Heavy rain and winds of up to 60mph are set to hit Wales as the first storm of the season arrives on Tuesday night.
Storm Aileen is expected to cause disruption across the country from 20:00 BST, with the worst winds expected in north Wales.
The Met Office has issued a yellow “be aware” warning and said journey times by road, rail and air were likely to be disrupted, with bridge restrictions.
There is also a chance of power cuts, and damage to trees and buildings.
An amber “be prepared” warning comes into force from 00:05 on Wednesday for north Wales when westerly winds with gusts of up to 65-75mph (105-120km/h) are expected.
Forecasters said flying debris and large coastal waves were possible, which could lead to injuries.
Conwy, Denbighshire, Flintshire, Gwynedd, Powys, Wrexham and Anglesey are likely to be the worst affected.
On Tuesday evening, rail companies warned of delays between Llandudno and Holyhead due to strong winds.