Weather: cold snap expected Post-Easter

A weather turnaround is on the horizon after a mild climate phase that marked the beginning of spring, and a glimpse of this March that will also include next week, with temperatures above average. As March progresses and April approaches, atmospheric conditions could undergo a significant change due to the intrusion of cold air masses, presumably from the northeast. This phenomenon can be seen as a direct consequence of the collapse of the stratospheric polar vortex, an event that tends to occur every spring when this vortex begins to disintegrate.

During the spring equinox, the polar region begins to be exposed to sunlight up to the North Pole. Consequently, the ground temperature gradually starts to rise, triggering significant changes in atmospheric dynamics even in these remote latitudes, thus beginning the semester. These global climate changes are influenced by the tilt of the Earth’s axis, which varies throughout the year. In our hemisphere, we are heading towards summer, while the southern hemisphere is preparing to welcome winter.

In this context, the role of the polar vortex comes into play, which, in response to certain critical conditions, facilitates the exchange of air masses along the meridians, i.e., from south to north and vice versa. When warm air masses move north, they can trigger heatwaves that, as recently observed, lead to record temperatures. Conversely, when cold air flows from north to south prevail, cold waves occur.

The disintegration of the polar vortex does not necessarily imply the immediate appearance of a cold wave. In fact, in some regions, this phenomenon can lead to phases of extreme heat, while in others it can cause intense cold. In the coming days, it is expected that cold air masses will move towards the Canary Islands and Morocco, and temporarily even further south, blowing very hot air from the Sahara towards Italy, heralding a heatwave.

However, the transitional nature of the intermediate seasons is characterized by greater climatic variability compared to summer. Therefore, a cold air mass heading south may be followed by another cold wave capable of reaching Italy.

The likelihood of this event increases in the early days of April, more so than during the Easter holidays, a period in which weather forecasts tend to be particularly uncertain. Weather forecasts for the Easter period are among the most scrutinized of the year, given the high number of people interested in knowing whether the weather will be sunny or rainy in the places where they intend to spend the holidays or in their place of residence. The volatility of the weather conditions during that period makes the forecasts subject to frequent updates.

Therefore, the beginning of April is expected to be characterized by probable meteorological instability, with a possible intrusion of cold air. Similar phenomena, also observed in past years, have caused late frosts in the Alpine valleys and in some areas of the Po Valley, as well as in France and Germany, with harmful consequences for agriculture. These events seem to have become more intense in recent years, although the past also records episodes of late snowfalls in April. However, due to climate changes, current atmospheric events tend to manifest with particular violence and intensity, sometimes reaching record levels. Although short-term weather forecasts can be relatively reliable, long-term forecasts only offer an approximate vision of possible future conditions, subject to significant revisions.