If a TAF report forecasts light rain changing to moderate snow, how would this appear?

The correct interpretation for a TAF report forecasting light rain changing to moderate snow is reflected in the option indicating light rain transitions to moderate snow. In this context, the use of the light rain prefix "-SH" before the precipitation type is crucial, as it signifies the intensity of the rain is light.

The "BECMG" indicates a change occurring over a specific time frame, in this case from 1709 to 1712. The "SHSN" denotes that the precipitation type is snow with the "SH" prefix indicating that it is of a moderate intensity. This makes the report accurate in describing the precipitation conditions as they evolve from light rain to moderate snow.

The clarity in using the appropriate meteorological notation helps in understanding the forecast accurately. In contrast, other options may lack the necessary information about intensity or the transition, which is key in weather reporting as it informs pilots and others about potential weather impacts on operations.