El Nino 2019 probability lowered to 50% as sea temperatures cool

The probability of an El Nino weather phenomenon developing during the first half of 2019 has dropped to 50% as sea surface temperatures in the Tropical Pacific continued to cool over the past month, the Australian Bureau of Meteorology said Tuesday.

Sea surface temperatures in the Pacific Ocean are an important indicator of a developing El Nino Southern Oscillation - a weather pattern that can bring drier weather to some regions and more rain to others. 

The BOM said that while temperatures remain warmer than average, “since late 2018 they have cooled from El Nino-like values towards ENSO-neutral values”.

That has seen the BOM’s ENSO outlook lowered from “alert” in its December outlook to “watch” this month, meaning there is approximately a 50% chance of an El Nino developing during the southern hemisphere autumn or winter.

An El Nino generally brings drier weather to Southeast Asia and Australia, negatively impacting large palm plantations and wheat crops, while increasing rains across parts of South America and the US resulting in improved corn and soybean yields there.

However, three of the eight weather models used by the BOM predict a resurgence in sea surface temperatures to breach the El Nino threshold from February onwards, indicating an El Nino could potentially develop later this year.

The remaining five models predict warmer temperatures, but still within the neutral zone that indicate an El Nino is unlikely to form.

“Outlooks remain mixed during the Southern Hemisphere autumn to winter,” the BOM said.

“Some models anticipate a continued decline in sea surface temperatures over autumn and early winter, however, half see a renewed warming.”