SIGNIFICANT ILLAWARRA WEATHER EVENTS - SUMMER 1998 / 99
Last update 4th February 1999
24th January 1999 - Minor Flash Flooding at Albion Park - Like the previous day, congestus drifting in from the E/NE was occasionally growing to cumulonimbus. One of these isolated cells developed over the south west parts of Albion Park giving localised torrential rain. No property damage occurred, nor were any roads cut. Thunder was heard. Unlike the 23rd the cells did not persist for very long. Below is a photo typical of the cells that day, this one was taken in the southern highlands about 3pm. The other is a video still of swollen drains in the Albion Park area ( normally dry ).
23rd January 1999 - Flash Flooding at Gerringong. - A slow moving thunderstorm dumped according to local media up to 200mm on Gerringong on the night of the 23rd January 1999. Several homes in the new Sandy Wha estate were affected by flash flooding. The synoptic situation saw a humid onshore flow feeding a trough over eastern NSW. The storm occurred from large congestus which had drifted in from the NE, as the congestus grow into cumulonimbus it was being weakly sheared towards the SE, this made the storm rear flank almost stationary. Thunder activity lasted from approx 9pm to 2am. The storm also gave rain to Kiama, but nothing to the extent of Gerringong. A servere thunderstorm advice was in affect.
14th December 1998 - First Severe Storm Advice for season - The Illawarra had the distinction of having the least number of severe storm warnings/advice's in the 1997-1998 season. A repeat could still be on the cards, but it is early days. For 3 days storms had built just to the west of the Illawarra near and west of Picton, but weak upper level winds ensured that the storms basically went up and decayed in the same spot. This all changed on the 14th when a slow moving trough triggered storms at approx 12.30pm in a line from Canberra to Bathurst. Around 1pm some of these storms became severe with hail and destructive winds. I was on a chase at the time and encountered the squall line at Robertson on the Illawarra escarpment. I experienced very heavy rain, small hail and winds strong enough to bring down some branches. The storm was also very active electrically.
