Final answer:
The SPECI observations for local ceiling, prevailing visibility, and runway visual range landing and circling minima at all EUs are generated by the weather technician.
Step-by-step explanation:
The SPECI observations generated for local ceiling, prevailing visibility, and runway visual range landing and circling minima at all EUs are performed by the weather technician and not AMOS. The local ceiling is the height of the lowest cloud layer above the ground, prevailing visibility refers to the horizontal distance one can see in clear weather conditions, and runway visual range landing and circling minima pertain to the visibility required for safe landing and circling of aircraft. These observations are crucial for aviation safety and are conducted by trained weather technicians.