Editing Weather map (section)

== Plotting of data ==
{{Main|Station model}}
{{multiple image|align=left
|image1=Lowcloudsymbols.gif|caption1=Low étage (Sc,St) and upward-growing vertical (Cu, Cb)
|image2=Midcloudcymbols.gif|caption2=Middle étage (Ac,As) and downward-growing vertical (Ns)
|image3=Highcloudsymbols.gif|caption3=High étage (Ci,Cc,Cs)
}}
[[file:Weather symbolsNEW2.png|thumb|Present weather symbols used on weather maps]]
[[file:Wind barbs.gif|thumb|Wind barb interpretation]]

A [[station model]] is a symbolic illustration showing the [[weather]] occurring at a given [[Weather station|reporting station]]. Meteorologists created the station model to plot a number of weather elements in a small space on weather maps. Maps filled with dense station-model plots can be difficult to read, but they allow meteorologists, pilots, and mariners to see important weather patterns. A computer draws a station model for each observation location. The station model is primarily used on surface-weather maps, but can also be used to show the weather aloft. A completed station-model map allows users to analyze patterns in air pressure, temperature, wind, cloud cover, and precipitation.<ref>{{cite web |work=Co Co RAHS |year=2005 |url=http://ccc.atmos.colostate.edu/~hail/teachers/lessons/pdfs/DRAWING_ISOPLETHS1.pdf |title=Introduction to Drawing Isopleths |archive-url=https://web.archive.org/web/20070428172620/http://ccc.atmos.colostate.edu/~hail/teachers/lessons/isopleths.htm |archive-date=April 28, 2007 |publisher=Colorado Climate Center |access-date=April 29, 2007 }}</ref>

Station model plots use an internationally accepted coding convention that has changed little since August 1, 1941. Elements in the plot show the key weather elements, including [[temperature]], [[dewpoint]], wind, cloud cover, air pressure, pressure tendency, and precipitation.<ref>[[National Weather Service]] (2003). [http://www.srh.noaa.gov/ohx/educate/station_model.gif Station Model Example.] Retrieved on 2007-04-29.</ref><ref name="LIZ">{{cite web |first=Dr. Elizabeth R. |last=Tuttle |year=2005 |url=http://www.du.edu/~etuttle/weather/weather.htm |title=Weather Maps |archive-url=https://web.archive.org/web/20080709005941/http://www.du.edu/~etuttle/weather/weather.htm |archive-date=July 9, 2008 |publisher=J. B. Calvert |access-date=May 10, 2007}}</ref> Winds have a standard notation when plotted on weather maps. More than a century ago, winds were plotted as arrows, with feathers on just one side depicting five knots of wind, while feathers on both sides depicted {{convert|10|kn|km/h}} of wind. The notation changed to that of half of an arrow, with half of a wind barb indicating five knots, a full barb ten knots, and a pennant flag fifty knots.

Because of the structure of the SYNOP code, a maximum of three cloud symbols can be plotted for each reporting station that appears on the weather map. All cloud types are coded and transmitted by trained observers then plotted on maps as low, middle, or high-étage using special symbols for each major cloud type. Any cloud type with significant vertical extent that can occupy more than one étage is coded as low (cumulus and cumulonimbus) or middle (nimbostratus) depending on the altitude level or étage where it normally initially forms aside from any vertical growth that takes place.<ref name="Etages">{{cite book |editor=World Meteorological Organization |title=Étages, International Cloud Atlas |volume=I |year=1975 |url=https://archive.org/details/manualonobservat00worl/page/15 |pages=[https://archive.org/details/manualonobservat00worl/page/15 15–16] |isbn=978-92-63-10407-6 |access-date=26 August 2014 }}</ref><ref name="Plymouth State Meteorology">{{cite web |url=http://vortex.plymouth.edu/cloudboutique/ |title=Plymouth State Meteorology Program Cloud Boutique |author=Koermer, Jim |year=2011 |publisher=[[Plymouth State University]] |access-date=2016-03-28 |archive-date=2014-07-01 |archive-url=https://web.archive.org/web/20140701173917/http://vortex.plymouth.edu/cloudboutique/ |url-status=dead }}</ref> The symbol used on the map for each of these étages at a particular observation time is for the genus, species, variety, mutation, or cloud motion that is considered most important according to criteria set out by the [[World Meteorological Organization]] (WMO). If these elements for any étage at the time of observation are deemed to be of equal importance, then the type which is predominant in amount is coded by the observer and plotted on the weather map using the appropriate symbol. Special weather maps in [[aviation]] show areas of icing and turbulence.<ref name="Format">{{cite book |url=http://atmo.tamu.edu/class/atmo251/LandSynopticCode.pdf|title=Federal Meteorological Handbook (FMH) Number 2|editor=[[NOAA]] |publisher=NOAA |date=September 3, 2007 |page=C-17 |access-date=26 November 2014}}</ref>