Planes, trains and ferries could all be disrupted tomorrow as severe gales and rain sweeps across Scotland.
Gusts of up to 75mph are expected to hit lower-lying parts of central Scotland, with the potential for 85mph winds on higher ground.
The Met Office has issued an amber "be prepared" weather warning for wind in the central belt which is expected to last from 8am to 5pm tomorrow. A yellow "be aware" warning for wind will also be in place for all of Scotland until 10pm.
Met Office spokeswoman Bonnie Diamond said: "Winds will start to pick up in the morning but will strengthen by lunchtime.
"We are looking at possible cancellations for longer journeys - road, rail, ferry and air services will all be affected. Roads and bridges are also likely to close, and large waves will affect coastal roads and seafront properties. With that, there is a risk of injury. Trees will also be uprooted more easily as many still have their leaves. It only takes one tree to fall on a train track to cause a lot of disruption.
"The yellow warning for wind covers the whole of Scotland but the amber zone is where winds will be strongest, so airports in this zone will see the most impact from the strongest winds. There could well be delays."
A raft of CalMac ferry services will also be affected tomorrow, with 23 of the 28 sailing routes subject to disruption or cancellation.
Wind gusts above 60mph could also mean the Queensferry Crossing has to close to double-decker buses. And gusts exceeding 70mph could mean closures for all high-sided vehicles and caravans.
The Scottish Environment Protection Agency has also issued flood alerts for Skye and Lochaber, Easter Ross and the Great Glen and Argyll and Bute.
The Met Office website also warns of some damage to buildings being possible, such as tiles being blown from roofs and the possibility of falling trees and branches.
There may also be power cuts and "injuries and danger to life" from flying debris.
Ms Diamond added: "Gusts inland within the amber zone will typically range between 65mph and 75mph but on higher ground they could reach 85mph."
Storm Helene, which was downgraded after initial warnings that it may pose a risk to life, is moving away towards the north east.
This morning, the Met Office renamed the current weather system Storm Ali - the first UK storm of the 2018-19 season.