Very clear and cold this morning, with temperatures in the low teens. The rest of the day stayed mostly clear with calm winds before scattered cirrus moved in by the late afternoon. The temperature rose to just above freezing in the afternoon. 

The morning data check showed no new data issues, other than a couple of HRXL’s not reporting. We reset the HRXL at CC, SP, and DCS around 10:15. This usb reset seems to be necessary every 1-2 days at these three sites. 

Since there were no other pressing issues, we decided to lower the PRS tower to replace the 32m thermocouple and retrieve an EC100 serial number for Dan. We started around 11:15 am and finished before 12:30 pm. Everything looked good when we left the site, but as is common the site dropped off the network shortly thereafter. It came back around 4:40 pm and everything was reporting normally. 

In the afternoon we lowered the DCS tower to replace the 7m and 32m thermocouples. Unfortunately we weren’t able to connect to the DSM to verify their function and the tower dropped from the network while we were there as well. Now that the site is back on the network, we can confirm that the new thermocouple at 32m is not reporting. We will plan on replacing it again tomorrow morning and may have to do more troubleshooting if it's not the thermocouple itself that is bad. The previous 32m thermocouple was reporting intermittently and at times with obviously bad data, so it's possible there is another problem at play.

We ended the day after the sounding and a quick data check, in which we found no other issues. Tomorrow we will swap batteries at DC and replace the thermocouple again at DCS.