Monday 26 February 2018

An east wind is no good for man nor beast.


The weather forecast for the Brecon Beacons National Park was:

Screen shot from Met Office https://www.metoffice.gov.uk/public/weather/mountain-forecasts/brecon-beacons

The windchill of -10C at 600m something to consider.

Screen shot from https://www.metoffice.gov.uk/public/weather/mountain-forecasts/brecon-beacons


Nic was suitably enthused by the forecast that she decided to accompany me with the enticing prospect of a good walk with late light illuminating the bleached moorland vegetation, rock outcrops and a possibility of twilight alpenglow. A check on other forecasts indicated the wind might well be stronger than the met office forecast and before leaving a check on the visible satellite imagery indicated there was cloud moving across the park from the east. The trip destination would be decided en route determined by the prevailing weather with the Black Mountains, Brecon Beacons and Fforest Fawr all in play. At Abergavenny the Black Mountains were ruled out by cloud and haze. From the highpoint of the A465 the visibility was excellent and the wind very 'fresh', ruling out the Brecon Beacons. Fforest Fawr would be the end destination. The walk was delayed waiting for a helpful farmer to pull the car from less firm ground, sigh, wheel mats under the tyre had proved useless.  However if you were going to get stuck, then this was a good place and time, sheltered from the wind, views, warm sunshine to bask in and a road only used by the farming community who were pro-actively preparing for a sustained cold blast of air from Siberia. After heartfelt thanks and lightening my wallet to reward the good samaritan farmer, I managed to park the car on more firmer ground, not my finest hour and Nic was less than impressed.

Exposed moorland, Devonian sandstone glacial erratic, limestone pavement, sink holes and haze.


Finally underway and on reaching the exposed moorland the wind was a tad stronger than expected, the windchill very noticeable, haze obscured views of the Brecon Fans and haze/cloud bank on the western horizon scuppered any hope of sunset light or alpenglow. A small positive was that the peat bogs were frozen.  A place of relative shelter was sought near a viewpoint and a cunning plan concocted. The plan involved minimising exposed walking and maximising taking in the views from sheltered sites, whilst basking in the warmth of sunshine.

Google satellite view illustrating the density of sink holes.
The area has one of the highest density of sink holes (dolines) in Britain and the geology of limestone, limestone overlain by quartz arenite sandstone and areas mantled by glacial till and peat, means there are good expressions of many sink hole types.

Sink hole (doline) types. Illustration from http://www.bgs.ac.uk/caves/sinkholes/home.html




To successfully photograph the extent of the sink holes requires very low angled side lighting and not for the first time the desired lighting failed to materialise at this location. Nevertheless there were views and limestone pavement to offer some foreground interest and relief from late winter moorland vegetation.


A good walk, decidedly fresh air, geology interest and some moorland visited which would otherwise have been overlooked in better weather.

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