BBC monthly outlook
Monday 30 April—Sunday 6 May
Cold and wet at first. Warmer later on.
Monday will become cold, wet and windy right across England and Wales with further chances of sleet on hills. The eastern half of England will have the heaviest rain with winds gusting 40-55 mph but winds will increase everywhere. Remaining mostly dry over Scotland and Northern Ireland apart from a little rain in the Borders.
A transient high pressure ridge should make Tuesday become drier but a frontal system looks like bringing rain right across the country around Wednesday. More rain and showers look like moving across northern areas during Thursday and Friday and fresh to strong winds, especially for Scotland, while the south becomes drier, although probably rather cloudy at times.
All the while there will be a warming trend with temperatures up to at least the high teens by Friday afternoon. Mostly dry and warmer for the weekend with highs of around 20 C or just over in the Southeast. Any rain will probably be confined to the NW. Rather humid, though, with overnight mist, fog and low cloud patches possible.
Monday 7 May—Sunday 27 May
Unsettled for a time but then becoming dry
The more settled and warmer conditions could last through Monday but it looks like the weather will soon take a turn for the worse with low pressure becoming more dominant again during the week, so periods of wet and breezy weather will alternate with drier, calmer spells. It won't really be cool, though, temperatures most likely near average. The forecast could go wrong in two ways - either even wetter and windier, so broadly not much different, or more likely there'll be a chance of continental high pressure building more strongly and pushing a warmer and drier air mass towards the UK. It's about a 30 % chance. It looks like a build of high pressure across the UK from Scandinavia will settle the weather down again in the second half of May - drier and calmer but not necessarily notably warm. With higher pressure potentially laying more across the north of the country rather than the south this would mean any rain chances would be more for the south than the north but with risks of becoming more widespread if high pressure weakens more quickly than expected.
Next Update
So if more settled and drier weather develops after mid-May as now expected there are a couple of questions: are there chances of getting significantly warmer; and will those conditions last until the end of the month? Or will high pressure recede back to the Nordic regions and open the door to rain from the south and west?
https://www.bbc.co.uk/weather/outlook
Originally Posted by: Gavin D