The running plots of 10-day means for 

 1958 at Ambrose, Five Fathom Bzink Etnd Winter 

 Quarter stations (Barnegat data missing) 

 show for September a similar situation, but 

 one triggered by a different mechanism. 

 Hurricane Daisy on August 28 and 29 sharply 

 reduced temperature gradients from Chesa- 

 peake norttward to Ambrose Lightships and 

 abruptly raised bottom temperatures. After 

 the storm, which was of limited area, thermal 

 stratification again became more pronounced, 

 conditions returning to a status quo ante. 

 Hurricane Helene on September 27 and 28 once 

 again caused an overturn and abrupt warming 

 at the bottom. The former storm produced 

 maximum bottom temperatures for the season 

 at Five Fathom Baink and Chesapeake stations; 

 the latter at Winter Quarter. 



Grand Harbour, Grand Man an 

 (Figure 2, Table 2) 



As was the case in 1956 and 1957, sur- 

 face water temperatures at Grsuid Harbour in 

 1958 were below the mean for the period of 

 record at Southwest Head during the winter 

 and zJxjve the mean during the summer. Tem- 

 perature fluctuations at Grand Harbour are 

 extreme and comparison between years diffi- 

 cult. Very generally, however, it can be 

 said that temperatures through July of 1958 

 were above those for 195 6 and quite close 

 to those of 1957. The maximum in early 

 August lies between the maxima for 1956 and 

 1957, the latter being highest. Cooling 

 through November appeared "normal", while 

 December values fell sharply to more than 

 5° F. below the readings for the two years 

 previous. 



Figure 2. Urand Harbour, Grand Manan, 1953 (solid line) and Southwest Head, 

 Grand Manan, 1929-1936 (dashed line). 



