Atlantic hurricanes and UK weather

  • Figure 1: Satellite image of Hurricane Gordon (top) and Hurricane Helene in the central North Atlantic on 18th September 2006. Source: NASA.

    Figure 2: Satellite image of Hurricane Michael on 7th September 2012. Source: NASA.

    Figure 3: Forecast track and intensity of Hurricane Michael. Once reaching the east coast of Newfoundland on Wednesday, the storm is expected to track eastwards towards the UK. Source: NOAA

  • Atlantic hurricanes and UK weather
    08.09.2012 12:36

    The sunny and warm weather that many areas of the UK have experienced over the last few days is set to continue through the rest of the weekend. However, next week looks set to return to more unsettled conditions with the chance that the remnants of an Atlantic hurricane may bring some very wet and potentially stormy conditions to the country towards the end of the week.

    Hurricanes do not directly hit the UK, owing to the fact that the country lies north of the tropics and that sea surface temperatures are below the 25-27 Celsius required to sustain such storms. However, if a hurricane or tropical storm takes a northerly track, its remnants can become engaged with a mid-latitude depression. This can occur quite regularly during the late summer and early autumn, and if the jet stream is located close to the British Isles, these storms can affect the UK and bring wet and windy conditions at this time of year.

    Probably the most notable of ex-hurricanes to hit the UK in recent times was Hurricane Charley back in August 1986. The storm formed in the north-east Gulf of Mexico, before moving across northern Florida and Georgia before tracking up the east coast of the United States, briefly making landfall as a category 1 hurricane in North Carolina. As the storm moved out of the tropics, it intensified into a deep extra-tropical cyclone and accelerated as it moved over the North Atlantic towards the British Isles. The storm tracked across southern areas of the UK on the 25th August bringing heavy rain and strong winds to much of England and Wales in particular. Many areas of south Wales received over 100mm of rain in just 24 hours, breaking some station records for daily rainfall. These severe conditions brought widespread flooding to some areas, particularly in Gloucestershire and Cumbria. More recently, the remains of Hurricane Gordon brought stormy conditions in late September 2006, bringing 70mph gusts of wind to western areas and large amounts of rain, with 21.8mm of rain falling at Wainfleet, Lincolnshire in just 1 hour on the 22nd.

    Currently there are two storms in the Atlantic. Leslie is tracking north towards Bermuda and is likely to re-intensify into a hurricane within the next few days. Hurricane Michael is also in the central North Atlantic, 925 miles south-west of the Azores. It is currently a category 2 hurricane with wind speeds of 110mph, but was briefly a category 3 hurricane last Thursday, the first category 3 storm of the current hurricane season. Also of note is the fact that this year is the third earliest that the 7th named storm has formed since records began. Michael will remain fairly stationary over the next few days, only slightly edging north-westwards. However, by Wednesday, the system will become a post-tropical storm off the coast of Newfoundland before it turns east towards the UK. By Friday, a deep area of low pressure, containing the moisture and energy of ex-hurricane Michael, is expected to be fairly close to the UK, which would mean strong winds and large amounts of rain. However, Friday is still a long way off, so details about which parts of the UK are likely to see the worst of the weather are still not clear.

    However, as mentioned earlier, the rest of this weekend is likely to remain warm and sunny for many areas. The weather should also remain dry and fine for the closing ceremony of the Paralympic Games at the Olympic Stadium in East London on Sunday evening, with just a slight increase in cloud from the west and temperatures of around 18-19 Celsius.

    By: Chris Burton