338 



ANNUAL KEPORT SMITHSONIAN INSTITUTION, 19 3 8 



SIMILARITIES BETWEEN THE OHIO FLOODS OF 1913 AND 1937 



The conditions causing the excessive rainfall of up to 14 inches in 

 northern Tennessee and 17 inches in northeastern Arkansas in January 

 1913, and from 13 inches in southwestern Indiana to 12.7 in north- 

 central Ohio in March 1913, were almost identical with those of 

 January 1937. The pressure at Bermuda was 0.19 inch above normal 

 in January 1913 and 0.30 above normal in March; which are to be 

 compared with 0.36 above normal in January 1937, though during the 

 heaviest rains the pressure departure of March 23-27, 1913, +0.39, 

 exceeded that of January 20-25, 1937, +0.20. 15 



The rainfall, though not so great over the Ohio and lower Missis- 

 sippi watersheds as in the flood of 1937, nevertheless produced excep- 



Fiquek 14.— Weather map of 8 p.m., March 24, 1913. (Courtesy U. S. Weather Bureau.) 



tional floods in the Ohio basin. In January 1913 a number of low 

 pressure troughs parallel to the Ohio in regular succession were 

 accompanied by heavy rains south of the river in the first half of the 

 month and north of it in the last half. A crest of 62.2 feet was reached 

 at Cincinnati on the 15th. Before the flooding rains the ground was 

 neither snow-covered nor frozen. 16 



The second flood, which, after rising 43.5 feet in 5 days, culminated 

 at 69.8 feet on April 1 at Cincinnati, was due to the tremendous rains 

 of March 23-27, lr when more than 10 inches fell at four stations (fig. 

 12). The occurrence of three tornadoes in southern Indiana, southern 

 Illinois, and Kentucky on the evenings of March 23 and 24 and tho 

 morning of the 25th was further evidence of an extraordinary intensity 

 of convection of the tropical air. The sudden rise of the Miami, at 



» Swenson, loc. cit., p. 36. 



io Henry, A. J., Rivers and floods, January 1913. Monthly Weather Rev., vol. 41A, pp. 148-149, 1913. 



w Idem: Rivers and floods, March 1913, ibid., pp. 485-492. 



