Royal Wedding weather update

  • Royal Wedding weather update
    26.04.2011 11:05

    As the big day creeps closer, eyes will be turning increasingly to the skies over London to see what the weather has in store.

    After a very warm Easter weekend, the weather has turned somewhat cooler today. This is due to the wind shifting to the north-east, bringing chillier air with it. As we head towards the end of the week, the wind will shift into the east and then the south-east. This is expected to bring somewhat warmer air in once again, from the near continent. However, this airmass will also be fairly moist.

    In the upper atmosphere, an area of low pressure will edge towards southern England from the south. This, coupled with the increasing low-level moisture, will encourage showers to spread across southern England during Thursday and Thursday night.

    On Friday, the atmosphere will be rather unstable: an unstable atmosphere is one where the air at lower levels wants to rise upwards rapidly, encouraging the formation of tall shower clouds and, sometimes, thunderstorms.

    As the fairly strong late-April sunshine starts to warm the lower atmosphere on Friday morning, the risk of showers will increase across the London area. Towards late morning, some of the showers could be heavy with thunder, sand the risk continues into the afternoon. The risk of showers across London is currently about 80%, although the risk at any one location is somewhat lower, at around 30-40%.

    As is the nature of showers and thunderstorms, one location can receive torrential rainfall whereas a few miles away it is completely dry with sunshine. This random nature means than predicting whether rain will occur during the ceremony and subsequent events is impossible at this stage. All that can be said is that there is a risk of rain.

    One small crumb of comfort which the Royal couple and well-wishes can take solace from is that with an easterly wind in spring, central London often misses out on the showers as the air is not warm enough to support them after due to passing across the chilly waters of the Thames estuary: instead, heavy showers and thunderstorms will often develop over west London, before spreading westwards across Berkshire and the rest of the Thames Valley.

    MeteoGroup will keep the forecast updated, of course, and on the day you can keep any eye out for any showers and thunderstorms on the rainfall radar at RainToday.

    And the heat map will keep you abreast of the changing and forecast temperature across the country.

    By: Paul Knightley