When the average 2-minute wind speed exceeds 6 knots, what degree variation prompts encoding a variable group in column 6?

When the average 2-minute wind speed exceeds 6 knots, a variable group in column 6 is encoded to indicate significant shifts in wind direction. The correct degree variation prompting this encoding is 60 degrees. This threshold is essential because it helps pilots and weather observers identify when wind conditions could potentially affect aircraft operations. A 60-degree variation is sufficient to indicate a meaningful change in the wind direction that could have tactical implications for flight plans, takeoff, and landing.

In this context, the other degree variations do not meet the standard for reporting. A 30-degree variation may not indicate a significant enough change to affect operations, while 45 degrees, although more substantial, still falls short of the necessary criteria. A 90-degree change is typically characterized as a direct quartering wind change, which is less common for routine reporting. However, the established reporting standard of 60 degrees offers a balanced approach, capturing essential variances without overwhelming the report with less significant changes.