A.N. Winchell— Great Dustfall of 1920. 351 



not having noticed anything, and the traces having dis- 

 appeared by the time the inquiry reached them. 



The Origin of the Dust. — The meteorological conditions 

 that produced this dustfall were quite similar to those 

 of the dustfall of March 8-9, 1918. The dust-bearing 

 winds accompanied Low V of Chart III, Monthly Weather 

 Review, March, 1920. The track of this storm is repro- 

 duced in fig. 1 of this paper. Excepting the secondary 

 center that developed in Arkansas on March 18, 1920, this 



Fig. 1.— Dust-bearing storm of March 15-20, 1920, ' ' 17a, " " 17p, ' ' etc., 

 show position of storm center at 8 a. m. and 8 p. m., March 17th, etc. 

 Shaded areas show total precipitation of rain and melted snow during the 

 storm, each shade corresponding to a range of half inch in depth of precipi- 

 tation. Dotted line is limit of snow on ground 8 p. m., March 15, 1920. 



track is practically identical with the track of the storm 

 that brought the dustfall of March 8-9, 1918 (Compare 

 iig. 1, Monthly Weather Review, November, 1918, page 

 502.) 



The storm of March 18-19, 1920 was more severe on 

 the High Plains, and less severe east of the Missouri 

 valley than the storm of March 8-9, 1918. Throughout 



