Between May 10 and 14, Spain experiences an episode of anomalous cold caused by a maritime polar air mass. Temperatures have dropped between 5 and 10 degrees compared to the average, with decreases of up to 15 degrees compared to the previous week. The origin is an anticyclonic ridge extending from the Azores to Greenland, diverting the polar jet stream southward. Although it is not considered a cold wave due to its duration, the event is striking after the warmest April on record.
3D visualization of the polar mass and thermal anomaly maps 🌡️
To understand the magnitude of the phenomenon, we can model in 3D the displacement of the polar air mass over the Iberian Peninsula. Using data from the State Meteorological Agency (AEMET), it is possible to overlay maps of normal temperatures against anomalous ones, highlighting the most affected areas: the upper Duero, the Iberian System, and the Central System. Here, frosts of up to -5 degrees are expected. The simulation of terrain and crops allows visualizing the impact of frost and hailstorms, helping to predict damage to vineyards and fruit trees in full bloom.
Is Arctic warming behind these undulations? ❄️
There is a scientific debate about whether accelerated Arctic warming is weakening zonal winds, favoring more pronounced undulations of the polar jet stream. Although not proven, this pattern is occurring more frequently. What is certain is that the countryside will be the hardest hit by these late frosts, which, while not unprecedented in May, are devastating for agriculture. AEMET warns that the week will likely be colder than normal, a reminder that extreme climate variability is already a reality we must integrate into our prevention models.
Considering the arrival of a maritime polar air mass in the middle of May, how can farmers and disaster experts model and predict these episodes of anomalous cold to mitigate damage to sensitive crops such as fruit trees and vineyards?
(PS: Simulating disasters is fun until the computer crashes and you are the disaster.)