Residents and traders in Hebden Bridge, Mytholmroyd and Todmorden are being urged to prepare for possible flooding today (Monday, September 24).
Flood warnings have been issued for the River Calder from Todmorden to Brighouse.
The Environment Agency put the area on amber alert this morning, warning there was a risk to homes and businesses.
The agenvcy said: “Heavy rain is forecast to fall through Monday, with the potential for locally very heavy downpours in some locations. We are expecting to see river levels rising through Monday. River levels in fast responding catchments may rise quickly as a result of heavy isolated downpours.
“There is also the potential for some surface water flooding where water is unable to drain away. Further unsettled weather is forecast for the rest of this week and so river levels are expected to remain high.
“Brearley Fields in Mytholmroyd are expected to flood. Centre Vale Park in Todmorden is not currently expected to flood because the river is not forecast to reach the required level.”
The Met Office says prolonged periods of heavy rain are likely and winds will increase to gale force, with gusts to severe gale force, particularly over high ground.
It adds: “The public should be prepared for an increased risk of both surface water and river flooding during this period. Flooding issues may be exacerbated in places by drainage impeded by debris, for example leaves and small branches blown from trees.”