Friday 23rd of December 2005

Chase Report

After a week of dry conditions produced by a blocking high, Friday the 23rd had reasonable low and mid level moisture, along with reasonable instability in an area around the the border ranges. Storms developed near the border and moved very slowly northwest along the ranges. The lack of shear and steering winds meant that all motion of the storms was due to propagation. It also meant that storms didn't last as long as they otherwise might have. I went for a chase in the eastern Darling Downs area.

I departed Redcliffe at 1:30 travelling through the city, and to the west via the Centenary Highway. After a short delay due to traffic, I joined the Cunningham's Gap Highway and headed for Warwick. All the way the anvils and occasional overshoots of a line of cells on the ranges was clearly visible. It was however quite hazy which reduced contrast significantly. Once I reached Cunningham's Gap I was quite close to the cells, but no real detail could be seen. They were high based and seemed to be weakening by the time I got there at nearly 3:30pm. This is confirmed by radar. The cells were most intense around 2:30pm in that area. Climbing through the Gap I only had light rain from the anvils. Although frequent noise was heard on the radio, I didn't see any lightning at this stage.

On the trip down the highway there had appeared to be two interesting cells. One was isolated to the north of the main band and another was at the southernmost end of the band. The latter had a well defined inflow band coming from the east, but did appear to be weak when I got there. In the absense of radar data to verify what was happening, I chose to go for the more visually intense isolated cell to the north. Unfortunately, first I had to travel all the way to the New England Highway then head for Toowoomba. I couldn't see the cell I was interested in because of the remnants of the main band of storms. Once I turned, however I could see some interesting activity to the north. There was a cell with what looked like a flanking line going up into it and also some interesting base features(see picture).

The cell gradually weakened and another cell nearby popped up and continued moving northwest. This one appeared to pass south west of Toowoomba, but I never could catch up to it before it died. It did produce a few decent clear air CG's, but at the time I was driving so I didn't get them on video. By about 5pm I was west of Toowoomba and everything seemed to have died. All that was left of the cell was a single precipitation cascade, which was weakening. So I decided to head home and after dinner, arrived back in Redcliffe around about 8pm.

Looking at the activity I probably should have headed straight for Toowoomba then moved south from there, but that probably would have taken just as long anyway. The low shear situation just didn't sustain the cells for long enough to reach them. Hopefully some other chasers got there earlier while the cells were still severe.