Storm Ciarán is expected to arrive in the UK and Ireland, France, and the Iberian peninsula on Wednesday night into Thursday. Gusts of up to 100mph (160km/h) could be possible off the western coast of France before the severe winds filter through the Channel. Brittany and the western French coast could experience wind speeds of more than 80mph, and it is likely to remain windy through the weekend. Torrential rain is also expected, with a chance of flooding in parts of western France and the north-western Iberian peninsula. Coastal inundation is also likely to be a risk along the northern Spanish and Portuguese coasts, as well as along the French coastline, with sea swell caused by strong winds and the low-pressure displacement of seawater. The rest of France could also experience heavy rain. Low-pressure systems are named when it is deemed that adverse weather warnings are necessary, and to give the public awareness and time to prepare. Meteorological agencies across Europe are grouped to produce such names, with Storm Ciarán named by the western group containing the UK Met Office, Ireland’s Met Éireann and the Netherlands’ KNMI. On the other side of the Atlantic, a chilly weather is expected to sweep the US this week, with temperatures 10-15C below the seasonal norm as a cold front spreads south. Denver, Colorado, endured a daytime maximum of about -1C (30F) on Sunday, 18C below average. Overnight lows in the Denver area on Monday and Tuesday could fall to a bitingly cold -11C, 11C below normal. The temperature will be some way off the October record, however, with -18.9C recorded in Boulder in 1917. Further south, San Antonio, Texas, is likely to peak at a meagre 9C on Monday, 16C below normal. The cold spell is expected to lift by the end of the week. South Africa and Lesotho have also been gripped by an unusually cold spell, with maximum temperatures struggling to reach double figures on Monday and Tuesday. Johannesburg is expected to reach daytime highs of about 8C, 16C below the average for late October.