There is a flood alert in force for the Upper River Tamar, based on a forecast for heavy rainfall over this evening (Friday) through to midday Saturday with the potential for surface water and river flooding from the early hours of Saturday morning.
There will be prolonged rainfall over this evening and throughout the night, with many places seeing 10-20mm of rain.
Within this, there is a potential for localised intense periods of rainfall leading to 30-40mm falling over a few hours.
The forecast is unclear on the precise location of these areas in Cornwall.
Over higher moorland areas rainfall totals could reach 80-90mm.
This rain is falling on wet ground, increasing the amount of surface water running off the land and into streams and rivers.
This rainfall will be accompanied by strong southwesterly winds which could lead to significant leaf fall, contributing to increased flood risk due to blocked drainage gullies.