On 21 August, the first sampling date, upwelling conditions prevailed. Southwest winds had been blowing for 2 d prior to sampling (Waldorf et al. 1995).surface waters to move shoreward and
downwell at the coast. The thermocline was bent downward until it contacted the bottom, and the bottom contact point moved steadily offshore over the period (Fig. 2). The 20°C isotherm was located about in the middle of the thermocline. On 23 August this isotherm contacted the
bottom at about 4 km from shore, on 24 August the contact point had moved offshore to about 7 km, and by 25 August it was 9 km offshore. Surface currents were onshore during downwelling days
with flows ranging from 5 to 20 cm s–1 (Waldorf et al. 1995, Cudaback & Largier 2001). On 24 and 25 August, very low-salinity water (