Development of Mid-Latitude Storms Sensitive to SST-Gradients

In an experiment with a regional numerical weather prediction model, the influence of strong
SST-gradients in the Gulf Stream region on the development of a number of historical wintertime storms is investigated. The response of storms to decreased SST-gradients is caused by changes in latent heat flux and by changes in the temperature structure of the atmosphere. The former strengthens (weakens) storms north (south) of the SST-front, where SSTs get warmer (colder) when decreasing SST-gradients. The latter weakens all storms. In the South, both act the same direction and all storms weaken. In the North they act in opposite directions, and about half of the storms weakens, the other half strengthens.