The Dartford bridge has been closed and ferries have been delayed by gusts of more than 60mph battering Kent.
The Highways Agency said the QEII bridge at the Dartford crossing was closed for safety reasons and the situation was being monitored.
BBC Travel news said cross-Channel sailings by P&O Ferries were disrupted and delays were possible on SeaFrance.
Kent Police said the A2 was blocked earlier after a lorry cab roof blew into the windscreen of another HGV.
Emergency teams were called to the crash on the coastbound carriageway near Dover at about 1145 GMT.
Storm force winds
The roof of the cab of a lorry on the London-bound carriageway was blown into the windscreen of a lorry coming in the opposite direction.
Officers said the glass was smashed and the driver suffered minor injuries.
The crash blocked both carriageways and the road was closed in both directions until about 1300 GMT, police added.
Kevin Richardson, harbour master at the Port of Dover, said: "We've had gusts of up to 55 knots this morning, that's Storm Force 10, so it's pretty extreme - right on the limit."
He added: "The ships are getting in and out at this moment, and we've got tugs out there, which are very powerful, and they earn their keep in this kind of weather."
He said high water was expected at Dover at about 1415 GMT but the port hoped to remain open.
Dover Castle closed
A spokesman for the Highways Agency said a contraflow was in operation at the Dartford crossing and both north and south-bound traffic were crossing the river through the tunnel bores.
He warned of longer queues during rush hour because of reduced capacity.
He also said latest Met Office information had suggested conditions would worsen from 1300 GMT until the early hours of Friday.
Divers of high-sided vehicles, caravans and motorbikes have been advised to take extra care.
All road users have been advised to check the weather forecast and road conditions before they travel.
Dover Castle, which is on top of the cliffs on the Kent coastline, was closed to visitors on Thursday because of the high winds.