In most of Styria, no one noticed on a hot Sunday afternoon that the weather in two regions was quite turbulent. “There were only two cells isolated from storms, but they were resilient,” says Zamg meteorologist Christian Pehsl. they taught about Schwanberg in western Styria and in Feistritztal in eastern Styria (especially Hainersdorf) up to 50 liters of rain per square meter in a short time – firefighters had to move for pumping operations.
On Monday, storm events intensified: “The ingredients for individual cells of violent storms are there. That’s why we also issued a weather alert,” Pehsl warned in the morning. Humid and quite hot air (up to 29 degrees) and very unstable stratified air masses. All this meant that storm clouds could rise very quickly and far into the air on Monday – only to be deflated again in the form of heavy rain and hail.
By early afternoon, the first heavy storm cells were moving towards Styria, especially from Carinthia. At around 4pm, a more violent storm cell developed in the Weiz district, which spread to Hartbergerland. It rained harder in the Sommeralm area.
At night, several storm cells also passed over western Upper Styria.
16:30: Lines of thunderstorms over eastern Styria and the Graz mountains © kachelmannwetter.com
The best day will be Thursday
According to Pehsl, it will be a few degrees cooler on Tuesday and Wednesday – mainly because the north wind is involved. However, Tuesday remains unstable. Wednesday and especially Thursday should be much sunnier. “Thursday will be a dream day, with about 25 degrees and little to no clouds.”
Hot days with potential for bad weather over the weekend
Both temperatures and the risk of thunderstorms increase from Friday to Sunday. According to Pehsl, the hot, humid air means there is “definite potential for severe weather.”
On Friday and Saturday, Zamg sees high chances that after the previous week (on Thursday, 31.6 degrees in Hartberg), the 30 degree mark will be broken again. According to Pehsl, this is “quite unusual for May” – because on a 30-year average there are about 0.5 warm days in May around Graz. “We didn’t have more than three days in May with more than 30 degrees, even in the summer of the 2003 century,” said Pehsl. Zamg had also published an analysis the week before, according to which the 30 degree mark was broken earlier and earlier in the year – which is seen as a sign of global warming.