had receded to north of 45° N. By I June, 60 bergs remained south 

 of 48° N. while the southern limits receded to north of 46° N. except for 

 a couple of bergs in the Labrador Current. While most of these bergs 

 were not threats to Tracks C and B, many were a threat to Tracks 

 E and F, which were being used by sliips plying Canadian ports and 

 ships using the St. Lawrence Seaway. 



The predominant winds along the east coast of Newfoundland and 

 Labrador for the first 3 weeks of May were north-northwesterly and 

 mostly paralleled the coast except in the Notre Dame Bay area, where 

 these winds were onshore. Only a couple of the 10 large bergs grounded 

 on the northeast slope of the Grand Banks at the start of May made 

 any significant progress toward the Tail of the Banks by the end of 

 May. At this time three bergs now classified as small had reached 

 45° N. There were no other known bergs south of 47° N. On the basis 

 of the known upstream distribution of bergs in early April and the 

 prevailing onshore winds in the areas north of the Grand Banks, the 

 conclusion by mid-May was that there were very few, if any, bergs in 

 the Labrador Current north of the Grand Banks to perhaps Belle Isle. 

 Thus with tbe major threat to Tracks C and B having evaporated, only 

 a very minor intermittent threat to these Tracks remained at least until 

 late June. This conclusion was fortified by fact, as a flight on the 19th 

 determined only a couple of offshore bergs from 48° N. to 53° N 

 There were approximately 200 bergs close ashore between Cape Bona- 

 vista and 51° N. There had been a southward movement of many 

 bergs from north of Belle Isle during the past 6 weeks, but these bergs 

 became trapped and accumulated near Notre Dame Bay. Any major 

 threat to Tracks B and C for the remainder of the ice season would have 

 to originate from this group. As southwest winds soon arrived, many 

 of these bergs began to drift into the Labrador Current aild rapidly 

 out to sea with the leaders reaching 48° 30' W. by the end of May. 

 See figure 42, mean sea level pressure 20 May-1 June, 1964. With 

 existing cold water temperatures and possible winds favorable for 

 drift south, this group of bergs could become a major threat to Track 

 C by late June and early July. An estimated 19 bergs drifted south 

 of 48° N. in May, which was well below normal and a sharp drop from 

 the high April total. This low number can be directly attributed to 

 the fact that prevailing winds from mid-April to mid-May were 

 slightly onshore, driving the many upstream bergs close into shore, 

 considerably delaying their southward progress. 



A combination of cold north-northwesterly winds, abnormal cold 

 water temperatures, and an abundant supply of heavy pack ice from 

 the north kept sea ice in the bays and along the east coast of Avalon 

 Peninsula until 20 May. The pack ice was especially heavy and abun- 

 dant in Notre Dame Bay and maintained by onshore winds there until 

 the fourth week of May when a narrow band of pack ice moved rapidly 



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