Where Has All The Rain Gone?

Where Has All the Rain Gone?

It’s hard to believe that this time last year our eyes were cast downward as we tried to avoid being washed away or getting bogged. This year our eyes are firmly on the sky as we watch the forecasts and wonder, where has all the rain gone?

Just one year ago Australia experienced the second-wettest June ever recorded by the Australian Government Bureau of Meteorology (BOM). In a marked contrast, this year Australia has recorded the second-driest June on record, with the rainfall averages for June generally 60 to 80 per cent lower than normal, with some regions missing out altogether.

Is ENSO to blame?

El Niño Southern Oscillation (ENSO), is a phenomenon that occurs in the Pacific Ocean and has a widespread environmental impact on Australia. ENSO affects sea-surface temperatures and creates the shifting rainfall and tropical storms that have a huge impact on our farming industry.

Most farmers are familiar with the unpredictable environmental duo of ENSO: El Niño and La Niña. El Niño events are generally characterised by a warming of the trade winds across the surface of the tropical Pacific Ocean which contribute to a decrease in rainfall over Australia. In contrast, La Niña events represent the reverse and are characterised by a cooling of these same areas resulting in an increase of rainfall across Australia.

Although the Bureau of Meteorology reports that the tropical Pacific Ocean is slightly warmer than usual, this warmth is within the ENSO neutral range. Thus, the BOM has downgraded its ENSO Outlook from El Niño Watch, to Inactive. Surprisingly then, the two usual suspects for extreme weather events in our region, El Niño and La Niña, are not to blame for our current experience of extreme wet to worrying dry.

Is it SAM?

The Southern Annular Mode (SAM), describes the changing position of the westerly wind and measures the impact of these winds as they circumnavigate Antarctica and drive rainfall variability across Australia. Although SAM has reported a slightly positive reading, which is a negative for our predicted rainfall, the overall measurements are close enough to normal to clear SAM of the blame for our current situation.

The Verdict

Experts at the Bureau of Meteorology have declared that at present the tropical Pacific Ocean remains ENSO neutral, and is likely to do so for the remainder of 2017. This means that neither El Niño nor La Niña are expected to have a major influence on Australia’s climate for the rest of this year.

Is That Good News For Farmers?

Yes! This news means that as the global drivers of the El Niño and La Niña weather patterns are not currently active in the Pacific region it is our smaller, local drivers of weather patterns that are the cause of our rainless weather.

Although difficult to predict, these local patterns perform at comparatively brief time scales and therefore have the capacity to shift rapidly in a small amount of time.

Due to the possibility that the local drivers of our weather patterns could alter at any time, there is still reason to hope that soon a cold front could escape from Antarctica’s grip and push up to give Australia some much needed rainfall.

The post Where Has All The Rain Gone? appeared first on ABC Sheds.