Weather Report for May 22, 2015

A productive night, with nearly 20 blazars successfully observed. It was a cold and windy start to the night, but clear with seeing varying between 1.5 and 2 arcsec. An orographic cloud formed after midnight that blotted out the entire northeast quadrant of the sky. It lasted about an hour and fortunately did not affect observations. Near the end of the night, clouds moved in from the northwest, but again only affected the northern half of the sky, leaving desired targets in the clear. By the end of the night, the seeing had degraded to around 2.5 arcsec.