From the 11pm advisory:
The storm has become better organized-looking on satellite imagery,
with strengthening central convection and developing banding
features. Upper-level anticyclonic outflow also appears to be
increasing over the system. Flight-level winds, Doppler radar
velocities, and dropsonde data from a NOAA Hurricane Hunter aircraft
indicate that Ian's intensity is now near 55 kt.
Ian has turned toward the northwest and the initial motion estimate
is now 315/11 kt. During the next 48 hours, the tropical cyclone
is expected to turn toward the north as it moves along the western
side of a mid-level high pressure area. Later in the forecast
period, a broad mid-tropospheric trough over the eastern United
States is likely to induce a slightly east of northward motion.
However, around 4 days, the steering currents are forecast to
weaken as the trough moves to the east of Ian's longitude. Some
of the guidance model tracks such as that from the GFS have, again,
shifted to the east, mainly after 48 hours. The official track
forecast has been shifted somewhat to the east of the previous one
and is mainly a blend of the latest ECMWF and GFS predictions. It
should again be stressed that there is still significant
uncertainty in the track of Ian, especially in the 3-5 day time
frame. Users should not focus on the details of the track forecast
at longer time ranges.