Storm in Poland – as expected as summer break. Why repeatedly July and August?

July and August are the happiest months for polish kids when they look into the calendar. With the end of June they begin the summer break. For their guardians it is relax time too – they usually take time off in their activity cause it is excellent occasion to use break in Poland. There is only one unknown – local climate.
That mentioned few months are the moment, when in Poland happens the highest temperature is deeply warm.

Lightning

Autor: David Prasad
Źródło: http://www.flickr.com
Generally, after week with 30-35 Celsius degrees warm wind near the Earth connect with cooler wind forthcoming from northward. Together it is create colossal, a few days long gale with lightning. The biggest storms in polish past times occurred over 80 years ago. First one in July 1928 over Warsaw and nearby towns. That gale causes enormous material losses.

There is no summary info but regional newapapers broke the news about 62 casualties, above 150 wounded, ruined houses, telegraph poles and trees. Lightning bolts caused over 100 houses fires. Second huge gale happened in July 1931 near Lublin. Regional press break the news about wind blowing at a speed of 500 km/h. In nowadays one of the most massive gale happened betwixt Wrocław and Łódź in 23rd of July 2009 – this two cities are above 200 km away from each other. Gale (called “Derecho”) causes death of 10 people and 100 wounded. In Poland gales with lightning are seasonal incident. Highest frequency of storms is in mountainous part of country – in places known as Żywiecczyzna, Bieszczady Mountains and Tatra Mountains it happen about one in ten days. Lowest recurrence is by the sea – 20 days per year.

Another curious matter are storms with hail. But what should occur to create that type of storm? 65 of 68 hailstorms occur when temperature was slightly above 15 Celsius degrees and air pressure is nearly 850 hPA. Second factor of incidence of hail is proximity of weather front with equator and polar air masses. How can we be clear that our vacation won’t be disturbed by gale? Pick late August time or early June, choose other land for a expedition or take a fancy to wintertime rest.