Regions of unrealistically high values appeared in the IMERG Early and Late files starting around 00:00 UTC on 17 October 2024.  Upon investigation, GPM scientists detected an operational problem on the GPM Core Observatory around 15 October 2024 that caused some corrupted CORRA data to be added to the CORRA-GMI calibration accumulator files for the IMERG Early and Late Runs.  These anomalous data affected the calibration when it was next updated (on 17 October 2024).  Repaired calibration files were applied at 06:00 UTC on 2 November 2024.  The time spans of the unrealistic calibrations in Early and Late are approximately the stated times minus each Run’s latency (4 and 14 hours, respectively).  Affected areas include:

• the central Indian Ocean and Maritime Continent extending across the Bay of Bengal and Southeast Asia into central China,
• southeast of South Africa,
• the Middle East,
• possibly north of the Caspian and Aral Seas, and
• the central Andes extending to Central America and the adjacent Caribbean Sea. 

Users who applied the Early and Late data as it was produced should check for negative impacts of this problem over these regions during this period.  Users who subsequently employ the Early and Late should avoid using the affected data.