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Landspout is a term created by atmospheric scientist Howard B. Bluestein in 1985 for a tornado not associated with a mesocyclone.^[3] The Glossary of Meteorology defines a landspout:

"Colloquial expression describing tornadoes occurring with a parent cloud in its growth stage and with its vorticity originating in the boundary layer.

The parent cloud does not contain a preexisting mid-level mesocyclone. The landspout was so named because it looks like "a weak Florida Keys waterspout over land."^[4]

Landspouts are typically weaker than mesocyclone-associated tornadoes spawned within supercell thunderstorms, in which the strongest tornadoes form.

Characteristics

Landspouts are a type of tornado that forms during the growth stage of a cumulus congestus or occasionally a cumulonimbus cloud when an updraft stretches boundary layer vorticity upward into a vertical axis and tightens it into a strong vortex. Landspouts can also occur due to interactions from outflow boundaries, as they can occasionally cause enhanced convergence and vorticity at the surface. These generally are smaller and weaker than supercell tornadoes and do not form from a mesocyclone or pre-existing rotation in the cloud. Because of this lower depth, smaller size, and weaker intensity, landspouts are rarely detected by Doppler weather radar (NWS).^[5]

Landspouts share a strong resemblance and development process to that of waterspouts, usually taking the form of a translucent and highly laminar helical tube. "They are typically narrow, rope-like condensation funnels that form while the thunderstorm cloud is still growing and there is no rotating updraft", according to the National Weather Service.^[2] Landspouts are considered tornadoes since a rapidly rotating column of air is in contact with both the surface and a cumuliform cloud. Not all landspouts are visible, and many are first sighted as debris swirling at the surface before eventually filling in with condensation and dust.

Orography can influence landspout (and even mesocyclone tornado) formation. A notable example is the propensity for landspout occurrence in the Denver Convergence Vorticity Zone (DCVZ).

Life cycle

Forming in relation to mesocyclones and under updrafts, a landspout generally lasts for less than 15 minutes; however, they can persist substantially longer, and produce significant damage. Landspouts tend to progress through recognizable stages of formation, maturation, and dissipation, and usually decay when a downdraft or significant precipitation (outflow) occur nearby. They may form in lines or groups of multiple landspouts.^[6]

Damage

Landspouts are usually at EF0 level where the intensity of winds is low and weak. However, winds inside a Landspout tornado can reach 100 miles per hour (MPH).^[7]

References

^ Judson Jones (21 May 2020). "Why Landspout Tornadoes are Common in Colorado". The Denver Post.
^ ^a ^b Judson Jones (8 June 2021). "The No. 1 US county for producing tornadoes just spawned another landspout". CNN.
^ Bluestein, Howard B. (1985). "A History of Severe-Storm-Intercept Field Programs". Weather and Forecasting. 14 (4): 267–270. Bibcode:1999WtFor..14..558B. doi:10.1175/1520-0434(1999)014<0558:AHOSSI>2.0.CO;2. ISSN 1520-0434.
^ American Meteorological Society (2000). "Glossary of Meteorology, Second Edition". ametsoc.org. Archived from the original on 6 April 2007. Retrieved 27 March 2007.
^ Wakimoto; Wilson (1989). "Non-supercell Tornadoes". Monthly Weather Review. 117 (6): 1113–1140. Bibcode:1989MWRv..117.1113W. doi:10.1175/1520-0493(1989)117<1113:NST>2.0.CO;2.
^ Forbes; Wakimoto (1983). "A Concentrated Outbreak of Tornadoes, Downbursts and Microbursts, and Implications Regarding Vortex Classification". Monthly Weather Review. 111 (1): 220–235. Bibcode:1983MWRv..111..220F. doi:10.1175/1520-0493(1983)111<0220:ACOOTD>2.0.CO;2.
^ "Tornado Facts". Retrieved August 9, 2024.

External links

Media related to Landspouts at Wikimedia Commons
Advanced Spotters' Field Guide
Online Tornado FAQ

[1] Judson Jones (21 May 2020). "Why Landspout Tornadoes are Common in Colorado". The Denver Post.

[CNN-2] Judson Jones (8 June 2021). "The No. 1 US county for producing tornadoes just spawned another landspout". CNN.

[landspout-3] Bluestein, Howard B. (1985). "A History of Severe-Storm-Intercept Field Programs". Weather and Forecasting. 14 (4): 267–270. Bibcode:1999WtFor..14..558B. doi:10.1175/1520-0434(1999)014<0558:AHOSSI>2.0.CO;2. ISSN 1520-0434.

[Glossary_of_Meteorology-4] American Meteorological Society (2000). "Glossary of Meteorology, Second Edition". ametsoc.org. Archived from the original on 6 April 2007. Retrieved 27 March 2007.

[5] Wakimoto; Wilson (1989). "Non-supercell Tornadoes". Monthly Weather Review. 117 (6): 1113–1140. Bibcode:1989MWRv..117.1113W. doi:10.1175/1520-0493(1989)117<1113:NST>2.0.CO;2.

