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
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....
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
.....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
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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