Editing Colorado (section)

===Extreme weather===

Extreme weather changes are common in Colorado, although a significant portion of the extreme weather occurs in the least populated areas of the state. Thunderstorms are common east of the Continental Divide in the spring and summer, yet are usually brief. Hail is a common sight in the mountains east of the Divide and across the eastern Plains, especially the northeast part of the state. Hail is the most commonly reported warm-season severe weather hazard, and occasionally causes human injuries, as well as significant property damage.<ref name="Childs">{{cite journal |last = Childs |first = Samuel J. |author2 = R. S. Schumacher |title = An Updated Severe Hail and Tornado Climatology for Eastern Colorado |journal = J. Appl. Meteorol. Climatol. |volume = 58 |issue = 10 |pages = 2273–2293 |date = 2019 |doi = 10.1175/JAMC-D-19-0098.1 |bibcode = 2019JApMC..58.2273C |doi-access = free }}</ref> The eastern Plains are subject to some of the biggest hail storms in North America.<ref name=ccc/> Notable examples are the severe hailstorms that hit Denver on July 11, 1990,<ref>{{cite web|url=http://denver.cbslocal.com/2014/07/11/historic-denver-hailstorm-was-called-worst-in-american-history/|title=Historic Denver Hailstorm Was Called Worst in American History|date=July 11, 2014}}</ref> and May 8, 2017, the latter being the costliest ever in the state.<ref>{{cite web|url=https://www.denverpost.com/2017/05/23/hailstorm-costliest-ever-metro-denver/|title=Hailstorm that hammered west metro Denver May 8 is costliest ever for Colorado|date=May 23, 2017}}</ref>

The Eastern Plains are part of the extreme western portion of [[Tornado Alley]]; some damaging tornadoes in the Eastern Plains include the 1990 [[Limon, Colorado|Limon]] [[Fujita scale|F3]] tornado and the [[Tornado outbreak of May 22–27, 2008#Windsor, Colorado|2008 Windsor EF3 tornado]], which devastated a small town.<ref>{{cite web |last =Slater |first =Jane |title =Thursday's Tornado State's 4th Costliest Disaster |publisher =[[KMGH]] |date =May 28, 2008 |url =http://www.thedenverchannel.com/news/16408116/detail.html |access-date =January 25, 2009 |archive-url =https://web.archive.org/web/20080604044140/http://www.thedenverchannel.com/news/16408116/detail.html |archive-date =June 4, 2008 |url-status =dead |df =mdy-all }}</ref> Portions of the eastern Plains see especially frequent tornadoes, both those spawned from [[mesocyclone]]s in [[supercell]] thunderstorms and from less intense [[landspout]]s, such as within the [[Denver convergence vorticity zone]] (DCVZ).<ref name="Childs"/>

The Plains are also susceptible to occasional floods and particularly severe flash floods, which are caused both by thunderstorms and by the rapid melting of snow in the mountains during warm weather. Notable examples include the [[1965 Denver Flood]],<ref>{{cite web|url=http://www.westword.com/news/the-1965-flood-how-denvers-greatest-disaster-changed-the-city-6668119|title=The 1965 Flood: How Denver's Greatest Disaster Changed the City|first=Alan|last=Prendergast|date=April 29, 2015}}</ref> the [[Big Thompson River]] flooding of 1976 and the [[2013 Colorado floods]]. Hot weather is common during summers in Denver. The city's record in 1901 for the number of consecutive days above {{convert|90|°F|°C|abbr=on}} was broken during the summer of 2008. The new record of 24 consecutive days surpassed the previous record by almost a week.<ref>{{cite web | title =Denver's Consecutive 90 Degree Streaks | publisher =[[National Weather Service]] | access-date =October 10, 2009 | url =http://www.crh.noaa.gov/bou/?n=consec90}}</ref>

Much of Colorado is very dry, with the state averaging only {{convert|17|in|mm|abbr=off|sp=us}} of precipitation per year statewide. The state rarely experiences a time when some portion is not in some degree of drought.<ref>{{cite web|url=http://ccc.atmos.colostate.edu/pdfs/ahistoryofdrought.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://ccc.atmos.colostate.edu/pdfs/ahistoryofdrought.pdf |archive-date=2022-10-09 |url-status=live|title=A History of Drought|access-date=July 30, 2010}}</ref> The lack of precipitation contributes to the severity of wildfires in the state, such as the [[Hayman Fire]] of 2002. Other notable fires include the [[Fourmile Canyon#Fourmile Canyon Fire|Fourmile Canyon Fire]] of 2010, the [[Waldo Canyon Fire]] and [[High Park Fire]] of June 2012, and the [[Black Forest Fire]] of June 2013. Even these fires were exceeded in severity by the [[Pine Gulch Fire]], [[Cameron Peak Fire]], and [[East Troublesome Fire]] in 2020, all being the three largest fires in Colorado history (see [[2020 Colorado wildfires]]). And the Marshall Fire which started on December 30, 2021, while not the largest in state history, was the most destructive ever in terms of property loss (see [[Marshall Fire]]).

However, some of the mountainous regions of Colorado receive a huge amount of moisture from winter snowfalls. The spring melts of these snows often cause great waterflows in the [[Yampa River]], the [[Colorado River]], the Rio Grande, the Arkansas River, the North Platte River, and the South Platte River.

Water flowing out of the Colorado Rocky Mountains is a very significant source of water for the farms, towns, and cities of the southwest states of New Mexico, Arizona, Utah, and Nevada, as well as the Midwest, such as Nebraska and Kansas, and the southern states of Oklahoma and Texas. A significant amount of water is also diverted for use in California; occasionally (formerly naturally and consistently), the flow of water reaches northern Mexico.