Storm Claudia Delivers Additional Flooding to Portugal and Spain

Portugal and Spain are once more battling the aftermath of widespread inundation in the wake of Storm Claudia unleashed torrential downpours and strong winds over the past seven days.

The Storm's Genesis and Journey

This weather system formed from a low-pressure zone that had beforehand caused unseasonably early chilly and snowy weather through the eastern sectors of the Canadian territory and the north-eastern US at the start of November.

This storm moved eastward across the Atlantic over the second weekend of November before losing momentum and stopping to the north-west of the Iberian region, caught in the trough of an increasingly amplified atmospheric river.

Impact on Spain and Portugal

The northwestern Spanish region of Galicia was initially impacted, with a substantial 80 to 150 millimetres of rain coming down along its west coast in just 24 hours up to the evening of Wednesday as a slow-moving band of rain pushed across the western sectors of the region.

Further showers and thunderstorms on the following Thursday caused inundations to Portuguese localities where an older couple lost their lives in the capital Lisbon after floodwaters from the swollen Tagus invaded their residence as they were asleep.

Stormy conditions continued into the weekend, with a violent whirlwind tearing through a campsite and a adjacent hotel in the town of Albufeira in the Algarve region on Saturday, killing an elderly British lady and harming two dozen and eight persons.

Broader Impacts across the European continent

This system triggered more extensive impacts across the western European nations. By siphoning heated 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 late autumn reading.

By Friday, this warm and humid air mass clashed with a cold air mass across the northern areas of Europe, creating a rainfall belt running from western Ireland to the Russian Federation.

In the United Kingdom, this stationary front of rain delivered record-breaking rain accumulations, resulting in major inundations in Wales.

As this weather phenomenon continues to weaken early this week, the chilly atmospheric system will advance southward, giving Europe its initial glimpse of winter.

Simultaneous Occurrences in California, USA

The US state of California underwent an "atmospheric river" last week, delivering torrential rain and powerful winds that provoked sudden inundations and landslides in zones impacted by forest fires previously in the year.

Over two inches of rain poured down in southern California on last Friday, with a further 50mm across extensive areas of California on the subsequent Saturday.

More than 100mm of rain fell over coastal parts of southern California in total, attaining a full 200 millimetres in spots on high ground.

Such a weather system is a concentrated stream of warm, moist air coming from the tropics or subtropics.

Locations with fire damage including Palisades and Altadena experienced the most intense the sudden floods and earth movements, prompting evacuations.

Elsewhere in California, a 71-year-old man passed away after his automobile was carried away from a inundated overpass, and a young girl aged seven and her father were swept into the Pacific by large waves on the California's Central Coast.