The Met Office has issued a weather warning about harbour flooding tonight, with Castletown particularly at risk.
An amber warning runs from 9pm, and says promenades in Douglas, Ramsey, Laxey and Castletown as well as Shore Road in Rushen could see waves breaking over them.
But from 11pm a yellow flood warning says the Tongue in Douglas, West Quay in Ramsey and Castletown harbour all face a risk of flooding at high tide.
The Met Office says flood defences will need to be deployed in Castletown.
A weather warning for severe gale force winds runs from 2pm as Storm Agnes approaches the Island.
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