The northeastern Pacific climate system is featured by an extensive low-cloud deck off California on the southeastern flank of the subtropical high that accompanies intense northeasterly trades and relatively low sea surface temperatures (SSTs). This study investigates climatic impacts of the low-cloud deck by turning low-cloud radiative forcing on and off only within the subtropical northeastern Pacific in a coupled atmosphere-ocean model. The low-cloud radiative forcing causes a local SST decrease of up to 3ºC on an annual average, with the response extending southwestward through the wind-evaporation-SST (WES) feedback. The SST decrease peaks in summer under the seasonally enhanced insolation and the seasonally shallow ocean mixed layer. The lowered SST suppresses deep-convective precipitation that would otherwise occur in the absence of the low-cloud deck. The resultant anomalous diabatic cooling induces a surface anticyclonic response in summer and autumn as a baroclinic Matsuno-Gill pattern. On its equatorward flank, the enhanced trade winds further cool SST as the WES feedback, leading to the southwest propagation of the coupled response. The enhanced trades accompany the intensified upper-tropospheric westerlies, strengthening the vertical wind shear that, together with the lowered SST, acts to shield Hawaii from powerful hurricanes. On the basin scale, the anticyclonic surface wind response accelerates the North Pacific subtropical ocean gyre to speed up the Kuroshio by as much as 30%. SST thereby increases along the Kuroshio and its extension, intensifying upward turbulent heat fluxes from the ocean to increase precipitation.