Bushfire awareness tips – know your wind

After the near-debacle of the other day, I realised I didn’t know anywhere near as much about bushfires as I thought I did. So I asked for some help from those who do. The following tips are ‘rule of thumb’ only, but so much better than nothing.

1. Know your wind

Any wind will push the bushfire in front of it, so knowing where the wind is comingย from tells you where it’s going to, roughly. In the graphics below, the blue arrows show wind direction. The red arrows show where the wind will push the fire from the point of ignition – i.e. from the point at which the fire starts.

– A north wind will push the fire to the SOUTH. [i.e. the wind is coming from the north so the fire is pushed to the south]

bushfire wind 1

A north westerly wind will push the fire in a SOUTH EASTERLY direction. [i.e. the wind is coming from the north west so the fire is pushed to the south east]

bushfire wind 2

A north easterly wind will push the fire in a SOUTH WESTERLY direction. [i.e. the wind is coming from the north east so the fire is pushed to the south west].

bushfire wind 3

The Bureau of Meteorology posts forecasts for heat and wind on its website every day. This is the forecast wind for today, January 16, 2014 :

“Winds northerly 15 to 20 km/h tending northwesterly in the early afternoon then becoming light in the late afternoon.”

I’ve just been outside [11.15am] and didn’t notice a wind…yet. Once it starts however, I’ll be keeping an even more wary eye on the Kangaroo Ground fire. It’s contained at the moment, but if it breaks out it will be heading south towards North Warrandyte.

“This is obvious, get to the point!”

-bites lip-

“This stuffย isn’t obvious to everyone, so shut be patient!”

2. Know your fire

On a day with no wind, a bushfire will spread out in all directions as it follows the terrain. It will spread, but it won’t spread quickly because it’s burning under its own steam, so to speak.

bushfire no wind

The graphic shows a very theoretical spread across flat ground – e.g. a field of grass. It’s always the outer edge that’s actively burning because the bit in the middle has already been burned, and fire needs fresh fuel to continue.

[Note: You will never see that neat bulls eye pattern in real life so take this graphic with a huge grain of salt.]

Once you add wind to a fire, however, the pattern of spread changes to a cone.

bushfire cones

The milder the wind, the wider the cone. The stronger the wind the narrower the cone.

“But what does this have to do with me?”

-rolls eyes-

“The point is that you can now be proactive! Oh don’t give me that look…”

Okay, what this all means is that you don’t have to sit staring at the CFA website, waiting for warnings and advice. You can grab your street directory, check the Bureau of Meteorology website, plot the direction of all fires within a twenty minute driving radius of your house, and either leave, or start getting ready to defend.

For me, defending my house involves running the pumps and sprinklers for 5 minutes [to make sure everything is working], closing up the house [with the shutters] and wetting down the area directly around the house – with mains water while it’s still available.

You do know that the water is likely to stop flowing if a fire hits your area…right? There won’t be anything wrong with the pipes, it’s just that everyone will be trying to do the same thing as you, and only so much water can come through the pipes at any one time.

If nothing happens, and the fire goes away, then you’ve lost nothing by being proactive. However, if something bad does happen, then being proactive could well save your life. Think about it.

In the next post I’ll try and explain why the wind change is the most dangerous point in any bushfire.

Stay safe, and drink lots of fluids.

Meeks

 

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About acflory

I am the kind of person who always has to know why things are the way they are so my interests range from genetics and biology to politics and what makes people tick. For fun I play online mmorpgs, read, listen to a music, dance when I get the chance and landscape my rather large block. Work is writing. When a story I am working on is going well I'm on cloud nine. On bad days I go out and dig big holes... View all posts by acflory

17 responses to “Bushfire awareness tips – know your wind

  • Yvonne Hertzberger

    Your heat wave and its dangers are headline news here in Canada. I hope you all get through it all right.

    Like

    • acflory

      Really? Wow. I had no idea. Thanks for your well wishes. Tomorrow will be the big test as a strong north wind is forecast. Hopefully by this time tomorrow I’ll be able to say it was another dry run. ๐Ÿ™‚

      Like

  • metan

    We have been really lucky with the wind over the last few days haven’t we, it has been almost non existent. Loving the CFA app too, I’ve set the area I know I need to keep an eye on around town and it tells me when there is something I should look out for.

    I’m in and out of the garden all day anyway, so I keep an eye on the wind etc. you’re right though, a fire on a windy or breezy day is very different from one on a still day.

    Looking forward to the cool change, pity we have to wait until saturday for it. ๐Ÿ™‚

    Like

    • acflory

      I’ve got the CFA app – the old one – but I don’t trust it, lol. Or perhaps I haven’t set it up properly.

