When do synoptic observations typically occur?

Synoptic observations are systematically collected at designated times to provide a consistent snapshot of weather conditions across a large area. The primary reporting times for these observations are usually set to occur every three hours at standard operational intervals. This schedule helps ensure that data is uniform and comparable across different locations, which is essential for weather forecasting and analysis.

In this context, the answer about main reporting times is correct because synoptic observations are not sporadic or limited to severe weather events; rather, they follow a consistent pattern to effectively represent prevailing weather conditions. Such structured timing facilitates better collaboration and data sharing among meteorological organizations, ensuring that all stations observe and report conditions at the same time.