As thundersnow rumbled on in a flurry of flakes, Scotland unveiled one of its best kept weather secrets this week, a natural phenomenon often reserved for the more northerly parts of the UK.

With weather warnings issued, rumbles of thunder were heard among snowy showers as strange rainbows devoid of colour were spotted and even ghostly images appeared on mountain ranges across Scotland.

As some of the country's best kept natural secrets emerged in the wintry weather, here are six of the weirdest and most wonderful ways snow, rain and fog have come together to create stunning natural phenomena over the past few years in Scotland.

Over the past few days, the threat of a 'thundersnow' storm loomed over Scotland as forecasts predicted a plunge in temperature and a yellow weather warning was issued.

Thundersnow is essentially a storm but with snow instead of rain.

The unusual phenomenon, which is a rare occurrence in Scotland, occurs when heavy snowfall is accompanied by thunder and lightning, unlike a regular thunderstorm where the thunder and lighting is accompanied by rain.

Freezing cold air picks up moisture and the difference in temperature sees clouds develop high in the atmosphere, resulting in thunder and lightning as the freezing temperatures allow for snowfall.

Reports are often rare as the snowfall can muffle the noise of the thunder, meaning only small areas can hear the rumbling clouds.

Mostly recorded in the Northern Isles, Scotland saw flurries and thunder in 2010 in Dundee, Perth, Aberdeen and Inverness, in 2015 over Tayside and more recently on Thursday over East Kilbride.

Like winter's version of a lily pad, these flat frozen circles which float upon the surface are created when waves jostle smooth pieces of ice together, rounding their edges.

Colliding with the waves, ice pancakes develop raised edges which imitate the baked goods, hence the name.

A phenomenon usually reserved for the frozen temperatures of Antarctica and the Baltic Sea, ice pancakes have been spotted on occasion floating on rivers in Scotland.

In November, motorist Dan McLeod captured these ice pancakes at Helmsdale in the Highlands and in 2014, they were spotted on the River Dee a few miles downstream of the Queen's royal residence at Balmoral.

Ice panckes aren't the only weather phenomenon that can occur in cold temperatures on Scotland's rivers.

The rounded pancakes shapes can meld together in certain conditions to transform back into sheet ice, which, if the water and ice is thick enough, can push upwards to create stunning shards called ice ridges.

Spotted on the River Ayr a few years ago, Bruce Philip, who snapped the icy display, said the spectacular sight caused traffic delays as motorists slowed to take in the stunning weather phenomenon.

Forming like muted rainbows, Fogbows are similar to their colourful cousins but appear completely white due to the size of the water partials suspended in the air.

During foggy conditions, the water particles are far tinier than raindrops and so cannot reflect the magnificent colours found in a rainbow.

The sun's light is still refracted by the water particles but the resulting colours are so weak they cannot be picked up by the naked eye.

A fogbow was spotted in November in Rannoch Moor by Melvin Nicholson, but more recently the phenomenon was photographed this week in the Trossachs - alongside another of nature's tricks.

As Scotland experienced extreme wintry weather this week, a retired police officer spotted himself as a mountain angel whilst photographing a fogbow.

Capturing two natural phenomenons at once, John McSporran spotted the rare weather moment after climbing Ben A'an in the Trossachs.

A brocken spectre is a natural phenomenon well known amongst climbers, occurring when the sun and a person's own shadow collide, often in misty conditions.

Also known as mountain angels, the spectres can seem enormous as the reflection is magnified and cast upon the upper surfaces of clouds.

A figure can appear to be surrounded by a glowing halo, as rings of coloured light are created when sunlight meets a cloud of water droplets.

Perhaps better known as the more palatable sea foam, coastal villages and towns are often at the mercy of spume churned from the sea which creeps up from the shoreline.

In 2012, Aberdeen fishing village Footdee woke to a covering of sea foam, engulfing cars and spraying up onto houses after a stormy night in the North Sea.

The thick foam occurs when sea water, often during stormy conditions, churns together with plant plankton residues, trapping air in the breakwater to create bubbles which clump together and blow ashore thanks to its low density.

Thankfully, residents of Footdee only had to endure the covering for a few hours, as the foam was washed away by a lunchtime shower and the area simply needed a good sweeping by council workers afterwards.