Sunday 19th of February 2006

Chase Report

On Sunday I went for a day long chase in the Northern Tablelands and Northwest Slopes of New South Wales. The forecast models indicated a marginal day, with resonable instability but little shear. There was a convergence line along the Northern Tablelands. I began my chase early in the morning, heading to Glen Innes. The action started shortly after lunch time.

I had originally intended leaving at 6 am sharp for my chase down into the Northwest Slopes of New South Wales, but somehow I turned my alarm clock off without waking up. So it was 7:30 before I finally got away. Heading down the Gateway and Logan Motorways, convection had already started with lots of small Cu's building everywhere. The atmosphere looked a little too stable for storms this far north though. I travelled along the Cunningham Highway through Warwick and then down the New England Highway. The further south I headed the better the clouds were looking. There were small areas of accas and some towering cumulus clouds.

My chase target area was Glen Innes. The best instability was further south and west, and I had originally been trying to decided between Glen Innes and Moree as the target. After some discussions with other chasers, I decided on Glen Innes. It was almost under a convergence line which ran along the ranges. I've had good sucess with convergence lines in the past so I decided this would be the place to be. I arrived in Glen Innes just after lunch at around 12:30 Eastern Standard Time. I decided to head up to the lookout above the town to wait for some action to start occuring.

I wasn't left waiting for long. A large cumulus cloud to the south rapidly built up and darkened. Within a few minutes it was rumbling with thunder and had a large rainfoot. To the east another tower was going straight up and moving north. It appeared that the cell to my south was going to come straight across my position, so after quickly getting some fuel I headed east along the road to Grafton. The cell to the east had now fully developed and was showing some interesting structure as it moved NNW. It eventually gained an flanking line that stretched halfway around the horizon. Meanwhile the cell to my south began to exhibit fast rotation and swirling on it's eastern side. This area was moving directly towards me and I headed east to get out of it's way. As I passed through a clearing a thin funnel was visible in it. The funnel was spinning rapidly but eventually died out. To the north east I could see just in front of the rainfoot another funnel, this one reaching all the way to ground as far as I could see. It was probably ten kilometres away though and hard to see. Couldn't tell if it was actually rotating, and photos don't really show it at all. A third funnel occured a short time later, nearby where the first one had been. This one was thicker, but again didn't reach the ground that I saw.

By this stage CG's were dropping everywhere around me. One hit a hill to my east, and shortly afterward smoke was visible from a fire it started. I continued east to get clear of the cells. After the Glen Innes cell moved north of the road another was visible to the south behind it. The eastern cell had moved northwest, so now there were at least 3 cells in a line moving due north. I decided at this point to head back towards the west and to head up the New England Highway. A radar report I received from my mother indicated that the cell directly to my north was near Deepwater heading towards Tenterfield, with a slight westward motion as well, and that it's core was black on radar. I took a shortcut road 30 kilometres east of Glen Innes which took me straight to the New England Highway, saving me about 50 kilometres.

The cells to my north and northeast were now producing huge stecato CG's every few minutes and had a very onimous look to them. Talking to some people in Deepwater they said they hadn't got much there apart from noise. Just north of the town though the sides of the road had water everywhere. Gullys were raging torrents, and on quite a steep hill there was evidence that the whole road had been under water. A man was there pulling debris off the middle of the road. There was lots of mud and the creek on the side of the road was full. It would have been amazing to see the water there when it came through. I continued further on and the cells were still well in front of me when I reached Tenterfield. Tenterfield wasn't quite so wet, so it appeared that the really intense one was moving north west, while another weaker cell was moving directly north. There were more cells to my south following me. I didn't want to end up in the rain and not be able to see anything, so I decided to take the road along the border, heading west towards Bonshaw and Goondiwindi. I was hoping to get ahead of the north west moving cell, expecting some structure to be visible.

I finally got away from the mess of anvil cloud out into the bright sunshine of the North West Slopes. To the west more cells were starting to get going, but weren't yet storms. Behind me it was a dark and turbulent sky. I was gaining on the cell, but still hadn't got west of it. Unfortunately the road took a turn to the south which really slowed me down, but I was able to get good views of the line along the ranges. There was outflow wind in excess of 80km/h. Also to the west one of cells had developed the spiral corkscrew structure that showed it's rotation. I believe it was a definate supercell. The stuff coming off the ranges was moving quickly west, so I wanted to get past it. I had planned to head into Queensland via Texas, but when I reached there, the supercell was over Texas heading north. It was producing a strong microburst. At this point I decided it was best to continue heading north rather than risk core punching a supercell. I hoped there would be a road that would lead to the north before having to go all the way to Goondiwindi, some 130km distant.

About 70 kilometres east of Goondiwindi was a dirt road leading north with a sign post indicating that it lead to Yelarbon in 40 kilometers. Yelarbon is a town on the Cunningham Highway 147 kilometres west of Warwick. I was a good 10 kilometres in front of the supercell storm now, so I headed along this road, trying to get through to the Cunningham Highway. As I drove along this road the storm was getting ever closer. I could see the main updraft going up extremely fast, so quickly that the motion could be seen with even a quick glance. It looked very intense so I was in quite a hurry to get through to the main road. The thought of a night stuck in the mud under a massive thunderstorm wasn't appealing. I managed to avoid the kamikaze galahs that kept flying in front of me and finally crossed the border and reached sealed road at Yelarbon. The cell to my east had weakened somewhat but was still producing nice structure and plenty of CG's. I decided to wait here for sunset.

The colour of the sunset was incredible, with the yellowish grass, red dirt and orange sky clouds looking incredible. Unfortunately I missed the best of this because my camera card was full and I had to download the shots to the computer. Once back operating again it quickly got dark. Lightning was every few minutes or so, but when it did fire the whole sky would light up with dozens of CG's all at once and a beautiful purple colour. Many of these occured while my camera was processing the previous time exposure, but I finally managed to capture some really good CG shots. I'm still not up to the standard of Dave Ellem and Michael Bath, but these are some of my best yet. Eventually it all died down and the cells appeared to have weakened so I decided to call it a night at 7:45 and begin long trip back home. On the way back through the line there was only moderate rain and the occasional flash of lightning. I reached Warwick at 9pm and had some dinner. Left for Brisbane at 9:30 and arrived home shortly before midnight.

All in all I had an excellent day, and I can't think of anything that I'd change if I was able to do this chase again. For a marginal day it turned out incredible with just about everything you could ask for on a chase. The new chase vehicle performed excellently. Thanks to the people on UHF 40 who helped me out by providing observations of where the heavy rain and hail were, and thanks to my mum for providing me with excellent radar reports. Unfortunately I couldn't include all the best shots in this report so I suggest you view the gallery linked above to see the rest of them.