Final answer:
Without the actual KMEM TAF data, it's impossible to provide the exact time, but typically, the TAF report would indicate when visibility is expected to drop below 3 statute miles, which is the FAA's minimum for sUAS operations.
Step-by-step explanation:
The student is asking about a forecast from the KMEM (Memphis International Airport) that pertains to the visibility for small Unmanned Aircraft Systems (sUAS) operations. Visibility is crucial for the safe operation of sUAS, and the Federal Aviation Administration (FAA) has set a minimum visibility of 3 statute miles (SM) for these operations. To determine when visibility might drop below this minimum on the 12th of the month (today), one would examine the Terminal Aerodrome Forecast (TAF) for KMEM. The TAF contains hourly weather forecasts for the airport and will detail when conditions such as visibility are expected to change.
Since the actual TAF is not provided in the question, we would look for an indication of visibility dropping below 3 SM within the TAF text. Often, this is noted by a forecasted visibility value followed by 'SM' for statute miles. It could also involve weather phenomena like fog (FG), mist (BR), or rain (RA) that can reduce visibility. If there was a forecast that said something like 'FM2000 2SM BR,' it would mean that from 2000Z (Coordinated Universal Time), the forecast predicts visibility to drop to 2 statute miles due to mist, which would be below the minimum for sUAS operations. Without the actual TAF data, one cannot determine the correct time, but the process described is how one would find it.