Since LHO is getting walloped by the remanants of a Pacific storm, the winds are high and the microseism is high, preventing locking. A while ago RichM had suggested that we try lowering the St1 RX blends when the wind was high, and it seems like this might be a good idea, under the right conditions. I started by switching ETMY, first attachment is ETMY ground vs ETMY RX during high winds, refs are 250 mhz (nominal, high)  blends, live measurement is with the 90 mhz, lower blends . There is a large improvement from .1 to 1 hz. We don't normally run this way because ground tilt is usually below T240 noise, but not today. To check that this wasn't making things worse at ETMY, I also checked the Y motion and it was similarly improved, second attachment, again, refs are 250mhz (nominal, high)  blends, live measurement is with the 90 mhz, lower blends. Again, there is some improvement in the .1-1hz band, low frequency doesn't seem to be any worse. If we look at the CPS as a low frequency witness (below the blend frequency) going to a lower blend doesn't seem to do anything bad, under these very bad, no good conditions, third attachment. Yet again, refs are 250mhz (nominal, high)  blends, live measurement is with the 90 mhz, lower blends. The brown trace shows the Y cps is moving somewhat less than the blue Y cps, so there is at least enough real low frequency signal that we are not injecting T240 RX noise into the Y loop.

Sheila and Evan were doing modecleaner measurements, so I didn't try to get any arm cavity signals. It would be nice if commissioners would give this configuration a shot while the environment is terrible.

I have left the ITMY and ETMY RX loops in these lower blends because it sounds like commissioners are probably packing it in. While winds and microseism are this high (20-50mph(?) wind, 95th percentile(?) microseism) I think we should try this configuration. When winds settle down the ITMY and ETMY ST1 RX blends should be switched back to the Quite_250 blends.