|
|
How on Earth can I ever do justice to this remarkable event?, using words I simply can't, through images the story is barely presented without the play of motion. However despite these handicaps I will do my best in the hope that the reader will get to re-live my most thrilling severe weather event to date. It all happened during the evening of Thursday April 29th 2010, the forecast for that day was for scattered showers, that's it. My mind was already focused on Friday as GFS had been showing all the ingredients for thunderstorms so Thursday really was a 'rest day', a chance to study the forecasts, charge the batteries, and look forward to the convective action 24 hours later. By force of habit I checked the models for Thursday anyway, GFS showed more than 200 CAPE however the LIs were positive and wind shear was virtually absent so not much chance of anything interesting, or so I thought.
By mid day those premature thoughts had ended and were soon replaced by keen observation and anticipation. If there's but one thing which I have learned during my many years of sky observing it's that exciting and unexpected transient events can happen at any moment no matter what the forecasts say, however to notice that potential for the unusual takes a trained eye and a natural ability to 'read' the sky. This was exactly what I was doing during the early afternoon when I noticed convective clouds bubbling up in the heat which didn't look out of place when a convective outlook had been issued. Towering Cumulus clouds began to fire up and within a few tens of min's they looked so good that my attention was stolen for the rest of the day, what struck me was just how well defined those solid dark updraught bases were, then soon inflow motion was obvious. A wonderful line of solid towers approached from the W and I had a stunning view of them from my home, as I watched, two areas of rotation quickly developed and persisted for a long time as the towers very slowly crept E, it didn't take a genius to work out that the chances of funnel clouds were very high, there must have been marked vorticity in the area. Just as I was thinking all this I got a call from Conor McDonald, he was just as captivated by the convection as I was and agreed there could be a good funnel today.
I hate being trapped in the house when there's something interesting in the sky so I decided to get in the car and go on a local 'chase' through the Maghera countryside to get a better look at those bases, I stayed on the Crewe Road, which led me onto a deeper country road, then I pulled over at a quiet spot on a hill looking W. Those rotating bases passed directly through the zenith with lovely churning motions, I watched them contently as they drifted into the E. It was turning gloomy outside but fairly humid at the same time so I just sat on the car bonnet enjoying the view of the sky. It wasn't long before a nice gust front arrived from the W over the Sperrin Mountains so I decided to stay out longer and watch it approach. I was quite impressed by just how menacing the sky was looking and by the quality of the convective clouds considering that this wasn't even 'a day'.
The dark gust front approached me, and just before it performed it's over-the-roof transit, I was amazed to see two black areas of cloud rotating in a lively fashion, I stood on the country road below, tilted my head back, and stared up as those two churning areas which coiled with impressive speed, I was thinking this was darn spectacular for a day when nothing was supposed to be happening. The sky darkened further, followed by a very heavy and prolonged shower which didn't want to stop, so I drove back home through it as the roads water logged and surface spray reduced visibility to a dangerous level. Back at home I checked the online radar and was shocked to see that shower had a blue echo - not a chance in hell, that should have been getting a moderate to heavy echo, another example why radar can't always be trusted. Another phone call with Conor was swapped and I told him about the rotation, he wasn't surprised, he'd been watching things from home and had taken images of the showers from there.
I did a quick drive down the street with my Sister to get some shopping, I spent half the time in a traffic queue staring at the sky because the clouds were looking menacing, I said to my Sister to be on the alert for funnel clouds, no sooner had a I said that when a wedge-shaped lowering developed under the clouds, unable to get a shot because I was driving I passed the camera to my Sister, she had a go at taking a 3-shot burst through the window but since she had never used the camera before the images turned out blurred, they were focused on the inside of the car and not the sky. Around dinner time we arrived back home and had a nice meal, after which I got a Magnum ice cream from the freezer then ran upstairs to check the radar. It's at this point that I should point out to the reader that one should always trust their instincts 100%!.
I was munching my Magnum while looking at the radar and saw blue shower echoes to my W moving in, a few others near Lough Neagh also got my attention and for a moment I seriously considered driving to the Marina incase a funnel formed. I was standing in my room unsure of what to do, stay or go?, after a long think I decided to stay home and not even go out at all. I glanced out the window towards the W and saw a remarkable sight far away over the Sperrin Mountains, the clouds in that direction looked absolutely brutal, I hate to sound cliche but the sky simply looked dark and heavy, it was obvious that trouble was brewing and I had a very powerful sensation that something major was going to happen. This feeling was so abrupt and focused that I actually threw the remainder of the magnum in the bin, fetched my Dog 'Drew', then went out to the car. My plan was to go out and watch for a while incase there was funnel from this then drive out to a country location for walk with Drew. As I stepped into the car I could see those threatening dark clouds in the W getting closer, even at a glance I could see strange lifting motions, then I all of a sudden felt like I had to get out to my location fast!.
