THE LOW-LEVEL SEA BREEZE OF NORTHWEST WASHINGTON

Abstract

Resultant winds, mean pressures, and mean pressure gradients are presented for each hour of the day for July and August at stations of northwest Washington. The end point of the resultant wind vector in some cases turns clockwise, in some cases counterclockwise. Circular, elliptical, and more complicated hodographs are found. The results are discussed in connection with recent sea-breeze theory. In some locations the pressure-gradient force changes in direction during the day, apparently as a result of topographical constraint, and in a manner which is consistent with the sense of rotation of the end point of the resultant wind vector and the shape of the hodograph. Spatial differences of resultant wind components suggest that the diurnal variation of stratus amount is related in part to vertical motion associated with the sea-breeze circulation. Hodographs for days selected for cloudiness show that the sea-breeze circulation in northwest Washington takes place on a huge scale. Applications of the resultant winds are briefly discussed.