Death toll from catastrophic flooding in eastern Spain exceeds 90 » Yale Climate Connection

A series of thunderstorms hit the eastern Spanish state of Valencia and nearby areas on Tuesday afternoon and evening, causing catastrophic flooding and becoming one of the country's worst natural disasters in years. According to The Nation, at least 92 people have died as of 2:21 pm ET on Wednesday.

Some of the worst flooding occurred in outer areas of the Valencia metropolitan area. As climate scientist Erich Fischer points out, the community of Chihua, located about 20 miles (32 kilometers) inland and about 1,000 feet (305 m) from the center of Valencia, reported 160 mm of rain in just one hour ( 6.3 inches), the 343 can move 13.5 millimeters (13.5 inches) in four hours, and 491 millimeters (19.33 inches) in eight hours. Fisher noted that the widespread weather conditions during the current floods are similar to the Valencian floods of mid-October 1957, which killed 81 people and caused the diversion of the region's major rivers: “Very similar, but now happening in a climate that Warmer and wetter.

Floodwaters rushed toward the sea through narrow streets in many towns and communities in the Valencia region late Tuesday night, piling up cars and stranding people.

Warm, wet weather in the Mediterranean this autumn has exacerbated flooding. Climate Central's Climate Change Index shows that the likelihood of unusually mild temperatures on Wednesday has increased by two to three over much of northeastern Spain due to human-caused climate change, while the likelihood of unusually warm ocean surfaces in the western Mediterranean has increased by four to eight times. twice as likely (Figure 1)

While the above factors intensified the rainfall, the storm itself was triggered by a “high versus low” blocking pattern, with the lower elevations over Spain separated from the polar jet stream and the higher elevations resembling summer. More anomalously than the lower elevations, it moved from the northeast The Atlantic Ocean passes through the British Isles and pushes towards Northern Europe. Before the lockdown, temperatures across Europe were 5-20 degrees Fahrenheit (3-11°C) above average this week. A stalled pattern could bring an additional two inches (50 mm) of rain to Spain's eastern coast and near-coastal areas next weekend.

This blocking pattern resulted in a deep corridor of moist easterly winds blowing from the Mediterranean to eastern Spain, spawning a set of intense thunderstorms that moved westward but continued to regenerate near Valencia.

The ongoing high pressure features and extreme weather events occurring in Western Europe, although occurring in the autumn, are similar to summer patterns associated with climate change and are expected to occur more frequently in the future. .

Record and near-record ocean temperatures in the Northern Hemisphere this year have pumped huge amounts of moisture into the atmosphere and triggered a series of catastrophic floods. These include multiple disasters in Africa, Asia and Europe, as well as the catastrophic flooding caused by Hurricane Helene in the southern Appalachian Mountains of the United States.

According to a recent New York Times analysis, horrific flooding in Maiduguri, Nigeria, in mid-September due to unusually heavy rains in the semi-arid Sahel region and the collapse of a dam due to years of neglect, could lead to multiple Up to 1,000 people died. In the Philippines, Tropical Storm Telami caused severe flooding last week, killing at least 81 people and leaving dozens missing.

Monitoring the Western Caribbean for Patty

A large area of ​​low pressure will develop over the southwestern Caribbean Sea over the next few days and may produce named storms in the Atlantic next week. Conditions in the area were generally favorable for development, with wind shear of 10-20 knots, a moist atmosphere and sea surface temperatures near 29°C (84°F), about 0.5-1.0°C above average.

GFS and European models have varying degrees of enthusiasm about the possibility of the next named storm developing here this season, with the latest forecasts being rather bleak on the outlook. Any storms that develop are likely to move north and then northwest, potentially bringing heavy rain to much of the western Caribbean and adjacent land areas next week.

In its Tropical Weather Outlook, released at 8 a.m. ET Wednesday, the National Hurricane Center gave the probability of a disturbance developing to 0 percent within two days and to 40 percent within seven days. The next name on the Atlantic storm list is Patty.

The harsh environment of the Gulf of Mexico

If future Patty ends up in the Gulf of Mexico, it will develop in much worse circumstances than the two recent catastrophic hurricanes Helen and Milton in the Gulf of Mexico. In recent weeks, recurring fall cold fronts have spread cold air over the bay, causing the water to cool significantly. More importantly, the jet stream has moved further south, which will bring strong wind shear and accompanied by dry air, making it difficult for tropical cyclones to strengthen in the Gulf area.