The running plots of 10-day means for 

 1958 at Ambrose, Five Fathom Bank and Winter 

 Quarter stations (Barnegat data missing) 

 show for September a sirailsir situation, but 

 one triggered by a different mechanism. 

 Hurricane Daisy on At^st 28 and 29 sharply 

 reduced temperature gradients from Chesa- 

 peake northward to Ambrose Lightships and 

 abruptly raised bottom temperatures. After 

 the storm, which was of limited area, thermal 

 stratification 2igain became more pronounced, 

 conditions returning to a status quo ante. 

 Hurricane Helene on September 27 and 28 once 

 cigain caused an overturn and abrupt warming 

 at the botiom. The former storm produced 

 maximum bottom temperatures for the season 

 at Five Fathom Bank and Chesapeake stations; 

 the latter at Winter Quarter. 



Grzind Harbour, Grand Manan 

 (Figure 2, Table 2) 



As was the case in 1956 and 1957, sur- 

 face water temperatures at Grand Harbour in 

 1958 were below the mean for the period of 

 record at Southwest Head during the winter 

 and cibove 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 1956 and quite close 

 to those of 1957. The maximum in early 

 August lies between the mjixima 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. 



J I 



J I 



Fo 5Si SfS SR Ju5 SJC *us scp oct Sov d£C 



Figure 2. Grand Harbour, Grand I<!anan, 1958 (solid line) and Southwest Head, 

 Grand Manan, 1929-1936 (dashed line). 



