178 



ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



make their appearance. In the same year reports were received for 

 the first time from Mexico, and in later years the establishment of a 

 number of stations in the Rocky Mountain and plateau regions 

 afforded much needed information to the forecaster. In 1900 the 

 daily survey -of atmospheric conditions was extended to the British 

 isles, continental Europe, Bermuda^ and the Azores, through the 

 cooperation of the meteorological services of those countries, and in 

 1907 the field was further extended to include Iceland, Asia, and 

 Alaska. 



At the present time there is prepared each morning in the fore- 

 cast room of the central office of the Weather Bureau a chart show- 

 ing the atmospheric conditions in middle latitudes around the north- 

 ern hemisphere. No other meteorological service prepares a world- 

 wide weather map. This chart not only affords material aid in the 

 preparation of the daily forecasts but has made possible the making 

 of forecasts for a week in advance. 



WEEKLY FORECASTS. 



The weekly forecasts are given wide publicity through the press, 

 and their accuracy has been the subject of much favorable com- 

 ment. This extension of the forecast period marks the greatest 

 advance of weather forecasting in recent years. That the enlarged 

 survey is also an important aid in the preparation of the daily 

 forecasts is attested by the following table, which shows the increase 

 in the percentage of accuracy for the year ending June 30, 1912, 

 over the year 1893 : 



The annual percentage of verification for the 12 months ending 

 June 30, 1912, was 88.5, or 7 per cent higher than in 1893. 



USE OF THE BADIOTELEGRAPH. 



During the hurricane seasons of 1910 and 1911 reports of wind, 

 barometer, and weather conditions were received by radiotelegraph 

 from vessels in the Gulf of Mexico and the Caribbean Sea and off the 

 south Atlantic coast, and on two occasions these reports gave the 

 first indications of the formation of hurricanes in those regions. 

 This was the first successful effort to employ the radiotelegraph in 

 weather forecasting. 



