Understanding Buienradar’s Forecast Discrepancies: Why +3 Hours and +24 Hours Differ
Buienradar is a beloved tool in the Netherlands, providing real-time precipitation data and forecasts that help millions plan their day. However, users sometimes notice that the +3 hour forecast and the +24 hour forecast don’t always align. This can be confusing, but it’s actually a result of how Buienradar combines different data sources. The key is that these two forecasts rely on two distinct models, each with its own strengths and limitations.
The +3 hour forecast is primarily based on real-time radar data from the KNMI (Royal Netherlands Meteorological Institute). The KNMI operates two precipitation radars, located in Herwijnen and Den Helder, which scan the skies every five minutes. This data is processed to create detailed images showing where rain is falling and how intense it is, with colors indicating intensity. Because this forecast is short-term, it can leverage the high-resolution, immediate observations from the radar, making it highly accurate for the next few hours.
On the other hand, the +24 hour forecast relies on numerical weather prediction models, which simulate the atmosphere’s future state. These models are excellent for longer-range predictions but are less precise in pinpointing exact locations and timing of precipitation. As a result, the two forecasts can diverge, especially when weather systems are fast-moving or when local conditions, like sea breezes or terrain effects, play a role. It’s important to understand that this discrepancy is not an error but a natural consequence of using different forecasting methods for different time horizons.
Buienradar remains committed to providing these forecasts for free, thanks to the support of advertising. If you’re using an ad blocker, you might be missing out on the revenue that keeps the service running. By allowing ads, you help ensure that Buienradar can continue to offer its valuable radar images and forecasts to everyone in the Netherlands. So next time you see a mismatch between the +3 and +24 hour forecasts, remember that it’s a sign of the sophisticated, multi-model approach that makes Buienradar so reliable for short-term planning and still useful for a longer outlook.
Shimanta Das 
