Define marginal weather.

• A. Destination below 1000 feet ceiling and 3 miles visibility
• B. Alternate below 600 feet and 2 miles visibility
• C. Both of the above
• D. None of the above

Answer: (C)

Marginal weather means conditions that are at or near the minimums used for IFR flight planning, especially for determining whether a destination is acceptable and whether an alternate is usable. For planning an alternate, the forecast must be at least 600 ft ceiling and 2 miles visibility; if it’s worse, that alternate is considered marginal. For planning the destination, the forecast should meet minimums around 1,000 ft ceiling and 3 miles visibility; anything worse is marginal for arriving. Therefore, weather that is below the destination minimums or below the alternate minimums is all considered marginal. Since both scenarios describe such borderline conditions, they together define marginal weather.