[:0-6] Forbes; Wakimoto (1983). "A Concentrated Outbreak of Tornadoes, Downbursts and Microbursts, and Implications Regarding Vortex Classification". Monthly Weather Review. 111 (1): 220–235. Bibcode:1983MWRv..111..220F. doi:10.1175/1520-0493(1983)111<0220:ACOOTD>2.0.CO;2.

[7] "Tornado Facts". Retrieved August 9, 2024.

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@@ Line 1: / Line 1: @@
 __NOTOC__
 {{Short description|Tornado not originating from a mesocyclone}}
+[[File:Lincoln County landspout3.jpg|thumb|A visible landspout seen in [[Lincoln County, Nebraska]] on May 22, 2004.]]
 [[File:Landspout Tornado.jpg|thumb|A landspout tornado forms from a developing thunderstorm near [[Cheyenne Wells, Colorado]]. Landspouts are exceptionally common in Eastern Colorado.<ref>{{cite web |title=Why Landspout Tornadoes are Common in Colorado  |date=21 May 2020 |author=Judson Jones |website=[[The Denver Post]] |url=https://www.denverpost.com/2020/05/21/landspout-tornado-colorado-how-do-they-form}}</ref><ref name ="CNN"></ref>]]
-[[Image:GID Landspout.jpg|thumb|right|A landspout near [[North Platte, Nebraska]], on May 22, 2004. Note the characteristic smooth, tubular shape, similar to that of a fair-weather [[waterspout]].]]
 [[File:Tornado em Araguari MG 29 set 2007 18 h.JPG|thumb|Landspout on September 29, 2007]]
 {{Weather}}
-'''Landspout''' is a term created by atmospheric scientist [[Howard B. Bluestein]] in 1985 for a [[tornado]] not associated with a [[mesocyclone]].<ref name ="landspout">{{cite journal  | title =  A History of Severe-Storm-Intercept Field Programs| author = Bluestein, Howard B.  | year = 1985  | journal = Weather and Forecasting| volume = 14 | issue = 4 | pages = 267–270 | doi = 10.1175/1520-0434(1999)014<0558:AHOSSI>2.0.CO;2 | bibcode = 1999WtFor..14..558B | issn = 1520-0434 | doi-access = free  }}</ref> The ''Glossary of Meteorology'' defines a landspout as
+'''Landspout''' is a term created by atmospheric scientist [[Howard B. Bluestein]] in 1985 for a [[tornado]] not associated with a [[mesocyclone]].<ref name ="landspout">{{cite journal  | title =  A History of Severe-Storm-Intercept Field Programs| author = Bluestein, Howard B.  | year = 1985  | journal = Weather and Forecasting| volume = 14 | issue = 4 | pages = 267–270 | doi = 10.1175/1520-0434(1999)014<0558:AHOSSI>2.0.CO;2 | bibcode = 1999WtFor..14..558B | issn = 1520-0434 | doi-access = free  }}</ref> The ''Glossary of Meteorology'' defines a landspout:
 : "Colloquial expression describing tornadoes occurring with a parent [[cloud]] in its growth stage and with its [[vorticity]] originating in the [[Atmospheric boundary layer|boundary layer]].
 : The parent cloud does not contain a preexisting mid-level mesocyclone. The landspout was so named because it looks like "a weak [[Florida Keys]] [[waterspout]] over land."<ref name="Glossary of Meteorology">{{cite web  | url = http://amsglossary.allenpress.com/glossary/browse?s=t&p=34  | title = Glossary of Meteorology, Second Edition  | access-date = 27 March 2007  | author = American Meteorological Society  | year = 2000  | website = ametsoc.org  | archive-url = https://web.archive.org/web/20070406051559/http://amsglossary.allenpress.com/glossary/browse?s=t&p=34  | archive-date = 6 April 2007  | url-status = dead  }}</ref>
@@ Line 11: / Line 11: @@
 ==Characteristics==
-Landspouts are a type of tornado that formss during the growth stage of a [[cumulus congestus cloud|cumulus congestus]] or occasionally a [[Cumulonimbus cloud|cumulonimbus]] cloud when an [[updraft]] stretches boundary layer vorticity upward into a vertical axis and tightens it into a strong [[vortex]]. These generally are smaller and weaker than supercell tornadoes and do not form from a mesocyclone or pre-existing rotation in the cloud. Because of this lower depth, smaller size, and weaker intensity, landspouts are rarely detected by [[Weather radar|Doppler weather radar]] (NWS).<ref>{{cite journal|last=Wakimoto|author2=Wilson |title=Non-supercell Tornadoes|journal=Monthly Weather Review|year=1989|volume=117|issue=6 |pages=1113–1140|bibcode = 1989MWRv..117.1113W |doi = 10.1175/1520-0493(1989)117<1113:NST>2.0.CO;2 |doi-access=free}}</ref>
+Landspouts are a type of tornado that forms during the growth stage of a [[cumulus congestus cloud|cumulus congestus]] or occasionally a [[Cumulonimbus cloud|cumulonimbus]] cloud when an [[updraft]] stretches boundary layer vorticity upward into a vertical axis and tightens it into a strong [[vortex]]. Landspouts can also occur due to interactions from [[Outflow boundary|outflow boundaries]], as they can occasionally cause enhanced convergence and vorticity at the surface. These generally are smaller and weaker than supercell tornadoes and do not form from a mesocyclone or pre-existing rotation in the cloud. Because of this lower depth, smaller size, and weaker intensity, landspouts are rarely detected by [[Weather radar|Doppler weather radar]] (NWS).<ref>{{cite journal|last=Wakimoto|author2=Wilson |title=Non-supercell Tornadoes|journal=Monthly Weather Review|year=1989|volume=117|issue=6 |pages=1113–1140|bibcode = 1989MWRv..117.1113W |doi = 10.1175/1520-0493(1989)117<1113:NST>2.0.CO;2 |doi-access=free}}</ref>
