Coastal chaos

Yet another East Coast Low - is our weather getting weirder?

ALREADY this winter the Northern Rivers has seen three East Coast Lows, begging the question: Are the destructive weather systems characteristic to Australia's eastern seaboard on the rise?

In this day and age of intense media coverage of extreme weather, it does sometimes feel as if we are being bombarded with increasingly intense events. Every time we get a hint of a storm, the media imagery, footage and running reports seem to grow exponentially.

We are a nation of weather watchers - albeit these days for most of us from the comfort of our armchairs; a spectator sport rather than a life and death affair.

The unknown questions over how global warming will shape our everyday lives also hangs over us, prompting us to ask whether the latest storm/heat wave/flood was because of climate change.

All of these factors beg the question: Are we getting more East Coast Lows (ECLs) than usual?

You might be surprised to know that the answer, at least for now, is no.

We had two ECLs in June, but June is the most historically common month for ECL development.

We've just had one in early August, which characterises it is as a "late season" affair but well within the usual parameters.

We could even get one more before winter ends, and it wouldn't be classed as "extreme".

When do they form?

 

East Coast Low causing havoc.
East Coast Low causing havoc. Trevor Veale

East Coast Lows are most common between February and August, although they can form any time of year.

There's two basic different types - "pure" East Coast Lows, which actually form in the Tasman Sea, and ex-tropical cyclones (more common in the late summer months), which move down from the Coral Sea.

"You'd expect to see about this number each winter," commented professional weather watcher Michael Bath, from Northern NSW Severe Weather.

"In previous years we've probably had less than normal, and in other years, it's above.

"There's been plenty of years when I've been looking at the weather that there has been a lot more, in fact substantially more East Coast Lows in some years."

The year 1998 stood out for him as a "bad year" for ECLs, as did 2007 - that was the year the Pasha Bulker ran aground at Newcastle during a June storm.

 

Wild weather in Ballina.
Wild weather in Ballina. Patrick Gorbunovs

Those years there were about eight, so we still have a few left before 2016 is in that class.

An according to the Bureau of Meteorology, which has a detailed database of ECLS beginning in 1973, there are about then "significant impact maritime lows each year, but only once per year do we see 'explosive' development."

With just three weeks to go to the end of winter, we could have seen the last of East Coast Lows for this year - until Christmas at least.

"September through to November is probably the least likely time of year to see them," Mr Bath said.