John Hammond’s Month Ahead – We need to change the month… May(be)?

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

My last update to this blog was written in T-shirt and shorts as temperatures soared to near-record heights. But I hinted then that we were due for a reality check. And as I post this instalment to the saga of a fickle spring, the jet stream is taking another quirky detour – this time, far to our south. As a result, we’re nearly 20 degrees colder! The winter wardrobe makes a comeback across the nation this weekend and my charts suggest we’ll need layers well into early May. But as the jet stream takes on yet another twist, I’m expecting a big bounce back in the mercury later in the month



Merry month of May?

April ends on a grim note across the southeastern half of the UK. Amidst the cold, wet and windy weather here, a few flakes of snow may bring a novel, if unwanted, addition to the chill. In contrast, across Scotland and Northern Ireland, the week starts with sunshine. But as the jet stream takes another dip towards us from the Atlantic, northwestern areas will see the tables turned on them, with wet weather spilling in during Tuesday, while the southeast slowly improves.

Through the middle of the week, showery rain will spread to most parts of the country. Whilst the details will be difficult to pin down, temperatures should slowly recover some respectibility in the brighter interludes. And these will be most prevalent across the east of the UK.

As we approach the Bank Holiday Weekend, there is, inevitably perhaps, much less agreement in computer model forecasts. So your weather apps won’t be trustworthy for several days yet. But I think the jet stream will begin to retreat away northwards again, bringing hope of a slow improvement for many. There’s a drier and warmer trend on the horizon, but it may take some time.

I’m cautiously optimistic that the Royal Wedding will not be a washout


On the up

This part of the forecast may go very wrong! Such is the lack of clarity in longer-term signals, it would be unwise to be too prescriptive. However, I’m expecting higher pressure to continue to weaken rain-bearing weather systems as they try to dig down from the north. The driest weather will tend to be across the south of the UK, with some southwestern areas probably seeing some of the best of the sunshine.

Indeed at this time of year coastal areas can often be sunniest of all – good news for holidaymakers. Under clear skies, the nights will still be quite cool. But by day, temperatures will continue to climb especially in the south. Back into the 20s for many.



By Royal command…

As we head through the middle of the month, the optimistic tone continues. High pressure will continue to deflect the jet stream and limit its influence. Some northwestern parts will be most prone to glancing blows from rain-bearing Atlantic weather systems. But most parts of the UK will have a lot of dry and pleasantly warm weather. Handily, Windsor is in a part of the UK that is well-placed in this set-up. I can’t pin my colours to the mast yet  – it’s still too far off. But I’m cautiously optimistic that the Royal Wedding will not be a washout. Still no invite though…

Heading towards the end of the month, we may see a rearrangement of the jet stream that shifts weather systems around.  The south may become more prone to showers – a common pattern at this time of year. So while those blooms at the Chelsea Flower Show will benefit from a watering, northern parts of the UK may become driest. A Whitsun holiday in western Scotland anyone?