In 2018, the first draft version of the IF-scale, version 0.10 was published. This version was based on a 12-step rating scale. Over the next few years, dozens of tornadoes would be rated on this version of the scale. Most notably, the 2021 South Moravia tornado received a rating (IF4) and full damage survey on the IF-scale conducted by ESSL, the Czech Hydrometeorological Institute and four other organizations.[2] On May 6, 2023, version 0.99.9d was published, which changed it to a 9-step rating scale.[3] In late July 2023, the first official version of the IF scale was published.[4]
The 12 categories for the International Fujita scale are listed below, in order of increasing intensity. Although the wind speeds and photographic damage examples are updated, which are more or less still accurate. However, for the actual IF-scale in practice, damage indicators (the type of structure which has been damaged) are predominantly used in determining the tornado intensity. The IF-scale steps are defined by a central value and an error. The errors have been estimated to be 30% of the central value, resulting in overlapping speed ranges. The distances between the central values of the steps have been so chosen that the upper bound exceeds the central value of the next step, ensuring a balance between the resolution of the scale and the expected errors. Since ESSL required that the steps be consistent with the original Fujita scale, they introduced steps with – and + suffixes indicating steps one third higher or lower than the central value of the original scale, e.g. F1- equals "F2 - 1⁄3F2" and F2+ equals "F2 + 1⁄3F2". Above F2, such a subdivision was not introduced and only full steps are used.
Scale
Wind speed (Estimated)
mph
km/h
m/s
IF0-
45 ± 14
72 ± 22
20 ± 6
IF0
56 ± 17
90 ± 27
25 ± 7
IF0+
67 ± 20
108 ± 32
30 ± 9
IF1-
70 ± 24
128 ± 38
36 ± 11
IF1
92 ± 28
149 ± 45
41 ± 12
IF1+
106 ± 32
170 ± 51
47 ± 14
IF2-
120 ± 36
193 ± 58
54 ± 16
IF2
135 ± 40
217 ± 65
60 ± 18
IF2+
150 ± 45
241 ± 72
67 ± 20
IF3
182 ± 55
293 ± 88
81 ± 24
IF4
234 ± 70
376 ± 113
105 ± 31
IF5
290 ± 87
466 ± 140
130 ± 39
2023 versionedit
On May 6, 2023, version 0.99.9d was published, which changed it to a 9-step rating scale.[3] In this version, the wind speed damage indicator was introduced, which made it the first tornado intensity and damage scale to use measured wind speeds and Doppler weather radar measured wind speeds.[3] When the first official publication of the IF scale, the 9-step rating scale was kept. It was noted that each scale's wind speed is to be taken with a 20% error margin on each side of the central value.[4] This was done to ensure the lower or upper bound of the overlapping rating came close to the central value of the other rating.[4]
A unique feature of the International Fujita scale compared to the Fujita or Enhanced Fujita scale is a new damage indicator based on measured wind speeds. For the IF scale, only wind speeds measured at or below 10 metres (11 yd) can be used to determine a rating. Doppler weather radar measurements are also able to be used to determine a rating if they are measured within damaging distance. For radar measurements, any readings below 60 metres (66 yd) can be used to determine a rating.[4][3]
Three second measurementedit
For three-second wind speed measurements, it is assumed to be an average of 88.8% of the three-second measurement.[4][3]
Degree of Damage (DoD) / Measured IF# Speed
Three Second Measurement
mph
km/h
m/s
DoD 0 / IF0
42.5–56
69–91
19–25
DoD 0.5 / IF0.5
57–74.5
92–120
26–32
DoD 1 / IF1
73.9–90
119–146
33–40
DoD 1.5 / IF1.5
91–109
147–176
40–49
DoD 2 / IF2
110–129
177–208
50–57
DoD 2.5 / IF2.5
129–156.5
209–242
58–70
DoD 3 / IF3
151–183.9
243–296
68–82
DoD 4 / IF4
184–231
297–373
83–103
DoD 5 / IF5
≥232
≥374
≥104
Two second measurementedit
For two-second wind speed measurements, it is assumed to be an average of 90.9% of the two-second measurement.[4][3]
Degree of Damage (DoD) / Measured IF# Speed
Two Second Measurement
mph
km/h
m/s
DoD 0 / IF0
43.4–58
70–94
20–26
DoD 0.5 / IF0.5
59–74
95–120
27–33
DoD 1 / IF1
75–93
121–150
34–40
DoD 1.5 / IF1.5
93–111.8
150–180
42–50
DoD 2 / IF2
111.8–132
180–213
51–59
DoD 2.5 / IF2.5
133–154
214–248
60–68
DoD 3 / IF3
154–188
249–303
69–84
DoD 4 / IF4
188–237
304–382
85–106
DoD 5 / IF5
≥238
≥383
≥107
One second measurementedit
For one-second wind speed measurements, it is assumed to be an average of 92.5% of the one-second measurement.[4][3]
Degree of Damage (DoD) / Measured IF# Speed
One Second Measurement
mph
km/h
m/s
DoD 0 / IF0
44.1–58
71–95
20–26
DoD 0.5 / IF0.5
59–76
96–123
27–34
DoD 1 / IF1
77–94
124–152
35–42
DoD 1.5 / IF1.5
95–113
153–183
43–51
DoD 2 / IF2
114–134
184–220
52–60
DoD 2.5 / IF2.5
135–156
218–252
61–70
DoD 3 / IF3
157–191
253–308
71–85
DoD 4 / IF4
192–241
309–388
86–107
DoD 5 / IF5
≥241.5
≥389
≥108
Zero second measurementedit
For zero-second wind speed measurements, it is assumed to be an instantaneous wind speed measurement.[4][3] This can only be used if it was 10Hz or higher sample rate.[4][3][6]
^"The International Fujita (IF) Scale Tornado and Wind Damage Assessment Guide" (PDF). ESSL.org. European Severe Storms Laboratory. Retrieved 26 June 2022.
