Forecasters are warning people to stay indoors on Friday night as Storm Arwen sweeps in with winds of up to 65mph.
Jersey Met issued a red warning to "avoid outside activity" and Guernsey Police are advising islanders to secure garden furniture.
Winds are expected to peak at about 06:00 GMT on Saturday said Jersey Met.
People are also advised to avoid walking on the coast and sea swimming and "expect disruption".
Today: Sunny periods and a few blustery showers. Clear intervals and showers from this evening, some heavy with hail and a risk of thunder. Max: 10°C. pic.twitter.com/xyY40fsWWW— Jersey Met (@Jersey_Met) November 26, 2021
Parts of the UK are expected to be battered by winds of up to 100mph when Storm Arwen arrives.
The UK Met Office has issued a red warning the highest level, which is issued only rarely, meaning there is potentially a risk to life.
Jersey Met said strong north-westerly winds would increase throughout the night but start dropping on Saturday morning with gales in exposed areas.
Guernsey Coastguard urged boat owners to check their vessels "when safe to do so" and call 999 if they get into trouble at sea.