This day will go down in history for South Australia as one of the great storm outbreaks of recent history. For anyone who lives north of about Balaklava, supercells affected a large swath, dropping multiple tornadoes on the many supercells that formed on a sharp cold front. This front, in response to a very deep developing low pressure system contained a shear profile more typical of the united states, and combined with a very wet winter and start to spring from the negative IOD, meant instead of dry air being dragged in from the continent we had relative to the time of year, high moisture levels. Add the vorticity from the wrapping front, and north-east winds of considerable strength ahead of the front, we had an environment primed for supercell development, despite modest CAPE (up to around 1000 j/kg). A powerful divergent jet stream above would have assisted storm development greatly in the instability department.
The rainband with embedded thunderstorms.
By mid morning, we had a rather lightning active mid level rainband develop out ahead of the front, in response to huge upper divergence from the jet exit of a VICIOUS 500mb jet moving in from the west. Apart from producing some locally intense Cg action, it acted to transport moisture from the mid levels to the surface, another necessary ingredient for lowering LCL’s in the afternoon, and providing a deeper moisture profile for storm development.
I drove out to the north of Blyth to watch it move in. It had that classic high shear, mid-level thunderstorm sky we often see in South Australia this time of year. A cell rapidly developed out ahead of the line, and proceeded to drop a barrage of Cg’s, running right over the top of me. They weren’t very pulsy, however they were very loud, with huge cracks associated with them. I had many bolts within a few km, the closest hitting <300m from me in a paddock and beading out.
Despite many Cg’s dropping, I somehow managed to only capture one Cc on the camera, I can’t even remember seeing a Cc, oh the irony.
I drove back into Blyth, being flanged the whole time, ears ringing from the close ones. I take a short video on my phone, and manage to capture one closish Cg on the back end.
A video screen grab of a bolt approx 1.5-2km away.
The barrage of bolts from this mature mid level cell is demonstrated on lightning tracker.
Now that this excitement had passed, my attention turned to the clear air behind, and the currently invisible passage of the front. I knew I would have trouble chasing these cells, with the Barunga Ranges off to my west. Roads are few and far between over this range, and tend to diagonal themselves across it. I also knew there was a chance cells would become too cluttered along the front as it progressed, so it was either sit on the Barunga Range and follow it east to the Clare Valley (therefore risking only seeing a linear line), where it would overtake me due to road networks, OR to drive to the coast to see the cells as close to initiation as possible, and have no road options to persue them with, however with what I believed to be a greater chance of seeing the storms in discrete modes. I chose the latter and drove over to Port Broughton. It’s hard to say whether this was the right choice, as it would turn out that storm cells would remain relatively discrete throughout the afternoon and would produce a significant tornado at my home town which I would have seen with the first option. However, instead I did get to see a very powerful supercell anchored on the cold front put down many funnels, and one short lived tornado, as well as a tornado at Crystal Brook on a weaker, but still significant supercell to this ones north. Unfortunately with storm chasing, decisions like this often need to be made, you simply can’t be everywhere at once!
The BoM weren’t messing around with their warnings. I’ve never seen destructive gusts forecast to 140km. They understood the severity of that was about to unfold.
I get to Port Broughton as the absolutely enormous anvils of the developing supercells to the west moved over. It was at this point I could tell for sure the cells had anchored onto the cold front…success!! This was key for increasing helicity in the storms vicinity and increasing updraft strength with the forced lift.
Here she comes, an impressive mammatus display forms under the anvil of a developing tornadic supercell.
I linger, very carefully watching radar to make the critical decision of where to go. On days like today, core-punching a storm can mean severe hail damage to your car, or being trapped by falling trees or flooding. You also need to be acutely aware of cells forming ahead of the line, right movers especially as these can rapidly develop and create potentially damaging storms, just ask the people at Cleve whom had just had a right mover drop large hail as the above image was taken.
A left mover had anchored on the line, and it become obvious that this was the cell to watch. I determined the downdraft region was going to t-bone Port Broughton, so to see the inflow region and flanking line I would need to head north, so I did. My decision was made, I would have to abandon this storm as it went past as there were no roads to track with it short of corepunching through this dangerous storm.
The first severe cells to develop on the cold front. The cell near Kimba would become a cyclic tornadic supercell dropping multiple tornadoes. The cell near Cleve turned hard right dropping large hail.
