COLUMN-La Nina has departed, but timing of El Nino’s potential arrival remains unclear -Braun

Credit: REUTERS/David Gray

By Karen Braun

NAPERVILLE, Illinois, March 21 (Reuters) - La Nina has officially fizzled after a near three-year stand, setting the stage for El Nino’s possible entrance later this year. The timing of that is not yet settled, but whether El Nino arrives by mid-year or later could have varying impacts for global crops.

Last week, sea surface temperatures across the equatorial Pacific Ocean averaged a half-degree Celsius above normal, the warmest in exactly three years. The anomaly in the all-important Nino 3.4 region reached 0.1 degree, the warmest since mid-2021 but short of the 0.5 degree normally associated with El Nino conditions.

That compares with a mid-February anomaly of minus 0.5 degree in the Nino 3.4 region, still characteristic of the La Nina phase within the El Nino-Southern Oscillation (ENSO).

Earlier this month, the official U.S. ENSO forecast showed 56% odds of an El Nino phase for the three-month period centered on August versus 40% for a neutral phase. The official forecast incorporates human judgment.

But the latest model-based outlook, issued on Monday, places 64% odds of El Nino in the period centered on July versus 35% for neutral ENSO. This more aggressive forecast could be explained by the rapid warming of the Nino 3.4 region in the last few weeks.

ENSO’s impacts on U.S. summer crops are not as pronounced as in the Southern Hemisphere, but an earlier arrival of El Nino may be better. While many of the best U.S. corn yields occurred during El Nino or neutral positive ENSO years, the neutral positive scenario also coincided with some of the worst corn outcomes.

Earlier El Nino may not be the best bet. Numerical model forecasts issued between February and May typically have the lowest skill, and they also tend to over-favor El Nino scenarios for later in the year.

By June, there should be a much clearer idea of whether El Nino is truly in store for 2023 and the likely timing. In addition to the recent warming of Pacific Ocean waters, the Indian Ocean’s version of ENSO is expected to trend increasingly positive in the next few months, often supportive of El Nino.

Argentine farmers may be the biggest cheerleaders for El Nino, as La Nina-induced dryness this year has resulted in perhaps their worst-ever harvests. A change in the pattern now will not help those crops, but a boost in soil moisture ahead of Argentina’s wheat planting, which begins in May, would be welcome after last year’s wheat production was nearly half the initially expected levels.

Australian farmers feel differently, as the string of La Ninas has allowed for three consecutive record wheat harvests. El Nino frequently brings dry and warm weather to Australia’s wheat regions, which have already been getting dry in recent weeks following below-average summer rainfall.

Australian wheat planting begins next month. Together, Argentina and Australia have accounted for as much as 20% of global wheat exports.

Karen Braun is a market analyst for Reuters. Views expressed above are her own.

Graphic- Weekly sea surface temperature anomalies in the Pacific Ocean

(Writing by Karen Braun Editing by Matthew Lewis)

((; Twitter: @kannbwx))

The views and opinions expressed herein are the views and opinions of the author and do not necessarily reflect those of Nasdaq, Inc.

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