Update #2: The time of impact has changed to August 19, 2021 1900 UTC to August 20, 2021 1900 UTC 
 
Update #1: This is a reminder that the GOES-17 Triple Wide Phase 2 Test  starts today, August 19, at 1800 UTC 
Topic: GOES-17 (West) Geostationary Lightning Mapper Test    
Date/Time Issued: August 19, 2021 2010Z
Product(s) or Data Impacted: GOES-17 GLM
Date/Time of Initial Impact: August 19, 2021 19:00UTC
Date/Time of Expected End: August 20, 2021 19:00UTC
Length of Outage: One 24 hour degraded product period. See Details below.
Details/Specifics of Change: Starting on Thursday August 19 at 18:00UTC, 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.