Editing Supercell (section)

== Supercell variations ==
Supercell thunderstorms are sometimes classified by [[meteorologist]]s and [[Skywarn|storm spotters]] into three categories; however, not all supercells, being hybrid storms, fit neatly into any one category, and many supercells may fall into different categories during different periods of their lifetimes. The standard definition given above is referred to as the '''Classic''' supercell. All types of supercells typically produce severe weather.

=== Low precipitation (LP) ===
[[File:Low precipitation supercell thunderstorm.gif|thumb|left|Schematics of an LP supercell]]
[[File:Front Range LP Supercell.jpg|thumb|A low precipitation supercell near [[Greeley, Colorado]]]]

LP supercells contain a small and relatively light precipitation (rain/hail) core that is well separated from the updraft. The updraft is intense, and LPs are inflow dominant storms. The updraft tower is typically more strongly tilted and the deviant rightward motion less than for other supercell types. The forward flank downdraft (FFD) is noticeably weaker than for other supercell types, and the rear-flank downdraft (RFD) is much weaker—even visually absent in many cases. Like classic supercells, LP supercells tend to form within stronger mid-to-upper level storm-relative wind shear;<ref name="variations">{{cite journal |last= Rasmussen |first= Erik N. |author-link= Erik N. Rasmussen |author2= J. M. Straka |title= Variations in Supercell Morphology. Part I: Observations of the Role of Upper-Level Storm-Relative Flow |journal= Mon. Wea. Rev. |volume= 126 |issue= 9 |pages= 2406–21 |date= 1998 |doi= 10.1175/1520-0493(1998)126<2406:VISMPI>2.0.CO;2 |bibcode= 1998MWRv..126.2406R |s2cid= 59128977 |url= https://zenodo.org/record/1234713 |doi-access= free }}</ref> however, the atmospheric environment leading to their formation is not well understood. The moisture profile of the atmosphere, particularly the depth of the elevated dry layer, also appears to be important,<ref name="Grant">{{cite journal |last = Grant |first = Leah D. |author2 = S. C. van den Heever |title = Microphysical and Dynamical Characteristics of Low-Precipitation and Classic Supercells |journal = J. Atmos. Sci. |volume = 71 |issue = 7 |pages = 2604–24 |date = 2014 |doi = 10.1175/JAS-D-13-0261.1 |bibcode = 2014JAtS...71.2604G |doi-access = free }}</ref> and the low-to-mid level shear may also be important.<ref name="midtropo">{{cite journal |last= Brooks |first= Harold E. |author-link= Harold E. Brooks |author2= C. A. Doswell |author3= R. B. Wilhelmson |title= The Role of Midtropospheric Winds in the Evolution and Maintenance of Low-Level Mesocyclones |journal= Mon. Wea. Rev. |volume= 122 |issue= 1 |pages= 126–36 |date= 1994 |doi= 10.1175/1520-0493(1994)122<0126:TROMWI>2.0.CO;2 |bibcode= 1994MWRv..122..126B |doi-access= free }}</ref>

This type of supercell may be easily identifiable with "sculpted" cloud striations in the updraft base or even a "corkscrewed" or "[[barber pole]]" appearance on the updraft, and sometimes an almost "anorexic" look compared to classic supercells. This is because they often form within drier moisture profiles (often initiated by [[dry line]]s) leaving LPs with little available moisture despite high mid-to-upper level environmental winds. They most often dissipate rather than turning into classic or HP supercells, although it is still not unusual for LPs to do the latter, especially when moving into a much moister air mass. LPs were first formally described by [[Howard Bluestein]] in the early 1980s<ref name="Bluestein LP">{{cite journal |last= Bluestein |first= Howard B. |author-link= Howard Bluestein |author2= C. R. Parks |title= A Synoptic and Photographic Climatology of Low-Precipitation Severe Thunderstorms in the Southern Plains |journal= Mon. Wea. Rev. |volume = 111 |issue= 10 |pages= 2034–46 |date= 1983 |doi= 10.1175/1520-0493(1983)111<2034:ASAPCO>2.0.CO;2 |bibcode= 1983MWRv..111.2034B |doi-access= free }}</ref> although storm-chasing scientists noticed them throughout the 1970s.<ref>{{cite journal |last= Burgess |first= Donald W. |author-link= Donald W. Burgess |author2= R. P. Davies-Jones |title= Unusual Tornadic Storms in Eastern Oklahoma on 5 December 1975 |journal= Mon. Wea. Rev. |volume= 107 |issue= 4 |pages= 451–7 |date= 1979 |doi= 10.1175/1520-0493(1979)107<0451:UTSIEO>2.0.CO;2 |bibcode= 1979MWRv..107..451B |doi-access=  }}</ref> Classic supercells may wither yet maintain updraft rotation as they decay, becoming more like the LP type in a process known as "downscale transition" that also applies to LP storms, and this process is thought to be how many LPs dissipate.<ref>{{cite journal |last = Bluestein |first= Howard B. |author-link= Howard Bluestein |title= On the Decay of Supercells through a "Downscale Transition": Visual Documentation |journal= Mon. Wea. Rev. |volume= 136 |issue= 10 |pages= 4013–28 |date= 2008 |doi= 10.1175/2008MWR2358.1 |bibcode= 2008MWRv..136.4013B |doi-access= free }}</ref>

