Weather Report for February 7, 2011

A generally excellent night. There was some scattered, thin cirrus at sunset, but the sky rapidly cleared and was photometric for the rest of the night. The seeing started out at 1.5-2 arcsec for the first few hours and then improved to 1.0-1.5 arcsec. However, the seeing deteriorated after about 0400 local time (2-3 arcsec). During this period, there were some exceptionally nasty (but brief) seeing bursts. At one point, observations were halted for about 10 minutes as the seeing blew up to something like 10 arcsec.