John gives us his latest thoughts on likely weather trends on the horizon over the next few weeks. To ensure you are reading the very latest weekly blog, check out Wow and Why
Just when many of us thought that we could safely shed a layer or two, winter comes surging back. Another blast of easterly winds interrupts spring’s emergence, and brings some late ‘fun and games’ from snow.
From the top of the atmosphere to the bottom, the weakness of the westerlies has been key this period. As a result, milder Atlantic air has failed to take full control of our weather. And with a faltering jet stream that is often deflected well to the south of us, there is nothing in the charts to suggest to me that we can rely on a prolonged drier and warmer spell just yet.
Of course, with the sun getting higher and the days becoming longer than the nights, each blast from Siberia or the Arctic tends to be less fierce than the previous one. Spring will progress, albeit too slowly for some…
MONDAY 19TH MARCH – SUNDAY 25TH MARCH
Yet another thaw-out
The weekend freeze will slowly loosen its grip as we start the new week. And with bitter easterlies fading, so will the last of the wintry showers. I expect hard overnight frosts, but by day the strengthening sun will do its work to melt the snow – most of which will be gone by Tuesday. As a ridge of high pressure topples across us, a very pleasant few days can be expected, with light winds and daytime temperature bouncing back towards normal.
Through the second half of the week, we look to the west and the approach of low pressure. The timing of this is not nailed down; but there’s an increasing chance of rain spreading eastwards, together with blustery winds.
…the mid-term report on spring so far? “Could do better”
So a rather ‘unfriendly’ weekend with some periods of wet and windy weather is in store. Unlike the previous weekend, it will be rain falling from the sky, rather than snow. For most, that is…
Yet again, the cold air has only really been nudged from centre-stage. It hasn’t left the scene entirely. There’s a significant chance that arctic winds will shunt the whole weather pattern southwards through the weekend, with rain turning to snow across northern parts of the UK. This is certainly one to watch.
MONDAY 26TH MARCH – SUNDAY 1ST APRIL
White Easter anyone?
Not for the first time through this apparently unending winter, the atmosphere is at loggerheads. The balance of power between warmer winds from the south and west and chilly northeasterlies will not be easily resolved by forecast computer models at this range. They – and the weather apps – that are driven by them – will fluctuate unreliably as each computer run comes up with a different solution.
I expect the week to turn quite chilly again for a time, though not as cold as recently. There will be a mixture of sunshine and heavy downpours, with the showers falling as snow at times. A White Easter Day is statistically rare, but given the weather pattern we’re in, it may be more likely this year than most. Yet again, there is a risk of disruptive snowfall, but this is most likely across the higher northern parts of the UK.
Perhaps of more concern to gardeners is the ongoing prospect of low overnight temperatures. Frosts may well be quite sharp and, as we arrive in April, the potential damage it can bring markedly increases.
MONDAY 2ND APRIL – SUNDAY 15TH APRIL
There is very little insight to be gained from computer forecasts at this range. At this time of year, the temperature contrast between the arctic and the tropics is lessening. As a result, the jet stream, having behaved half-heartedly for months, may in fact become even more ‘wishy-washy’. So I don’t expect an energetic blast of westerly winds to clear the chilly weather away in a hurry. What will be the mid-term report on spring so far? “Could do better”.
The cool theme of sunshine and showers will continue well into April, with an ongoing threat of night frosts. But with time, the chance of snow should finally wane; and by day, with strong sunshine and light winds, temperatures will climb.
We look to the south for the belated arrival of proper warmth. It’s only a matter of time.