Weather Report for July 19, 2012

The outflows from massive thunderstorms in northern Mexico ruined most of the night. However, eight bright blazars were observed, most in the last 1.5 hours of the night. Fortunately, Mrk421 was successfully observed during late evening twilight. This object is at it strongest gamma-ray output since the launch of Fermi. The seeing was good at 1.1-1.5 arcsec during the relatively brief periods when the dome was open. Photometry was attempted for only one target.

The forecast calls for increasing thunderstorm activity throughout southern Arizona during the next several days. It may be quite a challenge to squeeze more data out of this campaign.