The Nelson sea breeze in southwesterly airstreams
Investigations were made of 23 days i n summer when there were southwesterly airstreams over central New Zealand. On twelve days the surface wind at Nelson Airport remained southwesterly, while on the others a northerly sea breeze developed. It is suggested that, in these conditions, the presence of a lee wave train in the southwesterlies makes it almost impossible to predict the onset of the sea breeze, because its occurrence is related to the (unknown) location of troughs and ridges in the wave system. Interaction between the sea breeze and the lee wave train is thought to be the reason why wind shears associated with the sea breeze "front" at Nelson are greater than is normally the case.