As the UK grapples with the aftermath of a recent bout of harsh winter weather, forecasters warn that the battle between opposing air masses is far from over. Just as the country was beginning to thaw from the initial cold snap, a new phase of unsettled conditions is on the horizon.
The start of January saw Arctic winds sweep southwards, blanketing parts of the UK in heavy snow, widespread ice, and biting temperatures. A recent shift in the jet stream has since allowed milder Atlantic air to move in, lifting temperatures closer to seasonal averages. However, this sudden change has introduced a different set of challenges, with frequent rainfall, strong winds, and rapid snow melt leading to localised flooding in some areas.
Now, as the second half of the month approaches, the weather patterns are set to shift once again. “We’re entering a new phase with two competing weather influences, and it’s a waiting game to see which will dominate – more wind and rain, or more snow and ice,” explains Met Office forecaster Michael Okonkwo.
On one hand, an Atlantic low-pressure system will repeatedly attempt to move in from the west, bringing relatively mild, moist air and unsettled conditions. At the same time, areas of high pressure over eastern Europe and Scandinavia may push westwards, encouraging colder and more stable air to edge into eastern parts of the UK.
“The UK lies on the boundary of these air masses for the foreseeable future, with colder air around high pressure towards the east of the country perhaps winning out later in the month,” Okonkwo says.
For the next few days, the Atlantic influence is likely to dominate, with largely cloudy skies and changeable weather, including frequent showers or longer spells of rain. Temperatures during this phase are expected to be close to the seasonal average, reflecting the balance between mild-Atlantic air and occasional cooler interludes.
However, as we head through next week, the forecast confidence decreases, and there are indications that colder conditions could begin to take hold. “If high pressure to the east becomes more influential, allowing colder air to spread westwards across the UK, temperatures are likely to fall below average and the risk of wintry weather would increase,” Okonkwo explains.
Should this transition develop, any precipitation could potentially turn to snow, particularly over higher ground but possibly at lower levels too in some areas. The exact timing and extent of any colder spell, however, remains uncertain at this stage.
With the prospect of temperatures falling below average towards the end of the month, along with an increasing likelihood of further snowfall, there is growing potential for a renewed cold spell. When combined with the notable cold snap experienced at the start of the month, it raises the possibility that January as a whole could end up being colder than the long-term average.
“Such an outcome would be relatively unusual in the context of recent years,” Okonkwo notes. “As the climate continues to warm, months that finish below average have become less frequent, particularly during winter, when milder Atlantic influences increasingly dominate. But it does highlight how short-lived but significant cold spells can still occur and have a meaningful impact on monthly averages, even in a changing climate.”
