Which of the following observations is not included as an element of SPECI criteria?

The observation related to the ceiling changes from 2,500 ft to 3,000 ft AGL does not meet the criteria for a Special Weather Report (SPECI). SPECI criteria are specific weather changes that warrant additional reporting between routine observations. Typically, significant changes such as a new cloud layer being reported below 1,000 feet AGL, a substantial shift in wind direction, and the onset of thunderstorms are conditions that would prompt a SPECI due to their impact on aviation and weather conditions.

In this context, the change in ceiling from 2,500 ft to 3,000 ft AGL does not constitute a significant change that meets SPECI criteria, as it only involves a modest fluctuation rather than a threshold that would require immediate reporting. Conversely, the other choices refer to events that have a more direct and immediate effect on weather conditions, making them more relevant for inclusion in a SPECI report.