Croatia set to feel effects of rare spring polar vortex shift this April

The polar vortex, the vast circulation of cold Arctic air that dominates winter weather in the Northern Hemisphere, is entering its final seasonal phase. Although the system normally weakens in the upper atmosphere as spring arrives, meteorologists say its lingering influence could still bring colder spells across parts of Europe, including Croatia, during April.

Weather analysts note that the vortex is currently breaking down in the stratosphere due to seasonal warming. However, its core remains active in the lower layers of the atmosphere, meaning bursts of colder Arctic air can still move southwards before the pattern fully disappears, Severe Weather Europe writes.

In practice, this means that spring across Europe may still see occasional returns of cooler weather, and in some areas even late-season snowfall.

April has started relatively calmly across much of Europe, including Croatia, with temperatures close to or slightly above the seasonal norm.

The milder conditions are the result of strengthening high-pressure systems and gentle westerly and southerly airflows. These patterns have brought largely stable weather across central Europe, while parts of southeastern Europe, including areas of the Balkans, may see more unsettled conditions due to nearby low-pressure systems.

Cooler change expected in mid-April

Forecast models suggest that the weather pattern could shift during the second week of April. A combination of low-pressure systems and a strengthening high-pressure area over northern Europe may allow colder air to spread across much of the continent.

Temperatures in some regions of Europe could fall 5°C to 10°C below seasonal averages.

While this would not bring true winter conditions, it could result in noticeably cooler days for the time of year.

Croatia could also experience a brief drop in temperatures if the colder air mass spreads further south, particularly in inland areas. This may bring a more unsettled spell with increased cloud, rain and possibly cooler nights.

At the same time, rainfall patterns are expected to shift, with central and western Europe seeing above-average precipitation, while northern areas remain drier under persistent high pressure.

As April moves into its second half, the remaining core of the polar vortex is expected to weaken further, allowing temperatures to gradually recover across much of Europe.

However, long-range forecasts suggest the potential development of high-pressure blocking patterns, which can create more variable weather conditions.

During the third week of April, a low-pressure system approaching from the northwest could influence weather across parts of Europe. Warmer conditions may continue in northern regions, while southern and central areas, including parts of the Balkans, could see temperatures closer to or slightly below average.

Meteorologists stress that long-range forecasts remain uncertain, but the lingering influence of the polar vortex suggests that spring may still deliver a few surprises.