Western Mediterranean oscillation

The Western Mediterranean oscillation (WeMO or WeMOi) is an index measuring the difference between the standardized atmospheric pressure recorded at Padua (45.40◦N, 11.48◦E) in northern Italy, and San Fernando, Cádiz (36.28◦N, 6.12◦W) in Southwestern Spain. Whereas Padua is an area with a relatively high barometric variability due to the influence of the central European anticyclone, San Fernando is often under the influence of the Azores High.

Source: Wikipedia — Western Mediterranean oscillation (CC BY-SA 4.0)