Saturday 17th of December 2005

Chase Report

This report is an example of how a great storm day can easily turn into a bust chase with a few wrong turns and a lack of accurate information. The day produced a massive gust front through Brisbane, and three supercells in NE NSW, yet we only got a weak cell near Gatton, and views of distant cells offshore from the Gold Coast. Overall it was a bust chase for us, yet some people chasing not far away had one of the best chase days ever.

We left Redcliffe at 12:30pm and headed south along the Gateway Motorway. Lots of convection was already visible and the temperatures were in the high mid 30's with dew points around 20. At this point there were three main cells visible. One to the south passing through Logan and heading east, another to the west, quite large, and one much further south only just visible. We stopped just off the left of the highway to take some photos of this cell. It had quite a lot of strong convection and scud cloud beneath. The cell did seem to be fairly weak however, so we decided to head for the much stronger looking cell to the west.

Going back onto the M1 we continued south and then followed the Logan Motorway through to Ipswich and on to the Rosewood and Marburg area. Here there was already the beginnings of a gust front. We found a location up on a hill and took some photographs of the rain free base and precipitation following. Lightning was quite frequent, with quite a few good shots on video. This is where I think I made the mistake though. Rather than backtracking along the Warrego Highway heading back towards Ipswich, I spotted a gap in the line of storms and drove through it. This took us to a hill near Marburg radar. We still had a decent view but now we were behind the line of storms. Once we were behind the cell, the gap in the line closed up, and I wasn't willing to risk core punching not knowing if there was large hail in the cell.

We drove from there down to Rosewood. We could see quite good structured updrafts on the back of the cell going into Brisbane, which now appeared to be a squall line. Coming through the back way to Ipswich we tried to find a decent location that would provide a good view of the back of the storm. Eventually we ended up on Mt Crosby Road with a reasonable view. It became clear however that we weren't going to be able to catch up with the squall line through the city. Looking to the south there were some strong cells in the Boonah/Beaudesert area. So we set off after these ones. I underestimated how long it would take to get to Boonah though. Just getting back out of Ipswich took nearly half an hour, by which time the fast moving cell was already at Coomera. There were more cells towards the coast though. One drawback of Ipswich-Boonah Road is that there are no routes to the East until you reach Boonah. From Boonah we head straight for the coast, but the road via Beaudesert, Mt Tamborine, Canungra then Nerang is agonisingly slow.

We finally arrived on the Gold Coast around 5:30pm. Looking at the radar now, we probably shouldn't have bothered going that far. Had we stopped and waited in Beaudesert a cell would have arrived at 5:30pm. We left there around 4:30pm. After finding a decent location to setup near Miami we watch and photographed the cells out to sea. One directly east of us looked quite impressive. To the north, what was left of the Brisbane squall line was still visible, and to the south a cell had moved offshore near the border. None of these were producing visible lightning, but they still looked quite nice. I tried to take a timelapse as the sun went down, but low cloud ruined that. At this point we decided to call it a day and head for home. On the way though we got some reasonable shots of the sunset illuminating the Brisbane squall line. We stopped briefly to video lightning in the squall line from Yatala, then arrived home around 8:30pm.

In retrospect I should have kept us in front of that squall line. At the time I was thinking the Gatton cell was just a small weak cell, and that there'd be better stuff behind it, but I was wrong. Had we stayed on the highway in front of it, we would have probably ended up near Cleveland and had an excellent view of the whole thing. We could have stayed in Redcliffe and had a great view. The other option would have been to head to Northern NSW. We had a report of a strong cell moving for Lismore, and we could have made it if we hadn't decided to head west. I didn't fully understand the radar update though, so I dismissed it as another weak cell. So we basically managed to get a bust chase on a great day. Fortunately the lessons learned should help us to avoid the same fate again.