The State Meteorological Agency (AEMET) uses a warning system to alert the population about adverse meteorological phenomena that may affect the safety of people and material assets. An adverse meteorological phenomenon is considered to be any atmospheric event that, directly or indirectly, may cause significant damage. Even phenomena that, without being dangerous, significantly alter human activity in specific areas may be considered adverse.
To manage these events, AEMET follows the National Plan for Prediction and Monitoring of Adverse Meteorological Phenomena, known as Meteoalerta. This plan aims to provide information as far in advance as possible (up to 72 hours) on the forecast of these phenomena and to offer detailed updates on their evolution once they have begun.
What is a severe weather warning?
A warning is the minimum unit of information that AEMET issues when it is predicted or observed that certain risk thresholds will be reached or exceeded in a specific area. These thresholds are defined for phenomena such as heavy rain, snowfall, strong winds, storms, extreme temperatures, coastal phenomena and more. Each warning contains key data, such as the start and end date and time, the measured or expected value of the phenomenon, warning level, probability of occurrence and whether it is a prediction or a real-time observation.
The alerts consist of the date and time of the start and end of the phenomenon, the value "expressed in the unit corresponding to the parameter and included between the thresholds of the corresponding level", alert level, probability, expected/observed indicator and comments.
Warning levels: what do they mean and how to interpret them?
The AEMET classifies warnings into four risk levels. These levels are defined according to European climatological and adverse weather criteria to facilitate interpretation. The designations and recommendations are as follows:
- Green: No risk. The weather is not expected to cause significant impacts. It does not appear on the AEMET interactive map.
- Yellow: Low risk. Although the general population is not in danger, certain activities may be affected. The recommendation issued by the AEMET in this warning is: “Stay alert. It is advisable to regularly check the weather forecast, as some outdoor activities could be affected.”
- Orange: Major risk. Unusual phenomena are expected that may be dangerous for common activities. Recommendation: “Be prepared. It is advisable to take precautions and follow the latest weather information. Daily activities may be affected.”
- Red: Extreme risk. The forecast weather phenomena are exceptionally intense and pose a high risk to the population. The entity's recommendation is: "Take preventive measures and act." It is recommended to follow the instructions of the authorities, avoid unnecessary travel and constantly check weather updates."
Special notices
In some situations, when atmospheric factors of exceptional intensity or duration coincide, or in periods of high social relevance, AEMET may issue special warnings. These are intended to emphasize the need for attention by the population, complementing and reinforcing the importance of the usual warnings of the Meteoalerta system.
