Australian Equity Strategy

Research evidence excerpt

Australian Equity Strategy

Macquarie Equity Research Australian Equity Strategy

Rising risk of El Niño

• Official forecasters (BOM / NOAA) have not officially called an El Niño, but they both

highlight the rising risk. We created a nowcast / early warning system using daily data to get

ahead of the official El Niño call, as it could drive a sector rotation.

What is El Niño?

• El Niño is not just warm water. It is a coupled ocean–atmosphere event. For Australia,

the relevant pattern is warmer central/eastern Pacific SSTs, weaker trade winds, pressure

changes and lower rainfall across parts of eastern and northern Australia. BoM says El

Niño typically develops in autumn/winter, strengthens in winter/spring and has its greatest

Australian impact in winter and spring.

• El Niño can result in lower than average rainfall across parts of the globe including

Australia (particularly the East Coast - ECA). Historically, ECA rainfall in El Niño years has

been 19% below the long term annual average.

• We created an ENSO nowcast system that separates fast signals (daily, 7-day averages)

from the longer averages needed for formal confirmation. It includes:

Þ Surface temperature. We use industry standard Daily OISST (Optimum Interpolation

Sea Surface Temperature) Niño data. Daily Niño3.4 is already above the +0.8°C

threshold and warming is broad across multiple Niño regions. Monthly Niño3.4 is still

below the official confirmation level, but is likely to reach it on current trends.

Þ Atmosphere. This is based on a Daily SOI (Southern Oscillation Index). Here the 30-day

SOI is already below the -7 El Niño threshold, but the 90-day SOI is not yet persistently

negative. The way to think about this is that ocean temperatures are leading, while

the atmosphere is now starting to follow.