was milder, partly due to the adA^ancing season, partly to the more 

 southern locale of the patrol vessel, but more properly due to the 

 prevailing southwest winds. These conditions are characteristic of 

 the season and bring generally unsettled weather, frequent showers 

 and an increasing percentage of fog. On April 22 a deep disturbance, 

 practically stationary just south of Cape Race, Newfoundland, gave 

 strong northerly winds approaching gale force at times that day and 

 developed into a long trough or discontinuity line, giving strong 

 northv/est winds on its northern side for the next 2 days and drawing 

 a deep mass of polar air southward beliind it, bringing fine weather 

 until the 29th when southerly winds preceding the next disturbance 

 brought fog and rain. This second depression moved slowly east- 

 ward and by April 30 had developed the same sharp line of discon- 

 tinuity with the warm Atlantic air on the southeast side and a deep 

 mass of polar continental air on the northeast side. This cold front 

 moved slowly across the area on April 30 causing a sudden wind shift 

 from strong south southwest wind, warm weather and dense fog, to 

 north northeasterly winds with clear weather but cloudy and cold. 

 The passage of the front was marked by heavy showers. The aver- 

 age temperature for the month of April was 39.03° F., and the per- 

 centage of fog, visibility less than 2 miles, was 28.5 percent. (See 

 figs. 14 to 18.) 



MAY 



During the first days of May a wave disturbance developed along 

 the sharp cold front, described above on April 30, just northeast 

 of Bermuda and moved slowly northward, then retrograded slowly 

 and filled during the next few days without going to occlusion or mov- 

 ing appreciably. Tliis was followed by a long period of extremely 

 mild summer conditions bringing an extraordinary amount of fog to 

 the ice patrol area which persisted to May 24. The percentage of 

 fog during this period was 65.5 percent. The remainder of the month 

 was characterized by light to moderate west southwest winds bringing 

 warm mild conditions and less than normal percentage of fog. Low 

 visibility during this month materially int erf erred with scouting oper- 

 ations for the first time tliis year. The average temperature during 

 the month was 44.27° F., and the percentage of fog, visibility less 

 than 2 miles, was 38.1 percent. (See figs. 18 to 23.) 



JUNE 



The patrol vessel was in the Grand Banks region only during the 

 first 11 days of tliis month. During tliis time the weather was 

 seasonably warm and mild with south and southwesterly winds pre- 

 vailing and much fog. The average temperature was 50.2° F., and 

 the percentage of fog, visibility less than 2 miles, was 78.6 percent. 

 (See figs. 23 and 24.) 



