Fire damage in Spain visible from satellite, meteorological agency warns

France is facing a new type of threat during forest fire suppression—pyrocumulonimbus (pyroCb), also known as 'fire clouds.' This phenomenon arises from extreme forest fires and has the potential to worsen already dangerous conditions because it generates its own wind and even lightning, which can trigger new fire outbreaks.

Characteristics and impact of pyroCb

NASA explains that pyroCb is a serious meteorological phenomenon that is not well understood or predicted. It is caused by large and intense fires against a backdrop of unique weather conditions. These clouds, formed by combustion, are linked to extreme fire behavior, which complicates firefighting efforts and can lead to the destruction of settlements. Furthermore, pyroCb are capable of ejecting volcanic smoke plumes into the stratosphere, which can remain there for over a year, alter stratospheric circulation, increase the duration and size of the Antarctic ozone hole, and affect the Earth's radiation balance.

Comparison and scientific explanation of the phenomenon

Although similar phenomena occur relatively frequently in California, Australia, and Portugal (at least after the 2017 fires in Pedregulho Grande), they are rare in France. Previously, they were observed south of Bordeaux in 2022, but only briefly, reported researcher Jean-Baptiste Philippi to AFP. The scientist specified that pyroCb begins as a small white cumulus cloud, formed by the transformation of water vapor into tiny droplets. As the soil heats up under the sun, the vapor condenses suddenly.

The cumulus cloud transforms into a much larger one containing thousands of tons of suspended water. Then, when the surrounding air heats up sufficiently, a hammer-shaped column forms—a cumulonimbus. This condensation further saturates the air and generates energy, creating updrafts exceeding 150 kilometers per hour. Rain follows, but the water evaporates before reaching the ground.

Stance of services and climate influence

Deputy of the National Federation of Firefighters of France (FNSPF), Lieutenant Colonel Eric Brocardi, confirmed that this is 'something unprecedented in France,' told The Guardian. He explained that the extremely high temperature of the soil in the center of the fire rises in a column, meeting colder air masses above. This contact generates a pyrocumulonimbus—or fire cloud, albeit without moisture. The smoke cloud creates its own meteorological system, causing everything in its path to spontaneously ignite. Lightning occurs inside the cloud, striking embers on the ground and further fueling the fire.

Philippi also pointed out that global warming is the cause of these cloud formations, as 'one of the consequences of global warming is an increase in the frequency of heatwaves.' He noted that while storms are common in the region, the combination of weather conditions after three consecutive heatwaves is unprecedented.

Unpredictability and fire fighting

The danger of fire clouds lies in their unpredictability. The researcher reminded that meteorological services can forecast storms, but since these storms localize directly over the fire, knowing the exact location of the fire in advance is impossible. One can predict the conditions leading to fires, but not their precise location. The main problem is unpredictability. The fire in the Gironde region, southwest of France, initially moved from the north, then from the west, then from the south, then from the east, and then again from the south and west. Additionally, there is potential energy in the atmosphere that locally pulled embers and carried the fire further. Local conditions became catastrophic, and the rate of fire spread was astonishing.

Rio Grande do Sul began the week under a yellow alert issued by Inmet, forecasting adverse weather conditions for all of Monday, the 27th. Forecasts indicate the occurrence of heavy rains, strong winds, and the possibility of hail throughout the state territory.

Rain and Wind Forecast

According to information from the National Institute of Meteorology (Inmet), precipitation may reach between 20 and 30 millimeters per hour, potentially reaching 50 mm throughout the day. Winds are expected in the range of 40 to 60 km/h. The yellow alert signals potential danger, while subsequent levels on the Inmet scale are orange, indicating danger, and red, representing great danger.

Potential impacts associated with this alert include a low risk of electricity supply failures, possible damage to crops, falling tree branches, and localized flooding.

Flood Risk Persists

Additionally, the state maintains an active orange alert for floods until Wednesday, the 29th. Specifically, two regions received a red alert, covering locations such as Uruguaiana, Alegrete, São Gabriel, Rio Pardo, and Canoas. There is also a possibility of rising water levels in the Uruguay, Jacuí, Sinos, Ibirapuitã, Santa Maria, Ibicuí, and Quaraí rivers.

Civil Defense Monitoring

The Civil Defense of Rio Grande do Sul operates with a five-level warning system: green for normal conditions, yellow for attention, orange for alert, red for flooding, and purple for extreme flooding. Authorities recommend that the population follow official updates during the period of instability, as alerts were released by both Inmet and the agencies responsible for climate monitoring in the state.