Editing Jet stream (section)

====El Niño====
During [[El Niño]] events, increased precipitation is expected in California due to a more southerly, zonal, storm track.<ref>John Monteverdi and Jan Null. [http://tornado.sfsu.edu/geosciences/elnino/elnino.html "WESTERN REGION TECHNICAL ATTACHMENT NO. 97-37 November 21, 1997: El Niño and California Precipitation."] {{Webarchive|url=https://web.archive.org/web/20091227155828/http://tornado.sfsu.edu/geosciences/elnino/elnino.html |date=27 December 2009 }} Retrieved on 28 February 2008.</ref> During the Niño portion of ENSO, increased precipitation falls along the Gulf coast and Southeast due to a stronger than normal, and more southerly, polar jet stream.<ref>[[Climate Prediction Center]]. [http://www.cpc.noaa.gov/products/analysis_monitoring/ensocycle/ensorain.shtml El Niño (ENSO) Related Rainfall Patterns Over the Tropical Pacific.] {{Webarchive|url=https://web.archive.org/web/20100528035733/http://www.cpc.noaa.gov/products/analysis_monitoring/ensocycle/ensorain.shtml |date=28 May 2010 }} Retrieved on 28 February 2008.</ref> Snowfall is greater than average across the southern Rockies and Sierra Nevada mountain range, and is well below normal across the Upper Midwest and Great Lakes states.<ref name="cpc.ncep.noaa.gov">[[Climate Prediction Center]]. [http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/us_impacts/ustp_impacts.shtml ENSO Impacts on United States Winter Precipitation and Temperature.] {{Webarchive|url=https://web.archive.org/web/20080412000000/https://web.archive.org/web/20080412152736/http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/us_impacts/ustp_impacts.shtml |date=12 April 2008 }} Retrieved on 16 April 2008.</ref> The northern tier of the lower 48 exhibits above normal temperatures during the fall and winter, while the Gulf coast experiences below normal temperatures during the winter season.<ref>[[Climate Prediction Center]]. [http://www.cpc.ncep.noaa.gov/products/predictions/threats2/enso/elnino/UStrank/ond.gif Average October–December (3-month) Temperature Rankings During ENSO Events.] {{Webarchive|url=https://web.archive.org/web/20080530032315/http://www.cpc.ncep.noaa.gov/products/predictions/threats2/enso/elnino/UStrank/ond.gif |date=30 May 2008 }} Retrieved on 16 April 2008.</ref><ref>[[Climate Prediction Center]]. [http://www.cpc.ncep.noaa.gov/products/predictions/threats2/enso/elnino/UStrank/djf.gif Average December–February (3-month) Temperature Rankings During ENSO Events.] {{Webarchive|url=https://web.archive.org/web/20080530032314/http://www.cpc.ncep.noaa.gov/products/predictions/threats2/enso/elnino/UStrank/djf.gif |date=30 May 2008 }} Retrieved on 16 April 2008.</ref> The subtropical jet stream across the deep [[tropics]] of the northern hemisphere is enhanced due to increased convection in the equatorial Pacific, which decreases [[tropical cyclogenesis]] within the Atlantic tropics below what is normal, and increases tropical cyclone activity across the eastern Pacific.<ref name="ENSO TC influence FAQ">{{Cite web|url=http://www.cpc.noaa.gov/products/analysis_monitoring/ensostuff/ensofaq.shtml#HURRICANES|publisher=[[Climate Prediction Center]]|format=FAQ|access-date=21 March 2008|title=How do El Niño and La Nina influence the Atlantic and Pacific hurricane seasons?|archive-url=https://web.archive.org/web/20090827143632/http://www.cpc.noaa.gov/products/analysis_monitoring/ensostuff/ensofaq.shtml#HURRICANES|archive-date=27 August 2009|url-status=dead}}</ref> In the southern hemisphere, the subtropical jet stream is displaced equatorward, or north, of its normal position, which diverts frontal systems and thunderstorm complexes from reaching central portions of the continent.<ref name="Caio"/>