25 



MARCH 



Maxiiiiiiin air teinperature, 59° F. 



Minimum air temperature, 22° F. 



Averag-e air temperature, 39.6° F. 



Visibility was less than 4 miles 35.6 per cent of time. 



Visibility was less than 2 miles 26.4 per cent of time. 



It is very seldom that ice patrol begins early enough to enable a 

 <"omplete weather diagram to be made for March. This year the 

 patrol began in February, however, and Figure 12 shows the main 

 characteristics of the weather for the full month. From March 13 to 

 31 the average barometric pressure was much lower than it had been 

 during the preceding 27 days of the 1930 patrol. Throughout the 

 month there were frecjuent dips in the barometric curve with much 

 boisterous weather. The storm of March 18-19 was the severest one 

 of the month. The barometric dip on the 31st was extremely deep and 

 steep, but the ice patrol vessel itself did not get any winds of gale 

 force from this remarkable depression. 



There was considerable foggy weather during the month. A glance 

 at the weather diagram suffices to show how much of it was concen- 

 trated in the periods of low barometric pressure. The "highs," as 

 usual early in the season, brought fine clear w^eather with them. 



APRIL 



Maximum air temperature, 55° F. 



Minimum air temperature, 29° F. 



Average air temperature, 39.6° F. 



Visibility was less than 4 miles 34.2 per cent of time. 



Visibility was less than 2 miles 25.8 per cent of time. 



The first part of April was stormy. From April 4 to the 7th an 

 intense gale raged, more severe than any encountered by the ice patrol 

 for several years. The last part of the month, though marked by a 

 few short storms, was considerably more moderate than the first part. 



The percentage of fog and poor visibility was about the same as for 

 March. There were two prolonged foggy periods and a number of 

 short ones. Figure 13 shows the April weather plotted in the usual 

 way. 



The weather diagrams do not shOw the high percentage of cloudiness 

 prevailing in the ice patrol area. Hourly observations showed that the 

 sky was obscured 0.8 or more by fog or cloud during 64 per cent of the 

 time in March, 65.3 per cent of the time in April, and 59 per cent of the 

 time in Mav. 



