342 



ANNUAL REPORT SMITHSONIAN INSTITUTION, 193 8 



Fiquke 15.— Successive developments in the 

 weather situation March 12 to 17, 1936, in the 

 eastern United States (8 p. m. air-mass maps, 

 courtesy U. S. Weather bureau). 



velocity of 158 miles an hour from 

 the south-southeast. On the 18th 

 6.27 inches of rain fell and 4.05 more 

 on the 19th, while the winds on the 

 mountain reached 132 miles an hour 

 from the southeast. The total rain- 

 fall at Pinkham Notch in the 14 

 days from March 9 to 22 was 22.43 

 inches; at Randolph, north of the 

 mountain, 16.19; and on the sum- 

 mit of Mount Washington, 13.86. 



The Atlantic high on this occasion 

 was centered off the Middle and 

 North Atlantic States instead of 

 Bermuda and southward as in the 

 other three great floods. Never- 

 theless, the pressure at Bermuda in 

 March 1936, averaged 0.15 inch 

 above normal. Thus the tropical 

 air streams reached the United 

 States from the southeast and 

 mostly along the coast north of 

 Hatteras. The speed of inflow in 

 the lower levels was often 20 to 40 

 miles an hour and at higher levels 

 twice these speeds. 



A complicating factor was the 

 deep and dense snow cover and heav- 

 ily frozen rivers at the beginning of 

 March (fig. 18). Ice was reported 

 in all the northern rivers and in 

 the headwaters of the Ohio. The 

 Allegheny was frozen, New Jersey 

 rivers were ice-jammed, and the 

 West Virginia rivers were filled with 

 floating ice. 



In January 1936 precipitation 

 was above normal everywhere in the 

 section of the country considered — 

 New England, Middle Atlantic 

 States, Virginia, and the upper Ohio 

 Valley. Temperature everywhere 

 averaged below normal. In the last 

 decade of the month temperatures 

 below zero were reported every- 



