Rio Grande do Sul is facing a situation of extreme concern due to adverse weather conditions that have led to exceptionally high volumes of rain in recent days. A combination of weather systems has resulted in rainfall well above average for the region, leading to flooding, rising river levels and placing several areas on high alert.
Analysis of the last few days: Unusual rains
In some places, measurements have reached levels that are almost unimaginable for this period of the year, with records that double and even triple the historical monthly averages. In the last 5 days, regions like Faxinal do Soturno, for example, saw the skies dump an impressive total of 518.4 mm of rain, while Fontoura Xavier recorded 463.4 mm and Santa Maria was not far behind, with 452.2 mm. Nova Palma, Caxias do Sul, Lajeado and Estrela also faced notable volumes, all exceeding 400 mm. But the extraordinary rain was not limited to these locations. Alto Feliz, Bom Princípio and Teutônia received accumulated amounts of around 377.6 mm, 361.8 mm and 350.0 mm, respectively. Cruzeiro do Sul and Venâncio Aires also experienced a deluge of rain, with 319.0 mm and 312.6 mm, respectively. Soledade and São Francisco de Paula saw their records reach 286.6 mm and 286.0 mm, while Caçapava do Sul and Três Coroas faced considerable volumes of 263.6 mm and 261.6 mm.
River Basin Status: Critical Levels and elevation trends
In response to this intense precipitation, the state’s rivers are experiencing rapid rise and are, for the most part, significantly above flood levels. The basins of the Caí, Taquari and Jacuí rivers, including their tributaries São Sebastião, Montenegro, Estrela and Dona Francisca, are among the most affected. In addition, the Sinos and Ibirapuitã rivers are also recording rising flood levels. The expectation is that this upward trend will continue in the coming days, considering the forecast of new heavy rainfall in the next 48 hours. This will result in significant hydrological responses in the Vales and Baixo Jacuí basins, further increasing the risks of flooding and other impacts related to rising river levels.
Figure -1 Situation of river basins in RS.
Source – Civil Defense of Rio Grande do Sul
EXTREME DANGER: Warning for heavy rain and high risks
The weather scenario for the next few days is a cause for great concern, with a tendency for rain volumes to intensify, especially from this Thursday onwards. Regions such as Missões, Vales, Metropolitana, Norte and Serrana are under the highest level of alert, indicating unusual severity. Rainfall volumes are forecast to exceed 100mm in a 24-hour period, something that represents a significant threat to public safety and the well-being of local communities. This extreme level of alert is only triggered in exceptional situations, when there is a great convergence of meteorological models. The last time this alert level was used was during the tragedy that hit the Petrópolis region, in Rio De Janeiro, this year, highlighting the seriousness of the situation and the need for urgent preventive measures.
Climatempo” src=”https://imagens.climatempo.com.br/climapress/galeria/2024/05/59e09d4458f04424d27b27b240c8c7bc.jpg” alt=”Figure -2 Thunderstorm alert map Source: Climatempo” />
Figure -2 Thunderstorm warning map
Source: Climatempo
Forecast for the next few days
On Friday (03), the combination of several meteorological systems is expected to continue favoring the occurrence of rain in several regions of the state. The storms forecast for areas such as the central region, valleys, metropolitan region, mountains and north stand out. The western region will also be affected, although with a lower intensity, characterized by cloudiness, rain and few sunlight.
On Saturday (04), the tendency for a lot of cloudiness and rain will persist in a large part of the state of Rio Grande do Sul, with a specific warning for storms concentrated in the northern part of the state. However, it is important to highlight that the intensity of rain will remain moderate to heavy in other regions.
Sunday (05), the weather pattern will continue to be influenced by the flow of hot and humid air from the central belt of the country. In the west, campaign and south regions, the condition will be very cloudy, continuous rain and few sunlight. Although there is no warning for storms in these areas, it is necessary to remain alert. In the central, valleys, metropolitan, mountain, northern and mission regions, the sun will predominate for most of the day, but the possibility of rain showers in the morning and afternoon cannot be ruled out.
