Weather Report for September 17, 2017

Tonight was the official start of Steward Observatory optical observations in support of Fermi Cycle 10 and Campaign 100 of this program. Since bonus observations were made with SPOL at the 6.5m MMT at the end of August, these observations are not actually the first during Cycle 10. The August observations will be included in the Campaign 100 summary data tables from the Kuiper Telescope.

Unfortunately, tonight was very frustrating as almost half of the night was lost to high humidity and low clouds created by the mountain. This has been the weather pattern on Mt. Bigelow during the past week and there seems to be no end in sight to the flow of moist air from the south. Less than ten blazars were observed in gaps in the cloud cover. Conditions were typically very poor after about 0100 local time. The seeing was highly variable, ranging from about 1 arcsec to over 3 arcsec as clouds came and went.