Dozens of schools are closed today as Storm Goretti brought thundersnow and travel disruption to Wales.

An amber weather warning for heavy snow is in force for the south Wales valleys, mid Wales and parts of north Wales, running until 09:00 GMT on Friday.

About 10 to 15cm of snow was expected to fall in the warning area, with up to 30cm on higher ground. Hundreds of homes are still without power.

Police advised motorists to avoid mountain roads in Rhondda Cynon Taf due to the dangerous road conditions overnight, with a number of vehicles reported to have broken down.

Some rail services have been cancelled through to the end of Friday, with passengers advised to check before travelling.

The storm also led to around 600 homes across Wales being without power at 08:50 GMT, according to the National Grid and many more in north and mid Wales, especially in Powys.

At least 150 schools were closed, with Powys, Blaenau Gwent and Wrexham the worst affected areas.

In Pembrokeshire, the council said their staff driving snow ploughs and gritters were facing “extremely challenging conditions”, with ploughing “becoming unsafe at times for our crews leading to accidents, and therefore we may postpone actions to ensure the health and safety of our staff”.

Dyfed-Powys Police warned motorists to “avoid all but extremely essential journeys” across Ceredigion and Powys.

The force said extreme weather conditions across both counties had led to “numerous incidents”.

Transport for Wales reported services suspended on routes including:

• Llandudno Junction to Llandudno; Llandudno Junction to Blaenau Ffestiniog
• Wrexham to Bidston
• Craven Arms to Swansea service (via Heart of Wales Line)
• West of Carmarthen
• Maesteg to Ebbw
• Hereford to Shrewsbury
• Shrewsbury to Birmingham International and Shrewsbury to Aberystwyth.

Other services were subject to reduced timetables.

Cross Country Trains said services were not running between Cardiff and Birmingham.

Some major roads were also affected, including the A465 Heads of the Valleys road reported to be just passable, the A483 Newtown bypass was closed both directions between Crossgates and Newtown due to a fallen tree.

The A44 was closed both directions from Llangurig to Aberystwyth due to snow. Mountain roads in the south Wales valleys were also hit.

A yellow warning for wind has been issued for the south coast and Wales, where gusts of up to 70mph are forecast.

Met Office chief forecaster Neil Armstrong said: “Storm Goretti will be a multi-hazard event, with the most significant impacts from snow in parts of Wales and the Midlands and the very strong winds in the far South West, though heavy rain in some parts of Wales and East Anglia also has the potential to bring disruption to many.”

Meanwhile, an amber warning for snow runs until 9am today.

This rare phenomenon, which can only happen in very specific conditions, can bring heavy downpours of snow.

As with usual thunderstorms, thundersnow also comes with lightning, which the Met Office says will look “brighter” as the light reflects off the snowflakes.

However, because the snowflakes dampen the sound, it’s often much quieter than a typical thunderstorm. This rare phenomenon, which can only happen in very specific conditions, can bring heavy downpours of snow.

As with typical thunderstorms, thundersnow also comes with lightning, which the Met Office says will look “brighter” as the light reflects off the snowflakes.

However, because the snowflakes dampen the sound, it’s often much quieter than a usual thunderstorm.