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It was late evening on Monday May 18th and I was laying on my bed starring at my laptop screen editing video footage from a local storm chase earlier in the day with Roisin which was fun however there wasn't much in the way of photo rewards despite the abundance of Go Pro footage taken. The atmosphere this day was unstable enough for thunderstorms and big convective showers with 400-500 CAPE and LIs of -2 in a Wly flow with cold uppers, however there was no wind shear aloft to cause leaning of the towers and support updraught/downdraught separation which meant no organised storms so this would be another Spring day of chasing pulse storms, however considering the lack of storms this season so far I was more than happy to capitalise on the opportunity in the hunt for dramatic weather photo opportunities, I simply love storms and being on the road with that combination of anxiety and excitement from not knowing what nature was going to produce in the hours ahead. I was feeling in top form and ready for action and after an early morning of radar watching I drove off to intercept a cluster of big showers and growing cells which were moving swiftly in from the W. I spotted a beautiful young tower to my NW and soon it had sprouted a nice white anvil plume surrounded by clear air and was an obvious target, I drove through Swatragh then into the mountains to the W and pulled over to watch the convection plough across the landscape with dark clouds and curtains of blowing rain and small hail stones. The single cell I was after had collapsed which is pretty much what I had expected given the lack of shear for without the latter updraughts will drop their rain cooled air back through the base which ends up cutting off their supply of warm moist air (inflow) needed to sustain the updraught and hence killing the storm, cells like these may only last 20-40 min's at best so the plan was to be there when they were young and growing to catch them in the act.
I took some time lapse video as the wind howled across the barren landscape and wailed as it blasted through the wire fence lining the narrow country road on which I had parked and after several passes by from a nosey driver in a 4x4 who wouldn't leave me at peace I decided to change location and drove back through Swatragh then to the hills on the E side of town watching more convection grow. After 30 min's of watching I headed back along the Coleraine road to Maghera and intercepted a brand new cell which looked quite beautiful and watched it bubble up with a fancy white anvil spreading out however after much watching and hoping it didn't produce anything despite sporting twin red echoes on radar as it passed into the E near Antrim. I went back home, had a brew, then this time Roisin and I went chasing together. We were greeted by a big cell as we drove S along the Glenshane Rd taking up a large area of sky with grey mammatus and very large anvil, the precip curtain was long and had that dramatic black-blue colour often seen in storms, it looked a dramatic sight with the sunlit fields and gorse bushes in the foreground and even low the cell was on a downward trend it looked impressive enough to justify shooting, it was heading E over Lough Neagh so Roisin and I headed in that direction and soon we where parked at Ballyronan Marina facing E across the lough as the cell retreated into the distance. New convection was growing behind us to the W so we decided to stay here and let it come to us, I was hoping to get a mammatus display on the rear end of the cell once it crossed the water or perhaps even a funnel cloud although the chances of those happening this day were very slim. I spent the time taking time lapse video of the clouds crossing the lough and between cells it was pleasantly warm and sunny. A Swan took a big dislike to my Go Pro and tripod and made a show of hissing loudly at me then walking onto the sandy shore towards me while straightening his neck and trying his best to intimidate me, it was a funny show and despite his aggressive demeanor he really was a beautiful sight, I captured him hissing on video which you can view here.
I bumped into an old friend who I used to train with at Ju-Jitsu years ago then our new cells arrived delivering heavy rain, gusty downdraughts and hail stones which looked impressive blowing across the surface of the lough in brilliant curtains. Once the back of the cell moved over the water and the sun came out we could see two big updraughts which looked extremely tall, I was astonished there wasn't a single rumble of thunder from them, the base below also had inflow motion with scud tags revealing slow cyclonic rotation and for a few brief min's we thought we were going to get a funnel however the rotation stopped as the cell weakened, however it goes to show the effect of what Lough Neagh can do to cells which pass over this unique micro climate by fueling updraughts with an abundance of moisture and differential heating creating vorticity and local convergence for the topography is just as important as the atmosphere above it for the formation of funnel clouds and tornadoes. Later Roisin and I had lunch and by late afternoon Roisin was on her way home and I was back in Maghera in my room with nothing much photo-wise to show for the day's diesel expenditure.
