BoM Signals Imminent El Niño – Countdown to Winter

That needle shifted from ‘Watch’ to ‘Alert’ with today’s announcement Image:: BoM

Mountainwatch | Alex Horvath

In today’s updated El Niño Southern Oscillation wrap-up, The Australian Bureau of Meteorology has signalled that due to increasing average ocean temperatures across the tropical Pacific Ocean and a decrease in trade-wind activity, an El Niño ALERT has been issued – indicating a greater than 70% chance of an El Niño occuring. So with this news, Aussie skiers are left wondering exactly what does this mean for our upcoming ski season?

COMPULSORY PREPARATION: Before reading any further, go and have a read of The Grasshopper’s first Seasonal Outlook for Australia. Then come back when you’re done.

1. It’s not here yet.

In his first update for the year, The Grasshopper hinted that it was likely that we’re heading toward an El Nino event, although it’s currently too early to call. So where are we now? The closer we get to an event in weather forecasting, the greater the amount of certainty we can attach to the forecast. Since the beginning of the month, the BoM is now able to place greater confidence in their best-guess as to which way the ENSO is likely to swing. With this latest update, the BoM are predicting a greater than 70% likelihood, similar to the Grasshopper’s level of confidence a couple of weeks ago.

2. Which way will it fall?

Sorry to be a tease, but the long and the short of it all is that we still don’t know. For now, we will continue to monitor the BoM forecasts, and will be bringing you The Grasshopper’s update to The Seasonal Outlooks in early May. Remember the Grasshopper’s advice, it’s not just whether we get an El Nino, it’s what sort of El Nino it turns out to be.

Generally speaking, an El Niño event usually signals below-average seasonal rainfall over eastern Australia and above-average temperatures over the southern half of Australia. But confusingly, the BoM has also indicated that the period from April – June is likely to be wetter than average thanks to warm temperatures in the Indian Ocean. So does this mean we can expect decent pre-season conditions? The Grasshopper reckons this is a red-herring for now, and mostly applies to the April/May timeframe. Time will tell.

For now, check out this video to better understand the ENSO forecasting service that’s provided by the BoM: