Figure 26. — Ice conditions Grand Banks on 18 June 1964. 



Banks between 47° N.-48° N. and 15 bergs close along Avalon Penin- 

 sula. Upstream in the Labrador Current there were an estimated 30 

 bergs between latitudes 48° N.-49° N. and longitudes 49° W.-51° W. 

 with many more bergs to the north and west. At this time the weather 

 pattern changed with a shift in the Azores high to the northwest 

 causing lows to move northwest of Newfoundland and resulting in 

 south-southwesterly winds over the Grand Banks for the remainder of 

 the month. See figure 44, mean sea level pressure for the period 13-30 

 June 1964. Consequently, bergs were driven to the northeast out of 

 the main branch of the Labrador Current as evidenced by flights on 

 the 17th and 18th. At this time there were only 4 bergs east of 48° W., 

 all near 48° N., 47° W. with about 15 other bergs east of 50° W. and 

 only a couple large enough to reach Track C. Of the nine bergs on the 

 northeast slope of the Grand Banks on 1 June, only one remained. Of 

 the 25 bergs near 48°50' N., 50° W., only 3 remained. In spite of 

 an abundant supply upstream, the deterioration was exceeding the 

 supply. It was now obvious that no threat existed to Track B and only 

 a very minor threat to Track C was possible the remainder of the year. 

 A flight on tlie 30th revealed only 4 bergs south of 48° N. and only 

 11 bergs east of 50°30' W. The southernmost offshore berg was in 

 the main branch of the Labrador Current at 47°40' N., 46° 56' W. 

 This berg was a solid medium-sized dome berg and w^as expected to 

 last a;bout 2 weeks and not long enough to reach Track C. With con- 

 siderable warm air flow over the Grand Banks and vicinity during 

 the last 3 weeks of June the sea surface temperatures were almost back 

 to normal. See figure 8, isotherm chart for 16-30 June. Wliile any 



22 



