High waves that break over Molo di Levante. Caused by a well developed low pressure system over North Africa. Produces strong east to southeasterly winds and seas at Catania. Brings hot, humid weather. Sometimes brings northeasterly winds to Catania in an otherwise southeasterly situation.
Northeasterly winds dampen southeasterly swell.
Calm winds at Catania harbor when northeasterly wind passes through the Strait of Messina. Steep gradient resulting in general northwest or north flow will produce an offshore wind at Catania, but poses no problem for harbor operations. Can bring ash falls from Mt Etna into port. No strong wind effects for winds from southwest clockwise through northwest. Heavy rain with low cloud ceilings can occur at Catania when a low pressure system passes south of Sicily.