618 



GROEN AND GROVES 



[chap. 17 



of September 14-15, 1944. The hurricane's center passed about 50 km to the 

 east over the shallow, broad shelf. Fig. 6 (taken from Redfield and Miller, 1957) 

 shows the corresponding surge at Atlantic City and at other ports along the 

 same coast. 



These records are typical of hurricane-produced surges in this region. Redfield 

 and Miller (1957) consider the records as consisting of three successive stages : 

 the forerunner, hurricane surge and resurgences. The forerunner is a slow, 

 gradual change in water level, beginning several hours before the arrival of 

 the storm. The coherence between neighboring ports in the forerunner stage is 



Fig. 6. Surge of September 14-15, 1944, along the Atlantic Coast of the United States. 

 Vertical scale is in feet, abscissa is in Eastern Standard Time. The arrows indicate 

 the time of nearest approach of the hurricane's center, distance in miles and direction 

 of the tide gauge from the storm track. (After Redfield and Miller, 1957. By courtesy 

 of the American Meteorological Society.) 



usually good. Winds over a more extended region than the hurricane proper 

 are probably important in this stage. If the longshore motion of the hurricane 

 is "upcoast" (toward the right along the coast, facing the land from the sea), 

 the forerunner is observed to be a rise in water level ; if the longshore motion 

 of the hurricane is "down-coast" the forerunner is a gradual fall in level. 



The hurricane surge is the sharp rise in water level that occurs approximately 

 when the hurricane center passes near the port. The duration of this phase is 

 usually short — 2.5 to 5 h — but peak water levels of 3 m to 4 m have been 

 observed. The coherence between adjacent ports is not so good, indicating that 

 the strongest winds in the small region of the hurricane proper are responsible. 



