Brazil Heat Wave

Dear sir

I am a regular and appreciative user of Ventusky, which I find to be an excellent tool for weather visualization. However, I have encountered a significant discrepancy while trying to verify a major historical weather event, and I would appreciate your help in understanding the data source and modeling behind it.

I was researching the severe heat wave that hit Brazil in November 2023. According to official records from Brazil's National Institute of Meteorology (INMET) and Rio de Janeiro's Alerta Rio weather system, on November 12, 2023, at approximately 15:10 local time, a weather station in the Jacarepaguá district of Rio de Janeiro recorded an air temperature of 42.5°C with a heat index (feels-like temperature) of 58.5°C.

When I use Ventusky's historical data feature for the same date, time, and location (Rio de Janeiro), the application shows a temperature of around 33°C. This is a difference of nearly 10°C, which is substantial.

Could you please help me understand this discrepancy?
Sincerely,

Mouhanad

Mouhanad Ouwayed
Firstly, the archive contains data only at three-hour intervals, so it’s impossible to determine the exact time. Secondly, these are simplified gridded data. Just a few kilometers north of the given location, the map shows temperatures above 40 °C. It’s likely that the air intrusion extended further south than indicated by the reanalysis.

Ventusky
Thank you very much for your prompt and clear explanation, This was very helpful!
Best regards