Poland under storm warnings as low Cerry sweeps east; temperatures to hit 31°C by month's end

Stormy Tuesday across Poland

Low-pressure system Cerry, with its centre moving from the Baltic Sea toward Lithuania, will dominate Poland's weather on Tuesday, 21 July. The associated occlusion front and a broad band of spiralling clouds will bring heavy cloud cover with occasional clear spells, especially in the south and west. Scattered showers are expected mainly in the northern half of the country, with thunderstorms forecast for Gdańsk Pomerania, Warmia-Masuria, Podlaskie, and northern Mazovia. Rainfall totals in these areas will reach 15–20 mm, and locally up to 30 mm in the Suwałki region. Maximum temperatures will range from 15°C in the northeast and foothill areas to 22°C in the southeast, while the west may see 21°C. In Warsaw, atmospheric pressure at noon will be 1002 hPa and is expected to rise.

Poland remains in a mass of cold Arctic air, which, however, will ease slightly in the west with clearing skies, and temperatures will exceed 20 degrees Celsius in the afternoon.

Warnings and wind hazards

The Institute of Meteorology and Water Management (IMGW) has issued first-degree warnings for thunderstorms and strong winds. Thunderstorm warnings cover the eastern half of Warmian-Masurian and the northern half of Podlaskie from 11:00 to 20:00, with rainfall up to 20 mm (locally 30 mm), wind gusts to 60 km/h, and small hail. Strong wind warnings are in effect for the coastal counties of Pomeranian Voivodeship from midnight to 14:00, with average wind speeds up to 50 km/h and gusts reaching 80 km/h from the northwest and north. On the Baltic Sea, storm warnings are active for the southeastern part, where gusts may hit 9 on the Beaufort scale (76–87 km/h). In the mountains, gusts will reach 55 km/h in the Tatras, 60 km/h in the Bieszczady, and 80 km/h in the Sudetes. The strong onshore wind may also cause water levels to rise to high-water zones, locally exceeding warning levels, before easing in the afternoon as the low moves away.

Cool midweek with more rain

Tuesday night into Wednesday will see decreasing cloud cover, though more clouds will linger in the north, northeast, and initially the southeast, with scattered showers. Minimum temperatures will drop to 9°C in the east and central regions, and up to 16°C locally on the coast. On Wednesday, a new low-pressure system, Deborah, moving from the Norwegian Sea, will push a cold front into Poland from the west. This will bring cloudy skies to the west and north, with rain up to 5 l/m², while the rest of the country remains sunny and dry. Maximum temperatures will reach 19°C in the north, 21–22°C in the centre, and 24°C in Podkarpacie. Winds will be moderate to strong from the west. Thursday will be cooler, with moderate to heavy cloud cover, thunderstorms possible especially in the east, and rainfall of 10–20 l/m². Highs will only reach 17°C in Lower Silesia, 19°C in the centre, and 20°C in the southeast. Winds will shift to southwest and west, becoming gusty in storms.

Warm-up on the horizon

The cool spell will not last. From Sunday, 26 July, a significant warm-up is forecast, with temperatures climbing to around 30°C. The hottest days are expected at the end of the month, on 29 and 30 July, when thermometers may show up to 31°C in places, according to IMGW. This sharp shift from stormy, cool conditions to summer heat will mark a notable change in Poland's weather pattern.