SIXTY-YEAR WEATHER FORECASTS 



By C. G. abbot 

 Research Associate, Smithsonian Institution 



I wish to show that by employing a family of periods (which were 

 discovered to exist in variations of the solar constant of radiation^) 

 general weather forecasts of temperature and precipitation have been 

 made with success many years from their base. I do not claim that the 

 method is equally successful for all stations, or that it is successful at 

 any station at all times, or that it deals with detailed forecasts, or with 

 short times like a week or a month. But I hope to show by use of 

 records of St. Louis precipitation over a course of lOO years, sup- 

 ported by shorter excerpts from records of temperature and precipi- 

 tation at several stations, that, from a seasonal point of view, forecasts 

 for as much as 60 years from base, and over long intervals of time, 

 such as 5 to 25 years, are successful and give high correlations with 

 events. 



I shall present the matter in two parts. In the first, by means of 

 charts and correlation coefficients, I shall illustrate and support the 

 claims just stated. In the second, I shall disclose in considerable de- 

 tail the method now used to obtain the results. 



1. EVIDENCES SUPPORTING MY CLAIMS 



Before presenting results I must state several propositions : 



1. Twenty-three members of a family of regular periods are used. 

 All of these periods, to within i percent, are exact submultiples of 22| 

 years. 



2. This family was discovered in fluctuations of the solar constant 

 of radiation.^ 



1 This term has long been used to denote the intensity of the solar radiation 

 outside our atmosphere at mean solar distance. Daily Smithsonian determina- 

 tions of it for more than 30 years have shown that it is not quite constant but 

 varies over a range exceeding i percent. 



2 From other types of phenomena, including, among others, basal human pulse 

 rates, many additional members of the family are known. In all, more than 

 40 members have been discovered. All are within i percent submultiples of 

 365^ X 22.i days. 



SMITHSONIAN MISCELLANEOUS COLLECTIONS, VOL. 128, MO. 3 



