What is the difference between a shower, a period of rain, a rain shower and a trace of rain?
The difference between rain and rain showers has to do with the duration of the event and cloud type involved. For rain, which can last from a few hours to days, the cloud formation has to be more stratiform (horizontal) in nature. That is not to say that convective events cannot be associated with areas of rain. Rain showers are usually short in duration, a few minutes to an hour and are the product of convective activity. You get rain only on cloudy days but can get showers on somewhat sunny days due to convective or bubbly cloud formations such as towering cumulus or cumulonimbus type clouds. The term trace is used for rainfall amounts of less than 0.2 mm this amount of rain isnt enough to completely wet pavement, and generally does not disrupt outdoor activities.
