From Astronomy 1999:
Generally penumbral eclipses are of little interest, lacking the
darkness and spectacular colour changes seen in a total eclipse. If the
moon makes only a shallow entry into the penumbra, it will only be
slightly dimmed and difficult to see.
However, this eclipse is interesting because it is a
total penumbral eclipse, which means that the Moon will be wholly
immersed within the Earth's penumbral shadow.
Total penumbral eclipses are vary rare, and only account
for 1.2% of all lunar eclipses. At mid eclipse the moon will be less
than one arc minute from the Earths umbral shadow. Because of this total
immersion, the eclipse will be quite apparent to observers with the
lunar northern region noticeably darkened.
Hmm this eclipse caught me totally by surprise. I had
been extremely busy and hadn't noticed this written down in my diary.
However about midnight I wandered outside to check out the sky as I
usually do when up late. The first thing I noticed was the dark northern
region of the moon. Wow! I had observed this rare eclipse without even
knowing about it.