How often is a Transcribed Weather Broadcast (TWEB) issued?

The Transcribed Weather Broadcast (TWEB) is indeed issued every 4 hours and is valid for 12 hours. This schedule allows for timely updates on weather conditions, ensuring pilots and other aviation personnel have access to relevant and current information for flight planning and safety.

TWEBs provide critical weather information, particularly for areas where other forms of weather reporting may not be as easily accessible. By maintaining a 4-hour issuance cycle, TWEBs are able to reflect the changing weather patterns and conditions that can significantly affect aviation operations. This structure is designed to ensure that the information remains useful and actionable for those involved in aviation.

The other options suggest less frequent updates or longer validity periods, which would not adequately account for the dynamic nature of weather changes that can impact flight safety and operations.