A developing area of low pressure across central Europe will bring a spell of very unsettled weather across the Alps to the Baltic over the next couple of days, but also introduce increasingly hot conditions to southeast Europe.
Warm and moist air from the central Mediterranean will be drawn northwards across the Swiss-Italian Alps today which is likely to produce some significant rainfall as it rises over the higher ground, in addition to some locally severe thunderstorms. Much of Switzerland and the Italian Lakes are likely to see 50-75mm of rain, but southern slopes of the Alps may see as much as 200-300mm locally, bringing a risk of significant flash flooding and disruption to travel. Faido (TI), Switzerland has already recorded 78mm in 12 hours since rain started to fall on Wednesday night.
The area of low pressure is expected to deepen through Thursday night bringing heavy rain and strong to gale force winds as the system moves northeast across the Czech Republic and Poland on Friday. Whilst this region is not immune to strong winds during the winter, inland gales are very uncommon in the summer and can cause damage and transport disruption due to fallen trees in full leaf. Additionally, some locally severe thunderstorms are likely to develop across a broad region extending from northern Serbia to the Baltic States which bring the threat of damaging wind gusts, large hail and tornadoes.
Through Friday night, this low pressure system continues to move north into the Baltic bringing further heavy rain, scattered thunderstorms and unseasonably strong winds here on Saturday. Following this, there will be some respite across Poland and areas towards the Alps with lighter winds and a scattering of showers.
Meanwhile across southeast Europe, hot air will continue to be drawn north from Africa with temperatures quite widely rising 5-10 Celsius above average over the weekend. This is likely to result in maximum temperatures reaching and locally exceeding 35-40 Celsius across parts of the former Yugoslav Republic of Macedonia, Greece, Bulgaria and western Turkey. Current forecasts suggest that these very warm to hot conditions are likely to persist into next week too, potentially expanding northwards across much of eastern Europe.