METHODS OF FORECASTING THE WEATHER. 



By Prof. J. :M. Perntek. 



Allow mc to-day to address 3-011 once again on the subject of weather 

 prophets, and this time to bring before you not only one or two kinds 

 of weather forecasting, but to give you a more general survey of all 

 methods at present in use, be they right or wrong, with or without 

 results. I will keep strictly to the title of this lecture and give the 

 prominent place to the methods of forecasting. 1 shall explain them 

 and subject them to critical analysis, naming at the same time the 

 advocates of each of the various methods; in the technical investiga- 

 tion, we have to do with the value of the methods and not that of the 

 persons. I must, however, at once bring prominently forward the 

 fact that we have at present, uufortunatel}^, no method by which we 

 can forecast the weather with absolute certainty even for one day in 

 advance, to saj nothing of longer periods. This is already self-evident 

 from the fact that we are now able to speak of man}^ methods of fore- 

 casting, whereas if there were a sure and infallible method, then it 

 would be out of place to speak of the other methods to this society for 

 the advancement of scientific knowledge. 



All methods of weather forecasting, not excepting those in use b}^ 

 the central meteorological offices, are based upon observed weather 

 conditions, and have, therefore, an empirical foundation. Many of 

 them do not even make the slightest attempt to put their methods on 

 a theoretical basis and content themselves with setting up "'weather 

 rules." P^ven the scientific methods of professional meteorologists 

 have not yet succeeded in deducing a theory capable of determining in 

 advance the changes of the weather as the eflect of one or several 

 known causes. Only the advocates of the influence of the moon have 

 ventured solely by means of aprioristic theories to "calculate" the 

 weather for long periods in advance. 



« A lecture delivered by Prof. Dr. J. M. Pernter to the Association for the Advance- 

 ment of Scientific Knowledge, Vienna, January 14, 1903. Translated from the 

 Vortnige des Vereines znr Verbreitung natur\vi.«senscliaftlicher Kenntnisge in Wien. 

 43d Jahrgang, Heft 14. Printed in Monthly Weather Review, U. 8. Departiuent of 

 Agriculture, December, 1903. 



SM 1903 11 ^^^ 



