Topic: GOES-17 (West) Geostationary Lightning Mapper Test
   Update #2: Correction: The GLM Triple Wide Phase Two Test Outage will end on December 28th at 1300Z. 
   Update #1: Correction: The start time of the GOES-17 GLM Triple Wide Phase Two Test Outage is at 1800Z on December 27.
Date/Time Issued: December 20, 2021 1630Z
Product(s) or Data Impacted: GOES-17 GLM
Date/Time of Initial Impact: December 27, 2021 18:00UTC
Date/Time of Expected End: December 28, 2021 13:00UTC
Length of Outage: One 24 hour degraded product period. See Details below.
Details/Specifics of Change: Starting on Monday December 27 at 13:00UTC, GOES-17 GLM will perform testing to improve the data product. The degradation period is listed below:
This testing will be postponed in the event of a critical weather day. Events will slip one business day, remaining at the same time of day, until they do not conflict with critical weather day.