Satellite showing the developing supercell in relation to the deepening low to the west. I have circled it in red. Notice the broad area of convective rain off to the east that had developed earlier that morning.
It didn’t take long to see that we had a very significant storm on our hands. It forms a kink in the line, ensuring its inflow was now clear of competition.
I park in a very clear area with great views all around and sit for over half an hour now, watching the spectacle unfold. Slowly but surely the flanking line and wall cloud of this supercell came into view.
First views through the haze.
Spin, spin and spin some more. Countless funnels try their luck as it comes into view.
A phone grab, a very low wall cloud is apparent on the line now.
And then sure enough, a tornado rapidly forms, drops to the ground and dissipates in a rather short amount of time…success! My first ever mesocyclonic tornado.
Down she comes! A beautiful tornado under a large wall cloud.
Weatherzone radar and doppler, 2 minutes after the tornado occurrence.
Red shows a huge supercell forming, whilst the orange shows initiation of further cells north along the line, which would also produce some significant tornadoes.
The cell moves forward, and continues its relentless efforts to put down tornadoes. It was a strange feeling, having wind nearly at my back that was not only strong, but moist as well. Something rarely seen ahead of storms in Australia, the crucial lower level jet which greatly increases tornado chances.
Another well formed funnel comes down! The last ditch effort for this meso.
The storm gets closer, and what I believe to be an updraft replacement cycle occurs. The storm also starts to look mean…very very mean. An eerie green glow emerges the closer it comes, and as I start to see storms EXPLODING to the north of this one, I begin to get nervous, I have a dangerous supercell to my south ready to put down a tornado any minute, and rapidly developing cells sandwiching me in to the north.
BoM radar at the time of the image above.
Two mesocyclones here, the lowering on the left where the first tornado dropped is now occluding, the lowering to its right, further to the east is taking over as the main meso.
Angry Cg’s start dropping as the new meso really starts to wind up, and the rainfall intensity increases.
To the very left, behind the hail curtain is an occluding wall cloud, responsible for the first tornado observed, while a new and stronger mesocyclone forms just to NE, as the RFD begins to cut in and a broad funnel forms, chucking down numerous fingers.
The separation becomes even more defined and visible motion in this new area is observed.
I accept the fact that at least one of the right movers heading in from the north will hit me, so I wait for it to pass to the south, which would allow me to see this mesocyclone up close and personally!
The big cells I’m under have now cast a huge anvil across the land, and the cells that I’m worried about coming down from the NNE and forming rapidly. You can see how I was being sandwiched.
Oh what a moment. The green glows strongly, the winds start whistling from behind me, and the meanest storm of my life rages just to my south. Playing a mighty fine line, I can see rain/hail curtains only a few km to my west. You can see the curve here quite strongly.
Radar showing a nasty core.
I take this image and then floor it to the north to get to my NW road option and out of danger. I take no pictures until I reach the highway, but have to corepunch in front of a fairly benign looking cell coming down from the north, which blows at least 100km winds sideways across the road, with the odd bit of small hail and spray everywhere. The trees are swaying over the road but I just manage to get out to its east before the worst of the core crosses the road…success! I have avoided damaging my car in any way.
The strength of the inflowing winds is obvious here, the tall grass is bent right over, angled 70 degrees to the storm, thrashing around as the line of severe storms moves through.
Taking in the now two, left moving supercells. The one to the far next was now less than 20 minutes away from putting down a tornado at Blyth, the right side put a tornado down in Crystal Brook. Notice the inflow tail.
An enormous strongly rotating as indicated by radar, wall cloud, less than twenty minutes before producing the Blyth tornado, and hail as large, if not larger than tennis balls. A violent storm, more typical of the united states.
The radar I believe shortly before both the Blyth and Crystal Brook tornadoes occurred.
The now huge line of cells is very obvious from space!
I take a moment on the highway to see if there is anyway to get back in front of the southern cell. I rapidly conclude there isn’t, i’ll be driving directly under a rotating wall cloud region and then core punching the worst to do so…bugga! The cells to my west and north are rapidly developing and closing in quickly, nothing for it but to head to Crystal Brook to seek shelter, I simply can’t outrun this.
