Monday, 13 June 2011

wierd weather (or is it?)

Reading the news this morning I see that the prediction for Northern NSW to get high rains and flooding seemed to have been accurate. In the 24 hour period between 11am on the 12th till the 13th 153mm of rain fell quite consistently over the period:


The media seems to (a little less hysterically this time) be just reporting this, which I think is a good thing (for a change).

Weather has been a topic of conversation around my office a lot lately, with people feeling that somehow its all weird weather. Well it might seem that way for people who have only lived here for a few years (like say 10) but this sort of thing has certainly precedent in the recent past.

I chose Yamba to look at in the observations from BOM above as I have access to historical data on a Yamba. So since 1878 this is the average rainfalls for each of the months looks like this:


Getting wetter progressively from September and falling off in the middle of winter. The X axis of the graph looks a little unconventional as I've presented the data based around what I know (from experience and further research) that the rainfall here is seasonal, and the seasons aren't based on the European Calendar of Jan to Dec. I've wrapped it from August and back to there again so you can see the "cycle" more clearly (with the start and end points meeting).

Looking at the graph you can see that March seems to be the wettest season for that part of Nth NSW and things can and do stay wet till at least May. This being June we're only a little out of the peak periode and while the Average for May is 159mm and the Average for June is less at 132mm June has had a measurement of 548 back in 1968. High monthly averages for June include
  • 389mm (1886)
  • 369mm (1914)
  • 404mm (1945)
  • 462mm (1950)
  • 548mm (1968)
Its just that we haven't had much over 331mm since the seventys. So for the people who have not lived here long and or didn't grow up here it may seem as a surprise to get this amount of rainfall.

So far (till the time of writing) the accumulative rainfall for Yamba is 220mm, which means while we're over average already for the month we're a long way short from the peaks seen in previous years.

A quick look around in the area will show quickly how many of the older houses are build on stilts or on higher ground.

So no, the old timers weren't just "funny" in their styles, they built according to the environment and what can happen.

The reason I'm posting this is to try to start the idea in the community that before we rabbit on much about "climate change" it may be a good idea to actually KNOW what the climate of the region is. It can help you to build your house to avoid floods (or avoid buying one that some numbskull from Melbourn or Sydney has designed and built for you to rent from them) and all the heartache that goes along with that.

Its easy to go along with the herd and just burp out "climate change" as the explanation for everything, but if you don't know what it was then how do you know its changed?

Personally I wish we'd spend more time on the real environmental issues like pollution, land degradation (which effects how much food we can grow) and deforestation. People could stop creating more problems (like the foolish stuff with electric cars) and focus instead on understanding the issues and working towards solutions to them.

Of course that would require people to think for themselves and apply critical thinking ... so I'm not holding my breath on this happening any time soon. Still, I can dream.

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