What is the significance of the COR modifier in a weather observation report?

The COR modifier in a weather observation report indicates that a correction has been made to a previously reported observation. This is important for ensuring the accuracy and reliability of the data being shared. When an observer identifies an error in the original data - which could include issues such as an incorrect temperature reading or a misreported visibility - they can use the COR modifier to signal that the current report offers corrected information. This helps users of the data understand that the information might differ from earlier reports, promoting proper interpretation and use of the data.

The significance of marking corrections is crucial in fields such as meteorology, where precise data is essential for forecasting and informing the public about weather conditions. The use of the COR modifier maintains clarity and trust in observational data, as it informs all users that they should consider the updated observations as the most accurate.