Facts on Tornadoes in NSW

Tornadoes occur more commonly in NSW than most people would expect. The Bureau of Meteorology's database records 364 tornadoes across NSW from 1795 to June 2003. Most tornadoes in NSW occur in late Spring and Summer but they have been known to occur at all times of the year.

Tornadoes range in size from a few tens of metres across, up to around one kilometre in diameter. Because of this, damage is normally restricted to a small area, but is very intense.

Tornadoes are thought to be formed by the interaction between regions of strong updrafts and downdrafts of air within severe thunderstorm clouds.

Two views of the same tornado near Gilgandra, NSW on 29 September 1996.

Tornadoes are ranked using the Fujita F-scalewhich estimates wind speed based on the extent and severity of damage. Below is the Fujita scale with respective approximate wind speeds.

Recent examples of tornadoes in NSW include:

• 13 October 2002 - Niangala (Northwest Slopes) - F2. A tornado destroyed 2 houses in Niangala and damaged hundreds of trees. 6cm hail was reported from nearby Walcha.
• 18 November 2001 - Careel Bay (Sydney) - F0. Severe thunderstoms occurred across most parts of NSW - worst hit areas were around Sydney and Hunter districts. Storms were followed by an East Coast Low on 19th and 20th with gale force wind and rain causing further damage.
• 5 November 2000 - Nimbin and Uki (Northern Rivers) - F1. Several homes lost roofs, whole large trees uprooted and other very localised damage reported.
• 3 November 2000 - Greystanes (Sydney)- F1. A tornadic thunderstorm moved through the Sydney Metropolitan Area over the afternoon/early evening. Three tornado tracks were observed during damage survey.
• 27th July 1998 - Willow Tree (Northwest Slopes) - F2 tornado damages a house, moves a vehicle
• 1st July 1998 - Fingal Bay (Hunter) - F1 tornado damages a caravan park
• 29th September 1996 - separate tornadoes (likely F1-F2) at Elong Elong, Gilgandra (Central West Slopes) and Bundella (Northwest Slopes). Large trees uprooted & snapped. 4-tonne truck moved.