Lower Genoese Boris. “Miniature tropical cyclone” is getting closer to Poland. How will it mess up the weather?

In southern Poland, preparations are underway for the arrival of a wave of rainfall associated with the Genoese low Boris. IMWM issued meteorological and hydrological warnings, and four provinces are also in force RCB alert.

As explained by tvnmeteo.pl weather forecaster Arleta Unton-Pyziołek, although the rainfall is relatively light at the moment and the rain accumulation has decreased, the next few hours will not treat us gently at all. The greatest threat is still forecast for regions located along our southwestern and southern border, from Lower Silesia to part of Małopolska. There, the total rainfall may reach 200 liters per square meter.

– There is a lot of talk about the situation we are dealing with being reminiscent of 1997. Indeed, this is a classic flood situation in Central Europe – she said. – In 1997 (…) on Mount Pradziad in the Jeseníky Mountains, a total of 455 l/m2 fell, and we saw the effects. This year, there is supposed to be slightly less rain in this region. The optimistic scenario assumes (…) about 250 liters, while the Czechs assume that in the pessimistic scenario it will be 355 liters.

The weather forecaster explained that such rainfall amounts are recorded in the region on average over half a year. In just four days, rivers and reservoirs will have to absorb a huge amount of water.

According to weather forecasters, natural green areas should be well prepared for such a large amount of rain. The fact that most rivers have been low for weeks and their channels practically empty has also proved to be a saving grace. Current forecasts indicate that although we are unlikely to see a repeat of 1997, some regions affected then may again come close to danger.

– There will definitely be some destruction – Unton-Pyziołek said. – Please remember that if up to 150, 200 liters of water fall on the catchment areas of mountain and foothill rivers, the reaction will be quick, this water will overflow from the riverbeds.

The most difficult situation is predicted in the catchment areas Nysa Łużycka to the areas feeding the Nysa Kłodzka. It can also be dangerous in Wroclawthrough which not only water from precipitation over Poland will flow, but also from the Czech tributaries of the Oder, including Opava.

The weather forecaster drew attention to one more issue. The Genoese low Boris, which will bring us downpours, formed in specific conditions – over water with a surface temperature of 27 degrees Celsius. At such temperatures, tropical cyclones form.

– The Genoese low is a miniature tropical cyclone – she said, adding that rainfall will not be its only manifestation. – In Poland, we expect wind gusts of up to 60-80 kilometers per hour, in the Czech Republic over 100 kilometers per hour. (…) Trees, weakened by the downpours, will be exposed to strong wind gusts.

Things will start to get dangerous in Poland on the night from Friday to Saturday, when the downpour zone will cover the Sudetes and the Kłodzko Valley. On Saturday, the center of gravity of the rain will move slightly to the east, over Upper Silesia and Małopolska, where it will stop for a while, bringing more water. The good news, however, is that the downpour zone will be mobile, and the heaviest rain will occur in different regions with different intensity.