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It's early Autumn and already nature has beat all of late Summer hands down with convective activity in N. Ireland. Usually September is often associated with fine settled weather with parents often heard saying the weather always turns good when the kids go back to school, normally this would be the case but not this year. September has, and currently still is, a very unsettled month with Atlantic-drive disturbances bringing low pressure with numerous days bringing fronts and shower troughs, and unlike Summer, these troughs have been associated with instability. It's been so active that much to my shock during my previous chase on September 4th I captured a strongly sheared storm cell with transient supercell traits and the best structure of Summer, since that day I have chased three more times up to the time of writing this report mid month, there has almost been CAPE every single day back to back for days on end.
The first and best of those three new chases took place on September 11th and once again I was rewarded with a photogenic trophy from the chase. The 11th brought an unstable SWly flow with 700-800j/kg of CAPE with high resolution models showing pockets of 900 SBCAPE across parts of N. Ireland. With an upper cool pool aloft potentially dropping cloud tops to -40c this looked to be a day of good potential. As the day began shear would be zero across NI however by 15.00 onward a broad swathe of 30 knots DLS would descend across the country engaging with that modest instability. Such parameters are often good convection and lightning producers. My only concern was the maximum temperatures expected of 12c to 13c at most and cloud cover shutting off solar heating, the latter a necessary requirement for lift.
At face value I was liking this set-up, it had all the hallmarks of that synoptic transition zone between late Summer, Autumn, and even early Winter convection. The cloud cover issue was concerning me though, normally a SWly flow in Summer is a direction I love, however from Autumn onwards this moist surface flow tends to bring a lot of cloud, partially because it has crossed the more moisture-rich Atlantic ocean currently experiencing warmer SSTs, as a result greater cloud cover can accompany cells and hence completely ruin visibility and spoiling all photo potential. I had already anticipated this and was fully expecting a more cloudy and cooler day compared to the norm, however I was still buzzing after that Slemish supercell catch and was feeling very optimistic, as if I was in a state of flow and trusting my instincts I decided to chase anyway. Colleen Webb from Portglenone was also game for chasing too so we decided we would meet and spend the entire day out. I knew the cloud risk but I also knew that if we could get one decent clear sector with sunshine there was the prospect of getting a very nice cell, perhaps later in the day when shower activity waned somewhat.
Models indicated the W and NW was the place to be, anywhere from the Sperrins to Omagh to The Foyle area and Donegal. AROME showed more cells across the S. Sperrins so we decided a decent location would be at Beaghmore Stone Circles smack bang in the middle of the target area. I packed my new power charging unit so that we could charge drone batteries on location, filled a flask, then bought some snacks then Rhua and I hit the road, we arrived at Beaghmore at 12.15 and soon after Colleen arrived also.
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We arrived feeling optimistic however our nerves were starting to show and we began second guessing ourselves half an hour later. It felt completely like Autumn!, it was chilly and the sky was constantly cloudy, we had non stop showers, the ground was wet, muddy and saturated and it never let up to the point where we only got brief glances at the sky between episodes of rain, most of this time was spent in the car with the wipers on wondering what we were doing here, we began to think this was going to be a flop but we decided we would give it a few hours anyway.
Eventually the rain stopped and we got a clearance to the W and in that clearance beefy white cells could be seen heading our way, that was encouraging to see, eventually they blew over the hills towards our location. Drones were in the air fast, this was the first cell, annoyingly it looked good in the distance but it lost its looks as it moved more inland, there really wasn't any structure along the leading edge and the tops looked warm and less solid, however at least it gave us something to film.
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After an hour of grey skies gaps broke out ahead of the cell allowing the sun to light up the landscape in colour which was short lived as the cloud and rain filled in once again.
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We sat for another half an hour under rain then once again a clearance yawned open to the W and another big cell could be seen, this one had structure and got our interest and as it approached it too lost it's looks and hit us with more rain. We sat in the cars getting pounded with torrential rainfall, that core was quite intense, then suddenly the sun broke out out just as the dark rain core moved behind us to the E, we both were out in seconds, we knew we had the prospect of seeing a good rainbow and no sooner had we thought this when one appeared, faint at first then increasing in brightness and colour until it looked a striking sight against the dark wall of precip. The sun was high so this was a low bow neatly arching across the ancient landscape of this area.
It was still raining but we got the drones in the air anyway and began to take images. I flew E chasing the precip core so I could keep up with it and maintain a decent bow before it vanished. I obtained really nice footage flying over the sunlit landscape between Beaghmore and Davagh Forest with that lovely bow over the forest like a coloured crown. This is a still image however the footage is much better and can be viewed in the video below. This encounter raised our spirits, at least now we got something photogenic and if nothing else happened this day then at least we wouldn't be going home empty handed.
