Summer is losing ground: a storm front is approaching the Balkans and Greece

Powerful cold frontwhich meteorologists have already named “summer-killer pattern”dramatically changes the weather in Europe, but in Greece transition from summer to autumn will be much softer and will begin primarily from the western and northwestern regions.

Term summer-killer pattern – literally “weather pattern killing summer” — uses in his latest analysis Severe Weather Europe.

We are talking about a powerful high-altitude trough that emerges from the North Atlantic and destroys the dome of abnormally warm air that has formed over Europe.

A cold front collides with a very warm and moist air mass, and it is this combination that creates the conditions for severe thunderstorms, downpours, hail and squally winds.

Where is the biggest impact expected?

The main danger zone on Wednesday and Thursday will be north of Greece.

According to Severe Weather Europe, the most severe conditions are expected in:

• northern Italy;
• Alps region;
• Slovenia;
• Croatia;
• northern Adriatic;
• parts of the Western Balkans.

Supercell thunderstorms, large hail, squalls and very heavy rainfall are forecast in some areas.

On the coasts of Liguria, the northern Adriatic and the northwestern Balkans, locally estimated precipitation amounts can reach 150–200 mm in two days.

Why the Mediterranean Sea Intensifies Thunderstorms

A special feature of the current situation is the very high water temperature in the Mediterranean Sea after a long hot summer.

The warm surface of the sea saturates the lower layers of the atmosphere with moisture.

When significantly colder air arrives from above, vertical instability increases sharply.

That is why the beginning of autumn in the Mediterranean often becomes a time of particularly strong thunderstorms and downpours.

Severe Weather Europe estimates the potential convective energy of the atmosphere in the most unstable areas in 3000–4000 J/kg – this is a very high indicator, allowing powerful thunderstorm systems to form.

What will happen in Greece

And here it is important not to automatically transfer the European forecast to the entire territory of Greece.

So far, there is no reason to talk about a sharp transition across the country to cold and stormy weather on Thursday.

It is most likely that the western regions will be the first to feel the impact of the system:

• Ionian Islands;
• Epirus;
• western part of Central Greece;
• certain areas of northern Greece.

Here, as the front approaches, cloudiness and the likelihood of rain and thunderstorms will increase.

For example, current forecast meteo.gr for Ioannina shows on Thursday until +32 °C during the day, but by the evening – light rain, and later rain.

Summer isn’t over yet in Athens

For Attica the situation looks completely different.

According to the current forecast for Thursday, September 10in Athens the weather is expected to be mostly sunny and temperatures around +32 °C.

That is, the formulation “abrupt end of summer from Thursday” is clearly premature for Athens at the moment.

The south and east of the country will remain in the warm sector ahead of the front for some time.

Moreover, southerly flows before an approaching cyclone are capable of temporarily maintaining a fairly high temperature.

Why the forecast may still change

For Greece, the exact position of the secondary cyclone, which forms over the northern Mediterranean Sea and then should move towards the Balkans, remains critical.

Shifting its trajectory by just a few hundred kilometers can significantly change the picture.

If the system moves further south, the zone of heavy precipitation could enter deeper into Greece.

If the cyclone passes further north, the strongest phenomena will remain in the Adriatic and the western Balkans.

The real cold will come later

The main cold air after the passage of the front will first leave through Central Europe and the Balkans.

There the temperature in some places can plummet to 15–20 degrees in less than 24 hoursand even the first serious snow is expected in the highlands of the Alps.

In Greece, the temperature decline should be significantly more gradual.

But in the second half of September, increasingly frequent penetrations of cool air will gradually return the temperature to normal seasonal values.

What is important for the people of Greece

For the next few days the picture looks like this:

• Athens, Attica, Aegean Sea: While warm and mostly dry weather continues;
• west of Greece: the likelihood of precipitation begins to increase from Thursday;
• Epirus and northwest: the most likely first zone of rain and thunderstorms;
• north of the country: the situation will depend on the trajectory of the front;
• end of week: the forecast needs to be updated as the system approaches.

Sources: Severe Weather Europe, ΕΜΥ – National Meteorological Service of Greece, meteo.gr / National Observatory of Athens.

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