      How are your chickens holding up in the heat?

      Roll on the weekend, more than EVER before. ๐Ÿ™‚

      Like

      • metan

        You might need to update the app, it is completely different these days. I rely on it, but never completely trust anything like that! I still go outside and check the weather, smell the air, listen for helicopters…..
        They usually fly over our house if there is a fire in the area as there is a private lake nearby which they seem to use to fill up. A good fire barometer for me, I see them come and go, how long they take shows me how far away it is and how many choppers there are shows me how drastic!

        I keep checking the chickies but they seem to be coping better than I expected. I have been buying a chunk of watermelon each day, half for us and half for them, I think it is mainly to make me feel better as they were equally enthusiastic about some stale bread today!

        Is your turtle still around? I bet your pond is well patronised at the moment!

        Like

        • acflory

          -grin- I love rule of thumb thinking! I think that’s what we humans do best of all. It’s a pity that too many of us have become so reliant on gadgets instead.

          I’m glad your chickens are okay. Unfortunately, Sir Feral seems to have departed for parts unknown. I guess he was really Sir Nomad.

          Take care of yourselves. ๐Ÿ™‚

          Like

        • metan

          You ever know, he might be in the pond trying to keep cool, with only a pair of nostrils above the waterline!

          We have lived in the valley for many years and always relied on our own brains to keep us safe, it has been successful so far! I’ve even stopped listening to 774 all the time. If I think I need more information I will turn it on, but having it on in the background and hearing all the fire warnings all day is too stressful.

          Hopefully this cool change tonight is benign and wet, not stormy and dangerous….

          Like

        • acflory

          I have to agree about the stress of hearing all those warnings. Unfortunately I’m still too new to all this to trust my own skills. I didn’t even know about the colour of the smoke [will be talking about that in another post].

          Like

        • metan

          I think listening to the radio warnings all day, for places far from home and not affecting you personally, means you are living in an elevated sense of urgency all day for no reason at all. It is very wearing and probably doesn’t help you make good decisions if it DOES come your way later.

          Looking forward to the smoke post. ๐Ÿ™‚ Sometimes you don’t even notice the smoke on a still day though, you only notice that the entire world outside your window has taken on a strange and very strong orange tinge as the sun shines through the thick smoke rising in the air.
          This was the only thing that alerted me to a fire on the block of land diagonally across the street some years ago. From a small thing that could have been put out with a bucket to two trees and counting by the time I (heavily pregnant) filled said bucket. Eeek! Lucky my house is made of windows!

          Like

        • acflory

          Yes! That lurid colour is definitely something two of my sources mentioned! Yet you never really get told such things via the media.

          I remember after Black Saturday everyone was talking about how the day became black and dark but… I couldn’t imagine it, and thought it was some kind of…exaggeration.

          To be honest, I still can’t imagine it, but I don’t dismiss it as exaggeration any more.

          If you don’t mind, I’m going to pick your brains about the ‘feel’ of that fire before I write the next post. Expect an email soon ๐Ÿ™‚

          Like

        • metan

          I’ll look out for it! ๐Ÿ™‚

          Like

  • davidprosser

    I hope you all stay safe and there’s no destruction to property. Roll on the cool spell.
    xxx Huge Hugs xxx

    Like

  • Candy Korman

    The heatwave and fire threat have even made the news in the U.S. but they keep focusing on tennis. The real story is yours โ€” and the story of your neighbors… Know your wind. Know your fire. It sounds like poetry, but it’s REAL!

    Like

    • acflory

      It’s funny you should mention the tennis – the emergency channel providing alerts and warnings on the radio was broadcasting the tennis the whole time [in-between warnings]. So I now know far more about the Australian Open than I have ever wanted to learn. ๐Ÿ˜‰

      Unfortunately for us, bushfire is always a reality, and I think a lot of people who think they are in the suburbs are now learning that NO suburb on the edge of Melbourne is immune.

      At the moment, the focus of attention is to Melbourne’s Northwest [I’m in the east] where there are multiple grass fires racing towards outer suburbs. These suburbs are made up of fairly high density housing estates. Sadly these particular fires /may/ have been caused by arson. :/

      If things continue like this, or get worse year after year, every resident of Melbourne is going to have to rethink how they build their houses.

      As for my area…I hope this wake up call lasts into the cooler months. Apologies for the long reply.

      Like

  • pinkagendist

    I thought this was going to be a post about Kardashians and std’s ๐Ÿ˜‰

    Like

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