When might a meteorologist use a global weather map together with a regional map to make predictions for local weather

A meteorologist might use a global weather map together with a regional map to make predictions for local weather when they are trying to determine the potential for a storm system to move into the area. By looking at the global map, they can identify any large-scale weather patterns that could affect the region, and then use the regional map to get a more detailed look at the local weather conditions.