Storm Imogen is set to dump high tides and heavy showers across parts of Britain while also blasting it with 80mph gales.
It could bring floods, and the Met Office has issued amber warnings of wind for much of the South West. There is a yellow warning stretching from southern Wales to the Thames Estuary as the storm sweeps in from the English Channel.
Given the heightened flood risk, the Environment Agency's Jonathan Day warned: "Storm Imogen will lead to large waves and spray along the south and south-west coastal parts of England on Sunday night and Monday. We understand it is tempting to see the force of Mother Nature but people should take extreme care on coastal paths and not put themselves and rescue workers at risk."
The storm-force winds are set to create giant waves and spray for the South West and south of England, particularly in Cornwall , Devon, the Bristol Channel, and parts of the Kent and Sussex coastline on Sunday night and into Monday.
Imogen is threatening to fell trees, down power lines and wreak havoc with the morning commute, while high winds are expected to carry thundery downpours throughout the day that have the potential to cause problems into the evening rush hour.
Mr Day said there is also "a continued risk of minor river flooding into next week in the south and south west of England as rivers will continue to rise in response to recent rainfall".
Tracts of coastal Devon and Cornwall have been told to be prepared for large waves and localised flooding.
Met Office forecaster Craig Snell said: "We have issued a broad yellow warning of wind that encompasses Cardiff, Bristol and into the Thames Estuary.
"There is an amber warning for wind mainly focused on Devon and Cornwall but stretching into central England on Monday morning.
"This means people should be prepared for disruption to travel on roads, rail, bridges and ferries and we could see possible damage to structures and downed trees risk affecting power.
"The wind will be combined with some hefty showers with some thunder along the south coast."
The warnings will be in place from 3am until 6pm on Monday, with gusts of 60-70mph expected widely.
Exposed areas on the south coast are on alert for gusts of 80mph with the potential to whip up "very large waves", particularly in Cornwall and north Devon.
Forecasters said the morning rush hour will be "especially impacted" as Imogen tracks eastwards across an area south of the M4.
Drivers are being urged to check the weather and driving conditions before setting out and pay particular attention to exposed locations such as coastal and high-lying areas, and bridges which could be affected by the high winds.
Gary Webb from Highways England said: "If you do have to make a journey by road be prepared, plan your journey in advance and check the latest weather conditions along your route.
"Be aware of sudden gusts of wind, and give high-sided vehicles, caravans, and motorbikes plenty of space."