A complex, breezy weather night due to a cold front that moved through the area
at around midnight. Mt. Bigelow produced a cloud cap twice within three
hours as the front moved through. In all, about two hours of observing were
lost waiting for the orographic clouds to dissipate. Prior to the front's
passage there were occasional very thin cirrus clouds and seeing of 1.5-1.8
arcsec. After the front moved through, the temperature dropped sharply
and the seeing blew up to 2.5-3 arcsec. The sky remained clear after the
second cloud cap dissipated at about 0030 local time.