Plain English Meaning
A weather forecast for a large area rather than a single airport. It tells you what to expect across a whole region during your flight.
Full Definition
An aviation weather forecast covering general weather conditions over a wide region, typically several states, valid for a specified period. It describes expected cloud cover, cloud bases and tops, precipitation, visibility, icing, turbulence, and freezing levels across the forecast area. Used by pilots to get the broad weather picture between specific airport forecasts.