BBC monthly outlook
Monday 25 January—Sunday 31 January
The potential for disruptive rainfall totals.
We start off the week on a relative mild and breezy note. Northern Ireland, Scotland, Wales and western parts of England will see increasing amounts of cloud along with outbreaks of rain spreading from the west. The rest of England will remain largely dry with some bright and sunny spells during the day. The rain will clear eastwards through the evening and many of us will start off Tuesday on a briefly dry and chilly note with light winds.
It will soon turn windy on Tuesday morning and another pulse of rain will spread into northern and western areas through the day. The low pressure system bringing this rainfall originated in the US. It was called 'Jonas' by the Weather Channel and brought record breaking snowfall there. Although there is no chance of snow with this weather system for the UK, some potentially disruptive rainfall totals are possible as well as the risk of gales and severe gales. At the time of writing western parts of Britain look most likely to get the highest rainfall totals with areas further east escaping the heaviest of the rain. Given the sensitivities of some western parts of Britain due to exceptional totals before Christmas, careful monitoring of the situation is required. The rainfall could continue in western areas during the early hours of Wednesday morning.
The weather system will eventually move away eastwards during Wednesday, opening the door to a briefly chillier interlude with some wintry showers likely across north-western parts of Britain. A cool and quieter weather day is expected on Thursday although northernmost Scotland will see windier conditions as well as some wintry showers. Further mild, wet and windy spells will return through Friday and onto next weekend with some very brief chillier interludes. Overall we can categorise the weather as mild for the bulk of the week with a cautious reminder of the potential for some disruptive rainfall amounts midweek.
Monday 1 February—Sunday 7 February
Flip-flopping weather patterns
We expect the last month of meteorological winter to start off on a mild note. The first week in February is expected to be dominated by a changeable weather pattern. What does a changeable weather pattern mean for the UK at this time of year? We are expecting low pressure systems to pass mainly to the northwest of the UK. This will bring mild west or south-westerly winds with wet and at times windy weather. These spells of rain will likely quickly push through, with the main focus of the rain to be across the north and west of the UK.
Interspersed between the rain bands we are expecting to see our winds shift briefly in direction to a north or north-westerly direction. Where this happens by day it will bring mainly dry weather and when this shift in wind direction happens by night, it will bring a frost to many areas. As each day passes a different weather type will affect the UK but overall we are expecting the week on average to be mild with most of the rain affecting north and north-western parts of the UK, while the southeast of the UK is expected to see the driest of the weather.
Monday 8 February—Sunday 28 February
Something colder on the cards?
When we get to this range of forecasting, we start to look at general trends and patterns that are emerging from the various computer models. At this stage these models are indicating a greater risk of something colder emerging. This usually means that the wind direction will come more frequently from a northerly direction bringing cold air further south. The transition in weather from a relatively milder pattern to something colder will be a tricky one and is unlikely to set in suddenly; the change is likely to happen over a number of days.
However, it is worth mentioning that the colder pattern that is emerging is associated with high pressure across northwestern parts of Europe. This usually means that weather fronts that have the potential to bring snow, are kept away from the UK. So the likelihood of a snowfall event at this stage is low. Watch this space to see how this signal is shaping up next week.
Next week
Watch this space to see how the cold weather signal is shaping up next week and to see how the record breaking winter storm across the US affected the UK.
http://www.bbc.co.uk/weather/2635167#outlook