Today I noticed a large, sustained step in the 100-300mHz band at EY. I didn't know of work that could affect this band that was going on down there, and at first I didn't notice any environmental changes around that time. I asked Jim and he suggested that the sensor correction is the most sensitive from the wind around that band so I looked further into it. Even though the magnitude of the wind didn't increase appreciably at that time, the direction changed. On my plot the average wind speed at bubble 1 is roughly the same at 2 and 3, but the ground motion is higher after the direction change. I'd guess that this direction change just started getting around our wind fence and perhaps started hitting it head-on and this is the fence coupling. Either way, while obvious in concept, it's nice to see in real life as well.