WEATHER 



This section gathers together certain meteorological facts observed 

 on the ice-patrol vessels during the 1928 ice season. The conditions 

 can be taken as those that prevailed at 43° N., 50° W., for all practical 

 purposes, but too great stress should not be placed on this position, 

 for the patrol ships cruised from 46° 50' N. to 40° 40' N. and from 

 53° 00' W. to 43° 20' W. There were areas of cold surface water 

 and of warm surface water in the patrol area which had consequent 

 marked effects on local weather, especially with respect to fog and 

 surface air temperatures. It was noted that the air temperatures 

 followed the values of the sea temperatures closely and quickly most 

 of the time wherever the patrol vessels went. 



The weather diagrams for each month" give at a glance the wind 



directions and forces averaged for every 12 hours, the barometric 



curve, and the time and duration of fog and low visibility. This 



year maximum and minimum and average surface air temperatures 



are given for each month. The scientific value of these temperatures 



is mitigated by the above noted mobility of the observing stations 



and by the fact that ordinary poorly exposed ship's air thermometers 



were used in making the observations. It is believed that the values 



will be of interest, however, in showing about what temperatures 



should be expected and prepared for on ice patrol. The average air 



temperatures were obtained roughly by adding all the daily maxima 



to all the daily minima and dividing the sum by twice the number of 



davs. 



MARCH 



Maximum air temperature, 50° F. 



Minimum air temperature, 28° F. 



Average air temperature, 37.8° F. 



Visibility was less than 4 miles 57 per cent of time. 



Visibility was less than 2 miles 34 per cent of time. 



The ice patrol was in effect during onl}'^ the last 10 days of March. 

 The percentage of bad visibility was extremel}^ high for early in the 

 season. There were three days of dense fog from the 25th to the 

 28th caused by Southwest winds blowing, as in summer, over the 

 cold water. They were apparently caused by the atmospheric circu- 

 lation set up between a High over the ocean to the south and a Low 

 situated over the northeastern part of North America. 



Only two cyclones affected the barometer on the patrol vessel to 

 a marked degree. The one whose center passed just to the south on 



(50) 



