Brocken Spectre

Where to see a Brocken Spectre in Rannoch

It's not just where but when as well.

You need the right conditions and the right topography.

What is a Brocken Spectre? It is a rainbow-like phenomenon that is seen when the sun shines behind you onto a bank of mist that is below you.

It spring and autumn when there is a high pressure the glens may fill with mist overnight when cold dense air streams down into the valley. They warmer air sitting as a layer above can hold more moisture and so does not have the mist.

There may be a series of mornings when you get up and all is mist but you realise from experience that this mist will rise later in the day as the sun warms it up. The chances are that if you climb the hills early in the morning you will get onto sunlit ridges and see below you the magical sight of ‘lakes’ of mist filling valleys below. overall it's like a sea of mist with the hills poking out as islands. This atmospheric condition is called an inversion.

So what you want is an inversion. When you've got one then next thing you want is to be on a ridge with the sun behind you and then you will see your shadow in the mist below surrounded by a halo of spectral colours. When you move the ghostly apparition moves as well with the shadow and the rainbow colours that surround it in concentric rings. If you are with a companion they will see their own Brocken Spectre but will not see yours. The reason for this is that the mist is acting like a three dimensional screen. The image is projected tunnel-like into it and so is invisible from wider angles.

The name Brocken Spectre comes from the German mountain in the Harz range of northern Germany and the word Spectre means ghost.

The conditions for seeing a Brocken Spectre don't arise all that often but when they do you can more or less guarantee to see one if you know what you are about.

When an inversion arrives there will be a number of suitable local locations for the viewing of a Brocken Spectre but a convenient one is the ‘Sleeping Giant’ and the ridge that leads westwards from it towards Carie. Here, if you are on the ridge, the sun will be to the south east or south behind you as you look down on the mist that is filling the valley occupied by Loch Rannoch.

For more information see -

http://www.bbc.co.uk/news/uk-scotland-highlands-islands-31447148