Is El Nino coming and what would it mean?

5 07 2014
Mark Cochrane

Mark Cochrane

There is much interest in the likelihood of another El Niño occurring this year and even more uncertainty about the strength of the event if it does materialize. Although there has been some weakening in the forecasting models, current probabilities remain at 70% for El Niño conditions being met by the end of the Northern Hemisphere summer, rising to 80% during fall and winter. Best projections are for moderate strength but certainty is low so it could range from weak to strong (NOAA Link).

Globally, the main concern about whether or not El Niño arrives is that such events are coincident with the release of a lot of heat that is currently trapped in ocean waters. Translation – El Niño years are frequently the warmest years for global temperatures. Conversely, La Niña years, like we’ve been experiencing of late tend to be the coolest.

Given that April was the second warmest and May the all-time warmest respective examples of those months over the last 135 years, there is a good chance that 2014 will rival 2010 as the new warmest year on record.

That said, El Niño doesn’t mean the same things for everyone all around the world. On the upside, wind shear resulting from El Niño conditions usually weaken the hurricane season in the Atlantic. Regionally, average conditions during El Niño look like this around the world during the Northern Hemisphere summer:

And this in the Northern Hemisphere winter months.

Weather patterns can change substantially and with large differences depending on the strength of the resultant El Niño. For my work, the propensity for extreme drought in the Amazon and in Indonesia are critical since they are often coincident with extensive wildfires within ‘rainforests’.

NOAA provides some more detail for the US winters (link).

What you may find noteworthy is that southern California, and especially the mountains that hold the snowpack for the whole southwest do not show wetter conditions for ‘average’ El Niño conditions. The exceptional drought that is now impacting much of California and the prolonged drought throughout the southwest won’t likely see serious relief unless a strong El Niño arrives. Under those conditions, storms that normally drop water in the northwest get pushed south to wet California and build up the mountain snowpack.

If El Niño fail to materialize this year, and even if it is just weak to moderate in intensity then the severe drought issues that are plaguing the southwest are likely to continue. Lake Mead will keep getting a wider bathtub ring and both Las Vegas and the agriculture of California’s Central Valley are going to throw craps for another year.

AND……..  as a bonus, here is the latest BOM(Bureau of Meteorology) map showing temperature records broken for the whole of Australia.  Our area is “Highest on Record”  No surprises…..  But if things are this bad in a La Niña year, I dread to think what an El Niño Summer has in store for us…..





4 responses

8 07 2014

Re that last map – met yet another couple the other day, who’ve moved from WA to Tasmania, because they can’t stand the heat any more over there and think it’s only going to get worse. “Cool changers” they’re called. But I must say, it’s been a very mild winter down here so far, at least in northern (coastal) Tasmania. – Marg K, Port Sorell, Tas

8 07 2014

Very mild here too…….. though we did have a mild frost this morning, and could have another tomorrow. It’s so warm right now, flies have become a worse problem than they have ever been in Summer. Must be because their reproductive time has become so much longer…

31 07 2014

We’re in Ballan and although we’ve seen 1 morning of -6.5C it’s less than last year. It’s also been a warm winter for us with many more days over 15C (or thereabouts) than I remember.

31 07 2014

While you guys down South are freezing right now in the face of that amazing cold front, it is warm as for this time of the year here… 26 today, and likely 27+ tomorrow. I’ve let the AGA go out even, but the winter chill is due back on the weekend so will fire it up again……

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