April: Weather Outlook

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  • April showers can give impressive cloudscapes, as is seen in this capture from Tynemouth. Photo: Owen Humphreys/PA Archive/Press Association Images.

    Map representing the probability of surface temperature being above or below average between 4th-10th April. Source: Prescient Weather via www.worldclimateservice.co.uk.

    Should we source an air mass from the south, people may enjoy fine weather conditions as the sun rises higher in the sky. Photo: Anthony Devlin/PA Archive/Press Association Images.

  • April: Weather Outlook
    31.03.2016 14:54

     

    Following another cold and in places frosty start today, many of us will be looking ahead to the second month of the meteorological spring and pondering what conditions we are likely to see in the coming weeks. So far this year, spring has been reassuringly unremarkable after the mild and very wet preceding winter months, with temperatures through March coming out only a fraction of a degree below the long-term average. Two weeks of high pressure in March also led to a prolonged settled spell, buffered by a fairly wet start and end of the month

    April is, of course, a transition month between winter and summer and as such can vary greatly year-to-year in terms of temperature, precipitation and wind. We only have to cast our minds back to 2011 when Wisley in Surrey recorded a high of 27.8C, yet the following year in 2012 an ice storm brought down power lines in north-east England in an early-April cold snap. This coming April will kick off in characteristically changeable fashion with conditions alternating between wet and dry through the first seven days, and it will cool down next week following a mild start.

    As we progress towards mid- and late-April, complications become apparent and this represents a good example of the vagaries of long-range forecasting. Weather models typically run out to seven or ten days ahead, with skill becoming lower the further ahead in forecasting time due to the chaotic nature of the atmosphere. When looking beyond this point, meteorologists make use of specialist weather models that analyse the most likely scenario based on a complex set of algorithms. These models are currently unable to give detailed day-to-day weather conditions for specific locations three to four weeks ahead, but instead indicate likely trends in pressure, temperature and precipitation compared to ‘normal’.

    Here at MeteoGroup, we analyse long-range weather models and compare them to historical analogues, the latter for example being how warm or cold the UK has been in April after a winter when El Nino has been strongly positive. The good news is that weather models are in reasonable agreement until just after mid-month, with conditions across the UK often unsettled until then leading to above average precipitation and winds. Temperatures are likely to be around average, with no significant warmth or cold currently anticipated. Confidence then reduces through the latter stages of April as models conflict on the dominant pressure pattern that is likely to evolve, with this having a fundamental impact on the UK weather. Indeed, the last week or so of April is causing quite a few headaches to long-range forecasters at MeteoGroup, but signals of a build of high pressure across northern Europe around this time are giving some tentative hints of some settled weather prevailing at least for northern parts of the UK. In the meantime, make sure to keep up to date with the latest forecast at www.weathercast.co.uk.

     

    By: Nick Prebble