In conclusion, the general relationship between weather and the 

 Grand Banks iceberg problem has been discussed. Possible correla- 

 tion between specific measurable meteorological elements and the re- 

 sulting severity of the Grand Banks iceberg season has been explored. 

 See other sections of this article for a discussion of the relationship 

 between air temperatures and iceberg conditions and the relationship 

 between surface winds and iceberg conditions. In order to establish 

 meaningful and reliable relationships and thus improve forecasting 

 capability, considerable northern ice observation will be required to 

 determine the available supply, study its progress toward the Grand 

 Banks, and correlate it with measurable and assumed factors. 



THE EFFECT OF SELECTED MONTHLY MEAN SEA LEVEL ATMOSPHERIC PRESSURE DISTRIBUTION 

 ON THE GRAND BANKS ICE SEASON 



We in the Ice Patrol are naturally most interested in developing the 

 capability to forecast the relative severity or lightness of each ice 

 season before it begins. As stated in a previous section of this article, 

 winter weather along the berg route is critical in determining the 

 number of icebergs that will reach the Grand Banks. Specifically it 

 is planned to demonstrate here that excellent correlation does exist 

 between winter atmospheric pressure patterns and the relative severity 

 of the coming ice season. Smith's formula forecasting the number of 

 bergs south of 48° N. is based primarily on sea level pressure anoma- 

 lies in the North Atlantic during the previous winter. While Smith's 

 formula has been sufficiently accurate over the years to demonstrate 

 that a correlation does exist between winter pressure patterns and the 

 relative severity of the forthcoming Grand Banks iceberg season, it 

 has not been sufficiently reliable. Of course the main reason for the 

 shortcomings of Smith's formula is the fact that the available supply 

 suitably located prior to winter is not accounted for. It must also be 

 admitted that this formula is not sufficiently discriminating, as sig- 

 nificant pressure patterns are likely to be averaged out. It is proposed 

 that the sea level atmospheric pressure distribution be analyzed and 

 the resultant effect on iceberg drift be qualitatively estimated on a 

 monthly basis during the late autumn, winter, and spring in those 

 areas inhabited by the oncoming season's iceberg crop. A systematic 

 determination of the locations of the berg concentrations comprising 

 the supply upstream is an important essential in evaluating the effect 

 of pressure patterns on the drift of berg concentrations. The de- 

 velopment of a relationship between monthly pressure distribution 

 and resultant iceberg conditions will be useful for long range fore- 

 casting and will enable a more accurate assessment of the upstream 

 berg potential during the ice season and will therefore also be useful 

 in short range forecasting. 



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