Editing Weather forecasting (section)

=== Air traffic ===
[[File:Plume from eruption of Chaiten volcano, Chile.jpg|thumb|right|Ash cloud from the 2008 eruption of [[Chaitén (volcano)|Chaitén volcano]] stretching across [[Patagonia]] from the Pacific to the Atlantic Ocean]]
{{See also|Terminal aerodrome forecast}}
Because the aviation industry is especially sensitive to the weather, accurate weather forecasting is essential. Fog or exceptionally low [[ceiling (cloud)|ceilings]] can prevent many aircraft from landing and taking off.<ref>[[United States Government Publishing Office|Government Printing Office]]. [http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?c=ecfr;sid=199eb678c4c22b4202e5809c99045c7c;rgn=div7;view=text;node=14%3A2.0.1.3.10.2.5;idno=14;cc=ecfr Title 14: "Aeronautics and Space"]. Retrieved May 26, 2008. {{webarchive|url=https://web.archive.org/web/20110613085006/http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?c=ecfr;sid=199eb678c4c22b4202e5809c99045c7c;rgn=div7;view=text;node=14:2.0.1.3.10.2.5;idno=14;cc=ecfr |date=June 13, 2011 }}</ref> [[Turbulence]] and [[Atmospheric icing|icing]] are also significant in-flight hazards.<ref>Aircraft Owners and Pilots Association. [http://www.aopa.org/asf/publications/sa11.pdf "Aircraft Icing"]. Retrieved May 26, 2008. {{webarchive|url=https://web.archive.org/web/20070202074833/http://www.aopa.org/asf/publications/sa11.pdf |date=February 2, 2007 }}</ref> Thunderstorms are a problem for all aircraft because of severe turbulence due to their [[Vertical draft|updrafts]] and [[Outflow boundary|outflow boundaries]],<ref>[[National Weather Service]] Forecast Office Dodge City, Kansas. [http://www.crh.noaa.gov/ddc/research/bore/HPCtalk.ppt "Aviation Hazards They Didn't Tell You About"]. Retrieved May 26, 2008. {{webarchive|url=https://web.archive.org/web/20080910142824/http://www.crh.noaa.gov/ddc/research/bore/HPCtalk.ppt |date=September 10, 2008 }}</ref> icing due to the heavy precipitation, as well as large [[hail]], strong winds, and lightning, all of which can cause severe damage to an aircraft in flight.<ref>[[Bureau of Meteorology]] (2006). [http://www.caem.wmo.int/_pdf/thunderstorms/thunderstorms_02_effects.pdf "Aviation Hazards: Thunderstorms and Deep Convection"] {{Webarchive|url=https://web.archive.org/web/20080910142826/http://www.caem.wmo.int/_pdf/thunderstorms/thunderstorms_02_effects.pdf |date=September 10, 2008 }}. Retrieved May 26, 2008.</ref> [[Volcanic ash]] is also a significant problem for aviation, as aircraft can lose engine power within ash clouds.<ref>[http://www.usgs.gov/tech-transfer/factsheets/7.html "Volcanic Ash Aviation Hazard"]. Retrieved May 26, 2008. {{webarchive|url=https://web.archive.org/web/20080621085505/http://www.usgs.gov/tech-transfer/factsheets/7.html |date=June 21, 2008 }}</ref> On a day-to-day basis airliners are routed to take advantage of the [[jet stream]] tailwind to improve fuel efficiency.<ref>Ned Rozell. [http://www.gi.alaska.edu/ScienceForum/ASF17/1727.html "Amazing flying machines allow time travel"]. Retrieved May 8, 2008. {{webarchive|url=https://web.archive.org/web/20080605031147/http://www.gi.alaska.edu/ScienceForum/ASF17/1727.html |date=June 5, 2008 }}</ref> Aircrews are briefed prior to [[takeoff]] on the conditions to expect en route and at their destination.<ref>[[National Weather Service]]. [http://www.weather.gov/om/brochures/pilot.htm "A Pilot's Guide to Aviation Weather Services"]. Retrieved May 26, 2008. {{webarchive|url=https://web.archive.org/web/20080624042742/http://www.weather.gov/om/brochures/pilot.htm |date=June 24, 2008 }}</ref> Additionally, airports often change which [[runway]] is being used to take advantage of a [[headwind]]. This reduces the distance required for takeoff, and eliminates potential [[crosswind]]s.<ref>Eric C. King. [http://takeofftools.com/Documents/Crosswind%20Calculator%20Instructions.pdf "Takeoff Tools Crosswind Calculator Instructions"]. Retrieved May 26, 2008. {{webarchive|url=https://web.archive.org/web/20080910142826/http://takeofftools.com/Documents/Crosswind%20Calculator%20Instructions.pdf |date=September 10, 2008 }}</ref>