After the nearly 3hr long lock at ~50W, we were paused at Locking Arms Green due to an X-arm which started low in power and slowly recovered (probably due to cooling).

Backing up:  During the previous long lock at high power, Jenne noticed that ALS X was visibly misaligned in yaw (could easily see in camera).  

After the lockloss and attempting to get H1 back up, we could see the ALSX was slowly struggling to recover.  The theory was this is due to some sort of cooling effect after the 50W lock.  Attached is a screenshot  of trends for  oplevs, TMS pit/yaw, ALS transmission, and the PSL power.  The story here (starting from left to right) is:

1. 2-hrs of locking at low power, 
2. 2-hrs of the 50W lock
3. ALS locking for 7min after tonight's 50W lock

(For the plots, oplev pitches are the plots on the top & yaws are on the bottom)

• Notice the 7min plots' ALS-X_TR & ETMX yaw oplev (circled in blue).  Jenne hadn't seen this issue before.
• Compare the above effect with locking at 2W earlier in the day (circled in red).  Everything is flat.
• SIDE NOTE:  Also, for the BS pit oplev (circled in green), there is a cooling effect here----but this is a known effect.