I'm not sure why, but BS gets a large kick in Pit and Yaw just before it goes into the coil drivers state.  We've seen this 3 times in a row now, although these were the first times since ~lunch that the IFO was locked past DC readout.  So, it's perhaps related to our alignment / locking troubles, which are perhaps due to this LVEA temperature change that happened on Tuesday. 

The transient is visible in the LOCK_P and LOCK_Y channels for BS M3, but not in LOCK_L.  It is also visible in the WFS signals.