BAMOS
Jun 2018
18
Position
statement
Weather Analysis and Prediction in Australia
Prepared by an Expert Group comprising Michael Reeder (Chair), Noel Davidson, Beth Ebert, Terry Hart, Dean Narramore,
Liz Ritchie-Tyo and Claire Vincent
Editor’s note: The following represents an extended version of the AMOS Position Statement on Weather Analysis and Prediction in
Australia, which was formally adopted in August 2017.
1. Introduction
The term “Weather” refers to the state of the atmosphere
on spatial scales from that of an individual cloud to that of
global-scale wind systems and on time scales of seconds to
two weeks. Routine weather forecasts help the general public,
industry, agriculture, government, defence, and other sectors
make myriad daily decisions ranging from what to wear to
how to operate their business. Weather warnings alert users to
dangerous conditions, allowing them to take action to protect
life and property.
In Australia, the Bureau of Meteorology (BoM) has statutory
responsibility for making and issuing weather forecasts and
warnings. A recent study by London Economics estimated that,
“for every dollar spent on delivering Bureau [of Meteorology]
services, these services return a benefit of $11.60 to the
Australian economy.” Private-sector companies complement
these taxpayer-funded services by customising forecasts for
industry and other users. Research into the underpinning
science of weather and its application to weather prediction
is conducted in Australian universities, the Commonwealth
Scientific and Industrial Research Organization, and of course
the BoM. In addition, the universities and the BoM train the
nation’s future generation of meteorologists.
2.
How is the Weather Predicted? 1
warnings. The mapping of weather systems provided the basis
for investigating these travelling weather systems.
In parallel with these efforts, the fundamental laws of fluid
mechanics and the physics of the atmosphere were being
understood. Weather occurs on many scales from large-
scale features that move around the planet (for example, low
pressure systems and cold fronts) to smaller scale features
(for instance, sea breeze circulations and thunderstorms), to
very fine scale turbulence (such as the clear air turbulence
that occasionally affects aircraft). All these phenomena are
governed by the laws of physics. Today, weather forecasters
rely heavily on computer models that solve the mathematical
expressions for these classical laws of physics. The idea that this
was possible goes back to the first half of the twentieth century,
and in particular to the British mathematician and physicist
L. F. Richardson. Richardson’s approach, however, only really
became practical with the invention of the computer, which
could replace his imagined army of human calculators. The
subsequent development of computer weather prediction, or
numerical weather prediction as it is now called, has been one of
the great technological achievements of the second half of the
twentieth century. (Bauer et al., 2015).
To make the problem solvable on a computer, numerical weather
prediction approximates and solves these laws at discrete points
in space and time on a spatial grid covering the Earth (Figure 1).
Attempts to forecast the weather date back to antiquity as is
evident in the description of weather patterns captured in local
wisdom, folklore and early scientific treatises. As information
on weather across nations and internationally became
available, particularly the observation of changes in pressure
associated with storms, it was recognised that weather was
organised in large-scale systems that moved. The need to save
lives, especially on ships at sea, drove early attempts by public
servants, such as the Dutch meteorologist C. H. D. Buys Ballot
and English scientist and Vice Admiral (and commander of HMS
Beagle on Charles Darwin’s voyage) Robert FitzRoy, to provide
fore-warning of storms. The deployment of the telegraph
network allowed weather information to be exchanged quickly
and areas of potential storms identified in time to provide
Some suggested books on the history of weather analysis and
prediction are listed at the end of the article.
1
Figure 1. A schematic showing grid points, both horizontal and
vertical, at which calculations are made in a numerical prediction
model of the atmosphere. (Source: Bureau of Meteorology)