  Using near-infrared observations of Neptune from the Keck and Lick
Observatories, and the Hubble Space Telescope in combination with amateur
datasets, we calculated the drift rates of prominent infrared-bright cloud
features on Neptune between 2018 and 2021. These features had lifespans of
$\sim 1$ day to $\geq$1 month and were located at mid-latitudes and near the
south pole. Our observations permitted determination of drift rates via feature
tracking. These drift rates were compared to three zonal wind profiles
describing Neptune's atmosphere determined from features tracked in H band (1.6
$\mu m$), K' band (2.1 $\mu m$), and Voyager 2 data at visible wavelengths.
Features near $-70 \deg$ measured in the F845M filter (845nm) were particularly
consistent with the K' wind profile. The southern mid-latitudes hosted multiple
features whose lifespans were $\geq$1 month, providing evidence that these
latitudes are a region of high stability in Neptune's atmosphere. We also used
HST F467M (467nm) data to analyze a dark, circumpolar wave at $- 60 \deg$
latitude observed on Neptune since the Voyager 2 era. Its drift rate in recent
years (2019-2021) is $4.866 \pm 0.009 \deg $/day. This is consistent with
previous measurements by Karkoschka (2011), which predict a $4.858 \pm 0.022
\deg$/day drift rate during these years. It also gained a complementary bright
band just to the north.