I drove out along the country roads at a swift speed while periodically glancing up at those nasty clouds while trying to keep the car on the road, Drew was sitting happily in the back seat waiting for his walk. I pulled over at the same location I was at earlier, this was the third time I was here this day, approx 1 mile NE of Maghera on high ground, the car bonnet was facing S which allowed me a perfect view of the NW to S skyline through the driver's window. In the W was a very large cell with dark clouds along the leading edge of the gust front which was clearly bowing out on the N side, below the gust front ran a long curtain of heavy precip which had a dark silvery colour in the late evening light. Behind the gust front, and off-set on the SW side, where a group of black clouds arranged side by side with clear gaps between them. These solid lumps were displaying insane vertical motions as they appeared to lift upwards like a waterfall in reverse, these lumps stayed low to the ground though and never climbed any higher despite exhibiting obvious rapid lifting. To the N of these lumps was a large mass of 'scud fingers' which began to go nuts!.
 |
The bowing gust front advanced and hit so suddenly it was as if a switch had been flicked. The outflow from the cell was quite striking with complete torrential rain which felt like the core of a thunderstorm, the rain drops which splattered against the windscreen looked huge - more like massive wet snow flakes than normal precip. Everything turned to water around me, I quickly put the windows back up while getting splattered in the face, a quick look in the back seat where Drew was sitting revealed a frightened face, he looked shook up. Visibility dropped rapidly and soon the windscreen was smeared with rain with the glass misting over so I got the demister and wipers going. I was thinking that this rainfall really was truly convective in nature, I wouldn't have been surprised to hear thunder at any moment.
Once the window cleared a little I took this shot through the front windscreen, at this point the gust front had passed over with the precip still falling on me, it was that heavy it made a constant rumbling noise. The image captures the very rear of this shower/cell (SW side) showing several black sections of cloud which began shooting up vertically, the region to the R of this where you can see those scud fingers simply went nuts before my eyes. That area suddenly began rotating in a vertical and horizontal axis with astonishing speed, it was just above the ground too and began rotating faster and faster, I went into brief shock and just sat there staring not believing what I was seeing, once the rotation reached breathtaking speed I simply shouted out loud ''holy sh*t'', I kept repeating that over and over in a complete panic, the circulation speed at this point was the exact same as videos I had seen of powerful US tornadoes!. The vortex actually crossed my line of sight to the S from R to L above the road at fairly close range, despite it's incredible rotation, the cell it had dropped from was a slow mover so I had plenty of time to take in every detail. Above the vortex was a rotating mass of dark cloud which almost put me in shock, I needed to tell someone quick, had to, or no would believe this.
I fished out my mobile phone from my jeans with trembling hands and selected Conor's number, it took me three attempts to get it dialed because I kept pressing the wrong keypads due to the adrenalin pumping through me. I eventually got through to Conor on the 2nd or 3rd ring, as soon as I heard his voice I literally screamed into the speaker ''look to the east now!!!!'', while I was screaming this I saw not one, but two powerful vortices spinning close to the ground in the sky at my 11 o'clock position as the vortices moved into the SE. Conor confirmed in an extremely excited tone that he had been watching the same thing and had just seen it rotating over the edge of town before I rang, he was actually in the process of ringing me with the phone in hand just when my call went through to him - talk about great timing. Conor rushed to his car immediately and went after it.
 |
After the call ended I threw the phone on the seat and put down the passenger window, then leaned across the seats at an awkward angle and began taking rapid fire images as the vortices passed along my line of sight from R to L heading E. In a split second I realised that the camera was on 'auto landscape' mode, however now was not the time to be using manual and figuring out settings so I just left it on that mode and snapped away as I followed the vortex areas through the viewfinder. You can see part of the door frame and wing mirror in the frame, raindrops still fell outside and a few made it onto the camera, however the greater bulk of the precip line had now cleared through. Annoyingly that hedgerow was blocking some of the view, beyond this was a field along the slope of a hill, and beyond that hill was lower ground. Taken at 18mm.
In reality these clouds were almost pure black in colour, however the metering mode used a higher ISO which brings them out grey, the plus side of this is that it also brought to light some of the cloud structure. I cursed out loud that I hadn't brought my video camera with me, I just couldn't believe it, on any other day I would have had it but not on the one day in years when it was most needed, I was so annoyed at myself because before I left the house my instincts had told me to bring the camera and I ignored them, this was frustrating because without the video I doubted that anyone would actually believe what I was seeing. Upon reflection I'm actually glad I didn't have it because I couldn't have operated two devices at the same time in these conditions, it would have been one or the other, and when it comes down it I always prefer still images when possible.
 |
The scene at this moment was utter chaos, I just couldn't believe what I was seeing, I had always imagined what it would be like to experience an event like this, I had planned for it, trained myself for it, I was ready for it - however when it happens suddenly out of the blue without warning it completely throws you off guard and disorientates your thoughts. My world had now become this vortex event - it and the world through the viewfinder were my reality, it was target fixation or tunnel vision, which ever you wish to call it.
