A narrow plume of moderate-to-heavy cirrus that stretches more than
a 1000 miles to the southwest stayed pretty much centered on the
observatory all night as it moved past from the southwest to the
northeast. Observations were made through this muck all night long
and around a dozen blazars were measured for polarization, although
usually at a degraded S/N than is normal for this program. The
seeing roamed between 1 and 1.5 arcsec.