I walk briskly back from an errand across the bridge, realising that the next cloudburst could come at any moment. The river has turned brown too. As it rises it brings a new load of assorted flotsam, which includes plastic pipes, to the silt island.
As it gets darker the House Martins, a flock of a hundred of them, swirl around in agitated fashion along the edge of the wood. They're not flying in the relaxed arcs that they use when trawling the skies for insects.
When the deluge comes they seem to have difficulty even staying in the air. They dodge and dip as if trying to escape the heavy rain with its peppering of hail stones.
Half an hour later the storm is miles away, a great tower of cloud heading towards Selby. It leaves a sense of relief and a clear blue sky in its wake.