 |
Tornadoes
The afternoon of
2 February 1918 was humid and unsettled in Melbourne, with a slow-moving
low pressure trough crossing Victoria. As the trough approached, heavy
thunderclouds built up. About 4.50 pm, the so-called Brighton
cyclone struck: apparently two separate tornadoes, followed about
five minutes later by a third, hit the bayside suburb with great destruction.
Many buildings were totally destroyed, and even well constructed houses
severely damaged. At one location two tornado tracks crossed, creating
(in the language of the day) a veritable orgy of destruction.
In the few minutes that the storm lasted, two people were killed and
many others injured. Wind speeds were estimated at 320 km/h (Fujita
rating F3), making this possibly the most intense tornado to hit a major
Australian city. After hitting Brighton, the tornadoes apparently continued
east across open country (now densely settled); were such
a storm to occur today, the death and injury toll would likely be much
higher.
Tornadoes are not uncommon in southwestern Australia. They are reported
most frequently from the coastal strip south from Perth to Cape Leeuwin,
and from the adjacent inland, especially in the cooler months. Early
on 6 April 1960, a particularly violent tornado formed on a trough line
ahead of a major cold front and swept through jarrah forest near Collie,
cutting a path 32km long and 240 metres wide. Trees more than a metre
in diameter were uprooted, and many smaller ones were snapped off about
1.5 to 3 metres above the ground. Rated at F2 on the Fujita scale, the
storm would have inflicted great damage had it passed through a major
town. Many lesser tornadoes have in fact affected population centres
in the region, and while casualties have been few, many homes have been
severely damaged or destroyed. A similar tornado in northwest Tasmania
left a swathe of snapped trees in forest country near Smithton early
on 22 November 1992.
On the afternoon of 4 November 1973, intense thunderstorms built up
west of Brisbane. One particularly active storm generated several funnel
clouds, at least one of which touched down as a strong tornado west
of the city. At one house in its path only the water pipes remained!
The tornado continued through Brisbanes western and southern suburbs,
damaging nearly 1,400 buildings. No deaths occurred, but many were injured.
This tornado had a path length of 51km, with peak wind-speeds estimated
at over 250km/h; however American meteorologists studying the event
concluded that the wind-speeds could have topped 300km/h. This tornado
remains the most damaging in Australia to date. Southern
Queensland was also the site of perhaps Australias deadliest tornado,
with three people killed at Kin Kin (a small community between Gympie
and Noosa) on 14 August 1971. The most intense tornado recorded in Australia
- with a Fujita rating of F4 - occurred at Bucca, west of Bundaberg
(Queensland), on 29 November 1992. The intensity of the winds created
freak effects, such as embedding a picture frame in the wall of a room.
Hail the size of cricket balls accompanied the storm.
The
Bucca (Qld) tornado, 29 November 1992. The only F4 tornado so far officially
reported in Australia (photo courtesy of Emergency Management
Australia)
|