^Tomás Púcik; David Rúva; Miroslav Singer; Miloslav Stanëk; Pieter Groenemeijer (23 June 2022). "Damage Survey of the Violent Tornado in Southeast Czechia on 24 June 2021" (PDF). European Severe Storms Laboratory. pp. 1–31. Retrieved 16 May 2023.
^ abcdefghij"The International Fujita (IF) Scale" (PDF). European Severe Storms Laboratory. Retrieved 8 May 2023.
^ abcdefghijPieter Groenemeijer (ESSL); Lothar Bock (DWD); Juan de Dios Soriano (AEMet); Maciej Dutkiewicz (Bydgoszcz University of Science and Technology); Delia Gutiérrez-Rubio (AEMet); Alois M. Holzer (ESSL); Martin Hubrig; Rainer Kaltenberger; Thilo Kühne (ESSL); Mortimer Müller (Universität für Bodenkultur); Bas van der Ploeg; Tomáš Púčik (ESSL); Thomas Schreiner (ESSL); Miroslav Šinger (SHMI); Gabriel Strommer (ESSL); Andi Xhelaj (University of Genova) (30 July 2023). "The International Fujita (IF) Scale" (PDF). European Severe Storms Laboratory. Retrieved 30 July 2023.
^ ab. Archived from the original on 2012-10-04. Retrieved 2022-07-17.
^A. C. M. Beljaars (1 December 1987). "The Influence of Sampling and Filtering on Measured Wind Gusts". Journal of Atmospheric and Oceanic Technology. 4 (4): 613–626. doi:10.1175/1520-0426(1987)004<0613:TIOSAF>2.0.CO;2. ISSN 1520-0426. Retrieved 16 May 2023.
April 26, 2024
international, fujita, scale, abbreviated, scale, rates, intensity, tornadoes, other, wind, events, based, severity, damage, they, cause, used, european, severe, storms, laboratory, essl, various, other, organizations, including, deutscher, wetterdienst, state. The International Fujita scale abbreviated as IF Scale rates the intensity of tornadoes and other wind events based on the severity of the damage they cause 1 It is used by the European Severe Storms Laboratory ESSL and various other organizations including Deutscher Wetterdienst DWD and State Meteorological Agency AEMET The scale is intended to be analogous to the Fujita and Enhanced Fujita scales while being more applicable internationally by accounting for factors such as differences in building codes In 2018 the first draft version of the IF scale version 0 10 was published This version was based on a 12 step rating scale Over the next few years dozens of tornadoes would be rated on this version of the scale Most notably the 2021 South Moravia tornado received a rating IF4 and full damage survey on the IF scale conducted by ESSL the Czech Hydrometeorological Institute and four other organizations 2 On May 6 2023 version 0 99 9d was published which changed it to a 9 step rating scale 3 In late July 2023 the first official version of the IF scale was published 4 Contents 1 2018 version 1 1 Parameters 2 2023 version 2 1 Damage indicators subclasses and degrees of damage 2 2 DI Wind Speed Measurement 2 2 1 Three second measurement 2 2 2 Two second measurement 2 2 3 One second measurement 2 2 4 Zero second measurement 3 See also 4 References2018 version editSee also List of tornadoes rated on the 2018 International Fujita scale Tornado rating classifications 5 IF0 IF0 IF0 IF1 IF1 IF1 IF2 IF2 IF2 IF3 IF4 IF5 Weak Strong Violent Significant Intense Parameters edit The 12 categories for the International Fujita scale are listed below in order of increasing intensity Although the wind speeds and photographic damage examples are updated which are more or less still accurate However for the actual IF scale in practice damage indicators the type of structure which has been damaged are predominantly used in determining the tornado intensity The IF scale steps are defined by a central value and an error The errors have been estimated to be 30 of the central value resulting in overlapping speed ranges The distances between the central values of the steps have