Weatherman Derek Brockway explains cause of storm
23 December 2013 Last updated at 22:21 GMT
Gales and heavy rain are bringing problems across Wales, with a wind speed of 87mph recorded in Conwy.
The storm has brought fallen trees and blocked roads, property damage and cancelled trains and ferries.
BBC Wales meteorologist Derek Brockway explained the cause of the problem to Jamie Owen in the Wales Today studio.