Editing Weather forecasting (section)

== Specialist forecasting ==
There are a number of sectors with their own specific needs for weather forecasts and specialist services are provided to these users as given below:

=== 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>

===Marine===
{{See also|Marine weather forecasting}}
Commercial and recreational use of waterways can be limited significantly by wind direction and speed, [[Ocean surface wave|wave]] periodicity and heights, tides, and precipitation. These factors can each influence the safety of marine transit. Consequently, a variety of codes have been established to efficiently transmit detailed marine weather forecasts to vessel pilots via radio, for example the [[MAFOR]] (marine forecast).<ref>Great Lakes and Seaway Shipping. [http://www.boatnerd.com/facts-figures/mafor.htm "MAFOR Weather Code"] {{Webarchive|url=https://web.archive.org/web/20160616221137/http://www.boatnerd.com/facts-figures/mafor.htm |date=June 16, 2016 }}. Retrieved May 27, 2008.</ref> Typical weather forecasts can be received at sea through the use of [[RTTY]], [[Navtex]] and [[Radiofax]].

===Agriculture===
Farmers rely on weather forecasts to decide what work to do on any particular day. For example, drying [[hay]] is only feasible in dry weather. Prolonged periods of dryness can ruin cotton, wheat,<ref>Blair Fannin. [http://southwestfarmpress.com/news/061406-Texas-weather/ "Dry weather conditions continue for Texas"]. Retrieved May 26, 2008. {{webarchive|url=https://web.archive.org/web/20090703095038/http://southwestfarmpress.com/news/061406-Texas-weather/ |date=July 3, 2009 }}</ref> and [[Maize|corn]] crops. While corn crops can be ruined by drought, their dried remains can be used as a cattle feed substitute in the form of [[silage]].<ref>Dr. Terry Mader. [http://beef.unl.edu/stories/200004030.shtml "Drought Corn Silage"]. Retrieved May 26, 2008. {{webarchive|url=https://web.archive.org/web/20111005203246/http://beef.unl.edu/stories/200004030.shtml |date=October 5, 2011 }}</ref> [[Frost]]s and freezes play havoc with crops both during the spring and fall. For example, [[peach]] trees in full bloom can have their potential peach crop decimated by a spring freeze.<ref>Kathryn C. Taylor. [http://pubs.caes.uga.edu/caespubs/pubcd/C877.htm "Peach Orchard Establishment and Young Tree Care"]. Retrieved May 26, 2008. {{webarchive|url=https://web.archive.org/web/20081224112403/http://pubs.caes.uga.edu/caespubs/pubcd/C877.htm |date=December 24, 2008 }}</ref> Orange groves can suffer significant damage during frosts and freezes, regardless of their timing.<ref>{{cite news |date=January 14, 1991 |agency=[[Associated Press]] |url=https://www.nytimes.com/1991/01/14/us/after-freeze-counting-losses-to-orange-crop.html |title=After Freeze, Counting Losses to Orange Crop |newspaper=The New York Times |access-date=May 26, 2008 |archive-date=June 15, 2018 |archive-url=https://web.archive.org/web/20180615190918/https://www.nytimes.com/1991/01/14/us/after-freeze-counting-losses-to-orange-crop.html |url-status=live }}</ref>

=== Forestry ===

Forecasting of wind, precipitation and humidity is essential for preventing and controlling [[wildfire]]s. Indices such as the ''[[Forest fire weather index]]'' and the ''[[Haines Index]]'', have been developed to predict the areas more at risk of fire from natural or human causes. Conditions for the development of harmful insects can also be predicted by forecasting the weather.

