# KNMI weather forecasting updates and technical challenges > Developing situation record from CLSTR: https://clstr.news/situations/knmi-weather-forecasting-updates-and-technical-challenges > Updated: 2026-11-07T16:23:23.000Z. Sources: 6. Developments: 4. The Royal Netherlands Meteorological Institute (KNMI) is implementing changes to its warning systems and addressing technical disruptions to its radar capabilities. Following legal approval received in May, the KNMI officially transitioned to a localized weather warning system on November 2, 2026. While maintaining the existing color-coded scale of yellow, orange, and red, the institute has moved away from issuing warnings for entire provinces. Instead, alerts are now issued for specifically defined regional zones to better reflect localized weather patterns, such as thunderstorms or sea fog, which may affect one area while leaving a neighboring area unaffected. This shift allows emergency responders, such as the Amsterdam-Amstelland safety region, to engage in more targeted preparations. Additionally, improvements to the KNMI app now allow users to zoom in for more detailed local forecasts. On November 7, the KNMI issued its first regional yellow weather code, specifically targeting dense fog in parts of southern Utrecht, northern North Brabant, Gelderland, and South Holland. Meteorologist Peter Kuipers Munneke noted that the new approach improves credibility, as previous protocols would have required issuing warnings across four entire provinces for the same localized event. Simultaneously, the KNMI weather radar in Herwijnen is facing inaccuracies in precipitation forecasts for a corridor stretching toward Germany, including areas between Arnhem, Nijmegen, and Doetinchem. These errors are attributed to a row of fast-growing poplar trees obstructing the radar. Local authorities in West Betuwe cannot currently prune or remove the trees due to environmental protection laws, as ecological research is investigating whether the trees serve as a protected foraging area or flight route for bats. To mitigate these inaccuracies, the KNMI is utilizing higher-altitude radar scans and incorporating data from radars in Belgium and Germany. ## Timeline ### 2026-11-07: KNMI issues first regional yellow weather code for fog The KNMI has issued its first regional yellow weather code for dense fog in parts of Utrecht, North Brabant, Gelderland, and South Holland, replacing the previous province-wide warning system. 2 sources. https://clstr.news/cluster/knmi-issues-first-regional-yellow-weather-code-for-fog ### 2026-11-03: Netherlands KNMI implements localized weather warning system The Royal Netherlands Meteorological Institute is replacing province-wide weather alerts with localized regional warnings to provide more accurate, area-specific information for residents and responders. 2 sources. https://clstr.news/cluster/netherlands-knmi-implements-localized-weather-warning-system ### 2026-10-31: KNMI weather radar in Herwijnen disrupted by trees and bats Trees near the KNMI weather radar in Herwijnen are causing precipitation forecast errors, but environmental laws regarding protected bat habitats are delaying any pruning or removal of the trees. 2 sources. https://clstr.news/cluster/knmi-weather-radar-in-herwijnen-disrupted-by-trees-and-bats ### 2026-10-22: KNMI to implement localized weather warnings in the Netherlands From November 2026, the KNMI will issue more precise, localized weather warnings in the Netherlands, moving away from broad provincial alerts to better reflect specific weather impacts. 4 sources. https://clstr.news/cluster/knmi-to-implement-localized-weather-warnings-in-the-netherlands --- Cite as: KNMI weather forecasting updates and technical challenges. CLSTR, https://clstr.news/situations/knmi-weather-forecasting-updates-and-technical-challenges