Definition
Precipitation in the form of liquid water drops that falls from convective clouds, characterized by sudden onset, sudden ending, and rapid changes in intensity. Rain showers are associated with cumuliform clouds rather than the steady, layered stratiform clouds that produce continuous rain.
Plain English
Rain that starts quickly, often falls hard, and stops just as quickly. It comes from puffy, towering clouds rather than from a flat, gray overcast.
Context Anchor
Seen in weather reports, forecasts, and preflight weather briefings, often when conditions are unstable or rain is scattered rather than widespread.
Derivation
From the cumulus-type clouds that produce them. 'Shower' comes from Old English 'scur', meaning a brief fall of rain — capturing the short, bursty nature of the event compared to steady rain.
Why Pilots Care
Indicates possible turbulence, wind shifts, and rapidly changing visibility that can affect takeoff, landing, and enroute flight.
Grounding Statement
Picture flying toward a dark patch under a cloud: the air ahead may go from clear to heavy rain and back to clear within a few minutes.
Intuition Check
Do not read “shower” as just a light rain. In aviation weather, a rain shower can be light, moderate, or heavy; the key idea is that it is localized and changeable.
Example Sentence 1
The METAR reported SHRA, so the pilot expected brief, heavy rain showers near the field rather than steady rain.
Example Sentence 2
Rain showers moved through the area quickly, clearing the sky between cells.