Spring 2005 PART 3:
April Showers turn big and thundery (plus rain-wrapped funnel-cloud)! - 19th April 2005 (new images added 01:12:05)

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Conditions looked to be better according to the charts for Tuesday April 19th and so I was on a bit of a mission! An active trough had pushed up from the SW overnight and Machynlleth was at its northern edge. I was optimistic about encountering thunderstorms south of this feature, as opposed to within it, as I wanted clear skies and lots of warmth from the sunshine. Plenty of moisture was already available!

Setting out mid-morning it gradually dawned on me that finding that sunshine would be a little trickier than I had imagined! By the time I had got to Builth Wells I had driven under undulating grey skies with odd bits of rain for over 40 miles. They stretched away likewise to the south, it seemed. Was this going to be a wasted trip??

Luckily Builth Wells has internet access in its library so there I went and downloaded latest satellite images. These showed clearer skies well to the SW: "well I've come this far so what the hell?" was my decision and off I was again, finally coming out into glorious sunshine near Llandovery. 10-15 miles of clear skies and beyond that were developing towers of cloud. The grey cloud I had been driving under was cold, clammy outflow from the overnight trough, and the southern edge of the clear area marked a boundary between this outflow and the warmer, ascending air. Outflow boundaries are often a focus for storm formation in lines: so far, so good!

I decided to head well to the west so drove along the A40, passing Carmarthen. Skies here were getting to be quite threatening. A detour to the coast at Tenby proved a mistake as the road ran mostly along a deep wooded valley so I turned N again, through Narberth to the A40.....
....meanwhile, to my E, S and SW, the hoped-for line of convection had exploded into life. This is taken looking back E on the A40. The whole lot was drifting NW in the SE-erly steering flow. What to do next? Certainly the A40 is far too busy for safe storm-chasing: I needed a safe stopping point with a better view. Out with the OS map and I noted a B-road running up over the Prescelli hills from Haverfordwest to Cardigan. This would do nicely!
With clear skies to the north and this following me up from the south I was in good time. This was taken halfway to the hills. Here I heard the first rumbles of thunder. Just a better vantage-point required now....
...which was reached with time to spare. This is a wide-angle (28mm) shot of the storm growling along between Narberth and Haverfordwest. Tripod and telephoto time!
200mm tripod shot of the approaching storm on its way towards the refineries at Milford Haven. They made an excellent almost silhouetted foreground. Now it was just a matter of waiting....
...between the chimneys and the torrential rain of the storm's core an interesting lowering was present. For a moment I thought this might be a wall-cloud - i.e. a rotating area of inflow into the storm - although in a strange place on its leading edge!
The situation soon clarified itself as the feature approached the chimneys! Compare what the smoke's doing in this one to the shot above! Being blown forcefully and horizontally outwards from the storm-cloud! It was a gust-front seen sideways-on!
Scud-cloud was continuously forming, dissipating and breaking away from the ominous cloudbase. Sometimes these scud formations looked like little funnel-clouds. They weren't though! When looking at cloudbases from this distance, always have decent binoculars with you. You can soon tell a genuuine funnel-cloud from a "scud-funnel" as they're known!
Another example. Look carefully at its position relative to the chimneys before going to the next image in the sequence of slides, added December 1st 2005 - below!
This however is the real thing, just about visible through the rain to the left of the chimneys. According to my notes posted to the UK Weatherworld forum on the evening of April 19th: "not much happened vortex-wise except for one possible but unconfirmable funnel that I watched through binoculars behind too many shafts of torrential rain. It looked to be one but I cannot be certain!" This must have been it I guess! You see, I have to confess that I only found this image upon going back through the slides, while looking for something else altogether, on a cold late November afternoon! I must have dismissed it too quickly the first time around when I put this page together - I certainly cannot recall being that impressed at the time! Let's try some digital enhancement now in Photoshop:
Clearly a funnel-cloud with strong, smooth sides. Its position within the storm appears to be on its SW side, with the precipitation between it and me. Vortices like this are particularly dangerous if they are on the ground - this is where the phrase "rain-wrapped tornado" comes from - as you have no advance warning that one might be approaching....
Back to the original storyline - with the next storm to the S eventually threatening to engulf my vantage point, I headed north and down the other side of the Prescelli hills. Here the anvil of the storm I had just been photographing stretches out to the north over the clear air, indicating high winds aloft - a good supporting feature for thunderstorm development and sustainability....
....meanwhile, back to the south the next storm was starting to appear over the ridge. Here I was in an area of winding roads and sunken lanes - the beautiful countryside of North Pembrokeshire - but difficult in terms of vantage points. I searched and searched and searched....
...as the storm headed on towards me. Lightning flickered behind the developing gust-front, in the again torrential precipitation beyond...
....I first found one gateway...
...then a bit of road with a view, moving slightly north each time to try and keep ahead of its core...
...finally having to lose it here, with lightning getting close and the view to be obscured soon! The road-signs rather sum this area up as chase-country and to have more success some serious reconnaisance will have to be done. Getting clear of this storm, I was alarmed to see an absolute monster of a cell straight ahead. This I met at Cardigan and managed to keep just ahead of the main core (which totally obscured visibility), driving through still heavy rain all the way up to the Newquay turn-off at Synod Inn. By now it was evening and convection was decaying as the cells ran out over Cardigan Bay. I settled down to the last 40 miles of the 200+ miles I had driven that day, fairly satisfied with the results, a little frustrated regarding vantage points, but pleased with my forecasting (for a change!) and my strategy. I shall return to SW Wales and concentrate on finding a network of vantage points where it's safe to stop. The landscapes are beautiful in this area and so are the storms!
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