Conditions show little change in March. By April the intertropical 

 front runs over northern New Guinea, along the Solomons, to the north 

 of the New Hebrides and Fiji. Here again the north-east trades may 

 advance .well over the New Hebrides, while Fiji is well under the 

 influence of the south-east trades. High precipitation effectiveness is 

 therefore found in autumn over the New Hebrides, and even as far a§ 

 New Caledonia, whereas precipitation effectiveness is much lower in 

 Fiji (Map 4). 



In winter there is a tongue of high precipitation effectiveness running 

 along the northern side of the Solomons and extending, to Santa 

 Cruz (Map 6). The precipitation effectiveness decreases slightly farther 

 east, but the tongue is still clearly recognizable as far east as Manihiki 

 and Tongareva (Penrhyn). The standard works on the subject do not 

 mention the existence of any front, and convection due to heating is 

 out of the question at this time of the year. The explanation here put 

 forw^ard is the formation of shearing fronts due to the convergence of air 

 masses not from opposite directions as usually happens in normal fronts, 

 but from directions forming an angle of 15 or 20 degrees only. These 

 shearing fronts could only result in plentiful precipitation if the winds 

 forming them were steady and strong and if the warmer air mass were 

 quite unstable. They are provisionally shown with the stationary-front 

 symbol on Maps 7a and 7b. 



9^ 



4 — Pac. Conarress 