been so chosen that the upper bound exceeds the central value of the next step ensuring a balance between the resolution of the scale and the expected errors Since ESSL required that the steps be consistent with the original Fujita scale they introduced steps with and suffixes indicating steps one third higher or lower than the central value of the original scale e g F1 equals F2 1 3F2 and F2 equals F2 1 3F2 Above F2 such a subdivision was not introduced and only full steps are used Scale Wind speed Estimated mph km h m s IF0 45 14 72 22 20 6 IF0 56 17 90 27 25 7 IF0 67 20 108 32 30 9 IF1 70 24 128 38 36 11 IF1 92 28 149 45 41 12 IF1 106 32 170 51 47 14 IF2 120 36 193 58 54 16 IF2 135 40 217 65 60 18 IF2 150 45 241 72 67 20 IF3 182 55 293 88 81 24 IF4 234 70 376 113 105 31 IF5 290 87 466 140 130 392023 version editOn May 6 2023 version 0 99 9d was published which changed it to a 9 step rating scale 3 In this version the wind speed damage indicator was introduced which made it the first tornado intensity and damage scale to use measured wind speeds and Doppler weather radar measured wind speeds 3 When the first official publication of the IF scale the 9 step rating scale was kept It was noted that each scale s wind speed is to be taken with a 20 error margin on each side of the central value 4 This was done to ensure the lower or upper bound of the overlapping rating came close to the central value of the other rating 4 Tornado rating classifications 5 IF0 IF0 5 IF1 IF1 5 IF2 IF2 5 IF3 IF4 IF5 Weak Strong Violent Significant Intense Scale Wind speed Estimated Central value Full range of the 20 error margin mph km h m s IF0 55 44 66 90 72 108 25 20 30 IF0 5 75 60 90 120 96 144 33 27 40 IF1 90 72 108 150 130 180 40 32 48 IF1 5 110 88 132 180 144 216 50 40 60 IF2 135 108 162 220 176 264 60 48 72 IF2 5 160 128 192 250 200 300 70 56 84 IF3 180 144 216 290 232 348 80 64 96 IF4 230 184 276 380 304 456 105 84 126 IF5 290 232 348 470 376 564 130 104 156 Damage indicators subclasses and degrees of damage edit The IF scale currently has 23 damage indicators DI each with a varying number of subclasses and degrees of damage DoD 4 3 DI Abbr Damage indicator DI Subclasses Degrees of damage BS Building structure A AB B C D E F 0 1A 1B 2 BR Building roof A AB B C D E F 0 1 2 BN Building non structural elements SW SS TW TS HW HS 0 1 2 3 BM Building anchoring SM SI DB 1 VH Road Vehicles C E L T 0 1 2 3 4 TR Trees W A S 0 1 2 3 4 5 6 7 8 9 TS Tree stands WA S 0 1 2 3 4 WT Wind turbines A S 0 1 2 3 GH Greenhouses W A S 0 1 2 3 TC Train cars S F 0 1 MH Mobile homes Static caravans 0 1 2 3 4 5 PT Poles and towers W S T 0 1 2 SP Solar Panels 0 1 FC Fences W S 0 1 FW Free standing walls Z A AB B C D E F 1 2 SN Signs and billboards T M 0 1 2 SW Connected scaffolding 1 CP Carports garages 1 SS Service Station Canopies 0 1 2 3 SC Shipping Containers A B C D E F 1 2 3 CR Cranes G t 1 2 OF Outdoor Furniture L H 0 1 2 WM Wind Speed Measurement See section below See section below DI Wind Speed Measurement edit A unique feature of the International Fujita scale compared to the Fujita or Enhanced Fujita scale is a new damage indicator based on measured wind speeds For the IF scale only wind speeds measured at or below 10 metres 11 yd can be used to determine a rating Doppler weather radar measurements are also able to be used to determine a rating if they are measured within damaging distance For radar measurements any readings below 60 metres 66 yd can be used to determine a rating 4 3 Three second measurement edit For three second wind speed measurements it is assumed to be an average of 88 8 of the three second measurement 4 3 Degree of Damage DoD Measured IF Speed Three Second Measurement mph km h m s