Editing Snow (section)

===Event===
[[File:Winter Storm Jonas 2016 NYC Pershing Square.jpg|thumb|[[New York City]] during a [[January 2016 United States blizzard|2016 blizzard]], which produced strong winds and record-breaking snowfall.]]

[[Snow flurry]], [[Shower (precipitation)|snow shower]], [[snow storm]] and [[blizzard]] describe snow events of progressively greater duration and intensity.<ref>{{cite web|url=http://amsglossary.allenpress.com/glossary/search?id=snow-flurry1|author=Glossary of Meteorology|year=2009|access-date=June 28, 2009|publisher=[[American Meteorological Society]]|title=Snow flurry|url-status=dead|archive-url=https://web.archive.org/web/20071127144615/http://amsglossary.allenpress.com/glossary/search?id=snow-flurry1|archive-date=November 27, 2007|df=mdy-all}}</ref> A [[blizzard]] is a weather condition involving snow and has varying definitions in different parts of the world. In the [[United States]], a blizzard occurs when two conditions are met for a period of three hours or more: a sustained wind or frequent gusts to {{convert|sp=us|35|mph|m/s}}, and sufficient snow in the air to reduce visibility to less than {{convert|sp=us|0.4|km|mi}}.<ref>{{cite web |title = National Weather Service Glossary |url = http://www.nws.noaa.gov/glossary/index.php?letter=b |publisher = [[National Weather Service]] |year = 2009 |access-date = July 12, 2009 |url-status=live |archive-url = https://web.archive.org/web/20090509183315/http://www.nws.noaa.gov/glossary/index.php?letter=b |archive-date = May 9, 2009 |df = mdy-all }}</ref> In [[Canada]] and the [[United Kingdom]], the criteria are similar.<ref>{{cite web|title=Blizzards |url=http://www.mb.ec.gc.ca/air/wintersevere/blizzards.en.html |work=Winter Severe Weather |publisher=Environment Canada |date=September 4, 2002 |access-date=July 12, 2009 |url-status=dead |archive-url=https://web.archive.org/web/20090211120800/http://www.mb.ec.gc.ca/air/wintersevere/blizzards.en.html |archive-date=February 11, 2009 }}</ref><ref>{{cite web|title= Key to flash warning criteria |url= http://www.metoffice.gov.uk/weather/uk/guide/key_warnings.html |archive-url= https://web.archive.org/web/20101229172227/http://www.metoffice.gov.uk/weather/uk/guide/key_warnings.html |archive-date= December 29, 2010 |author= Met Office|author-link= Met Office |date=November 19, 2008|access-date= July 12, 2009}}</ref> While heavy snowfall often occurs during blizzard conditions, falling snow is not a requirement, as [[blowing snow]] can create a [[ground blizzard]].<ref>{{cite web |title = Blizzards |url = http://www.wrh.noaa.gov/fgz/science/blizzard.php?wfo=fgz |author = [[National Weather Service]] Forecast Office, [[Flagstaff, Arizona]] |publisher = [[National Weather Service]] Western Region Headquarters |access-date = July 12, 2009 |date = May 24, 2007 |url-status=live |archive-url = https://web.archive.org/web/20090115090647/http://www.wrh.noaa.gov/fgz/science/blizzard.php?wfo=fgz |archive-date = January 15, 2009 |df = mdy-all }}</ref>

Snowstorm intensity may be categorized by visibility and depth of accumulation.<ref>{{cite web|url=http://www.nws.noaa.gov/om/brochures/wntrstm.htm |title=Winter Storms...the Deceptive Killers |publisher=United States [[Department of Commerce]] |date=November 1991 |access-date=June 28, 2009 |author=National Oceanic and Atmospheric Administration |author-link=National Oceanic and Atmospheric Administration |url-status=dead |archive-url=https://web.archive.org/web/20090608185155/http://www.nws.noaa.gov/om/brochures/wntrstm.htm |archive-date=June 8, 2009 }}</ref> Snowfall's intensity is determined by [[visibility]], as follows:<ref>{{cite web|title=Snow|author=Glossary of Meteorology|url=http://amsglossary.allenpress.com/glossary/search?id=snow1|publisher=[[American Meteorological Society]]|year=2009|access-date=June 28, 2009|url-status=dead|archive-url=https://web.archive.org/web/20090220090504/http://amsglossary.allenpress.com/glossary/search?id=snow1|archive-date=February 20, 2009|df=mdy-all}}</ref>
* ''Light'': visibility greater than {{convert|sp=us|1|km|mi|sigfig=1}}
* ''Moderate'': visibility restrictions between {{convert|sp=us|0.5|and|1|km|mi|sigfig=1}}
* ''Heavy'': visibility is less than {{convert|sp=us|0.5|km|mi|sigfig=1}}
[[Snowsquall]]s may deposit snow in bands that extend from bodies of water as lake-event weather or result from the passage of an upper-level front.<ref name="popsci/nasa-snowstorm">{{cite news |date=3 February 2022 |title=NASA's storm-chasing planes fly through blizzards to improve snowfall forecasts |work=[[Popular Science]] |url=https://www.popsci.com/science/nasa-planes-improve-snowstorm-forecasts/ |access-date=9 March 2023}}</ref><ref name="weather/bandedsnowfall">{{cite web |author1=NOAA |title=What causes bands of heavy snowfall? |url=https://www.weather.gov/fsd/news_bandedsnowfall_20151121 |access-date=9 March 2023 |website=weather.gov |publisher=US Department of Commerce |language=EN-US}}</ref><ref name="nbcmontana/snow-bands">{{cite web |last1=Coombs |first1=Mitchel |date=28 November 2022 |title=3D Weather: Science of snow bands |url=https://nbcmontana.com/news/local/3d-weather-science-of-snow-bands |access-date=9 March 2023 |website=[[KECI]] |language=en}}</ref>

The ''International Classification for Seasonal Snow on the Ground'' defines "height of new snow" as the depth of freshly fallen snow, in centimeters as measured with a ruler, that accumulated on a [[snowboard (meteorology)|snowboard]] during an observation period of 24 hours, or other observation interval. After the measurement, the snow is cleared from the board and the board is placed flush with the snow surface to provide an accurate measurement at the end of the next interval.<ref name = Classificationonground/> Melting, compacting, blowing and drifting contribute to the difficulty of measuring snowfall.<ref>{{cite web|url=http://www.crh.noaa.gov/iwx/program_areas/snow_spotters/SnowMeasurement.pdf|title=Snow Measurement Guidelines for National Weather Service Snow Spotters|author=National Weather Service Forecast Office Northern Indiana|author-link=National Weather Service|publisher=National Weather ServiceCentral Region Headquarters|date=October 2004|url-status=live|archive-url=https://web.archive.org/web/20100215064901/http://www.crh.noaa.gov/iwx/program_areas/snow_spotters/SnowMeasurement.pdf|archive-date=February 15, 2010|df=mdy-all}}</ref>