AUTUMN 2004 - PART 4:
An early snowfall - 19:11:04

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On the 18th of November an early taste of winter arrived in many northern parts of the UK as a cold front came south with a cold northerly airflow setting up in its aftermath. Here, at nightfall on the Thursday it was raining heavily at the top of the Machynlleth-Llanidloes mountain road (510m above sea-level), and still fairly mild, despite the fact that sleet was falling less than a hundred miles to the northeast in Liverpool - at sea-level! This demonstrates how sharp the warm and cold airmass boundaries can be as a front approaches!

A disturbance off the NW coast of Scotland was noticed on satellite images on Thursday afternoon and there was much debate on the Internet as to whether this was a polar low or not. Snow enthusiasts get very excited when a polar low ploughs south across the UK, as the snowfalls they produce are often significant. This relatively weak feature came down through Wales in the early hours of Friday and that morning I awoke to fog and sullen grey skies in Machynlleth. Not wanting to miss out on some snow myself, I decided to drive back up towards Dylife, to see if there was any or not. This proved to be a good decision!

Getting to about the 250m contour, the light drastically improved with a hint of blue sky overhead, and the visibility began to get better and better. I knew what this meant and so carried on in anticipation....
...of this! Emerging from the fog was like being in an aircraft coming up out of the cloud. Sunshine, snow and blue skies in all directions. This sort of weather tends to occur when there is what is known as a temperature inversion. Normally, temperature decreases with altitude - warm in the car-park but freezing on the summit is what one might expect in most cases. An inversion occurs when the opposite happens, and heavier cold air settles in the valleys, with warmer air above. This is not uncommon during the late autumn and winter months. With the ground so moist after Thursday's rainfall, evaporating water-vapour condensed in this cold air into trillions of tiny water droplets, each less than 1/20th of a millimetre in size, and the result was a deep blanket of valley-fog (or inversion-fog). For it to persist, fairly calm conditions are needed, as was the case on this occasion. Windy weather mixes up the layers of the air, thereby forcing the fog to disperse.
I continued on up towards Dylife, getting a photo here and another there. This is looking due north...
....due east....
.....and due west. It was pleasantly warm in the sunshine, and as one might expect in these conditions, certainly warmer than it had been when I left Machynlleth.
Due north again, from the Wynford Vaughan-Thomas memorial pulpit, on the edge of infinity...
Wynford Vaughan-Thomas (1908-1987) was a highly respected BBC broadcaster and war correspondant. With roots going back to the pre-war cafe scene in Swansea (which he shared with the likes of Dylan Thomas and other poets, writers and composers), he was decorated for his reporting during wartime, which included a live broadcast, under heavy fire, from a Lancaster bomber during an air-raid over Berlin. Following the war, he continued to work as a broadcaster and produced several classic books on the hills, history and people of Wales. He always maintained that the view from the roadside near the top of the mountain road was one of the best (if not the best!) in Wales, and fittingly, after his death, this slate monument was erected there as a memorial to him. The monument shows the horizon, with the summits you can see individually named. It also marks one of the area's best storm-chasing venues!
Continuing to the top of the pass this was the view SW. Plynlimon lies in the background across the wide expanse of snow-covered tussock-grass moorland.
On the way back down I stopped and set the tripod up to get a few rather surreal shots of the Mynydd Cemmaes windfarm. Then it was back down into the murk and on with the work (odd how those two words rhyme...) but the dose of sunshine was extremely welcome, having spent the previous week cooped-up at home with a flulike thing!
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