Tropical cyclone nursery: Could the triplets become quintuplets?

Hurricane Fiona is joined by Tropical Storm Gaston and Tropical Depression Nine, plus, two other disturbances.

After a quiet start to the season the Atlantic is finally ramping up, and with all eyes on the nursery basin, Tropical Storm Gaston is the latest to be born.

Gaston is currently affecting the Azores with heavy rainfall, but is likely to remain a 'fish storm' after passing through, which means it poses no further threat to land and will remain out at sea.

Nine is due to strengthen in the coming days, looking to reach hurricane status by early next week as it curves northwards towards Cuba and southern Florida. Nine is likely to become the next named storm on the list, Hermine.

As for the other two disturbances; one has a 20% chance of cyclone formation over the weekend, whilst the newest off the coast of the Western Sahara has an 80% chance of formation.

Though not the only factor involved in cyclone development, the exceptionally warm waters of the Atlantic have played a big role in supplying these storms with the fuel they need to strengthen.

Water temperatures need to reach at least 26C to sustain tropical systems. Wind is also needed, which in the Atlantic blows westward from Africa, carrying warm air along with showers. This warm air then rises, cools and condenses to build towering storm clouds.

As more of this air rises, the winds begin to blow around the centre of this rotating system, which creates more organised thunderstorms. As the system further strengthens, it can reach different wind speed thresholds to become a depression, storm and then a hurricane.