  PG 1448+273 is a luminous, nearby ($z=0.0645$), narrow line Seyfert 1 galaxy,
which likely accretes close to the Eddington limit. XMM-Newton observations of
PG 1448+273 in 2017 revealed the presence of an ultra fast outflow, as seen
through its blueshifted iron K absorption profile, with an outflow velocity of
about $0.1c$. Here, the first NuSTAR observation of PG 1448+273, performed in
2022 and coordinated with XMM-Newton is presented, which shows remarkable
variability of its ultra fast outflow. The average count rate is a factor of 2
lower during the last 60 ks of the NuSTAR observation, where a much faster
component of the ultra fast outflow was detected with a terminal velocity of
$0.26\pm0.04c$. This is significantly faster than the outflow component which
was initially detected in 2017, when overall PG 1448+273 was observed at a
lower X-ray flux and which implies an order of magnitude increase in the wind
kinetic power between the 2017 and 2022 epochs. Furthermore, the rapid
variability of the ultra fast outflow in 2022, on timescales down to 10 ks,
suggests we are viewing through a highly inhomogeneous disk wind in PG
1448+273, where the passage of a denser wind clump could account for the
increase in obscuration in the last 60 ks of the NuSTAR observation.
