Environmental factors useful tool for predicting weather

What do pukeko, blue cod or pohutukawa have to do with what weather is on its way?

While modern state-of-the-art high-resolution forecasting models, like those run by Niwa's supercomputer, have demonstrated significant accuracy and continue to improve each year, mother nature can tell us even more about the weather ahead - just by observing patterns and sequences.

Using environmental indicators to anticipate local weather and climate outcomes is common practice among many indigenous people around the world, including Maori.

By observing patterns and sequences in natural events - such as the behaviour of birds, the blooming of certain trees and flowers, and the movements of the stars, Maori have long used environmental indicators to forecast local weather and climate - helping to manage daily and seasonal activities.

Traditional indicators to forecast weather and climate vary from place to place because of geography, different landscapes and seascapes, and between iwi or hapu.

For example - central North Island iwi Ngai Tuhoe use the sun to predict approaching storms.

When a vivid halo encircles the sun, the expected outcome is a storm approaching.

A pale and dim halo encircling the sun suggests a storm is far away.

When pukeko are observed heading for higher ground, Northland iwi Ngati Wai will expect a storm and possible flooding.

South Island iwi Kai Tahu predict that a long, hot summer will follow when the ti kouka (cabbage tree) flowers early and profusely.

Often more than one indicator is used to forecast weather or climate in the days, months and seasons ahead.

Where there are discrepancies among the indicators, a consensus-based approach is usually taken.

If the majority of indicators point in a given direction then a forecast is most often made in that direction - in a similar way to probabilistic seasonal forecasting methods that rely on consensus amongst different computer models to forecast changes in climate.

NIWA environmental scientist Darren King has been studying traditional Maori methods for predicting weather and seasonal conditions with kaumatua (elders) from across Aotearoa, and says modern and traditional forecasting systems can complement each other.

"Using Maori knowledge to forecast local weather and climate reflects the Maori worldview that all things are connected by whakapapa (genealogy) and that subtle natural linkages in the environment can reveal much about atmospheric conditions," Mr King said.

"Climate has always been important to Maori. It influences which plants, trees and birds are found in various parts of the country and it affects winds, waves and ocean currents.

"This knowledge has not only been vital to survival - by helping whanau to prepare and plan for weather hazards and climate variability, but also influences decisions about when to plant, harvest or fish.

"Learning more about the Maori knowledge system can contribute to better understanding of local weather and climate changes as well as promote awareness of the inherent linkages between people and the natural world.

"Lessons such as these are critical for informing adaptation strategies for the future."

Environmental indicators are still used by many indigenous peoples around the world in the same way.

For example, the blooming of the golden shower tree is used to predict the onset of the monsoon season in India.

And in Peru, farmers forecast the start of the wet season using the position of certain stars.