PREFACE TO THE FIFTH EDITIONWhen, in 1967, the Meteorological glossary came under consideration for reprinting,it was decided to ask Dr McIntosh to undertake a revised edition, with cooperationfrom within the Meteorological Office. The opportunity has been taken inthis edition, to delete some terms which are considered no longer appropriate, andto include various new entries and revisions which stem from recent advances andpractice.Units of the Systeme International have been adopted in this edition. In somecases, however, the traditional British or metric units are also included because ofexisting World Meteorological Organization recommendations and for the convenienceof user interests during the period before complete national and internationaladoption of SI units.Meteorological Office, 1970.PREFACE TO THE FOURTH EDITIONIn 1916, during the directorship of Sir Napier Shaw, the Meteorological Officepublished two pocket-size companion volumes, the 'Weather map' to explain howweather maps were prepared and used by the forecasters, and the 'Meteorologicalglossary' to explain the technical meteorological terms then employed. With theadvance of the science and the elaboration of its techniques the publications havebeen in continuous demand, many times reprinted and on several occasionscompletely revised. The second edition was in 1930, the third in 1938-39, and soonafter World War II it was obvious that radical revision was necessary once again.In 1956 the fourth edition of the 'Weather map' was issued but, for the first timein forty years, it was not found possible to prepare simultaneously a new edition ofthe 'Meteorological glossary' which had become very much out-of-date and inneed of a complete remodeling. For earlier editions the task had been sharedamongst the professional staff of the Office and the result was an interesting andup-to-date volume containing much useful information, although the freedomallowed to the many contributors had led to a unique volume of quite unevencharacter with articles varying from brief dictionary definitions to encyclopedicessays. For the fourth edition the number of new entries was to be larger than everbefore and it was decided that the need was now for a more systematic referencework containing a brief definition of all the terms in ordinary use rather than for acompilation of miscellaneous articles giving information which would moreproperly be looked for in one of the many modern textbooks. For this purpose asingle author, assisted if need be by expert referees, would, it seemed, be advantageousand the Office was fortunate in finding in Dr D. H. McIntosh of theUniversity of Edinburgh a physicist and meteorologist of wide experience willing toundertake the major task. Before being passed for printing every article has beenread critically by more than one member of the scientific staff of the Office and Dr.McIntosh has shown a remarkable readiness to compromise. In this way it is hopedthat the excellence of the author's original draft has been fully retained whileproviding a work which will adequately meet the needs of the official service. Itwould, however, be too much to hope that no further improvement will be possibleand the Office will be pleased to receive from any source criticisms and suggestionscalculated to increase the value of the work, not only for the professionalmeteorologist, but for interested people everywhere.Meteorological Office, 1962.