We left Cobar at about 9:30am after filling up with petrol and started heading N towards Bourke. We’d spoken to the Doc this morning and he informed us that the trough was sitting to the W of Cobar, Bourke and Cunnamulla and was probably aligned SE - NW from near Cobar out to about Thargomindah. LI’s were forecast to be about -8 or so in the area and DP’s were in the low 20’s with temps around the low to mid 20’s as well. Things weren’t looking so good at about 10:00am with fairly thick Strato Cu but we continued N.

One of the hazards of driving in these areas is that there are no fences to keep stock in and at 10:25am we had to slow to a crawl to avoid a herd of cows which were wandering aimlessly along the road. It was also interesting to note the amount of water lying on the sides of the road, indicating heavy, slow-moving storms from the previous few days. By 10:45am we’d driven into clearer skies to the S of Bourke and some heavy showers with nice dark bases had developed. We called the Doc as we drove through Bourke and he informed us of a big storm which had just hit Thargomindah, dumping 32mm of rain in a fairly short period of time. Their current obs out there were now 25C/21C. By 11:30am we were well N of Bourke and the sky was looking nice with some TCu to our W and some sporadic static on the radio. We stopped for a quick break and took some obs with the temp sitting on 30C and the DP on 22C.

We continued heading N and by 12:00am we saw the first anvil way off to our NW about 150km away. We drove a little further on (crossing the border into QLD) and then pulled up in an open flat area with a decent view. We could now see distant CB’s to our SW, W and NW. We took some more obs with temp now up to 31.5C and DP up to 24C with light NE’ly winds up to about 8knts. While watching and waiting, a family of emus wandered into the field in front of us.

Emus. Capture: Andrew McDonald.

We continued to watch the storms develop in the distance from this location with 7 separate storms identifiable in a line running SE-NW, most probably along the trough line. While watching, Anthony did a quick LI and CAPE calculation given the current obs and estimated a lifted index of about -10 and CAPE of about 3000j/kg. We decided at 1:45pm we would move up the road to try and get a little closer and perhaps a better view of the cells to our WNW. We drove about 5km, finding an excellent view of some small CB’s sitting on the line about 40km to our W. We watched for a short while before pressing on to Cunnamulla where we had more road options and also allowed us to pick up some lunch. Just before we arrived in Cunnamulla we saw a big cell to our W so we raced into Cunnamulla, fuelled up, grabbed some lunch and then raced W towards Thargomindah. Ahead of us was a much larger cell than we’d been watching earlier and we guessed it was somewhere between Thargomindah and Cunnamulla. We spoke to the Doc while in Cunnamulla and he said that to our W was a line of storms which had literally thousands of lightning strikes on tracker.

We were on the road heading W by about 3:30pm with some TCu showers to the S of Cunnamulla and we encountered some minor flooding with water left over in flood ways from previous days storms.

Greg’s car ploughs through the water. Capture: Andrew McDonald.

The sky began to darken to our W and just after 4:00pm we saw the first CG. We could also just make out a very low gust front on the horizon and static on the am radio had increased to once a second if not more (almost constant). We approached the town of Eulo from the E as the gust front came in from the W. It was as black as black under the guster and above the main front there was a nice green tinge. We drove through town to find a nice little clearing from which we could watch from. The guster was about 3km out of town to the W and it made for amazing photos and video. The red dust and the green grass made for excellent contrast against the blue-black sky.

Awesome gust front just W of Eulo in SW QLD. Capture: Andrew McDonald.

Another capture of the gust front near Eulo. Capture: Andrew McDonald.

While we were watching a massive CG ripped through the guster within about 3km of us but unfortunately I missed it on video. It was getting a little close for our liking so we left Eulo at 4:25pm and raced back E with the guster hot on our tail. We were hoping to stay ahead of it to get the best photo opportunities. Red dust was being kicked up in front of the guster. Thundery showers were popping up rapidly ahead of the main guster and we had to punch through one before being able to stop for more photos. The gust front extended as far as the eye could see to the S and was still producing some nice lightning.

The whole area was very lightning active still. Capture: Andrew McDonald.

A quick check of the temperature saw it up to 33C at 4:50pm with the DP down a little to 21C. We continued to leapfrog the line but with more cells developing to the E of the line and also to the N we drove well ahead to near Cunnamulla.

The chasers watch the sky to the W. Capture: Andrew McDonald.

Upon taking off E again we saw some HUGE cells building way off in the distance to about 150-200km away. Another cell developed ahead of us and once again we had to punch through it with more heavy rain and winds gusting up to about 30knts. We stopped about 2km from Cunnamulla to take more photos of this impressive gust front and then kept heading E to say ahead of it. The slow drive through Cunnamulla allowed the guster to catch us as we were going through town and there were leaves, branches and dust blowing everywhere and people trying to get out of the oncoming storm. We continued E along the Balonne Hwy towards St George and we decided to get a long way ahead of the gust front before stopping again. While driving we were watching those massive storms build in the distance to the E. We estimate the tops to have been in the vicinity of 40,000ft with one pushing close to 45,000ft after it developed a MASSIVE overshooting top.

Massive overshoot to our E. You can see the level of the anvil cirrus on the right. Capture: Andrew McDonald.

A quick look behind us showed the guster losing structure and weakening fast and we soon turned our attention to the bigger cells to our E. Three cells to our ENE, E and SE had become distinctly more dominant than the others. We decided that the cells to the SE and E were too far away although they were probably bigger and better we had to think about where we would stay the night. If we went after the bigger cells then we’d probably have a 150km drive to the nearest town after the chase ended. Our decision was made for us as the cell to our ENE developed some nice photogenic structure. We drove to within 25km of it and although not very lightning active it was a nice way to end the day. We watched this cell for about 45 minutes as it reached its peak and then weakened.

The cell to our ENE near Cunnamulla. Capture: Andrew McDonald.

By 7:20pm we started heading back towards Cunnamulla for the night with the possibility of something still developing later with the temperature still at 30C and the DP at 22C. On the drive back to Cunnamulla while dodging kamikaze kangaroos (which tried to jump between our cars), we saw some sporadic lightning to our SSE and also again when we were unloading the cars at the caravan park to our E. All in all it was a pretty good chase but a better road network and less trees would’ve been nice but I guess its all part of the challenge of chasing out west -   its very hit and miss and a bit of luck can be very handy.

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TDU2K Day 5