===Utility companies===
[[File:Air handling unit.JPG|thumb|right|An [[air handling unit]] is used for the heating and cooling of air in a central location (click on image for legend).]]
{{Main|Degree day}}
Electricity and gas companies rely on weather forecasts to anticipate demand, which can be strongly affected by the weather. They use the quantity termed the degree day to determine how strong of a use there will be for heating ([[heating degree day]]) or cooling (cooling degree day). These quantities are based on a daily average temperature of {{convert|65|F}}. Cooler temperatures force heating degree days (one per degree Fahrenheit), while warmer temperatures force cooling degree days.<ref>[[Climate Prediction Center]]. [http://www.cpc.noaa.gov/products/analysis_monitoring/cdus/degree_days/ddayexp.shtml "Degree Day Explanation"] {{Webarchive|url=https://web.archive.org/web/20100524040629/http://www.cpc.noaa.gov/products/analysis_monitoring/cdus/degree_days/ddayexp.shtml |date=May 24, 2010 }}. Retrieved May 25, 2008.</ref> In winter, severe cold weather can cause a surge in demand as people turn up their heating.<ref>{{cite news |date=February 26, 1993 |newspaper=[[The New York Times]] |url=https://www.nytimes.com/1993/02/26/business/futures-options-cold-weather-brings-surge-in-prices-of-heating-fuels.html |title=Futures/Options; Cold Weather Brings Surge in Prices of Heating Fuels |access-date=May 25, 2008 |archive-date=June 15, 2018 |archive-url=https://web.archive.org/web/20180615135320/https://www.nytimes.com/1993/02/26/business/futures-options-cold-weather-brings-surge-in-prices-of-heating-fuels.html |url-status=live }}</ref> Similarly, in summer a surge in demand can be linked with the increased use of [[air conditioning]] systems in hot weather.<ref>[[BBC News]] (July 25, 2006) [http://news.bbc.co.uk/2/hi/uk_news/5212724.stm "Heatwave causes electricity surge"] {{Webarchive|url=https://web.archive.org/web/20170629200832/http://news.bbc.co.uk/2/hi/uk_news/5212724.stm |date=June 29, 2017 }}. Retrieved May 25, 2008.</ref> By anticipating a surge in demand, utility companies can purchase additional supplies of power or natural gas before the price increases, or in some circumstances, supplies are restricted through the use of [[Brownout (electricity)|brownouts]] and [[Power outage|blackouts]].<ref>Toronto Catholic Schools. [http://www.tcdsb.org/environment/energydrill/EDSP_KeyMessages_FINAL.pdf "The Seven Key Messages of the Energy Drill Program"]. Retrieved May 25, 2008. {{webarchive|url=https://web.archive.org/web/20120217042744/http://www.tcdsb.org/environment/energydrill/EDSP_KeyMessages_FINAL.pdf |date=February 17, 2012 }}</ref>

===Other commercial companies===
Increasingly, private companies pay for weather forecasts tailored to their needs so that they can increase their profits or avoid large losses.<ref>CSIRO. [http://www.csiro.au/science/pps9c.html#1 "Providing specialized weather forecasts"]. Retrieved May 25, 2008. {{webarchive|url=https://web.archive.org/web/20080419071008/http://www.csiro.au/science/pps9c.html |date=April 19, 2008 }}</ref> For example, supermarket chains may change the stocks on their shelves in anticipation of different [[consumer spending]] habits in different weather conditions. Weather forecasts can be used to invest in the commodity market, such as futures in oranges, corn, soybeans, and oil.<ref>Stephen Jewson and Rodrigo Caballero. [http://search.ssrn.com/sol3/papers.cfm?abstract_id=405780 "The Use of Weather Forecasts in the Pricing of Weather Derivatives"]. Retrieved May 25, 2008. {{webarchive|url=https://web.archive.org/web/20110716125422/http://search.ssrn.com/sol3/papers.cfm?abstract_id=405780 |date=July 16, 2011 }}</ref>

===Military applications===

====United Kingdom====
The British [[Royal Navy]], working with the [[Met Office]], has its own specialist branch of weather observers and forecasters, as part of the Hydrographic and Meteorological (HM) specialisation, who monitor and forecast operational conditions across the globe, to provide accurate and timely weather and oceanographic information to submarines, ships and [[Fleet Air Arm]] aircraft.

