Commuters have been warned to expect widespread travel choas as Scotland feels the force of Storm Gertrude.

It is expected to bring further heavy rain and wind gusts of up to 90mph throughout Friday and during the weekend.

Rail passengers experienced problems tonight as all low-level trains out of Glasgow Central were reportedly subject to delays and cancellations after a signal failure.

The problems are believed to have been traced to Yoker.

Elsewhere, it has been announced that the Forth Road Bridge is likely to be closed to all traffic except cars on Friday morning, and may be shut entirely as winds peak at around 8am.

Operator Amey said: "The bridge is expected to be closed to cyclists and pedestrians throughout the day, and remains closed to HGVs while repairs to the truss end links continue.

"Public transport is likely to be affected, with winds forecast in excess of the level at which buses would be permitted to cross from approximately 4am onwards."

Amber 'be prepared' warnings for winds have been issued from 3am until 10am tomorrow for the Highlands and the Western Isles, Grampian, Strathclyde, Central, Tayside & Fife, and Dumfries, Galloway, Lothian & Borders.

The Met Office has issued also yellow 'be aware' warnings for rain, snow and ice in these areas.

The amber warning means all schools in the Western Isles, Orkney and Shetland will close for the day and Western Isles bus services have been suspended until noon.

Orkney Island Council's head of schools, Peter Diamond, said: "At the moment, the severe winds are predicted to be at full strength in the early morning when pupils would be travelling to school. Given the forecast, we have decided to close all schools on Friday."

ScotRail will operate a limited service, with routes in the Highlands and west coast particularly affected.

In the central belt, no trains are expected to run until at least the afternoon between Perth and Inverness; Glasgow and Fort William; Dumbarton and Helensburgh; Kilmarnock and Stranraer; Kilwinning and Ardrossan; Ayr and Girvan; and Glasgow and Dunblane.

Hundreds of engineers will be deployed across the network to inspect lines, repair damage and reopen routes as quickly as possible.

Phil Verster, ScotRail Alliance managing director, added: "We will be withdrawing some services until the worst of the storm has passed.

"The safety of our passengers and workforce is our top priority and we cannot run services on these lines until our engineers have thoroughly inspected the network for any damage.

"In order to get the most up to date information about their journey, customers should check our website or app before setting out to travel. Leaving more time for travel is also advised.

"We will be monitoring the weather conditions closely throughout the day and have specialist teams ready to deploy quickly to deal with any issues caused by the storm.

"We are also working closely with our industry partners to limit disruption while maintaining a safe network for passengers."

A succession of storms since December has seen widespread flooding and major disruption to travel, with the latest misery expected to continue through to the weekend.

The Met Office has also issued an amber "be prepared" warning for high winds in Northern Ireland, north west and north east England.

Yellow "be aware" warnings for rain, snow and ice are in place across much of the UK.

Forecasters said: "West to south-westerly gales are expected to develop widely across Scotland, Northern Ireland and parts of northern England early on Friday.

"Winds are expected to widely gust 60-70mph, possibly up to 80mph along exposed coasts and over hills.

"Be prepared for the likelihood of difficult driving conditions and disruption to travel, such as cancellation to ferry services and bridge closures.

"Some structural damage is also possible, as well as disruption to power supplies. Heavy rain and surface water will be additional hazards in places."