Editing Hook echo (section)

{{short description|Weather radar signature indicating tornadic circulation in a supercell thunderstorm}}
[[Image:Tornadic classic supercell radar.gif|thumb|250px|right|Classic-style hook echo of the F5 [[1999 Bridge Creek-Moore tornado]].]]
A '''hook echo''' is a pendant or hook-shaped [[weather radar]] signature as part of some [[supercell]] [[thunderstorm]]s. It is found in the lower portions of a storm as air and precipitation flow into a [[mesocyclone]], resulting in a curved feature of [[reflectivity]]. The echo is produced by rain, hail, or debris being wrapped around the supercell.<ref>{{cite book |editor-last = Glickman |editor-first = Todd S.  |title = Glossary of Meteorology |publisher = American Meteorological Society |edition = 2nd |year = 2000 |url = http://glossary.ametsoc.org/wiki/Hook_echo |section=Hook Echo |isbn = 978-1-878220-34-9 }}</ref> It is one of the classic hallmarks of [[tornado]]-producing supercells.<ref name="review">{{cite journal |last = Murkowski |first = Paul M. |title = Hook Echoes and Rear-Flank Downdrafts: A Review |journal = Mon. Wea. Rev. |volume = 130 |issue = 4 |pages = 852–76 |year = 2002 |doi = 10.1175/1520-0493(2002)130<0852:HEARFD>2.0.CO;2 |bibcode = 2002MWRv..130..852M |s2cid = 54785955 |doi-access = free }}</ref> The [[National Weather Service]] may consider the presence of a hook echo coinciding with a [[tornado vortex signature]] as sufficient to justify issuing a [[tornado warning]].<ref>{{cite web |last = Angel |first = Jim |title = ISWS is Pioneer in Tracking Tornadoes by Radar |publisher = Illinois State Water Survey |date = Apr 9, 2013 |url = http://www.isws.illinois.edu/hilites/press/130409radar.asp |access-date = 2013-05-22 |archive-date = 2013-06-01 |archive-url = https://web.archive.org/web/20130601140628/http://www.isws.illinois.edu/hilites/press/130409radar.asp |url-status = dead }}</ref><ref>{{Cite web | url = http://www.wdtb.noaa.gov/modules/twg02/TWG2002.pdf | title = Tornado Warning Guidance | date = Spring 2002 | publisher = National Weather Service | access-date = June 16, 2013 | url-status = dead | archive-url = https://web.archive.org/web/20130306015738/http://www.wdtb.noaa.gov/modules/twg02/TWG2002.pdf | archive-date = March 6, 2013 }}</ref>