Incoming tide
The sea rising up the beach — a slow, certain advance you cannot push back against.
An incoming tide in a dream is the dream's image of a slow, certain advance that does not respond to argument. The tide is not aggressive; it is on schedule. The dream brings the incoming tide when something in your life — an ageing, a deadline, an institutional change, a piece of accumulating evidence — is moving up the beach toward you and the only sensible response is to move what you want kept further inland. A tide watched and the things on the sand collected in time is the dream affirming the right reading of the schedule. A tide that arrives at the picnic with everything still spread out is the dream noting that the schedule was clearly available and you decided not to consult it.