Summer 2012 Part 3: Llŷn magic, August thunderstorms and general liveliness...


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It's August 10th and time for the next update, with a definite summery feel to the weather as the stalled Rossby Waves have gotten going again, bringing a much better variety of conditions as opposed to the relentless gloom and wet of June and the first half of July. Yesterday's temperatures in the mid-20s felt quite a shock to the system after weeks of 15-18C and there's more to come into the weekend before the threat of a few thundery showers on Sunday. This post begins early in the morning of July 21st, at the top of Mynydd Gwyddel, the low hill that overlooks the last campsite before the sea, SW of Aberdaron on the end of the Llŷn Peninsula....

sunrise from Uwchmynydd

Having turned in earlyish the night before, I was up before first light, searching the northern horizon for noctilucent clouds without success - it having been the first clear night for weeks. Cloud has scuppered most chances of observing these ghostly night-shining clouds, 80km above the Earth in the Mesosphere and it's been the first year for a while when I've not seen them. As dawn broke, some more typical mid-level cloud crept up, promising some interesting photographic possibilities for sunrise, so it was on with the boots and off up the hill-path. This was the view ESE towards N Cardigan Bay and the hills of Mid-Wales beyond.....

sunrise from Uwchmynydd

Zoomed in, the sleepy (because of the time of day) SW
Llŷn with in turn the headlands of Penrhyn Mawr, Penarfynydd and Trwyn Cilan, with the Rhinogydd in the background...

sunrise from Uwchmynydd

Trwyn Cilan and a distant but distinctive Cadair Idris across the Bay....

sunrise from Uwchmynydd

Bardsey catching the first rays of sunshine, heralding what was to become a perfect if sunburnt day...

Bardsey Island just after sunrise

The fishing was slow. Four of us worked hard at it to manage enough mackerel for a feast, with various wrasse, pollack and dogfish. There was evidence of competition...

Seal at Penrhyn Mawr

On the following morning, the weather was set to change with strong winds forecast. But the day dawned fine and I set off in the opposite direction, up Mynydd Mawr. Here, Bardsey forms the backdrop to Mynydd Gwyddel with the campsite at its foot....

Mynydd Gwyddel and the campsite

As usual in this rugged corner of Wales, the aerobatic choughs were everywhere, a delight to watch as they wheel through the sky...


By mid-morning, the wind had got up as forecast, as evidenced by the choppy waters SW of Bardsey lighthouse, viewed from the road down from the coastguard lookout atop Mynydd Mawr...

Road down from Mynydd Mawr and Bardsey

An hour later and getting tents down became quite a job! By this point, Bardsey Sound was a mass of white-caps and in the image below another area of very rough water marks the dangerous shallows of the Bastram Shoal, one of several notoriously dodgy bits of water in the vicinity. Until next time....

Bardsey Sound and Bastram Shoal roughing-up

Winds eased off into the following week although a trailing old front slid back and forth across the west at times. Early on July 25th it was situated close to the coast, but its cloud was mostly thin enough that brighter stars were visible through it. This was taken at Ynyslas, looking up the Dyfi Valley:

Sunrise at Borth

As it got lighter, masses of bird-activity became evident, with thousands of Shearwaters moving northward. In the distance, off Tywyn, they could be seen massing together with hundreds of Gannets, diving repeatedly on a mackerel-shoal working the sandeels and whitebait. Life in abundance - always a joy to witness!