-Landspouts share a strong resemblance and development process to that of waterspouts, usually taking the form of a translucent and highly [[Laminar flow|laminar]] helical tube. "They are typically narrow, rope-like [[condensation]] funnels that form while the thunderstorm cloud is still growing and there is no rotating updraft", according to the [[National Weather Service]].<ref name ="CNN">{{cite web |title=The No. 1 US county for producing tornadoes just spawned another landspout |date=8 June 2021 |author=Judson Jones |website=[[CNN]] |url=https://www.cnn.com/2021/06/08/weather/colorado-tornado-landspout/index.html}}</ref> Landspouts are considered tornadoes since a rapidly rotating column of air is in contact with both the surface and a [[cumuliform cloud]]. Not all landspouts are visible, and many are first sighted as debris swirling at the surface before eventually filling in with condensation and dust.
+Landspouts share a strong resemblance and development process to that of [[Waterspout|waterspouts]], usually taking the form of a translucent and highly [[Laminar flow|laminar]] helical tube. "They are typically narrow, rope-like [[condensation]] funnels that form while the thunderstorm cloud is still growing and there is no rotating updraft", according to the [[National Weather Service]].<ref name ="CNN">{{cite web |title=The No. 1 US county for producing tornadoes just spawned another landspout |date=8 June 2021 |author=Judson Jones |website=[[CNN]] |url=https://www.cnn.com/2021/06/08/weather/colorado-tornado-landspout/index.html}}</ref> Landspouts are considered tornadoes since a rapidly rotating column of air is in contact with both the surface and a [[cumuliform cloud]]. Not all landspouts are visible, and many are first sighted as debris swirling at the surface before eventually filling in with condensation and dust.
 [[Orography]] can influence landspout (and even mesocyclone tornado) formation. A notable example is the propensity for landspout occurrence in the [[Denver Convergence Vorticity Zone]] (DCVZ).
 == Life cycle ==
-Formingg in relation to [[misocyclone]]s and under updrafts, a landspout generally lasts for less than 15 minutes; however, they can persist substantially longer, and produce significant damage. Landspouts tend to progress through recognizable stages of formation, maturation, and dissipation, and usually decay when a [[downdraft]] or significant [[precipitation]] (outflow) occur nearby. They may form in lines or groups of multiple landspouts.<ref name=":0">{{cite journal  |last=Forbes  |author2=Wakimoto  |year=1983  |title=A Concentrated Outbreak of Tornadoes, Downbursts and Microbursts, and Implications Regarding Vortex Classification  |journal=Monthly Weather Review  |volume=111  |issue=1 |pages=220–235  |bibcode=1983MWRv..111..220F  |doi=10.1175/1520-0493(1983)111<0220:ACOOTD>2.0.CO;2 |doi-access=free  }}</ref>
+Forming in relation to [[mesocyclone]]s and under updrafts, a landspout generally lasts for less than 15 minutes; however, they can persist substantially longer, and produce significant damage. Landspouts tend to progress through recognizable stages of formation, maturation, and dissipation, and usually decay when a [[downdraft]] or significant [[precipitation]] (outflow) occur nearby. They may form in lines or groups of multiple landspouts.<ref name=":0">{{cite journal  |last=Forbes  |author2=Wakimoto  |year=1983  |title=A Concentrated Outbreak of Tornadoes, Downbursts and Microbursts, and Implications Regarding Vortex Classification  |journal=Monthly Weather Review  |volume=111  |issue=1 |pages=220–235  |bibcode=1983MWRv..111..220F  |doi=10.1175/1520-0493(1983)111<0220:ACOOTD>2.0.CO;2 |doi-access=free  }}</ref>
 == Damage ==
+Landspouts are usually at EF0 level where the intensity of winds is low and weak. However, winds inside a Landspout tornado can reach 100 miles per hour (MPH).<ref>{{cite web|url=https://www.tornadofacts.net/tornado-types/landspout.html#|title=Tornado Facts|access-date=August 9, 2024}}</ref>
-Landspouts are commonly weak; however, on rare occasions, a landspout can be as strong as an [[Enhanced Fujita scale|EF2]] or [[Enhanced Fujita scale|EF3]] tornado.
 ==See also==