A complicated night for weather, but at least a lot of observing could be
accomplished. The first couple of hours of the night were marred by mid-level
clouds. These clouds formed, dissipated, and moved over the observatory
with maddening rapidity. The sky was mostly clear by 2200 local time, but
another shorter interval of clouds had to be endured around midnight. The
humidity rose steadily from 61% to 89% by morning twilight. The seeing was an
unremarkable 1.5-2 arcsec during the first half of the night and afterward
improved to 1-1.4 arcsec.