Wednesday, October 20, 2010

Day 69


Don't shoot me, but I haven't been living in Australia long enough to feel the full fury of a draught.  When we arrived from NZ, sure there were water restrictions but in all honesty, it took a good six months to turn the tap off when cleaning teeth and to be more water conscious.  I come from a land where water is plentiful, I've simply never had to be water savvy.  And I do love a long, hot, dry summer.  It's such a novelty.  And I actually do enjoy the 40+ days.  It's like one of my weather extremes, and I'm living it.

So you may understand (although not accept, especially our Country Australia folk) , my profound disappointment when I heard on the Weather Channel (geek right?) that we are in for a La Nina weather pattern this summer.  Farmers all around are breathing mass signs of relief. Me, I'm just a little disappointed.  I don't want summer to be cooler, more humid and with a significantly higher rainfall.  That's just not summer in my books.  I want to plan picnics/bbq's and beach trips safe in the knowledge that the weather will be predictably gorgeous.

So who actually knows what the difference is between La Nina and El Nino, and more to the point, how long is this La Nina going to last?

El Niño/La Niña Southern Oscillation, (or ENSO), is a climate pattern that occurs across the tropical Pacific Ocean on average every five years.  It is characterised by variations in the temperature of the surface of the tropical eastern Pacific Ocean.  The warm oceanic phase, El Niño, accompanies high air surface pressure in the west Pacific, while the cold phase, La Niña, accompanies low air surface pressure in the west Pacific. ENSO causes extreme weather such as floods, droughts and other weather disturbances in many regions of the world.  La Niña is the name for the cold phase of ENSO, during which the cold pool in the eastern Pacific intensifies and the trade winds strengthen.  In Australia changes to the atmosphere and ocean circulation during La Niña events include cooler than normal ocean temperatures, increased cloudiness over tropical Australia, and stronger than normal (easterly) trade winds across the Pacific Ocean.

In other words it is a see saw of the ocean temperature that constantly rocks back and forth across the equatorial Pacific. Normally the sea surface temperatures across the western equatorial Pacific Ocean are much warmer than those in the east because of prevailing winds and ocean currents. Currently La Niña conditions predominate and we have seen a persistence of well above average rainfall over much of inland Australia during the last six months.

At the moment we also have warmer than average sea surface temperatures to the northwest of Australia, and together with the prevailing La Nina conditions, this increases the possibility of above average rain over much of the continent during the remainder of spring.  So folks, when will we be done here?  March 2011 is the prediction.  Keep a brolly handy until then.
And that's you too my kiwi friends.

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