storm reports
November 30, 1997... Line of Thunderstorms
During the days previous to these storms, days were typically hot and humid with the usual afternoon seabreeze. Two days earlier, a dry storm set off a tremendous electrical display lasting several hours to the west with beautiful CC and CG lighting and later, the brilliant 'anvil crawlers'. The weak coastal trough that produced the storm moved north of us, so we missed out on the 29th when storms developed near Rockhampton. It was encouraging to see storms develop east of the broader inland trough over the southern and central Qld inland. Also, another coastal trough was working its way up the NSW Coast, with some cold upper air ahead of it.
By 1pm, the temperature was up to 32C and humidity in the 60-70% range, and just through the heat haze I could make out developing Cb and TCu to the NW, W, SW and SSW. I issued 'my own' severe storm advice at that stage, because the Weather Bureau had not. After a long wait in the swimming pool, my friend and I, knowing that is was pointless to chase them because they were already heading our way, travelled to the usual lookout in Sunnybank at around 3:30pm. Still, no warnings had been issued, but we knew something good was going to happen, with the area of dark anvil extending from the south and west and the development of a single cell storm to the NW.
Finally, the first warning of the day was issued at 4:05pm. Apparently these storms had originated in northern NSW, dropping small hail in Ballina and Lismore then propagated northward over the SE Qld inland. By 4:30, the telltale signs of a gust front emerged from the SSW. Over the next half-hour, the front approached steadily, with several shades of green and brown. After about 10 minutes of gusty gale force winds and occasional CG lightning, the rainsquall struck at 5:07pm.
Immediately, the power in the area went off as torrential rain lashed the city. The heavy rain and intermittent bursts of half-pea size hail lasted 25-28 minutes causing flash floods across the area. My rain gauge had 53mm in it, and many areas through the city also received 35-60mm. Winds gusted just over 90km/h; blowing down some powerlines and causing some very light structural and tree damage. In Albion, in the northern suburbs, a tree fell onto a house, but this was an isolated event. One of the many houses that were struck by lightning was destroyed by fire. During the height of the storm, 52 000 properties were without power.
During the evening we experienced another terrific lightshow, with CC lightning extending across the sky from the NE and ENE. The day after, I realised we got off very lightly, considering the potential of the storms. Cloud tops had reached between 16.1 and 16.5km over SE Qld, while a cloudtop of 18.9km was recorded by the Mt Kanigan Radar in the Wide Bay Region to the north.