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So there I was laying on bed editing videos on my lap top however I had not given up on this day yet and although it had been somewhat of a bust so far I was aware of the fact that the GFS evening run had shown that the unstable air remained across N. Ireland rite through sunset and even into the night hours so there was still a chance of something unexpected happening so I made a note to occasionally glance out the window from time time to check the sky. Sometime between 20.30 and 21.00 UT I felt a strong instinct to check the sky so I looked out my bedroom window and at the corner of the frame it looked like the sky was on fire!, something spectacular was happening and it was best viewed from the other side of the house so I grabbed my camera bag and ran downstairs and out the front door into the garden and looked up. The scene got an instant 'WOW' from me however in truth I used language a lot more colourful than this, I was simply blown away by the best mammatus cloud display I had ever seen in my life!, I felt an instant rush of panic and pressure to get images and video before the moment was gone for one never knows how long a scene like this would last so every second counted. I quickly whipped out the Canon 600D with Samyang 10mm lens like a Texas Ranger drawing a Colt 45 from his holster and began taking images. This massive cell was moving slowly from W to E (R to L in the images) and was an eye catching sight dominating the entire S to SW skyline with its precip core passing directly over Slieve Gallion.
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The cell had a huge sweeping anvil which fanned across a vast area of sky with its outer wispy edges almost directly overhead and under this dissipitating anvil was a spectacular display of mammatus clouds, or simply 'mamma' in storm chasing jargon. The light was unbelievable with the entire cell and mamma lit into stunning yellow and gold colours by the setting sun with clean blue sky visible in it's wake which offered a superb photo opportunity and by some stroke of good fortune my house happened to be located to the N of the cell which provided me with an unobscured perfect view of the spectacle. As the min's ticked by I had to quickly get the correct settings in manual mode with the 10mm which has an enormous FOV, remember this was much closer and larger than what it looks in these first two images. I stopped the lens down to F/5.6 to get some depth and had to increase the ISO to 200 then 400 to compensate for the low light to enable me to take quick hand held shots with a shutter speed of 800/sec, there was no time to waste going back inside for my tripod. I yelled for my Mum to come outside and together for the second time within a week we both witnessed a brilliant mammatus sky show during golden hour and again from my home area of Maghera.
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I needed to get closer in on the structure so I switched to the Canon 24-70mm F/2.8 then I set my samsung video camera on the garden path below me on its mini tripod and let it film the upper portion of the display above the garden fence, I had no time to get the Go Pro which was charging upstairs so this video camera would have to do the job, I just left it there to film away as I concentrated on getting still lmages.
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This portrait image captures very well what the scale was like as seen with the naked eye, the display was huge and the mammatus udders were very well defined and of 'solid' appearance and arranged in rare lines or streamers across the sky very similar to what mammatus displays look like from the Great Plains of the US, normally in Ireland I most often see mamma grouped in clusters or in a sporadic fashion however these organised lines are most certainly much more rare.
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The udders must have been huge in size considering their great height in the upper Troposphere with the cold sinking air and winds aloft sculpting these most magnificent of clouds.
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Anyone in town who looked up at this moment would have been treated to an amazing sight as the mamma were now directly over Maghera. I was kicking myself for not having any interesting foreground to shoot with the clouds, had I been in a field or near a lake the photo potential would have been epic, however getting to witness this at all was an honor no matter where it was from and in some ways it felt more personal and special getting this present from nature directly from my front garden.
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Cell mid section and flank with mammatus and sweeping anvil with clear sky behind and another anvil with mammatus behind the main cell further to the SW.
