Editing Surface weather analysis (section)

{{short description|Type of weather map}}
{{Redirect|Surface analysis|other uses|surface science|and|etymology}}

[[Image:Surface analysis.gif|thumb|400px|A surface weather analysis for the United States on October 21, 2006. By that time, [[Hurricane Paul (2006)|Tropical Storm Paul]] was active (Paul later became a hurricane).]]
'''Surface weather analysis''' is a special type of [[weather map]] that provides a view of [[weather]] elements over a geographical area at a specified time based on information from ground-based weather stations.<ref>''Air Apparent: How Meteorologists Learned to Map, Predict, and Dramatize Weather.'' University of Chicago PressChicago: 1999.</ref>

Weather maps are created by plotting or tracing the values of relevant quantities such as [[sea level pressure]], [[temperature]], and [[cloud cover]] onto a [[geographical map]] to help find [[synoptic scale]] features such as [[weather fronts]].

The first weather maps in the 19th century were drawn well after the fact to help devise a theory on storm systems.<ref name="MILLER">Eric R. Miller. [http://docs.lib.noaa.gov/rescue/mwr/061/mwr-061-07-0189.pdf American Pioneers in Meteorology.] Retrieved on 2007-04-18.</ref> After the advent of the [[telegraph]], simultaneous [[surface weather observation]]s became possible for the first time, and beginning in the late 1840s, the [[Smithsonian Institution]] became the first organization to draw real-time surface analyses. Use of surface analyses began first in the United States, spreading worldwide during the 1870s. Use of the [[Norwegian cyclone model]] for frontal analysis began in the late 1910s across Europe, with its use finally spreading to the United States during [[World War II]].

Surface weather analyses have special symbols that show frontal systems, cloud cover, [[Precipitation (meteorology)|precipitation]], or other important information. For example, an ''H'' may represent [[high-pressure area|high pressure]], implying clear skies and relatively warm weather. An ''L'', on the other hand, may represent [[low pressure]], which frequently accompanies precipitation. Various symbols are used not just for frontal zones and other surface boundaries on weather maps, but also to depict the present weather at various locations on the weather map. Areas of precipitation help determine the frontal type and location.