Latest on El Niño predictions for 2016: A looming La Niña?

El Niño continues to hold sway over global weather patterns, and its influence is likely to persist into Spring 2016.This is according to the El Niño Global Impact Forecast, a special report written by researchers at the National Center for Atmospheric Research for the Willis Research Network, which examines expected impacts for February to April 2016.

Tuesday, February 2, marked Groundhog Day in the U.S., when predictions of an early Spring were set for 2016, based on the folklore of whether a groundhog sees its shadow after coming out of its burrow. Questions were raised over how accurate a service Punxsutawney Phil provides, (46% for those who are interested), but I am inclined to agree with our furry forecaster this year (for Pennsylvania at least). El Niño predictions call for a return to more neutral conditions in the next few months, but globally we are still in with a chance of a warmer 2016 than 2015. Bear in mind that 2015 was the world’s hottest year in at least the past 800 years.

El Niño is an abnormal weather pattern caused by the warming of the Pacific Ocean near the equator, off the coast of South America. La Niña, the opposing sister of El Niño, is characterized by extensive cooling sea surface temperatures across the east-central Equatorial Pacific. Global climate La Niña impacts tend to be the reverse of El Niño impacts.

Spring 2016 Predictions: More Extremes to Come

Currently El Niño is expected to maintain its strength for a little bit longer, but to then steadily weaken as spring approaches in the Northern Hemisphere.

2016-ENSO-prediction_IRI.

Figure 1: Ensemble El Niño Southern Oscillation (ENSO) forecast using 16 dynamical models and 8 statistical models. Values above +0.5 indicate El Niño conditions. Source: IRI.

Figure 1 (right) is a plot of the latest forecast ‘plume,’ which shows us a number of different long-range forecasts of the climate, and tells us whether we can expect an El Niño or La Niña, or neutral conditions in between. The forecast is based on the Nino 3.4 index which describes the sea surface temperature in a certain area of the equatorial Pacific Ocean.

The first thing to note is that the entire set of forecasts lays well above 0.5 through Northern Hemisphere winter, indicating continued El Niño conditions. We also see a shift towards neutral and perhaps La Niña conditions later in 2016.

As summarized in Figure 2, we can expect the following in the next few months:

  • An increased likelihood of above-normal temperatures over most of Earth’s landmass, with the strongest signals over northern parts of South America, Southern Africa and Indonesia.
  • The above regions coincide with increased likelihood of below-normal rainfall and increased potential for heat waves.
  • The southern U.S. stands out as being one of the few regions where cool and wet conditions may be expected.
2016-forecasts_IRI

Figure 2: Global temperature (top) and rainfall (bottom) forecast for Feb-Mar-April 2016. Source IRI.

La Niña Establishing?

We should possibly brace ourselves for a potential La Niña (Figure 1), the opposite phase of El Niño, over the next fall or winter.  Although there is generally a 50% chance that La Niña will follow El Niño, currently, the odds are slightly in favour of La Niña conditions occurring towards the end of 2016, something that should be closely monitored.

Consequences for Re/Insurance Industry from La Niña

El Niño and La Niña have well-established links to hurricane activity. Together they have a see-saw effect, shifting enhanced hurricane activity between the North Atlantic (threatening the east and Gulf coasts of the U.S., Mexico and the Caribbean), and the East Pacific (putting the west coasts of the U.S. or Mexico at risk). Impacts from El Niño and La Niña also extend to the cyclone activity in the Western North Pacific and the Australian region.

The impact on the re/insurance sector largely depends on when the potential La Niña sets in. Some of the predictions are calling for La Niña to start as early as mid-summer which would overlap with the North Atlantic hurricane season (early June to late November), meaning 2016 could see greater than normal hurricane activity.

If this is the case, the companies covering the hurricane risk along the U.S. coast, and particularly in Florida and around the Gulf of Mexico, will be on high alert. Of course, regardless of the underlying climate conditions, it only takes one strong hurricane to hit the coastline in a highly exposed region to cause a major disaster.

Download the full report.

Download the full report.

A La Niña occurring during the second half of the year would generally imply a higher chance of wetter conditions around the Indian Monsoon, Southeast Asia and Eastern Australia. Warmer-than-normal temperatures would often be found in Southeast Asia, while cooler-than-normal temperatures might be expected over parts of Africa, South America and India. More information on expected conditions during El Niño / La Niña, is available on the International Research Institute for Climate and Society’s (IRI) website.

Despite each El Niño / La Niña episode having its own subtleties, long-range seasonal forecasts remain helpful in working out what is most likely to happen in a given season. The associated temperature and rainfall variations can impact flooding and droughts around the world, which may have a knock-on effect for property and health, as well as farming and aquaculture.

If a La Niña event does develop in 2016, then it will likely bring enhanced chances of extreme climate conditions and impacts in some parts of the world. By closely monitoring related climatic changes, we can better prepare for extreme events and assist the re/insurance world to manage and provide recovery from the myriad of connected risks.

This post was originally published February 18, 2016.

About Geoffrey Saville

Geoffrey Saville is a member of Willis Towers Watson's Analytics Technology Team, having joined the company in 2013…
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