Ever wondered why our forecasts for 5 days and beyond are written on the scale of the UK as a whole? When looking at forecasts beyond five days into the future the chaotic nature of the atmosphere starts to come into play - small events currently over the Atlantic can have potentially significant impacts on our weather in the UK in several days' time. Therefore whilst we can still forecast the general feel of the weather to a relatively high level of accuracy using our ensemble models, it becomes harder to offer local detail to as high a level of accuracy as our shorter range forecasts. For this reason our text forecasts for 5 days and beyond are written on the scale of the UK as a whole.
Long range forecast
Wednesday 13 Dec - Friday 22 Dec
Briefly unsettled with showers and potential for a band of rain before becoming more settled later in the week as high pressure affects southern areas, though remaining in a more wet and windy regime in the north. As such, the wettest weather likely across western high ground, mainly in Scotland and occasionally parts of Northern Ireland and northwest England. Settled conditions in the south with average temperatures and cloudy at times with patchy light rain near coasts and over hills. Clearer spells favouring the southeast but these also allowing potential for fog or frost overnight. The following week sees potential for high pressure to shift allowing a return to unsettled conditions but average to mild temperatures, favouring the northwest for wettest and windiest conditions.
Saturday 23 Dec - Saturday 6 Jan
More likely to be unsettled compared to preceding settled spell with bands of rain crossing the UK with brighter conditions and showers in between. The wettest and windiest conditions are most likely in the west and northwest. The chance of a colder spell of weather, with hazards such as snow and ice, does increase later in December and into the New Year period. However, conditions are more likely to remain generally mild and wet.
Why isn't there more detail in the long range forecast?
Our long range forecast (which is updated on a daily basis) provides an indication of how the weather might change, or be different from normal, (i.e. warmer, colder, wetter, drier) across the whole UK. Met Office meteorologists consider output from a range of weather models when writing these forecasts. These models include those from the Met Office as well as models from other global forecasting centres such as the European Centre for Medium Range Weather Forecasts ( ECMWF).