View source for Waterspout

==Types==
=== Non-tornadic ===
[[File:Three waterspouts Kijkduin.jpg|thumb|upright=1.1|Non-tornadic waterspouts seen from the beach at Kijkduin near [[The Hague]] in the [[Netherlands]], 27&nbsp;August 2006]]
Waterspouts that are not associated with a rotating updraft of a supercell thunderstorm are known as "non-tornadic" or "fair-weather" waterspouts. By far the most common type of waterspout, these occur in coastal waters and are associated with dark, flat-bottomed, developing convective cumulus towers. Fair-weather waterspouts develop and dissipate rapidly, having life cycles shorter than 20&nbsp;minutes.<ref name="Choy"/> They usually rate no higher than EF0 on the [[Enhanced Fujita scale]], generally exhibiting winds of less than {{convert|30|m/s|mi/h km/h|abbr=on|0}}.<ref>{{cite web|author=National Weather Service Weather Forecast Office |location=Milwaukee/Sullivan, WI |date=30 April 2008|title=Threat Definitions for Waterspouts|url=http://www.crh.noaa.gov/mkx/?n=threat-definitions-waterspouts|url-status=dead|archive-url=http://archive.today/2012.08.03-131013/http://www.crh.noaa.gov/mkx/?n=threat-definitions-waterspouts|archive-date=3 August 2012|access-date=27 August 2009|publisher=[[National Weather Service]] Central Region Headquarters |website=crh.noaa.gov}}</ref>

They are most frequently seen in tropical and sub-tropical climates, with upwards of 400 per year observed in the Florida Keys.<ref name="NWS"/> They typically move slowly, if at all, since the cloud to which they are attached is horizontally static, being formed by vertical [[convection|convective action]] rather than the subduction/adduction interaction between colliding [[weather front|fronts]].<ref name="NWS">{{cite web
|url= http://www.srh.noaa.gov/key/HTML/spottertraining/index.html
|title= Basic Spotter Training Version 1.2
|date=12 September 2002
|access-date=21 July 2008
|author= National Weather Service
|location=Key West, FL
|website= srh.noaa.gov
|pages= 4–24
|publisher=[[National Oceanic and Atmospheric Administration|NOAA]]
|url-status=dead
|archive-url = https://web.archive.org/web/20071009082237/http://www.srh.noaa.gov/key/HTML/spottertraining/index.html |archive-date = 9 October 2007}}
</ref><ref name="Bruce"/> Fair-weather waterspouts are very similar in both appearance and mechanics to landspouts, and largely behave as such if they move ashore.<ref name="NWS"/>

[[File:Ocean Today - Waterspouts 5stages.webm|thumb|left|Five stages of a fair-weather waterspout lifecycle]]
There are five stages to a fair-weather waterspout life cycle. Initially, a prominent circular, light-colored disk appears on the surface of the water, surrounded by a larger dark area of indeterminate shape. After the formation of these colored disks on the water, a pattern of light- and dark-colored spiral bands develops from the dark spot on the water surface. Then, a dense [[wikt:annulus|annulus]] of sea spray, called a "cascade", appears around the dark spot with what appears to be an [[eye (cyclone)|eye]]. Eventually, the waterspout becomes a visible funnel from the water surface to the overhead cloud. The spray vortex can rise to a height of several hundred feet or more, and often creates a visible wake and an associated wave train as it moves. Finally, the funnel and spray vortex begin to dissipate as the inflow of warm air into the vortex weakens, ending the waterspout's life cycle.<ref name="Bruce">{{cite web|url=https://www.weather.gov/apx/waterspout |title=Waterspouts |author=Bruce B. Smith |date=22 February 2007 |access-date=21 March 2021 |publisher=[[National Weather Service]] Central Region Headquarters |website=weather.gov |url-status=live |archive-url=https://web.archive.org/web/20190407121247/https://www.weather.gov/apx/waterspout |archive-date=7 April 2019
}}</ref>

