While some weather apps and websites are boldly predicting temperatures soaring well above 30°C (86°F) next week, the Czech Hydrometeorological Institute (ČHMÚ) cautions that the reality may be more nuanced. The meteorological situation remains particularly complex, especially from Friday onward.
Until Thursday, weather patterns appear relatively stable and predictable. However, a significant temperature boundary forming across Central Europe introduces considerable uncertainty into forecasts. “The exact position of this boundary remains unclear, which explains the enormous variation in predicted temperatures for our region from Friday onward,” explains ČHMÚ in their recent statement.
Weather apps typically display what meteorologists call “deterministic calculations” from numerical models, which can be misleading for longer-range forecasts. This explains why some sources might be promising scorching temperatures. To address this uncertainty, meteorologists run multiple calculations with slightly different initial conditions—known as ensemble forecasts—to gauge the range of possible outcomes.
The contrast in predictions is striking: the American GFS model’s main calculation shows temperatures exceeding 35°C (95°F) in many parts of the Czech Republic by Sunday, while the average of all calculations from the same model suggests a more moderate 29°C (84°F). The official ČHMÚ weekly forecast aligns more closely with this average, predicting maximum temperatures between 26°C and 31°C (79-88°F) from Saturday through Monday.
This significant model divergence begins as early as Friday, with some forecasts showing temperatures well above 30°C while others suggest a more comfortable 25°C (77°F). As ČHMÚ meteorologists pragmatically conclude, “What can we do? We must wait for further model calculations that will gradually clarify the situation.”