Convective rain, or showery precipitation, occurs from cumulonimbus clouds. The weather in spring and autumn is usually showery and cool. Precipitation became more showery in nature during the evening hours. Convective rain, or showery precipitation, occurs from convective clouds, e.g. cumulonimbus or cumulus congestus. Convective rain, or showery precipitation, occurs from convective clouds (e.g., cumulonimbus or cumulus congestus). Showery Tor, Little Rough Tor, and Rough Tor. The weather at this time is often changeable (within each day) and occasionally showery.