SYNOPSIS...A high pressure ridge will build over the NW portion today as a low pressure trough weakens near the California coast. The ridge will shift W tonight as a weakening cold front moves SE over the northern waters. A stronger ridge will build NW of the waters Sat and Sat night as a trough redevelops and strengthens along the northern California coast. The offshore ridge and coastal trough will slowly weaken Sun through Mon night. High pressure will rebuild NW of the waters Tue and Tue night, as the trough strengthens along the northern and central California coast.