Morning Mid-level Thunderstorms 22 November 2014

Models had been toying with the idea of a nice mid level outbreak of storms, with some reasonable CAPE values up to 800J/kg. It reminded me quite a bit of November 5 2012, albeit a little less unstable. There was a solid sheer profile, with from memory 60 knot 0-6km sheer, with a solid 80 knot jet overhead and good moisture above 850. I had initially expected stuff to be in a line through the mid north into the riverland after later morning, but convergence stayed south and nailed the north Adelaide Plains and eventually Adelaide with a train of storms. The strongest were the initial cells very early in the morning, large hail was reported on Yorke Peninsula around sunrise. A very lightning active cell exploded to the north of Gawler around 8, and I was at outer harbor watching it at the time, was some nice cg’s out ahead of the rain curtain, some of the better daytime cg’s I’ve seen for quite a while.

Another strong cell was lining up for the area slightly further south and I headed north to try and intercept it. I hung south for a bit to watch the heavy cell heading for northern Adelaide, which was quite noisy with a lot of nice cg’s, before watching a gustfront develop alone the storm line, rapidly before my eyes. The Adelaide cell had quite nice mid level vorticity, with a couple of funnels, and a largish rotating funnel like protrusion for a period.

Nice funnel protrusion in the centre, and a heavy rainshaft, possibly with hail heading for northern burbs.

Very heavy rain aimed at the northern burbs. Very bright bolts amongst this. Quite a wavy edge to this base, probably from the vigorous speed sheer.

Thin elongated mid level funnel.

I headed north and stopped south of the Gawler River in a nice open area and watched the gustfront develop. Lightning was infrequent, but the bolts were big hitting a few km to the west as the shelf moved over. Outflow hit but was very tame, the higher winds were to the north where the gustfront was thickest, I was right on the southern edge. Having seen images of the first, and stronger storm of the morning, it appeared to have a much higher shelf and it dropped a substantial amount of rain along its path, up to 10mm. I feel the reason the line I was on became so meaty so quick was during a brief outflow stage where it undercut the moisture from the previous storm, lowering the lcl. This is supported by radar as the echoes and lightning frequency weakened about 15 minutes before hitting me, and restrengthened moments after going over me, quite substantially. Images from the storm just moments later in its life show a much less defined shelf.

Shelf cloud developing.

As the gustfront really began to develop, a 180 degree pano, the downdraught area of the cell really had a blue tinge to it.

A better perspective of the scale of this thing in a short tele image. Really dwarfed the landscape, one of the coolest things I’ve seen!

Moving overhead, brilliant colours and textures! Very wide image.

Shelf rolls on over me, in the danger spot for bolts now. 30 seconds after this a bolt hit 3-500m away in that paddock.

I jumped in the car, reversed and went to drive off before a bolt hit in the paddock to my east 3-500m away with a huge crack. The cell became much more lightning active just to my east, with frequent big cg’s raining down between the shelf and the rain where I was, was a spectacular sight. Rain was reasonably heavy but nothing to write home about, I think the heavier stuff was to my north, but overall it moved through very quickly and I could see the clear air behind after only ten minutes, even after driving east. The line retained intensity to my east, and I got to watch 20 odd minutes of frequent cg’s over the hills, the northern end of the line in the inflow region appeared to have a wall cloud, although I’m still not sure as it looked to be retrograding against the prevailing winds. My thoughts are it was an outflow push from the cell, that pushed back and formed a bit of a roll cloud, however I’m not sure.

Wall cloud-like structure. Bolt was a complete random event but no complaints πŸ˜›

I had to head home at this stage for work, but storm were frequent all the way until I got to work at 2pm. Was a brilliant day really. The texture and colour of the clouds were something else!

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6 Responses to Morning Mid-level Thunderstorms 22 November 2014

  1. Chris says:

    Awesome mark that guster is one of the best cloud photos I’ve seen from SA. Should submit it for the calenders next year.

    • MarkDawsonPhoto says:

      Cheers mate! Yeah I was massively surprised by what this storm produced visually. Pity I couldn’t have had a better composition but was too risky to race off from such a clear field and miss it altogether.

  2. banni2014 says:

    Great photos and write up – thanks.

  3. Crikey Mark – some excellent photos and description there, most particularly the developing shelf cloud stretching off into the distance πŸ™‚ Definitely an exposed position sitting in a car in that paddock! That’s when I look around for some trees or poles etc to park near. There’s probably some way to set up a vehicle so it’s safer for occupants in the event of a strike but I don’t know what it is.

    • MarkDawsonPhoto says:

      Yeah it is always something that needs to be taken into consideration. Fortunately in SA bolts are fairly easy to predict and the risk can be reduced but you still get nervous standing out there. While the car also provides protection, I’d rather not have the electronics fried πŸ˜› Generally I see it as something out of my control, that’s what insurance is for I guess!

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