What is required to make a weather observation when there is total obscuration?

When total obscuration occurs, the visibility is severely limited due to factors such as fog, heavy rain, or snow. In such conditions, standard methods of weather observation, which typically rely on visual cues, are inadequate. A special observation is required to accurately assess and report the weather conditions during total obscuration.

Special observations are specifically designed to capture critical weather information that may not be represented by standard or routine observations. They involve the use of instruments and technology to gather data such as temperature, humidity, wind speed, and other meteorological factors. This ensures that even when visual cues are unavailable due to total obscuration, valuable and accurate information about the weather is still being reported, which is crucial for flight safety and operations.

Other types of observations, like standard or routine observations, may not sufficiently account for unusual or severe weather conditions like total obscuration, hence they would not be appropriate in this scenario.