{m.'leod 4 BARNES] LOCAL TEMPERATURE FORECASTING 



TABLE III. 



PREDICnONS FROM ApRIL RECORDS. 



161 



Prediction from the chart. 



Actual change in temperature on th3 

 following day shown by thermograph 

 record. 



As an example of the method of judging, we reproduce some typi- 

 cal curves in one instance, where the value of our method to meet local 

 conditions is illustrated. 



Fig. 1 shows a trace from 6 o'clock in the afternoon of March 

 4th, extending to 12 o'clock (noon) on March 5th. This shows in- 

 creasing negative difference over a period of 18 hours, indicating 

 change to colder weather for the afternoon and night of the 5th. 

 The temperature actually remained on or about 0° F. all day of the 

 5th, and fell on the morning of the 6th to 10° below zero. 



Fig. 2 shows the trace obtained from noon on the 5th to noon 

 on the 6th. The temperature gradient in the upper strata becomes 