LP supercells rarely spawn tornadoes, and those that form tend to be weak, small, and high-based tornadoes, but strong tornadoes have been observed. These storms, although generating lesser precipitation amounts and producing smaller precipitation cores, can generate huge hail. LPs may produce hail larger than [[Baseball (ball)|baseballs]] in clear air where no rainfall is visible.<ref>{{cite web|url=http://www.theweatherprediction.com/habyhints/237/|title=RADAR CHARACTERISTICS OF SUPERCELLS|work=theweatherprediction.com|access-date=24 January 2016}}</ref> LPs are thus hazardous to people and animals caught outside as well as to storm chasers and spotters. Due to the lack of a heavy precipitation core, LP supercells often exhibit relatively weak radar reflectivity without clear evidence of a [[hook echo]], when in fact they are producing a tornado at the time. LP supercells may not even be recognized as supercells in reflectivity data unless one is trained or experienced on their radar characteristics.<ref name="recognition">{{cite journal |last= Moller |first= Alan R. |author-link= Alan Moller |author2= C. A. Doswell |author3= M. P. Foster |author4= G. R. Woodall |title= The Operational Recognition of Supercell Thunderstorm Environments and Storm Structures |journal= Weather Forecast. |volume= 9 |issue= 3 |pages= 324–47 |date= 1994 |doi= 10.1175/1520-0434(1994)009<0327:TOROST>2.0.CO;2 |bibcode= 1994WtFor...9..327M |doi-access= free }}</ref> This is where observations by [[Storm spotting|storm spotter]] and [[Storm chasing|storm chasers]] may be of vital importance in addition to [[Weather radar#Velocity|Doppler velocity]] (and [[Weather radar#Polarization|polarimetric]]) radar data. 

LP supercells are quite sought after by storm chasers because the limited amount of precipitation makes sighting tornadoes at a safe distance much less difficult than with a classic or HP supercell and more so because of the unobscured storm structure unveiled. During spring and early summer, areas in which LP supercells are readily spotted include southwestern [[Oklahoma]] and northwestern [[Texas]], among other parts of the western [[Great Plains]].{{citation needed|date=June 2014}}

=== High precipitation (HP) ===
[[File:High precipitation supercell thunderstorm.gif|thumb|left|Schematics of an HP supercell]]
The '''HP supercell''' has a much heavier precipitation core that can wrap all the way around the mesocyclone. These are especially dangerous storms, since the mesocyclone is wrapped with rain and can hide a tornado (if present) from view. These storms also cause flooding due to heavy rain, damaging [[downburst]]s, and weak tornadoes, although they are also known to produce strong to violent tornadoes. They have a lower potential for damaging hail than Classic and LP supercells, although damaging hail is possible. It has been observed by some spotters that they tend to produce more cloud-to-ground and intracloud lightning than the other types. Also, unlike the LP and Classic types, severe events usually occur at the front (southeast) of the storm. The HP supercell is the most common type of supercell in the [[United States]] east of [[Interstate 35]], in the southern parts of the provinces of [[Ontario]] and [[Quebec]] in [[Canada]], in [[France]], [[Germany]] and the [[Po Valley]] in north Italy and in the central portions of Argentina and [[Uruguay]].
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=== Mini-supercell or low-topped supercell ===
Whereas classic, HP, and LP refer to different precipitation regimes and mesoscale frontal structures, another variation was identified in the early 1990s by Jon Davies.<ref>{{cite conference|first=Jonathan M. |last=Davies |author-link=Jonathan M. Davies |title=Small Tornadic Supercells in the Central Plains |book-title=17th Conf. Severe Local Storms |pages=305–9 |publisher=American Meteorological Society |date=Oct 1993 |location=St. Louis, MO |url=http://www.jondavies.net/1993_SLS_mini-sprcl/1993_SLS_mini-sprcl.htm |url-status=dead |archive-url=https://web.archive.org/web/20130617101224/http://www.jondavies.net/1993_SLS_mini-sprcl/1993_SLS_mini-sprcl.htm |archive-date=2013-06-17 }}</ref> These smaller storms were initially called mini-supercells<ref>{{cite book |editor-last = Glickman |editor-first = Todd S. |title = Glossary of Meteorology |publisher = American Meteorological Society |edition = 2nd |year = 2000 |url = http://amsglossary.allenpress.com/glossary/search?p=1&query=mini-supercell |archive-url = https://archive.today/20120701115430/http://amsglossary.allenpress.com/glossary/search?p=1&query=mini-supercell |url-status = dead |archive-date = 2012-07-01 |isbn = 978-1-878220-34-9 |access-date = 2012-02-09 }}</ref> but are now commonly referred to as low-topped supercells. These are also subdivided into Classic, HP and LP types.