Two hours later we were back under grey skies and relentless showery rain and radar looked an awful mess with a big cluster of showers heading our way which would take a long time to pass, it looked so bad that heading back home seemed an attractive proposition. I still had a vibe about late afternoon when that mess would clear, while we waited we decided to change our location, this time we went to Davagh Forest and got out for a short walk, and again the rain arrived chilling us. It was just annoying now as we couldn't even enjoy outside, it looked and felt like late Autumn under a frontal system. At 16.00 Colleen called it a day, she had other plans for the evening and decided to head back home. I felt like doing the same, actually I was going to do just that and rite this day off as a bust.
My view of the sky had been blocked by the trees in the forest so when I entered a clearance on that back country road the entire sky was unveiled and much to my delight was a huge sector of blue skies to the NW with clearing cloud overhead and in the distance was a big row of beautiful sunlit convection which was the best I had seen all day. I pulled over at the side of the road to study the sky, mmmm, I wasn't going home anymore, this was too good to ignore, I liked the look of the convection, the updraughts were big and fairly solid, their bases seemed to go all the way down to near the surface, I even saw a tiny pileus cap above one updraught, a visual cue from nature that the sky had potential. The convection was far away, there was no doubt it had come in over Donegal and was making it's way across the Sperrins, the cluster was definitely getting closer, I decided I would find a good spot and get the drone up for a look.
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I pulled into the lady Of Wayside chapel at Broughderg, a beautiful peaceful part of the country, no one was about which added to the experience, I felt like I was in the middle of nowhere. I got the drone in the air to get a better view away from the trees and hedges. This was the cluster stretching from Donegal to the Sperrins, moving L to R, the lead cell looked very beefy, I recorded footage, the wind was strong at this location, I kept getting the props in the field of view when flying towards the cell. The sunshine on the convection was so bright and clean, it reminded me of Winter convection in a Nly air mass, it just had that look about it.
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The lead cell was getting closer and bigger however my battery was getting low so I landed and shot a few stills with the phone and began doing a vlog. While I waited for the cell to grow I poured myself a warm brew and walked Rhua.
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A few swallows of tea later I looked up and saw the cell had transformed into a beast and looked absolutely gorgeous. I was quite shocked how big it looked, this was many miles away yet I was craning my neck at an acute angle to see the top of it, the drone was back in the air once more with a fresh battery, the time was almost 17.00, or five o'clock magic as it's known to chasers.
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A gorgeous mature Cumulonimbus dominated the sky, lit brilliant white by strong sunshine and framed by a deep blue sky background. The sight of it over the Sperrins, an area of outstanding natural beauty, made the moment even more special. Pockets of sunshine would light up the landscape bringing a combination of light and shadow, tones of green, orange and brown complimented the icy mountain above.
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I was in awe of this completely unexpected sight, this was the photo opportunity of the day for me and I enjoyed every second of the experience. I managed to record nice aerial footage here, the wind was strong, it was shocking how fast moving the low level dark clouds were moving near the surface which you can see in the footage. I was amazed there wasn't even a rumble of thunder from this, it was massive, fully glaciated, strong on radar, with anvil top in -40c air, however thunder or no thunder it made no difference to me, this was beautiful.
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Ten minutes passed, I let the drone hover and recorded video while I shot images with the phone. The cell looked surreal like a glistening mountain of ice and water droplets shaped into the classic anvil, below and in front of me was the famous crucifixion scene at the chapel with three huge crosses, with three figures nailed to the crosses and figures praying below, it was such a spiritual scene as if nature was revealing her wonders for a precious moment.
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Phone shot from the ground using the standard wide angle camera with sheep grazing in the fields, the cell was beginning to weaken now as it passed by but I couldn't take my eyes off it, to go from hours of grey cloud and rain to this bright spectacle made the sighting all the more dazzling. The cell passed away and became lost in low level cloud, it's flanking area had convection with a low dark base so I inserted a fresh battery and got the drone back in the air.
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Flanking convection moving in quickly over the sunlit countryside between Broughderg and the scenic route over the Sperrins which would lead to Moneyneany and Mullaghmore. The tops were a little low here but the scene was quite photogenic so I took it. The the rain hit and it was back to grey skies and showery blasts with absolutely nothing else to see. I honestly felt fortunate and privileged to have seen that beautiful white cell, no doubt dropping a trail of hailstones across the country in the middle of nowhere. Soon after thunderstorms broke out over E N. Ireland, over The Mournes in Co. Down and the North Channel. I drove home well pleased with this chase, a transient supercell and beautiful sunlit Cb all within less than a week is a good catch for this time of year.
Vlog and drone footage of the Davagh rainbow and the Broughderg anvil, I edited the video to by a relaxing experience with the soundtrack accentuating the spiritual emotions of this isolated cell, I hope you enjoy it. Thanks very much for reading.
Martin McKenna
