Extreme Weather Across Europe

  • Visible satellite image of thunderstorms developing over north Italy at 12:00 UTC on June 28th. Credit: NASA.

    Observed hourly temperatures over south-eastern Europe at 12:00 UTC on July 1st. Credit: MeteoGroup.

    ECMWF forecast 24 hour precipitation accumulation from 00:00 UTC on July 3rd for the eastern Balkans. Credit: MeteoGroup.

  • Extreme Weather Across Europe
    01.07.2017 17:49

    From extreme heat in the south-east, to severe thunderstorms and tornadoes across Italy and central Europe, to the recent heavy rain here in the UK, Europe has had its fair share of extreme weather recently.

    Heatwave in south-eastern Europe

    Turkey, Greece, Bulgaria and surrounding countries in south-east Europe are in the grip of a major heatwave currently. Temperatures have so far hit at least 42.0°C in Bulgaria and Greece, while the mercury hit 44.1°C in south-western Turkey on Saturday afternoon. And if you think you can escape this heat in Turkey with a pleasant hike in the mountains, think again – temperatures on some peaks 1000m high have climbed above 34.0°C.  And there will be little relief from the heat overnight, as some low-lying resorts on the Turkish coast have struggled to drop below 30.0°C.

    Sunday night will signal the end of the period of most intense heat for Bulgaria, Romania and Greece, but this will be accompanied by severe thunderstorms developing during the evening and overnight. These may join together to form a large complex of thunderstorms (a Mesoscale Convective System), and could drop 100-150mm rain in 12 hours or less. Although the heat will linger for Turkey and southern Greece, temperatures in the eastern Balkans are likely to fall by 15-20°C once the storms have finished.

    Severe thunderstorms

    Many countries across Central and Eastern Europe have seen the combination of ingredients required for severe thunderstorm development at times this week. France, Spain, Germany, Poland and the Czech Republic have all seen the severe weather associated with these storms. Perhaps the most significant example occurred on the 28th June around northern Italy and the surrounding western Balkans. The combination of high instability and large wind shear in the atmosphere (changes in wind direction and speed with height) resulted in the development of supercell thunderstorms that were triggered by an approaching upper-level trough.  The storms gave gusty winds, frequent lightning, giant hail and there were reports of a tornado too.

    Heavy rain in north-western Europe

    After the heatwave Western Europe and the UK experienced earlier in June, the weather took a turn towards the end of the month, as low pressure dominated. Provisional data from the Met Office reveals that Scotland has had its equal-wettest June on record, with 156mm of rainfall. The station at Edinburgh Botanic Gardens had its wettest June on Record, with 180.6mm falling. The reason for this rainfall was several areas of low pressure that remained near-stationary close to the UK. Their circulating fronts brought heavy and persistent rain to mainly eastern and northern parts of the country. A cold northerly flow developed as the low pressure dissipated, resulting in the coldest June 28th since records began in central England.  Persistent frontal rain with embedded thunderstorms also resulted in significant flooding in the Netherlands. 

    By: Richard Martin-Barton