Editing Thundersnow (section)

===Upslope flow===
Similar to the lake effect regime, thundersnow is usually witnessed in terrain in the cold sector of an [[extratropical cyclone]] when a shortwave aloft moves into the region. The shortwave will steepen the local lapse rates, allowing for a greater possibility of both heavy snow at elevations where it is near or below freezing, and occasionally thundersnow.<ref>National Weather Service Office, Sacramento, California. Alexander Tardy. [http://www.wrh.noaa.gov/wrh/02TAs/0213/index.html Western Region Technical Attachment No. 02-13: Thundersnow in the Sierra Nevada.] Retrieved on 01-11-2006. {{webarchive|url=https://web.archive.org/web/20061014210656/http://www.wrh.noaa.gov/wrh/02TAs/0213/index.html |date=2006-10-14 }}</ref>