Today was an interesting setup, and something that I can’t recall seeing very often at all. Overnight a rainband had significantly moistened the lowers leading to widespread dewpoints of 12 degrees, up to 14 degrees in places with 20 degree or so temps. There was very slack shear, predominantly from the SW up to around 25 knots at the steering level, decreasing further east with the upper trough. Even the 300’s into what would become an upper low were very slow. However this upper feature had a cold pool and caused lapse rates to be steep enough to quite a depth, and with the dewpoint and temperatures so close we had relatively low bases (for SA). This led to rather deep convection and whilst CAPE was quite skinny, it was enough. There were broad area of high and mid level cloud earlier on, and storms formed in areas that managed to attract sunlight.
Convergence over the Murraylands led to a line of storms during the arvo, which kept back building along flanking lines, and this was the main point of interest storm wise this day. However a small cell developed over the gulf just south of Port Wakefield, probably in response to the SBF and moved NE towards Clare. I noticed it, and looking at the skies knew it would either be a long drive SE to see anything, or this small chance. It weakened, however a line of convection formed ahead of it and I sat just east of Clare watching to see what it would do. After one cell grew particularly tall, it rapidly died and I noticed the top of a tall cell to the SW, and once checking radar, realised another cell had formed on the flank of the previous.
It was glaciating as I left the ranges, and by the time I arrived at Blyth was thundering away nicely. It was incredibly discrete compared to all of the other cells seen this day, even at initiation there was hardly any competing convection, with just a flanking line of cells, and a couple mediocris to congestus to the south.
I corepunched straight into it, the first core was in the stages of decay but was still heavy, out the back another cell was just bursting, and there was a magnificent updraught and base right next to it. The cutoff from the wet to dry was merely meters, and was seriously heavy. Enough rainfall was produced to creates quite a bit of runoff on the sides of the road.
I followed the cell north, watching the flanking cells strengthen then dump in spectacular fashion, the lack of shear meant it was straight up then straight down, nearly every new cell produced a rock solid rainshaft and rainfoot. The thing was producing near constant thunder by the time it was north of Blyth and frequent flashes. Some real nice cracks in there as well.
It weakened off soon after and I was hesitant to stick with it, given I could see a whales mouth out just ahead as the multicell became outflow dominant. I decided to stick with it given the lack of anything else within 1 hours drive, and had to work around horrible road networks to get back up behind it. At this stage a long line of flanking cells nuked in spectacular fashion just out ahead of me. I wanted to get back in front so was forced to core punch. It wasn’t too bad at first but the inevitable downburst occurred just to my west and moved overhead just south of Spalding. The rainfall rates, while relatively narrow were rather impressive, a complete whiteout, I could only just make out the road and there were sheets of water on the road in a couple of very narrow strips. Towards the front there was also plenty of hail, up to maybe half a cm in size.
I got north of Spalding and the cell that had dumped was rapidly collapsing and proceeding to decay but still presented a spectacular sight. The flanking line was still in decent shape, so I followed it up to near Jamestown, before it eventually gave up.
The convergent storm line to the SE looked very spectacular at this stage, boiling away in the distance, and so I drove to Burra given it wasn’t far out of the way to get a closer look. I ended up driving a little way down onto the plains and watching the cells during sunset. Whilst not huge, the convection was nice and the colours tremendous.