In an attempt to understand the causes of low frequency flow through the Strait of Belle Isle, we relate sea level data from four stations in the northeast Gulf of St. Lawrence to meteoroligical forcing. Our main tool is a multiple regression, at each frequency, of sea level on local atmospheric pressure and two orthogonal large scale pressure gradients which represent geostropic winds. The results shown in inverted barometer response to atmospheric pressure and a frequency-dependent response to wind which can be tentatively interpreted in terms of coastal setup due to wind driven longshore currents, or barotropic setup of semi-enclosed regions (such as the northeast Gulf or the whole Gulf). A simple model for barotropic flow through the Strait is developed in order to provide an estimate, from data at the western end of the Strait, of sea level changes on the Labrador shelf.