for the past 9 years. For the future it is recommended that accumu- 

 lated FDD's be determined for each particular station only for the 

 period when the berg crop is in the vicinity of each particular station. 

 It is also recommended that warming degree days be deducted so as 

 to obtain the net FDD's for the stations of Hopedale, Cartwright and 

 St. Anthony. For example, FDD's would be accumulated for the 

 following stations during the intervals listed : 



Station : Period 



Clyde River September-December 



Cai>e Dyer October-January 



Resolution Island November-February 



Hopedale November-March 



Cartwright December- April 



St. Anthony January-May 



A forecast at the start of the ice season can be prejudiced by the 

 accumulation of FDD's of the various stations at that time as compared 

 to mean accumulations. 



Mean accumulations listed in table IV are for the entire period 

 September-15 March. Mean accumulations for each month would 

 enable a monthly comparison of actvial FDD accumulations during 

 each winter. See table V for monthly mean accumulations of FDD's 

 graciously supplied by Mr. W. Markham, head of Ice Forecast Central, 

 Department of Transport, Halifax, Nova Scotia. Note that the annual 

 means from tables IV and V are in fairly good agreement when it is 

 realized that the means are based on different periods of time during 

 each year and a different number of years. The values in table V are 

 probably more representative of true means as they are assumed to be 

 based on many years data. It is felt that the correlation of FDD's of 

 selected stations and the relative severity of the Grand Banks iceberg 

 season is sufficiently promising for use in prejudicing iceberg forecasts 

 made on the basis of monthly pressure patterns and the available 

 supply before the season starts. 



BAFFIN ISLAND, LABRADOR, AND GRAND BANKS, NEWFOUNDLAND WEATHER DURING THE 



1964 ICE SEASON 



The monthly atmospheric pressure patterns and their effect on ice 

 conditions for 1964 were previously discussed. As indicated in table 



III, predominant winds were generally favorable for iceberg drift 

 toward the Grand Banks and for iceberg survival during the late 

 autumn, winter, and spring months along the berg route. See figures 

 54—61 for the U.S. Weather Bureau monthly mean sea level atmos- 

 pheric pressure distribution from November 1963-June 1964. The 

 climate was abnormally cold as indicated by the greater than normal 

 accumulations of frost degree days at selected stations. See table 



IV. Note that each selected station had a greater than normal amount 

 of FDD accumulfftions for the winter of 1963-64. Indication of the 



60 



