In the coming days, the polar jet current will undergo a significant change in its dynamics over Europe, leading to amplification of its ripples. This phenomenon may result in the arrival of depression valleys and depressions isolated at altitude to Portugal, influencing the state of time in early February.
Changes in atmospheric dynamics
The last weeks have been marked by Atlantic storms that impacted Portugal and other European countries. Systems such as Garoe, Éowyn, Herminia and Ivo were intensified by a very active jet stream and high thermal contrasts between polar and subtropical air masses over the North Atlantic.
However, the recent Ivo storm presented a different behavior from the previous ones. Although it had a rapid development, it did not have such a pronounced intensification. His passage originated a more sharp descent of temperatures and an atmospheric dynamics that begins to modify.
The role of the polar jet
The polar jet, a very strong wind chain located between 9 and 16 km altitude, is becoming more irregular. Although it remains strong about the Atlantic, its trajectory will be more wavy, giving rise to anticyclonic crests in the highest latitudes and favoring the displacement of depression valleys to lower latitudes. This configuration will be more evident during the first week of February 2025.
Impact expected in Portugal
With this change, the depressions that will affect Portugal will be weaker than the previous ones, resulting in a reduction in wind intensity and less persistent precipitation. However, a descent of the minimum temperatures is expected, increasing the likelihood of frost in the north and center, particularly in the districts of Vila Real, Viseu, Bragança and Guarda.
For Sunday, February 2, the arrival of a little intense depression valley, accompanied by a front of weak activity, is scheduled to arrive. According to Alfredo Graça, from Portugal, it could generate weak and irregular precipitation, as well as the possibility of snowfall in the highest areas of the country’s mountains.
POSSIBILITY OF ANTICICLONIC BLOCK
Another relevant factor for the next few days will be the positioning of anticyclonic crests in more northern latitudes. If an anticyclone of blockade is consolidated in northern Europe, atmospheric circulation may be altered, leading to retrograde flows that would carry cold air to the east of the continent and to the Eastern Mediterranean.
If this pattern persists, cold air masses may move to the Iberian peninsula, significantly altering the weather panorama. In the short term, Portugal will no longer be exposed to the classic Atlantic circulation, making the meteorological predictions more complex and subject to greater uncertainty.
Continuous monitoring of this scenario will be essential to assess the impact of changes in the jet current and eventual repercussions on the state of time in Portugal and Europe.
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