A mobile unit in the [[Royal Air Force]], working with the Met Office, forecasts the weather for regions in which British and allied armed forces are deployed. A group based at [[Camp Shorabak|Camp Bastion]] used to provide forecasts for the [[Operation Herrick|British armed forces in Afghanistan]].<ref>[[Met Office]]. [https://www.metoffice.gov.uk/about-us/weather-forecasting-for-military-operations "Weather forecasting for military operations"] {{Webarchive|url=https://web.archive.org/web/20171012094709/https://www.metoffice.gov.uk/about-us/weather-forecasting-for-military-operations |date=October 12, 2017 }}. Retrieved October 23, 2012.</ref>

====United States====
[[File:Npmoc.gif|thumb|right|The emblem of the Joint Typhoon Warning Center (JTWC).]]
Similar to the private sector, military weather forecasters present weather conditions to the war fighter community. Military weather forecasters provide pre-flight and in-flight weather briefs to pilots and provide real time resource protection services for military installations.

Naval forecasters cover the waters and ship weather forecasts. The [[United States Navy]] provides a special service for itself and the rest of the federal government by issuing forecasts for tropical cyclones across the Pacific and Indian Oceans through its [[Joint Typhoon Warning Center]].<ref>[[Joint Typhoon Warning Center]]. [https://web.archive.org/web/20061208162203/http://metocph.nmci.navy.mil/jtwc/menu/JTWC_mission.html "Joint Typhoon Warning Center Mission Statement"].  Retrieved May 27, 2008.</ref>

Within the United States, the [[557th Weather Wing]] provides weather forecasting for the Air Force and the Army. [[United States Air Force|Air Force]] forecasters cover air operations in both wartime and peacetime and provide [[United States Army|Army]] support;<ref>[[United States Air Force]].[https://web.archive.org/web/20070714070133/http://www.af.mil/factsheets/factsheet.asp?fsID=157 "Air Force Weather Agency"]. Retrieved May 26, 2008.</ref> [[United States Coast Guard]] marine science technicians provide ship forecasts for ice breakers and various other operations within their realm;<ref>[[United States Military]]. [https://www.usmilitary.com/coastguardenlistedoccupations.html#engineeringscienceandtechnical "US Coast Guard Jobs – Enlisted Occupations"] {{Webarchive|url=https://web.archive.org/web/20160312201542/http://www.usmilitary.com/coastguardenlistedoccupations.html#engineeringscienceandtechnical |date=March 12, 2016 }}. Retrieved May 26, 2008.</ref> and Marine forecasters provide support for ground- and air-based [[United States Marine Corps]] operations.<ref>Rod Powers. [https://www.thebalance.com/field-meteorology-oceanography-3345698 "United States Marine Corps Enlisted Job Descriptions and Qualification Factors: Field 68 – Meteorology and Oceanography (METOC)"] {{Webarchive|url=https://web.archive.org/web/20170806102458/https://www.thebalance.com/field-meteorology-oceanography-3345698 |date=August 6, 2017 }}. Retrieved 2008-05-26.<!-- as of October 11, 2017, Updated August 13, 2016--></ref> All four of the mentioned military branches have their initial enlisted meteorology technical training at [[Keesler Air Force Base]].<ref>[[Keesler Air Force Base]]. Military officers usually received their education from a civilian institution. [http://www.keesler.af.mil/shared/media/document/AFD-061113-086.pdf "Keesler News: March 9, 2006"] {{webarchive|url=https://web.archive.org/web/20080910142826/http://www.keesler.af.mil/shared/media/document/AFD-061113-086.pdf |date=September 10, 2008 }}. [[United States Air Force]] Retrieved May 26, 2008.</ref> Military and civilian forecasters actively cooperate in analyzing, creating and critiquing weather forecast products.