Storm Eunice has brought 122mph winds - the strongest ever recorded in England, the Met Office has confirmed.
The Needles, on the Isle of Wight, recorded the unprecedented wind gust this morning, according to a tweet by the national weather agency.
It adds that this is provisionally the highest gust ever recorded in England.
Dr Simon Lee, an atmospheric scientist, shared a photo of a satellite image of the storm on Twitter which he said "gave me chills".
"Storm Eunice is exploding in intensity west of Britain and Ireland," he wrote.
"I hope everyone has made the necessary preparations and stays safe."
The Met Office had already issued two rare red warnings, only the 11th time this highest level has been implemented by the national weather agency.
Meteorologist Alex Deakin said a "hook" in the swirls of cloud displayed in weather maps is "a sure sign that this storm is really intensifying".
Its strongest winds on the southern flank, "as the isobars really pinch together", he continued.
"Just because you're not in a red warning area does not mean that these winds aren't going to be severe.
"Potential for disruption across the amber warning areas as well.
"Serious threats to life across large parts of England and Wales, with these gusty winds throughout Friday."
Forecasters fear the cyclone could unleash a devastating sting jet, not seen in Britain for more than three decades.
The cyclone storm system is expected to bring hurricane winds to parts of the UK as Brits are advised to hunker down for the day.
Schools, businesses and transport have been locked down, with an array of other warnings to remain through the weekend.
The worst of the weather is forecast for South Wales and the south of England.
A sting jet is a rare system that sees an incredibly powerful, highly concentrated area of wind within a high-speed storm.
The worst of the damage caused in the Great Storm of October 1987 has been attributed to the phenomena - so named because its satellite photos resemble a scorpion's tail.
They are just 30 miles in width and last up to four hours in storms that pass across Europe.
The jets form when a stream of cold air is pulled down into a warmer system at the head of a storm, creating evaporation and accelerating airspeeds.
Major incidents have been declared across come cities and counties, with people advised not to travel unless essential.
Suffolk is the latest to do this, with residents warned to charge up their phones and prepare for a blackout, as high winds threaten the power supply.
Suffolk Resilience Forum has sent out a message to all residents as severe winds of up to 80mph are expected until 3pm.
Eunice comes on the back of Storm Dudley, which claimed one life and left thousands of people without power.
Meanwhile, travellers are being warned to check with their airline before making their way to an airport as a huge number of flights across the country have been cancelled.
In London City Airport, all flights have been cancelled and many have also been delayed or cancelled from Heathrow, Gatwick and Stansted.
London Mayor Sadiq Khan echoed TfL's advice to avoid non-essential travel in the capital.
He said: "I urge all Londoners to stay at home, do not take risks, and do not travel unless it is absolutely essential."
