IMGW issues first-degree thunderstorm and wind warnings across 11 Polish voivodeships, with flood alerts in the north

Overview

Poland's Institute of Meteorology and Water Management has activated first-degree warnings for almost the entire northern half of the country, plus parts of central and eastern regions. The alerts cover two distinct windows: Sunday afternoon through late evening for thunderstorms, and a separate strong-wind event on Monday along the Baltic shoreline. First-degree is the lowest of three warning levels but still signals conditions that may cause property damage and threaten health and safety.

Where the storms will hit

Thunderstorm alerts are in place for all of Zachodniopomorskie, Pomorskie, Warmińsko-Mazurskie, Podlaskie, Kujawsko-Pomorskie and Mazowieckie, as well as portions of Lubuskie, Wielkopolskie, Łódzkie, Świętokrzyskie and Lubelskie. Within these areas, forecasters expect intense bursts of rain delivering 15–25 mm of precipitation, with isolated totals around 30 mm. Wind gusts may reach 75 km/h and hail is possible locally. The Sunday warnings are timed from 11:00 to 23:00, while a narrower set of Monday thunderstorm warnings will remain active until 23:00.

Northern belt under additional strain

Coastal and near-coastal districts face a more complex threat. Separate level-one warnings for heavy rain with embedded storms apply to parts of Pomorskie and Zachodniopomorskie until 20:00 on Sunday. These zones could see up to 45 mm of rain, accompanied by wind gusts to 70 km/h and small hail. Once the rain clears, a strong-wind event takes over: from 07:00 to 19:00 on Monday, the western coast (counties including Gryfice, Kołobrzeg, Koszalin, Sławno, Słupsk, Lębork, Wejherowo and Puck) will experience sustained westerly winds averaging 40 km/h, with gusts again hitting 75 km/h.

Rivers on the rise

Hydrologists have placed the same northern counties under a first-degree flood watch until 21:00 on Sunday. The warning states that the forecast bursts of rain—especially those of a stormy character—are expected to push river levels higher, with a local risk of breaching warning marks.

“Due to forecasted intense rainfall, including of a storm nature, rises in water levels in rivers are expected, locally with the possibility of reaching warning levels. In areas of forecasted storm rainfall, on smaller rivers, especially in urbanized catchments, rapid rises in water levels and flooding may occur.”

What a yellow alert means

A meteorological first-degree warning indicates conditions that favour dangerous phenomena capable of causing material losses and posing a risk to health and life. Outdoor activities become difficult and hazardous; the public should expect disruptions to road traffic, possible cancellation of open-air events, and should monitor weather updates closely. A hydrological first-degree warning means that observed or forecast water levels are below warning thresholds but may briefly touch or exceed them locally.