Brazil’s central and southern regions brace for intense storm activity this week

Isolated storms are forecast in various regions of Brazil over the next several days as November concludes. These storms, ranging from moderate to severe in intensity, are linked to the presence of hot and humid tropical air, which is creating atmospheric instability.

The regions most at risk include the South, Central-West, and Southeast, where daytime heating and atmospheric conditions will favor storm development.

The storms are expected to develop primarily in the afternoon and evening. This pattern, driven by rising air (convection) caused by daytime heating, results in the formation of large vertical clouds such as Tower Cumulus (TCu) and Cumulonimbus (Cb), which can reach heights exceeding 10 km (6.2 miles). These clouds often produce localized thunderstorms that, although isolated, may be intense.

High temperatures and increased humidity act as fuel for these storms. Low atmospheric pressure further increases the potential for severe weather. On hotter days, the likelihood of thunderstorms rises, provided the air is not excessively dry. This week, atmospheric instability across Brazil’s Central-South regions is expected to result in a higher frequency of these localized weather events.

Instability will be most pronounced in the latter half of the week and during the weekend. The states most at risk for severe storms include:

• South Region: Northern areas of Rio Grande do Sul, Santa Catarina, and especially Paraná are likely to experience strong isolated storms later this week.
• Southeast Region: São Paulo is at heightened risk, particularly on Thursday and Friday. On Thursday, extreme heat with temperatures expected to exceed 35 °C (95 °F) in Greater São Paulo, combined with rising humidity, is likely to trigger strong storms in the afternoon and evening. The risk increases on Friday, with forecasts predicting multiple storm cells capable of heavy rainfall.
• Central-West Region: States in this region are also at elevated risk as atmospheric instability builds.

Central-South states are likely to experience strong wind gusts, hail, and lightning. The most significant risk is localized heavy to torrential rainfall with very high volumes over short periods.

References:

¹ CENÁRIO DE RISCO: TEMPORAIS ATINGEM VÁRIOS ESTADOS NOS PRÓXIMOS DIAS – Metsul – November 27, 2024

Rishav Kothari

I am an Assistant Editor and Severe Weather & Science Journalist at The Watchers, specializing in real-time severe weather coverage, geophysical event reporting, and research-driven scientific analysis. You can reach me at rishav(at)watchers(.)news.

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