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This was absolute Heaven to watch, I felt on a natural high and awestruck by their beauty as the Birds sang their dusk chorus while these massive golden udders drifted slowly aloft accompanied by the frantic clicking of my camera shutter. Note the tufts of cloud at mid levels (lower in the sky) passing below the larger mammatus which where located at higher levels making for a great sense of height and depth within the atmosphere, those lower clouds were moving swiftly in comparison to the more gentle and elegant motion of the mamma above.
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I was now using the Canon 50mm F/1.8 prime lens which collected a lot of light and allowed me it get away with useable hand held shutter speeds while getting me in closer to the mamma. Note the linear segments streamlining across the sky to the upper right by the winds aloft which reminded me somewhat of the ion streamers within the tail of an active comet.
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These reminded me of reptilian eggs in the process of hatching. When you watch mammatus it becomes quite obvious that these are a very dynamic phenomena and in a constant state of evolution for you can observe them change size and shape in real time giving the observer the impression that they are in fact 'alive'. Mammatus clouds are still a mystery and the exact atmospheric ingredients required for their formation have yet to be understood however sinking air is an obvious factor for you can see the mammatus lowering below the anvil however the other factors involved are likely very complicated, it is this unknown factor which adds to their beauty.
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Epic show at this stage as the lowering sun turned the anvil and mammatus into a golden entity taking up the entire southern sky. This was at 24mm which really shows a fantastic sense of scale in comparison to the cars on the street below, just look at the size of the mamma, I still couldn't believe I was seeing this from my garden.
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Alien clouds
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Beast of a cell and a spectacular sight to see this drifting across your home town. Note the diagonal cut-off line between the gold colours above the grey section of the cell below, the sun was now so low it was behind the tip of the Sperrins and casting the shadow of Glenshane Pass and surrounding mountains across the sky into the E, soon the sun would drop out of sight entirely and I would loose these amazing colours so I continued taking as many images as possible while explaining to my Mum what mammatus clouds are and what they meant.
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Simply stunning, people often ask me why I like to photograph storms and clouds, this is the reason why, nature is incredible and if you devote enough of your life to scanning the skies with true passion then sooner or later she will reward you with something very special.
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Mammatus typically form under the anvils of thunderstorms and heavy convective showers and are most likely to be observed under the rear or downshear portion of the anvil or under a back sheared anvil, their presence usually indicates that the cell has just passed its mature stage and is on a downward trend and weakening because the updraught which carries moist air parcels from the surface into the Tropopause aloft where the anvil forms and spreads out becomes weaker and eventually fades until the supercooled air aloft begins to sink again forming these wonderful clouds. Years ago there was a belief that mammatus clouds were a visual indication of a tornado forming however this is untrue, however that is not to say that a tornado was not already present before the formation of mammatus. The exception to this is in severe thunderstorms with very strong updraughts which can form mammatus on the forward edge of the anvil or upwind of the updraught, seeing these on the anvil ahead of an approaching storm can indicate the presence of serious air rising into the storm which I have observed here in the past on strong multicell storms in 2009 which also exhibited overshooting tops.
I had watched this sublime sky show for over 10 min's then I grabbed my gear and went back to my room to download the images and video footage onto my lap top. It was dark outside and dusk had fallen and just when I thought the show was over I heard several distant rumbles of thunder, I looked out the window once again to the SE and sure enough it was my old friend letting me know it was still there, the cell was now in shadow and had taken on a dark blue colour as it crossed Lough Neagh heading for Antrim before decaying as the solar heating (the only source of lift today) was shut off for the night, this was my first thunder of Spring so I was rather fond of that cell for breaking the drought.
Video clip of the mammatus with real time segments combined with a time lapse section at the end, this footage doesn't even come close to conveying what the scale and colours were like with the eye however it is some kind of record and as far as I know it is the only video footage taken of the display from Maghera. I wonder what else nature has in store during the weeks and months ahead?, I can't wait to find out. Thanks very much for reading.
Martin McKenna