Editing Fog (section)

== Definition ==
The term ''fog'' is typically distinguished from the more generic term ''cloud'' in that fog is low-lying, and the moisture in the fog is often generated locally (such as from a nearby body of water, like a lake or ocean, or from nearby moist ground or [[marsh]]es).<ref name=DistinguishCloud>Use of the term "fog" to mean any cloud that is at or near the Earth's surface can result in ambiguity as when, for example, a [[stratocumulus cloud]] covers a mountaintop. An observer on the mountain may say that he or she is in a fog, however, to outside observers a cloud is covering the mountain. ({{cite book |title=Standard practice for the design and operation of supercooled fog dispersal projects |last=Thomas |first=P. |year=2005 |page=3 |publisher=American Society of Civil Engineers |isbn=0-7844-0795-9 |url=https://books.google.com/books?id=AIvBjD_HXpEC&pg=PR2 |access-date=27 March 2016 |archive-date=3 September 2016 |archive-url=https://web.archive.org/web/20160903082350/https://books.google.com/books?id=AIvBjD_HXpEC&pg=PR2 |url-status=dead }}) In fact, some people commonly mistake mist for fog. These two are a little bit different as mist is thinner than fog. () Further distinguishing the terms, fog rarely results in rain, while clouds are the common source of rain.</ref> By definition, fog reduces [[visibility]] to less than {{cvt|1|km|mi}}, whereas [[mist]] causes lesser impairment of visibility.<ref>{{cite web |url=http://www.ofcm.gov/fmh-1/pdf/H-CH8.pdf |title=Federal Meteorological Handbook Number 1: Chapter 8 – Present Weather |date=1 September 2005 |pages=8–1, 8–2 |access-date=9 October 2010 |publisher=Office of the Federal Coordinator for Meteorology |url-status=dead |archive-url=https://web.archive.org/web/20110521015053/http://www.ofcm.gov/fmh-1/pdf/H-CH8.pdf |archive-date=21 May 2011}}</ref> For aviation purposes in the United Kingdom, a visibility of less than {{cvt|5|km|mi}} but greater than {{cvt|999|m|ft}} is considered to be mist if the [[relative humidity]] is 95% or greater; below 95%, [[haze]] is reported.<ref>{{citation |title=Annex 3 |edition=17th |date=July 2010}}</ref>{{Full citation needed|date=February 2010}}