DoD 0 IF0 42 5 56 69 91 19 25 DoD 0 5 IF0 5 57 74 5 92 120 26 32 DoD 1 IF1 73 9 90 119 146 33 40 DoD 1 5 IF1 5 91 109 147 176 40 49 DoD 2 IF2 110 129 177 208 50 57 DoD 2 5 IF2 5 129 156 5 209 242 58 70 DoD 3 IF3 151 183 9 243 296 68 82 DoD 4 IF4 184 231 297 373 83 103 DoD 5 IF5 232 374 104 Two second measurement edit For two second wind speed measurements it is assumed to be an average of 90 9 of the two second measurement 4 3 Degree of Damage DoD Measured IF Speed Two Second Measurement mph km h m s DoD 0 IF0 43 4 58 70 94 20 26 DoD 0 5 IF0 5 59 74 95 120 27 33 DoD 1 IF1 75 93 121 150 34 40 DoD 1 5 IF1 5 93 111 8 150 180 42 50 DoD 2 IF2 111 8 132 180 213 51 59 DoD 2 5 IF2 5 133 154 214 248 60 68 DoD 3 IF3 154 188 249 303 69 84 DoD 4 IF4 188 237 304 382 85 106 DoD 5 IF5 238 383 107 One second measurement edit For one second wind speed measurements it is assumed to be an average of 92 5 of the one second measurement 4 3 Degree of Damage DoD Measured IF Speed One Second Measurement mph km h m s DoD 0 IF0 44 1 58 71 95 20 26 DoD 0 5 IF0 5 59 76 96 123 27 34 DoD 1 IF1 77 94 124 152 35 42 DoD 1 5 IF1 5 95 113 153 183 43 51 DoD 2 IF2 114 134 184 220 52 60 DoD 2 5 IF2 5 135 156 218 252 61 70 DoD 3 IF3 157 191 253 308 71 85 DoD 4 IF4 192 241 309 388 86 107 DoD 5 IF5 241 5 389 108 Zero second measurement edit For zero second wind speed measurements it is assumed to be an instantaneous wind speed measurement 4 3 This can only be used if it was 10Hz or higher sample rate 4 3 6 Degree of Damage DoD Measured IF Speed Zero Second Measurement mph km h m s DoD 0 IF0 47 8 64 77 103 22 28 DoD 0 5 IF0 5 64 82 104 132 29 36 DoD 1 IF1 82 101 9 133 164 37 45 DoD 1 5 IF1 5 102 123 165 198 46 55 DoD 2 IF2 124 145 199 234 56 65 DoD 2 5 IF2 5 146 169 235 273 66 75 DoD 3 IF3 170 207 274 333 76 92 DoD 4 IF4 208 260 334 420 93 116 DoD 5 IF5 261 421 117See also edit nbsp Weather portal nbsp Physics portal List of tornadoes rated on the International Fujita scale Beaufort scale Saffir Simpson hurricane wind scale Severe weather terminology United States TORRO scale Tornado intensity and damage Enhanced Fujita scale Wind engineering Lists of tornadoes and tornado outbreaks List of F5 and EF5 tornadoesReferences edit The International Fujita IF Scale Tornado and Wind Damage Assessment Guide PDF ESSL org European Severe Storms Laboratory Retrieved 26 June 2022 Tomas Pucik David Ruva Miroslav Singer Miloslav Stanek Pieter Groenemeijer 23 June 2022 Damage Survey of the Violent Tornado in Southeast Czechia on 24 June 2021 PDF European Severe Storms Laboratory pp 1 31 Retrieved 16 May 2023 a b c d e f g h i j The International Fujita IF Scale PDF European Severe Storms Laboratory Retrieved 8 May 2023 a b c d e f g h i j Pieter Groenemeijer ESSL Lothar Bock DWD Juan de Dios Soriano AEMet Maciej Dutkiewicz Bydgoszcz University of Science and Technology Delia Gutierrez Rubio AEMet Alois M Holzer ESSL Martin Hubrig Rainer Kaltenberger Thilo Kuhne ESSL Mortimer Muller Universitat fur Bodenkultur Bas van der Ploeg Tomas Pucik ESSL Thomas Schreiner ESSL Miroslav Singer SHMI Gabriel Strommer ESSL Andi Xhelaj University of Genova 30 July 2023 The International Fujita IF Scale PDF European Severe Storms Laboratory Retrieved 30 July 2023 a b Severe Thunderstorm Climatology Archived from the original on 2012 10 04 Retrieved 2022 07 17 A C M Beljaars 1 December 1987 The Influence of Sampling and Filtering on Measured Wind Gusts Journal of Atmospheric and Oceanic Technology 4 4 613 626 doi 10 1175 1520 0426 1987 004 lt 0613 TIOSAF gt 2 0 CO 2 ISSN 1520 0426 Retrieved 16 May 2023 Retrieved from https en wikipedia org w index php title International Fujita scale amp oldid 1219295037, wikipedia, wiki, book, books, library,
