GOES-18 became the operational GOES-West satellite at 1800 UTC on 4 Jan 2023 from the 137.0W position. The accompanying press release for the move can be found here. GOES-17, currently at 137.3W, will begin its drift to the 104.7W storage position on 10 Jan 2023, where it will serve as the on-orbit spare for both GOES-East and GOES-West.
Loading PACUS Sector GOES-West ch08 water vapor imagery in AWIPS over the EPAC cyclone, one observes the change in imagery appearance from 1756 UTC (GOES-17) to 1801 UTC (GOES-18), becoming slightly “cleaner/smoother” (Fig 1). Of course, users are well aware of the particular improvement of imagery going from GOES-17 to GOES-18 during the GOES-17 “warm periods“, which resulted in significant degradation of the GOES-17 imagery. See past examples of transition from G17 to G18 into interleave periods.
Zooming out on the impressive cyclone approaching the west coast, and viewing a longer animation of GOES-West Airmass RGB imagery, we can again note the transition from GOES-17 to GOES-18 midway through the loop (Fig 2). Specifically, areas of horizontal striping from GOES-17 are not present from GOES-18.
Bill Line, NESDIS/STAR