Travel disruption, power cuts and flying debris are possible as Storm Ali brings severe gales of up to 80mph to the UK and Ireland.
The first named storm of the season is forecast to bring windy weather to all parts on Wednesday.
An amber warning covering Northern Ireland, northern parts of England and southern Scotland has prompted the Met Office to issue advice for the public to beware of flying debris which could pose a danger to life.
There is also potential for damage to buildings, fallen trees, travel cancellations, road closures and large waves in coastal areas, the forecaster added.
A yellow weather warning covering the rest of Scotland, Yorkshire and northern parts of Wales warns of gusts of up to 60mph.
While southern parts of England and Wales could reach continued unseasonable highs of up to 24C, it will feel cooler due to the strong winds, meteorologist Mark Wilson said.
Even areas outside the official weather warnings are unlikely to escape wet and windy conditions, he added.
He said: “The strong winds are going to continue throughout the day into the evening. It’s only really overnight the winds start to ease off and even then it stays pretty windy across Scotland so, a very windy spell throughout Wednesday into Wednesday night as well.
“It’s going to be windy everywhere and there will be a band of rain that pushes its way across the UK as well.”
Ali is first on the storm names list for 2018-19 announced by the Met Office and Met Eireann, which has run the Name Our Storms scheme for four years.
The season’s names have been compiled from a list of submissions by the public, choosing some of the most popular names and also selecting those which reflect the nations, culture and diversity of the UK and Ireland.
The practice is aimed at raising awareness of severe weather before it hits, with polling finding almost 80% of people think naming storms is useful in making them realise severe weather may have a greater impact than normal.
The unsettled weather is due to last right through the week, Mr Wilson added, but an improvement is expected early next week as drier weather is set to take hold.