in southern arizona, as in southeast asia, each year seasonally rains appear, driven by planetary weather engines like heat, humidity and prevailing winds. one feature of the arizona desert monsoon is the chubasco, a violent squall often accompanied by thunder and lightning.
this morning, during my daily check of the university of arizona webcam, i discovered that the site features a vault of time-lapse videos, http://www.cs.arizona.edu/camera/vault/ , including one on 26 june showing the arrival of the season's first chubasco. in addition, the 5 september 2007 video is a most impressive recording of a violent desert thunderstorm's arrival over the santa catalina mountains. check'm out !