In the image above, the overexposed region is the precip core which was moving away into the distance and to the L (E), that's the outflow area of the cell. The giant mass of cloud to the R is the area of interest, that whole mass had amazing motion, call it a lowering or wall cloud if you like, what it was for sure is not known, however this is the inflow region at the rear (SW) of the cell. To the R of the telegraph pole is a large fat funnel which was rotating VIOLENTLY, I mean this was spinning at serious speed in the league of a powerful tornado, you can make out it's smooth cylindrical shape on the still image. Immediately to the R of this was another funnel/vortex, this one was slimmer with a nice acute bend visible in its form just above the wires. This vortex was also rotating violently at the same time. The larger dark lowering to the far R was also rotating, imagine all three of these behaving in the manner I have just described at close range and you can imagine how exciting this was.
 |
Zoomed into the multiple vortex area at 41mm. The big cylindrical funnel is very striking here, even on the still image you can actually see it's rotation direction with sections of bright grey scud wrapping around the funnel. Funnel 2 to the R of the first had a great looking bend in it's pipe, scud to the L and R of this vortex was wrapping around that tube at rapid speed, check out the three 'coils' of cloud wrapping around the 2nd funnel. I was awestruck by how fast these two vortices/funnels were rotating at this time, they were obviously moving at tornadic speed, however trying to describe this speed is next to impossible, and even if I could the reader might think I was exaggerating. Unfortunately you had to have been there to believe the power of this thing (s). I was hoping that there would be at least one other person who was watching this because it was just so unbelievable.
 |
Same scene at 41mm. There was violent vertical and horizontal rotation going on here at the exact same time. The 2nd funnel was now fast becoming the centre of attention as it became the strongest vortex in the region. Drew was panting away in the back seat and clearly frightened and confused by all the commotion because I was shouting ''Drew...look...a tornado'' over and over again like a nutter. Drew is terrified of thunderstorms and I think he thought he was about to get another, I thought so too, but amazingly there were no rumbles. I was certain at this point that this was on the ground doing some kind of damage but there were no signs of debris going up into the sky from what I can remember.
 |
Vortex 2 steals the show and is located between two other areas of rapid rotation, including that big dark lowering to the R which sucked scud upwards from below the hedge in a fast streaming circular motion. That 2nd funnel at centre was displaying absolutely incredible rotation with a messy bowl of cloud and scud spinning around the circumference of the funnel, it looked more like a vertical black pipe visually.
 |
Watch how vortex 2 changes shape and profile in the top six images. Meanwhile, unknown to me at this time, Conor was on the road chasing this cell, he stopped briefly on the Crewe Road and got a great structure shot showing the rear of the cell complete with outflow and inflow regions in the same frame as the shower surged E. Conor then continued on at high speed through the narrow country roads trying to stay in close visual range as it rotated across the fields, he was just waiting for a major tornadic touch down at any moment.
 |
This entire area of multiple vortices was huge, easily the size of several large fields side by side. The annotated image above shows the main regions as the cell heads into the distance. Yes you read that correctly, not only where there three areas of rotation, there where also satellite vortices forming on the S side of funnel 2. I hoped to goodness someone else was looking at this, however I never seen a single car or person at this spot the entire time - typical isn't it, had I wanted some peace there would have been none stop traffic. Conor was now driving towards Lavey and pulled up beside a field and began shooting images with the 500D, I tried ringing Conor again but couldn't get through, I was so excited by what was happening that I wanted to phone someone at random and tell them, I was tempted to phone home but eventually saw sense and realised that I needed to stay focused and get more images to document this event.
 |
Big 'wall cloud/lowering' with multiple vortices/funnels moving further away into the distance. Notice that my view is looking across an upwards slanting field, ground level was marked by my car. I was beginning to loose sight of this thing and knew I had to re-position at any moment. That's a satellite vortex forming between the two main areas of rotation. Just to clarify, that entire mound of black cloud filling a large portion of the frame was churning and rotating all over the place.
 |
That satellite vortex then developed a semi-transparent funnel/tube. All three regions rotated like crazy as I snapped away with the camera while leaning out the passenger window. This really was absolutely insane, lots of thoughts passed through my mind at high speed during this, one was about trusting instincts and timing, because if I had stayed longer at home to eat that Magnum ice cream I may have missed the event entirely, or had I made the decision to not check the radar and just stay in then I would be completely unaware that this was happening, however most important of all were my instincts from earlier in the day which made me watch the sky carefully all afternoon and evening, everything could so easily have turned out different, and now, thanks to a multitude of chance events and random decisions, I was seeing my most spectacular severe weather event since I got interested in this field, I couldn't believe it was happening though, it was complete sensory overload. More on page 2.
Martin McKenna