Sea surface temperature is one of the fundamental forcings on the dynamics of marine boundary layers. Specification of the SST field for mesoscale models is crucial for realistic simulation of the boundary layer structure. During the CBLAST (Coupled Boundary Layer/Air-Sea Interaction) pilot experiment in July-August, 2001, we performed twice daily 48 hour-real-time forecasts using high resolution COAMPS (54, 18 and 6 km horizontal resolution) making use of the COARE surface flux parameterization. The forecast cycles used constant-in-time SST field assimilated based on latest satellite data whose space resolution is about 10km. Initial evaluation of the model forecasts reveals that (1) the COAMPS surface layer stability regime is frequently opposite to that derived from the buoys; (2) the COAMPS boundary layer structure is generally more convective than those observed from the field experiment; and (3) SST diurnal variation is significant in the buoy observations compared to the constant-in-time field used in COAMPS. We felt that the weakness in the model boundary layer structure is likely to be related to the insufficient representation in the SST field both in time and space. Therefore, we conducted reanalysis with the SST field assimilated with the 1-km and 4-times-daily NOAA-AVHRR satellite data. The simulation is improved both for the surface layer and vertical structure. The mesoscale flows are also better defined because of the improved representation of the land-sea and diurnal contrasts.