risk was initially issued at 06Z 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 (three since 2000).[282] Many Midwest cities (including Chicago, South Bend, and Fort Wayne) outside the climatologically most frequent High Risk locations experienced their second High Risk day of 2013. It was the second latest date in the year a high risk has been issued since 2000 (the 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 largely in and near the High Risk area; two were rated EF4, both occurring in the western portion of the High Risk area. 579 wind reports were also recorded, including 19 hurricane-force.[283] The high risk was discontinued at 0100Z; by that time, the storms had moved east of the areas that had been in that risk area and weakened slightly, such that a maximum threat of Moderate Risk in areas still downstream was appropriate.
April 27 2014 Southwestern Arkansas[284] 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 risk area before the high risk was discontinued in a special outlook update at 0230Z. The outlook period as a whole produced 18 tornadoes.[285]
April 28 2014 Alabama, Mississippi[286] 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 strongest tornadoes were in or nearby to the High Risk. This is the last occurrence of back to back high risk days for at least a decade (continuing as of May 2024; and three consecutive high risk days have not occurred in 25 years, since May 1999). The high risk was discontinued at 0100Z.[287]
June 3 2014 Nebraska, Iowa, Missouri[288] 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[289] 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 at 13Z for a 30% probability of significant tornadoes, primarily in northern Florida and southern Georgia.[290] This was also the first high risk issued under the five-category system (which began in October 2014), and also the furthest southeast (Florida panhandle) a High Risk has been issued in the 21st century. There were 17 confirmed tornado touchdowns 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[291] 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 tornadoes that touched down were relatively weak and short-lived, seven of them were more than 12 mi (0.80 km) wide, including one that reached a peak width of just over 1+14 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.[292]
April 5 2017 Georgia, South Carolina[293] 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 at 1630Z 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.[294]
May 18 2017 Kansas, Oklahoma[295] 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 at 06Z for a 30% probability of significant tornadoes. 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 area of heavy rain when the most favorable tornado parameters arrived; the strongest tornadoes occurred to the east of that area. The high risk was discontinued at 01Z.[296]
May 20 2019 Oklahoma, Texas[297] 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 at 06Z for a 30% probability of significant tornadoes; this risk area was subsequently expanded and upgraded to a 45% probability of significant tornadoes, exceeding the minimum high-risk criteria at the 1630Z outlook. This high risk produced the second known tornado watch with a >95% chance of all hazards (PDS Tornado Watch 199).[298] The event did not quite live up to the high parameters that were in place for the day with sustained supercells failing to develop in the 45% risk. However, 50 tornadoes were confirmed during the outlook period, many in/near the High Risk area and one of which was rated EF3 (one of the tornadoes was also well outside of the risk area in Arizona). The high risk lasted for the entire outlook period, although the 01Z outlook had only a much smaller High Risk area focusing on one lone supercell.[299]
† – Value is estimated
* – Peak wind gust of 151 mph (243 km/h) measured during the EF5 El Reno tornado

2020–present

[edit]

There were no high-risk days in 2020 or 2022.

Storm Prediction Center High Risk Events – 2020–2024[nb 1]
Date Year Region Tornadoes[nb 3] Max rating Peak gust Fatalities Outlook Notes
March 17 2021 Mississippi, Alabama, Louisiana, Arkansas[300] 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, which lasted the entire Day 1 Outlook cycle, 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.[301]
March 25 2021 Mississippi, Alabama, Tennessee[302] 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 at 06Z 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, and was east of where the High Risk had been in place in earlier outlooks. A total of 20 tornadoes were confirmed during the outlook period.[303]
March 31 2023 Upper and Lower Mississippi Valleys[304] 146
EF4
85 mph (137 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, whereas the southern zone was subsequently maintained. Multiple tornado emergencies and mass causality events were issued during the outbreak. A total of 136 tornadoes were confirmed during the outlook period, one of which was rated EF4 and occurred in the northern High Risk area prior to its 01Z removal. This was the first instance of two separate high-risk areas since the initial 06Z outlook on April 14, 2012, and the first time in the 21st century in which the 1630Z and 20Z outlooks had separate high-risk zones. This was also the deadliest high-risk day since March 2, 2012.[citation needed]
May 6 2024 Oklahoma, Kansas[305] 47
EF4
82 mph (132 km/h) 2[306] Tornado outbreak of May 6–10, 2024 - A high-risk zone was issued at the 13Z outlook and subsequently maintained for a 30% hatched area for tornadoes.[305][307] 47 tornadoes were confirmed, including a violent EF4 tornado that struck Barnsdall and Bartlesville, Oklahoma after dark, occurring within the High Risk area in the 01Z outlook update and killing two people. However, all of the other tornadoes were weak, and the southern portion of the High Risk generally lacked tornado reports.

See also

[edit]

Notes

[edit]
  1. ^ a b c d e 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

[edit]
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