Portugal and Spain are once more dealing with the consequences of extensive flooding in the wake of Storm Claudia brought torrential downpours and strong winds last week.
The Storm's Formation and Trajectory
The storm system originated from a low-pressure zone that had earlier caused unseasonably early cold and snowy conditions through the eastern sectors of the Canadian territory and the north-eastern United States in early November.
Claudia tracked eastwards across the Atlantic Ocean over the second weekend of November before decelerating and halting to the north-west of the Iberian region, trapped within a trough of an ever more meandering atmospheric river.
Consequences for Iberia
Galicia in north-west Spain was the first affected, with 80-150mm of rain pouring down along its western coastline in just one full day up to Wednesday night as a sluggish front of rain crawled across the western areas of the peninsula.
Additional rainfall and electrical storms on Thursday led to floods to Portuguese localities where a senior pair perished in the capital Lisbon after floodwaters from the swollen Tagus entered their home as they slept.
Tempestuous weather continued into the weekend, with a tornado tearing through a campsite and a close-by inn in Albufeira in the south in southern Portugal on Saturday last week, fatally injuring an 85-year-old British woman and harming two dozen and eight persons.
Broader Impacts across Europe
The storm produced broader repercussions across western Europe. By drawing warm air from the subtropical zones, the system helped temperatures in France's south-west to 29.8C (85.6F), the nation's all-time high autumn temperature.
By last Friday, this warm and humid air mass clashed with a chilly atmospheric body across the northern regions of the continent, creating a band of rain running from Ireland's west to Russia.
In the United Kingdom, this stalling band of rain delivered record-breaking rain accumulations, leading to significant waterlogging in the Welsh region.
As Claudia loses strength in the coming days, the frigid air will move towards the south, giving Europe its first taste of colder weather.
Parallel Events in California
The Golden State encountered a plume of tropical moisture the previous week, causing heavy rain and high-velocity gusts that provoked rapid flooding and debris flows in areas affected by forest fires in the recent past.
Over two inches of rain fell in California's southern part on Friday, with a further 50mm broadly over the state on the subsequent Saturday.
Over four inches of rain fell over shoreline regions of Southern CA in total, attaining 200mm overall in spots on high ground.
Such a weather system is a plume of hot, humid air coming from the equatorial or near-equatorial zones.
Locations with fire damage including Palisades and Altadena region endured the most intense the sudden floods and landslides, forcing residents to flee.
In other parts of the state, a elderly male died after his car was carried away from a flooded bridge, and a young girl aged seven and her dad were pulled into the Pacific by large waves on the the state's central shoreline.