Weather Report for February 2, 2011

Clear skies for the start of Campaign 25, but a very cold, windy night. At the start of the night, the temperature was around freezing. By morning twilight, it had dropped to 9 deg F (-12.8 deg C). This was the coldest that this observer has ever experienced on Kitt Peak and the forecast for the next two nights are for slightly colder temperatures. The sky was clear throughout the night but seeing was quite poor, as expected from such a rapid cooling. There were brief periods when the seeing approached 1.5 arcsec, but usually 2-4 arcsec seeing had to be endured. The poor seeing prevented observations of the faintest blazars on the target list, but presented little problem for the core objects that are gamma-ray bright at this time.