A huge wall of near ground scraping wall cloud advances from the west, there is no escape now. I head into Crystal Brook to find shelter for my car from the storm…little did I know.
Another enormous tornadic wall cloud was bearing down on me. This produced a weak multivortex tornado through Crystal Brook shortly after.
See the inflow ripping in from the north on the right side. Very fast motions, very dynamic storms, VERY low wall cloud. My last view of the cell.
I snap this last shot of the line and drive into Crystal Brook. I turn the corner and see a large piece of roof flying hundreds of metres in the air…oh crap I’ve made a mistake. I see more bits of tin roofing being wrapped around in the air, low cloud rotating above and the trees being shredded down the road. I slam the car into reverse and this fast moving and nearly invisible multivortex tornado moves diagonally towards me at fast speeds, probably around 50km/h as a rough estimate. Rapid motions are observed at ground level and i whip the car around, turn left and watch the tornado pass to my east by a couple hundred metres as I sit in the ‘bears cage’ region of the storm. The trees in front of me get a clipping from this tornado and are violently thrown around. It passed and I drive a short distance down the road to find a front yard full of trees, powerlines down and the owner visually distressed, whom I don’t think had any idea what was coming, it came through very quickly.
I manage to snap only one shot on my phone (thought It was videoing, stupid thing). I think the most disturbing thing about this image, is you can see next to nothing. This tornado was nearly invisible. The low cloud above was spinning rapidly, probably some 200m off the ground.
Cloned out a couple of raindrops here and up the contrast. What is it I captured? You can see the vague outline of a multivortex tornado. The black objects in the air are pieces of roofing being lifted a long way up. More interestingly however we can see a tube like blur just left of centre…given the fast shutter speed it can’t have been debris blurring. Hence my conclusion, a small vortex spinning just above the ground. These vortex’s are the reason why tornadoes can do severe damage in tiny areas, while leaving nearby objects untouched.
A quick pic again from the phone camera before I check to see if everyone there is okay. These trees were shredded in front of me like a hedge trimmer was going through.
Then comes the rainfall a couple of minutes afterwards. I carry on to find the source of the airborne debris. 90-100km winds and some very heavy wind come through.
I go a bit more up the road and see the very real damage from the near invisible tornado. The damage path was sporadic, this thing was briefly touching down and bouncing through the town. I talk to a local who saw the worst of it happen and he mentions a thin wall of black…given the wetness and the fact it was across an oval…we have had a condensation funnel touch down, gain momentum and slam through the netball courts. This guys property had faired okay, but a large piece of wood and bounced straight through his fence knocking it down, and there was a hole in his shed roof from debris.
I head in for a closer look, now it is all good and well to see pictures of tornado damage, but seeing it first hand is something else. This was only a weak tornado, but it became quickly apparent that had anyone been outside in this, they would have been killed.
The roof was torn off this shelter…and thrown backwards to the rest of the debris, gently enough that it held its shape.
Some gauging of the surface of the oval. A closer look showed wood had been speared into the ground, along under the grass and became wedged into the ground, hows that for power. There were many examples of this on the oval.
This building on the right was a write off. Quite bad damage.
A bit of force to push this skip over!
Check out the tin wrapped around the chair, and the wood driven through the tin on that shed. Deadly stuff.
Some of this tin had originated from the Crystal Brook football club roof on the other side of the oval.
Carnage through such a narrow strip.
The only apparent damage on this side of the oval was this tower blown over, and the roof off the back of this building had been lifted off. Yet shade cloths 40m away were fine. It’s like a funnel clipped the top of this building, but didn’t drop any lower until it reached the oval.
Was hard at times to explain where all this tin came from.
The tornado must have lifted just after this bit, only a few tree branches down until about 300m down the road where a whole heaps of branches and powerlines had come down.
These weren’t the only severe storms of the day, oh no. I believe the biggest tornado of the day belongs to north of Melrose, where some very wide and severe damage was recorded. River reds de-branched and stripped, and some severe property damage. If anyone reading this knows of any pictures of this tornado I’d love to see them!
So far based on pictures I have seen, I think we can confirm 5 tornadoes, and possibly 7 or 8 damage paths possibly so far. This truly was an exceptional storm outbreak, thanks to a very powerful weather system. Something very rarely seen in South Australia. All types of severe weather would result from this low. A day I will never forget, and some things I might never see again.