A sudden stratospheric warming event - similar to the same one that brought over the original Beast from the East - has been forecast to be "increasingly likely", a forecaster has claimed.
As a result, March's forecast is filled with "significant uncertainty" as such an event can bring various degrees of weather - from "unseasonable warmth" to "bitter cold".
For most of March, it is expected that high pressure and southerly and south-westerly winds will be dominant - but the stratospheric event will throw a "spanner in the works" in the first half of the month.
As a result, Netweather's Ian Simpson has warned that making long-range predictions are "particularly challenging" under such uncertain circumstances.
As a result, Netweather's Ian Simpson has warned that making long-range predictions are "particularly challenging" under such uncertain circumstances
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This pattern "tends to result in the break-up of the polar vortex (low heights over much of the Arctic), an increase in blocking highs over the Arctic, and an increased likelihood of cold air outbreaks in the northern hemisphere", Simpson explained.
He warned that such a pattern of weather "does increase the likelihood of colder outbreaks affecting Britain" - an extreme example being the Beast from the East in 2018.
In February of that year, a similar sudden stratospheric warming event occurred which was promptly followed by two snowy easterly outbreaks bringing thick blankets of snow across swathes of Britain.
Such extreme wintry weather happened as late as March 18 across the UK.
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Simpson recalled: "Parts of the West Country, which are normally relatively snow-free and see average maximum temperatures well over 10 degrees in March, had persistent snow and daytime maximum temperatures within a degree of freezing."
However, the event "does not guarantee colder weather" for the nation because "if a blocking high sets up to the east and south-east of Britain, it can pull in very warm air masses".
For example, in February 2019, sudden stratospheric warming took place in January which led to high daytime temperatures accompanied with bright sunshine.
On February 26, the highest temperature was recorded at 21.2 degrees in Kew Gardens in west London.
He warned that such a pattern of weather "does increase the likelihood of colder outbreaks affecting Britain" - an extreme example being the Beast from the East in 2018 (Pictured)
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Equally, there is a chance that such a warming event could produce "outcomes somewhere in between" which generally fall more often on the cold side.
During early spring, Simpson noted that snow remains "relatively common" despite being quick to melt as the sun shines throughout the day.
However, he added that there has been some "shortening of the snow season" over the past few decades and that new weather patterns are more likely to bring sleet or cold rain for most.
"Already some of the medium-range forecast models are starting to show high pressure developing to the north of Britain and bringing in colder air, although there is considerable uncertainty over this, and there are no guarantees that high pressure won't stay close to southern and south-eastern Britain," the forecaster concluded.
