BBC monthly outlook
Monday 11 January—Sunday 17 January
Turning even colder, with a little snow for some.
The week will commence with a slow moving and very large area of low pressure swirling over the UK. Within this area of low pressure, we can expect bands of relatively slow moving and, at times, rather heavy showers to form across many areas. These showers will present the risk of snowfall to some higher ground across the northern half of the UK, and even some higher ground across parts of southern England and Wales will not completely escape some wintry weather. In between the bands of showers though, we can expect some good spells of sunshine, although conditions will still feel pretty chilly in any winter sun. On Tuesday, northwesterly winds will strengthen, particularly across western areas of the UK where gales are possible at times, making for a bitingly cold day for many.
A mix of sunshine and showers can again be expected, and again there will be a risk of some wintry conditions for the highest ground just about anywhere in the UK. The coldest night of the week is likely to be Tuesday night into Wednesday, as a transient ridge of high pressure crosses the UK from the west and the large area of low pressure exits to the east. This will allow a hard frost to develop across all parts of the UK and a risk of icy conditions just about anywhere. Dry, bright and chilly conditions will prevail for many parts on Wednesday, though further wintry showers will move in from the west later. At time of issue, Thursday, Friday and Saturday were all expected to be cold days, with frosty starts, and the further risk of some sleet and snow showers, even to low levels at times, and even across southern parts of the UK.
By the end of the weekend, there will be a possibility that high pressure will start to dominate from the southwest, maintaining the cold feel, but introducing the prospect of drier conditions, at least for a time.
Monday 18 January—Sunday 24 January
Starting cold, but finishing a bit mild perhaps?..
As we move into the third full week of January, the majority of forecasting computer models and tools suggest that the UK in its entirety will begin on a relatively cold note. At time of writing, the most likely synoptic set up in the vicinity of the UK will comprise of lower pressure just to the east of the UK, and higher pressure over or just to the west, resulting in a continuation of the cold, north to northwesterly air flow that dominated much of the previous week. It is therefore likely that a mixture of rain, sleet and snow showers will affect most places at times and some clearer intervals in between.
Drier conditions may well begin to dominate as the higher pressure in the west starts to become a greater influence on the UK. Night frosts and some pretty low daytime maxima are also likely. As we approach the middle of the week, there are indications that we will start to see a return to an Atlantic westerly airstream, which may well herald the beginning of a slightly milder spell, with low pressure systems bringing the wettest and windiest conditions to western areas. In this type of scenario, eastern parts of the UK often see the best of any drier weather.
There is a degree of uncertainty regarding the timing of the transition back to slightly milder conditions, and we will of course keep you updated here at the BBC Weather Centre.
Monday 25 January—Sunday 7 February
A milder end to the month.
Most of the longer range forecasting output points to a slightly milder end to January that will likely last into the first few week of February. Models suggest that a predominantly westerly flow will dominate weather conditions across the UK, bringing spells of wet and windy weather in association with Atlantic low pressure systems. There are signs that pressure will build to the south or southwest of the UK for a time, meaning that northwestern areas of the UK are most likely to experience the most unsettled conditions, with drier spells anticipated for southern districts.
Next week
It will be interesting to see if longer range computer models suggest any further cold spells as we move into the middle of February. Find out next week...
http://www.bbc.co.uk/weather/2635167#outlook