BAMOS 3
Applying the concept of the“ front” to synoptic analysis in Australasia
An anecdotal history
By Terry Hart, Sue Barrell, Ciaran Doolin, John Garratt, Barry Hanstrum, Jenny Hopwood, John McBride, Graham Mills, Peter Noar, Michael Reeder, Roger Smith, John Zillman
Introduction
The years following World War I saw major advances in synoptic analysis and weather forecasting. Perhaps most influential was the Bergen School of Meteorology with its emphasis on the role of“ air masses” and“ fronts” and the Polar Front theory of cyclone development 1. The Bureau of Meteorology’ s then new head of research, Edward Kidson, born in England but raised in New Zealand, was proactive in the introduction of air mass and frontal concepts to southern hemisphere synoptic meteorology during the 1920s and his influence on Australian practice continued after he moved to New Zealand in 1927 to become Director of the Meteorological Service.
Doolin( 2020) has documented the work of Kidson and the role he played in the adoption of the Norwegian frontal model to the Australasian region. Kidson visited Bergen, Norway, twice during the 1930s – in 1931 and 1935 – working closely with leading Bergen scientists such as Jacob Bjerknes and Sverre Petterssen to gain a greater appreciation of the new methods. His research was further aided by the fortuitous visit of Jørgen Holmboe, another Bergen meteorologist, to New Zealand during 1934; Holmboe spent seven months working with Kidson at the Meteorological Service to implement the Norwegian approach to synoptic analysis and forecasting in New Zealand. Interestingly, Doolin notes how Kidson in his synoptic charts extended fronts to the tropics and even analysed tropical cyclones as wave disturbances on a front.
Despite scepticism from some, by the time of the outbreak of World War II, there was a general acceptance of the usefulness of frontal analysis. The AMFA( Air Mass and Frontal Analysis) Section had been established in Melbourne and forecaster recruits were schooled in the intricacies of air mass recognition, frontal identification and the use of the frontal model for weather forecasting.
This paper describes the subsequent debates over the application of this theory, including quotes and recollections
1 The term“ front” originated from the imagery of the lines of conflict that occurred where the competing armies confronted each other in World War I. from many of those involved up to the early 1980s by which time most of the debates seem to have been finally resolved. However, that initiated a rich period of study of fronts and related phenomena that has greatly enhanced understanding of fronts and other atmospheric discontinuities, and the ability to apply that knowledge in weather forecasting. This latter period deserves its own story which is covered only briefly in this paper. However, there is an excellent, comprehensive summary in Reeder and Smith( 1998).
World War II and the 1950s
The frontal theory was put to a stern test as forecasters attached to the Australian and New Zealand Air Forces struggled to reconcile the theory of fronts with their experience in the tropics in support of war-time operations. In the years following the War there was a period of debate and the development of a new understanding of tropical weather patterns. New concepts were developed for tropical analysis focusing on stream-lines rather than isobaric and frontal analysis.( The July 2022 Edition of the AMOS Bulletin contains an outline of the evolution in synoptic analysis and forecasting from World War II to the present.)
For middle and high latitudes, the frontal concepts continued to under-pin synoptic analysis and forecasting. Fronts started to appear as part of the Bureau’ s communication to the general public.
One aspect I have often wondered about is when the Bureau first used the concept of fronts, particularly in Melbourne. The“ cool change” is mentioned in newspapers way back in the 19th century; and I expect the association of the wind change and extreme fire weather would have also been well known.
I was curious as to when these events were first recognised as fronts. Going to The Age newspaper on Trove, cold fronts were mentioned in weather summaries from about 1935; but they were not drawn on the daily weather maps until they suddenly appeared on the newspaper chart on 13 April 1946.
— John McBride.