The Azores High, which has risen as far as Norway, almost touching the vast dome of the Russian High, has been the dominant pressure system over the Mediterranean in recent days. It is undoubtedly something significant, as it is rare to see on weather charts (Like the one from February 6th attached) such a vast connection between the two main anticyclonic systems affecting Europe, effectively diverting Atlantic disturbances on their path from Canada towards our latitudes.

However, this succession of stable and sunny days will experience a first setback this weekend, when the deepening of a Mediterranean low, drawing in very cold air from northern Europe, will lead to increasingly unsettled weather over our seas. In the second chart attached to this article (showing the forecast for Sunday at 12 UTC) you can observe the aforementioned Mediterranean low centered over the Sardinian Channel.

Bracknell_06Feb (credit UK Met Office)

While it may seem like a “minor” system compared to the massive Atlantic cyclones, it should not be underestimated. The associated wind circulation will reach gale force over Provence and several areas of the Tyrrhenian Sea, while precipitation will be abundant and snowy over northern regions and take the form of strong thunderstorms over Sicily and the Ionian Sea.

The educational value of this chart lies precisely in this: in the Mediterranean, so-called “minor” low-pressure systems should never be underestimated. While they may not immediately stand out to an untrained eye at the forecast scale used by the Met Office, they are nonetheless significant weather systems that require close monitoring and, if necessary, a more detailed modeling approach.

Did you notice the pressure value of this depression? 1022 hPa, a value so high that it might initially seem incorrect. However, bear in mind that a depression is defined in relative terms, relative to its surrounding environment, which in this case is strongly anticyclonic, with pressure values reaching 1030 hPa over the Alps and east of the Balkans.

What does the future hold? A highly dynamic February, with renewed instability along the edge of this vast anticyclone, which seems likely to remain centered over the Scandinavian Peninsula for many days, channeling Arctic air into the heart of the Mediterranean.

Casarino Alessandro – Navimeteo