===Tornadic===
[[File:Punta Gorda waterspout.jpg|thumb|Tornadic waterspout off the coast of [[Punta Gorda, Florida]], caused by a severe thunderstorm, 15&nbsp;July 2005]]
"Tornadic waterspouts", also accurately referred to as "tornadoes over water", are formed from [[mesocyclone]]s in a manner essentially identical to land-based tornadoes in connection with [[severe thunderstorm]]s, but simply occurring over water.<ref>{{cite web|url=http://www.srh.noaa.gov/mlb/ghwo/waterspout_levels.html|title=Graphical Hazardous Weather Outlook: Waterspout Threat|author=National Weather Service Forecast Office |location=Melbourne, FL |access-date=21 June 2009|date=25 January 2007|publisher=Southern Region Headquarters | website=srh.noaa.gov |url-status=dead |archive-url = https://web.archive.org/web/20051219191304/http://www.srh.noaa.gov/mlb/ghwo/waterspout_levels.html |archive-date = 19 December 2005}}</ref> A tornado which travels from land to a body of water would also be considered a tornadic waterspout.<ref>{{cite journal|title=The 12 July 1995 Pinellas County, Florida, Tornado/Waterspout|journal=Weather and Forecasting |volume = 15|issue=1 |date=February 2000|pages=122–134|author1=Waylon G. Collins |author2=Charles H. Paxton |author3=Joseph H. Golden |doi=10.1175/1520-0434(2000)015<0122:TJPCFT>2.0.CO;2|bibcode=2000WtFor..15..122C |doi-access=free }}</ref> Since the vast majority of mesocyclonic thunderstorms in the United States occur in land-locked areas, true tornadic waterspouts are correspondingly rarer than their fair-weather counterparts in that country. However, in some areas, such as the [[Adriatic]], [[Aegean Sea|Aegean]] and [[Ionian sea]]s,<ref>{{Cite web|url=https://www.youtube.com/watch?v=RwPIULKDikY|title=Rare: Waterspout tornado came ashore in Palermo, Sicily, Italy |date=6 August 2020 |work=Disasters News channel |via=YouTube}}</ref> tornadic waterspouts can make up half of the total number.<ref>{{cite journal|title=Waterspouts of the Adriatic, Ionian and Aegean Sea and their meteorological environment|journal=Journal of Atmospheric Research |volume=83|issue=2–4|pages=542–557|author1=Michalis V. Sioutasa  |author2=Alexander G. Keul |name-list-style=amp |date=February 2007|doi=10.1016/j.atmosres.2005.08.009|bibcode = 2007AtmRe..83..542S }}</ref>

=== Snowspout === 
A ''winter waterspout'', also known as an ''icespout'', an ''ice devil'', or a ''snowspout'', is a rare instance of a waterspout forming under the base of a [[snow squall]].<ref>{{cite news
|url= http://www.acsu.buffalo.edu/~insrisg/nature/nw03/0414waterspouts.htm
|title= Waterspouts
|date= 14 April 2003
|publisher= [[SUNY Buffalo]]
|access-date=21 July 2008
|newspaper= The Buffalo News
|url-status=live
|archive-url=https://web.archive.org/web/20080401084334/http://www.acsu.buffalo.edu/~insrisg/nature/nw03/0414waterspouts.htm
|archive-date=1 April 2008
}}
</ref> The term "winter waterspout" is used to differentiate between the common warm season waterspout and this rare winter season event. There are a couple of critical criteria for the formation of a winter waterspout. Very cold temperatures need to be present over a body of water, which is itself warm enough to produce [[fog]] resembling [[steam]] above the water's surface. Like the more efficient [[lake-effect snow]] events, winds focusing down the axis of long lakes enhance wind convergence and increase the likelihood of a winter waterspout developing.<ref>{{cite web|url=https://www.weather.gov/media/btv/events/15Jan2009.pdf|title=15 January 2009: Lake Champlain Sea Smoke, Steam Devils, and Waterspouts: Chapters IV and V|author=National Weather Service Forecast Office |location=Burlington, VT |publisher=Eastern Region Headquarters|website=weather.gov|date=3 February 2009|access-date=21 June 2009 |url-status=live |archive-url=https://web.archive.org/web/20170127200634/https://www.weather.gov/media/btv/events/15Jan2009.pdf |archive-date=27 January 2017}}</ref>

The terms "snow devil" and "snownado" describe a different phenomenon: a snow vortex close to the surface with no parent cloud, similar to a [[Dust devil#Related phenomena|dust devil]].<ref>{{cite web|url=https://cloudatlas.wmo.int/en/snow-devil.html |title=Snow Devil |website=[[International Cloud Atlas]] |access-date=11 January 2023 |url-status=live |archive-url=https://web.archive.org/web/20220830094433/https://cloudatlas.wmo.int/en/snow-devil.html |archive-date=30 August 2022}}</ref>