Editing Hook echo (section)

==History==
[[File:NEXRAD radar of an EF2 tornado in Kansas on March 13, 2024.png|thumb|250px|right|Classic hook echo can be seen for this [[Tornado_outbreak_of_March_13–15,_2024|Kansas EF2 tornado]] in 2024]]
Because of the unpredictable and potentially catastrophic nature of tornadoes, the possibility of detecting tornadoes via radar was discussed in the meteorological community in the earliest days of meteorological radar.<ref name="isws.illinois.edu">Huff, F.A., H.W. Hiser, and S.G. Bigler, 1954: [http://www.isws.illinois.edu/pubdoc/RI/ISWSRI-22.pdf Study of an Illinois tornado using radar, synoptic weather and field survey data]. Report of Investigation 22, Champaign, IL, pp. 73</ref> The first association between tornadoes and the hook echo was discovered by E.M. Brooks in 1949.<ref name=Brook>{{Cite journal | last= Brooks | first= E. M. |year = 1949 | title= The tornado cyclone | journal = [[Weatherwise]] | volume = 2 | issue = 2 | pages = 32–33 | doi= 10.1080/00431672.1949.9930047 | bibcode= 1949Weawi...2b..32B }}</ref> Brooks noted circulations with radii of approximately 8–16&nbsp;km on radar. These circulations were associated with supercell thunderstorms and were dubbed “tornado cyclones” by Brooks.

The first documented association between a hook echo and a confirmed tornado occurred near [[Champaign–Urbana metropolitan area|Champaign–Urbana, Illinois]], on 9 April 1953.<ref name="isws.illinois.edu"/><ref>{{cite web |last = Angel |first = Jim |title = 60th Anniversary of the First Tornado Detected by Radar |work = Illinois State Climatology |publisher = Illinois State Water Survey |date = Apr 9, 2013 |url = https://climateillinois.wordpress.com/2013/04/09/60th-anniversary-of-the-first-tornado-detected-by-radar/ |access-date = May 22, 2013 }}</ref> This event was unintentionally discovered by Illinois State Water Survey [[electrical engineer]] Donald Staggs.
Staggs was repairing and testing an experimental [[precipitation]] measurement radar unit when he noticed an unusual radar echo which was associated with a nearby thunderstorm. The unusual echo appeared to be an area of precipitation in the shape of the number six - hence the modern term “hook echo”. Staggs chose to record the echo for further analysis by [[meteorologists]]. Upon review of the unusual echo data, meteorologists F.A. Huff, H.W. Heiser, and S.G. Bigler determined that a destructive tornado had occurred in the geographical location which corresponded with the "six-shaped" echo seen on radar.

Prominent [[severe storm]] researcher [[Ted Fujita]] also documented hook echoes with various supercell thunderstorms which occurred on 9 April 1953 - the same day as the Huff et al. discovery.<ref name=Fujita>{{Cite journal | last=Fujita | first= T. T. | year = 1958 | title= Mesoanalysis of the Illinois tornadoes of 9 April 1953 | journal =  Journal of Meteorology| volume= 15 | issue= 3 | pages = 288–296 | doi=10.1175/1520-0469(1958)015<0288:MOTITO>2.0.CO;2|bibcode = 1958JAtS...15..288F | doi-access= free }}</ref> After detailed study of the evolution of hook echoes, Fujita hypothesized that certain strong thunderstorms may be capable of rotation.

J.R. Fulks developed the first hypothesis on the formation of hook echoes in 1962.<ref>{{Cite book | last= Fulks | first = J. R. | year = 1962 | title = On the Mechanics of the Tornado | work = National Severe Storms Project Rep. No. 4 | publisher = U. S. Weather Bureau }}</ref> Fulks analyzed [[wind speed|wind velocity]] data from [[Weather radar#Velocity|Doppler weather radar]] units which were installed in [[Central Oklahoma]] in 1960. Doppler data on wind velocity during thunderstorms demonstrated an association between strong horizontal [[wind shear]] and mesocyclones, which were identified as having the potential to [[tornadogenesis|produce tornadoes]].<ref name="review" />