Frontal fog is most likely to occur when warm, moist air is forced to rise over a colder air mass, leading to precipitation. If this precipitation falls through cooler air near the surface, it can

Here are the solutions to the questions:

11. Frontal fog is most likely to occur when warm, moist air is forced to rise over a colder air mass, leading to precipitation. If this precipitation falls through cooler air near the surface, it can saturate the air and cause fog. This scenario is most common in advance of a warm front (pre-frontal fog).

    • a) in summer in the early morning - More typical for radiation fog.
    • b) at the rear of a warm front - While fog can occur, pre-frontal fog is a more classic example of frontal fog.
    • c) in winter in the early morning - Could be radiation fog, but not specifically frontal fog.
    • d) in advance of a warm front - This is a classic scenario for pre-frontal fog, where warm rain falls into cooler air ahead of the warm front, saturating it.

    The correct option is d).

    $$\boxed{\text{d) in advance of a warm front}}$$

12. In a METAR (Meteorological Aerodrome Report), specific identifiers are used to designate different weather phenomena.

    • a) +SHRA - Heavy showers of rain.
    • b) TS - Thunderstorm.
    • c) SHRA - Showers of rain. This is the correct identifier for "showers of rain".
    • d) +RA - Heavy rain.

    The correct option is c).

    $$\boxed{\text{c) SHRA}}$$