HDWN #63

September 15, 2023
3-5 minutes

Flooding in Greece

Greece was recently hit by flooding on an unprecedented scale, with rainfall reaching 600-800 mm in just 24 hours in the mountainous region of Magnesia, in the center of the country. This meteorological catastrophe, described by experts as unprecedented, had devastating consequences.

The heavy rainfall caused by storm Danielle, which also affected Bulgaria and Turkey, caused extensive material and human damage, with a death toll of 15 as of September 10.

The phenomenon also caused major damage, with flooding, collapsed bridges, destruction of the road network, drowning of animals and beehives swept away by the raging waters. Thousands of hectares of crops were also swallowed up by water and mud, leaving farmers in a critical situation.

Damage to the water supply infrastructure, particularly in Volos, made the situation critical, exacerbating the difficulties faced by residents in coping with the disaster.

In all, more than 4,250 people have been rescued and brought to safety since the onset of the bad weather, according to the Greek fire department.

Devastating rains in Libya

After hitting Greece, Bulgaria and Turkey, storm Danielle hit Libya hard this week. The torrential rains caused catastrophic flooding, notably in the city of Derna.

According to Libya's National Meteorological Center, the flooding was the result of torrential rains of rare intensity, with rainfall accumulations ranging from 150 to 240 mm. The absolute record was set in Al Bayda, where a daily rainfall rate of 414.1 mm was measured.

The floods took a heavy human toll, with over 3,800 confirmed deaths, according to the spokesman for the Ministry of the Interior of the government in power in the east of the country. To this must be added more than 5,000 people still missing and around 7,000 injured, according to the emergency services.
An immediate international response was taken by countries such as France, Egypt and Turkey, which offered aid to Libya. The European Commission also reacted by announcing the dispatch of vital aid from Germany, Romania and Finland to the city of Derna. This assistance is part of the EU's civil protection mechanism.


Heatwave in the UK

A late heatwave swept across the UK, breaking records for the warmest September on record. On Saturday September 09, thermometers rose to 33.2°C at Kew Gardens in London, setting the highest temperature of the year so far.

This was followed by a week in which temperatures hovered around or above 30°C for seven consecutive days - an unusual length of time for September and a record.

The UK's national weather agency, the Met Office, pointed out that this heatwave was the longest ever recorded for a month of September. The records were relayed on social networks, with a maximum temperature of 32.5°C recorded in Cambridge on Sunday September 10. The last time such heat was recorded in September was in 2016, when the Kent region in south-east England reached a peak of 34.4°C.

Prior to this recent spell of exceptional heat, the Met Office noted that the record for the duration of a September heatwave was just three days, dating back to 1906, with a peak of 35.6°C recorded in South Yorkshire, northern England.

Torrential rain in Hong Kong

ⓒ Tyrone Siu, Reuters

Hong Kong was confronted with historic rainfall related to the passage of typhoon Haikui last week, recording the heaviest rainfall ever recorded since weather records began in 1884. The torrential downpours caused flooding and disrupted city activities, less than a week after the passage of a super typhoon.
The Hong Kong Observatory, the city's meteorological agency, measured an impressive 158.1 millimeters of rain in a single hour, a level unprecedented in nearly 140 years of records. The massive downpour forced the authorities to take immediate action, including closing schools due to the extreme weather conditions.
In the space of 24 hours, Hong Kong was subjected to an impressive amount of precipitation, reaching a total of 600 mm of water, equivalent to 600 liters of water per square meter. This represents a quarter of the region's average annual rainfall, according to data provided by the Hong Kong Observatory, the city's meteorological agency.

Faced with this exceptional weather situation, the authorities decided to activate a black alert, the highest level of alert, and urged residents to stay at home for their own safety.

Storms in the Pyrénées-Orientales region

Violent thunderstorms broke out in the Pyrénées-Orientales region on Tuesday September 12, causing considerable damage. The first signs of weather disturbance appeared in the Estagel area in mid-afternoon. Subsequently, the Rasiguères and Latour-de-France areas were the first to experience hail showers, already causing some damage.
After 6 p.m., a large part of the Pyrénées-Orientales region was hit by torrential rain and hail.

The Thuir - Trouillas area was particularly hard hit in the early evening, with roads cut off and traffic problems spreading around Thuir. The violent winds were remarkable, reaching peaks of up to 118 km/h in Sainte-Colombe-de-la-Commanderie. Hailstones, some measuring up to five centimetres in diameter, caused significant damage, particularly in the Canohès area.
The most impressive rainfall total was recorded in Thuir, where no less than 111 mm of rain fell, the equivalent of four months' rainfall in a single night.