People have been warned Storm Eunice is a “risk to life and limb”, as the government emergency response Cobra committee is due to meet.
Strong winds have prompted two rare red weather warnings for much of the south of England and part of Wales on Friday.
Security minister Damian Hinds said the public should “take precautions” and said the army was on “high readiness standby” to help.
“We are strongly encouraging people to take precautions and make sure they stay safe,” he told Sky News.
Hinds warned the red weather warnings indicated a “risk to life and limb”.
“Cobra have been convened about making sure the readiness is in place for this storm,” he added.
The second rare highest alert – meaning a high impact is very likely – was issued to run from 10am until 3pm over the East of England on Friday.
The warning covering Greater London, Kent, Surrey and other parts of the South East joined an earlier-announced red weather warning starting from 7am along the coastline of Devon, Cornwall and Somerset.
Wind gusts in the most exposed coastal areas could exceed 90mph, the Met Office said, while an amber warning for gusts up to 80mph covers the whole of England from 5am to 9pm.
The Met Office added that the dangerous weather phenomenon known as a sting jet – a small area of highly intense wind inside a storm – could form later on Friday.
It comes after Storm Dudley caused travel disruption and power cuts to parts of the UK on Wednesday.