There has been increasing interest in the possibility of abrupt climatic changes in the North Atlantic and their potential impacts on the downstream regions of northwestern Europe. Here, we investigate whether this system undergoes abrupt change in a large ensemble of CMIP6 climate models. We define two metrics based on subpolar sea surface temperatures (SSTs) or mixed layer depths (MLDs) to explore the link between surface temperatures and convection collapse. These metrics yield similar numbers of abrupt events but represent seemingly unrelated phenomena. Abrupt MLD changes appear related to ongoing warming. Abrupt SST changes follow a pattern of decadal timescale cooling and warming related to coupled dynamics involving the NAO. Constraining the models by their representation of NAO variability increases the estimated likelihood of an abrupt SST event from 15% to 29%. Both the cooling and warming phases have important implications for impacts and adaptation, particularly over the British Isles.