COR
Indicates that the METAR is a correction to a previously issued observation. When an error is found in a routine or special observation, the corrected report replaces the original. The COR indicator appears near the beginning of the METAR, before the station identifier, to alert users that this supersedes an earlier report.
METAR COR KJFK
COR KORD 121856Z
METAR COR KLAX
COR stands for "Corrected Observation" in the remarks section of a METAR report. Indicates that the METAR is a correction to a previously issued observation. When an error is found in a routine or special observation, the corrected report replaces the original. The COR indicator appears near the beginning of the METAR, before the station identifier, to alert users that this supersedes an earlier report.
COR appears in the remarks (RMK) section at the end of a METAR observation. The remarks section follows the main body of the METAR and provides additional details about the observation that don't fit into the standard coded format.
Here is an example: "METAR COR KJFK". This appears in the remarks section and indicates corrected observation information as part of the weather observation.