Extreme heat across Western Europe

  • Forecast maximum temperatures for June 19th, in southern Arizona. Credit: NWS Pheonix.

    Observed maximum temperatures for the Iberian Peninsular on the 16th June 2017. Credit: MeteoGroup.

    ECMWF forecast maximum temperatures for the UK on the 18th and 19th June. Credit: MeteoGroup.

  • Extreme heat across Western Europe
    17.06.2017 17:23

    If you think it’s hot in the UK right now, then spare a thought for our neighbours in Iberia. Here, temperatures have been at near record levels for June, with Spain and Portugal experiencing an early summer heatwave. 

    Although high temperatures are normal in Spain at this time of the year – the average maximum in June for Madrid is 27C for example – the extreme temperatures that have been experienced recently are highly unusual. Madrid reached  40.5C (105F) on the 15th June.  Several weather stations broke their monthly records, and the heat peaked on the 16th June, with 43.8C (111F) recorded at Córdoba Airport in south-central Spain.  At least 6 provinces were put on a significant amber alert for high temperatures to climb above 40C by the Spanish meteorological agency.

    Across France, high temperatures of 30 – 35C combined with high humidity to create an explosive environment for thunderstorms to develop from the 13th – 16th June. The powerful supercell thunderstorms produced thousands of lightning strikes, reaching a peak frequency of over 250 strikes per minute from the strongest storms. In the Haute-Loire department of central France, houses were submerged, vehicles swept away and roads blocked by fallen trees and debris after a powerful flash flood was triggered.  One site recorded 122mm of rain in 1 hour – that’s over 2 months’ worth – with 185mm in 3 hours. The storms also dropped large hail up to 5 cm in diameter, with reports of funnel clouds as well.

    However, heat in south-eastern parts of the USA manages to trump anything from Europe. Highs of 49C (120F) have been forecast for Pheonix, Arizona on the 20th June, with temperatures expected to peak at 53C (127F) at Death Valley on the same day. That’s not far off the Earth’s record high temperature of 56.7C (134F), recorded here in 1910!

    Forecast for the UK

    Temperatures are on the rise in the UK too, with highs of 31-32C possible around the London area on Sunday and Monday. This is a result of high pressure building over the country from the south-west, importing a warm and humid airmass. With largely clear skies for England and Wales, the strong June sunshine will help temperatures to soar. It’s not fine weather everywhere though – a cold front will bring cloudier, damp and cooler conditions to much of Scotland and Northern Ireland. The heat and humidity may trigger isolated thunderstorms across central and southern areas too. Tuesday will see the very warm conditions restricted to southern areas, with further isolated thunderstorms possible, and it will gradually turn cooler from the north as we move into the middle of the week. 

    There are indications that temperatures may rise once more later in the week, as a brief Spanish Plume develops ahead of an advancing cold front from the west. This could trigger further thunderstorms, although there is some uncertainty over the details and timings of this event. 

    By: Richard Martin-Barton