Shearwaters at Ynyslas

Despite it being a dismal year in many areas for butterflies and moths, the coast, where still unspoiled, has been alive on warmer days. At Tonfanau, the Six-spotted Burnet moths were everywhere...

six-spotted burnet moth

Among the dunes at Ynyslas, dozens of butterflies were in evidence, including Small Skippers...

skipper butterfly

...and many Gatekeepers. A Dark Green Fritillary was also present, but it wouldn't settle for long enough to be photographed!

gatekeeper butterfly, ynyslas

Some areas at Ynyslas were ablaze with Evening Primroses....

evening primrose, Ynyslas

The Pyramidal Orchids were still going strong, and here and there the Marsh Helleborine could be found amongst the undergrowth. Ynyslas is a superb spot for anyone who, like me, prefers to see land that is relatively uninterfered-with and how, even in such harsh environments, Nature adapts and thrives.

marsh helleborine, ynyslas

With early August there came a slow-moving area of low pressure that settled for a while on the weekend of the 4th and 5th just to the west of the UK, bringing a slack unstable airflow over most areas and widespread diurnal thunderstorms as temperatures rose each afternoon. On the 4th I headed up onto the high ground SE of Machynlleth to see what was brewing. This was the view eastwards towards Trannon:

Storm over Trannon

Zoomed-in with the Trannon wind turbines towered-over by stormclouds....

Storm over Trannon

Back over the other side of the pass, a funnel-cloud developed briefly in the vicinity of Cadair Idris....

Funnel-cloud over Cadair Idris

Here's a digital zoom. It was breaking up at this point and had gone a few minutes later, but any walkers out on Cadair must have had a good view of it! Wind-shear was flabby both days, so the risk of anything more spectacular was pretty minimal, although a few other funnels were reported from scattered locations around the UK, most likely forming in response to storm updraughts ingesting local vorticity as the airflow was forced around barriers of high ground - just as you get little whirlpools in a river downstream of bridge pontoons.

Funnel-cloud, Cadair Idris

As the afternoon wore on, convection seemed more intense further east: this is the view north....

north from top of Machynlleth-Llanidloes Mountain Road

...while this is looking a little more NE. Hammering it down over there!

north from top of Machynlleth-Llanidloes Mountain Road

Briefly, a patch of sunlight caught the Cemmaes wind-turbines, with an ongoing deluge beyond...

Cemmaes windfarm and storm

Back in Machynlleth that evening, a lively thunderstorm came up from the south, with overhead lightning for a while and torrential rain that was shooting straight over gutters. Fears of a flash-flood led to the Fire Service attending a flood-prone area close to home - there have been big problems here on a number of occasions when water has been forced from the town's main drainage culvert that runs beneath the street. Its manhole cover has been ripped from the enclosing tarmac on a number of occasions.

flooding, Garsiwn, Machynlleth

On the 5th, convection fired quickly again by early afternoon....

Convection firing-up from the Forge road

On this occasion though, it seemed a bit inhibited...

storms over the Plynlimon Group

...until this developing cell brewed up over Plynlimon. Things started to get interesting as a sea-breeze made its way in from the NW, whereas the steering-flow was from the SW. The main cloud here is coming straight at me, albeit slowly, but the small clouds low down on the RHS are being pushed along R-L by the sea-breeze. That's healthy wind-shear: would it produce anything?

storms over the Plynlimon Group

The answer was no: instead the storm exploded into life with blinding rain obscuring everything! I headed back north out of its way, to be greeted by a similar sight. Cadair Idris is supposed to be in the middle of the image!

cloudburst over Cadair Idris

The areas of heavy rain expanded until nearly merging - I ended up sandwiched between them in the Dyfi Valley, from where this was the view back southwards to where I had just been:

the storm from the Dyfi Valley

After throwing out this weak gust-front, the Plynlimon storm quickly decayed, thus bringing a conclusion to an entertaining weekend!

gust front from the Forge road

We are now entering the time of year when Nature's larder is well-stocked, as a walk in some local woods showed on the 9th. Amongst the edible fungi, Chanterelles are unbeatable in my opinion - and I'm not alone in that sentiment!

first chanterelles 2012

Looking forward to the rest of August, it's not looking too bad - often quite warm but with a few showery and possibly thundery interludes. Hopefully the warmth and sunshine will cheer up the denizens of the veg-garden - the plants, not the slugs! It's been a tough year for many growers, the culprit having been the low temperatures, excessive rains and severe lack of sunshine in June and early July. Here's to less of all of those things in the coming weeks!


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