"The sea swell generated by Storm Dennis is expected to be truly phenomenal and is likely to be larger than that generated by Storm Ciara," says Offaly man Cathal Nolan, of Ireland's Weather Channel.

"Current indications suggest sea swells and wave heights both reaching in excess of 15 metres or some 50 feet between Sunday and Monday.

"The Atlantic west will get a battering," Cathal states simply.

While he warns there will be 130km/h winds along the west coast, and 100km/h winds across the Midlands.

"Dennis will see its central pressure drop to between 913 - 915 hPa, which would make this the deepest pressure reading ever recorded in the North Atlantic Ocean, not from a Hurricane," Cathal continues. "Such a pressure reading is truly phenomenal.

"Trees loosened by Storm Ciara puts everything at greater risk, but the risk from flooding is likely to be greater.

"River courses are significantly flooded after 'Ciara', so 'Dennis', with its strong winds, heavy downpours, and wintry precipitation to follow could cause significant flooding from inland river courses.

"It's a three-day storm event," Cathal adds. "We will start to feel the impacts on Saturday and on into Sunday and Monday. Essentially this is a beast of a storm," he admits. "In terms of size, the length and depth of it is phenomenal.

"With strong winds and heavy precipitation, followed by wintry precipitation, basically 'Dennis' will throw everything at us but the kitchen sink."