Final answer:
On a TAF, BKN250 indicates a broken cloud layer at an altitude of 25,000 feet.
Step-by-step explanation:
On a TAF (Terminal Aerodrome Forecast), the code BKN250 indicates a broken cloud layer at an altitude of 25,000 feet. The term "broken cloud layer" refers to a sky condition where there are gaps or breaks in the clouds, allowing some sunlight to pass through. The number "250" represents the base of the cloud layer, which means that the lowest portion of the clouds is located at 25,000 feet above the ground level.