What do the terms "PROB40 2102 +TSRA" signify in a Terminal Aerodrome Forecast?

The correct answer indicates that "PROB40 2102 +TSRA" communicates a four-decimal probability forecast related to weather conditions at an aerodrome. In this case, the term signifies that there is a forty percent probability of heavy thunderstorms and rain, which is relevant to pilots and aviation operations. This expression helps in planning and decision-making for safe flying.

The "PROB40" suggests a significant chance of the specified weather occurring, reaffirming its relevance. The "2102" denotes that this probability forecast applies starting at 2102Z (Zulu time or Coordinated Universal Time), allowing for effective timing in scheduling flights or taking necessary precautions. The "+TSRA" indicates the weather condition expected, specifically heavy thunderstorms and rain, providing further insights into what pilots may encounter.

Understanding this terminology is crucial for effective weather briefings in aviation operations and helps ensure safety when flying in potentially hazardous conditions.