April’s forecast didn’t exactly go to plan, at least for the second half of the month. We were expecting a wet, windy and slightly cool April, but in the end, we only saw those conditions for the first 10 days. After that April tended to be very dry with lower winds. However, the temperatures never did get overly warm except for a few days thankfully placed over the Easter bank holiday weekend. April did see an above normal number of frosts, and interestingly saw more frost days than February this year, thanks to a pretty mild February!
One thing that threw a spanner in the works for April’s forecast was much more tenacious high pressure in northern Europe than we were expecting. For May, it looks like this will continue to be the case with high pressure favoured in western and northern Europe more often than not. The maps above show the long-range computer model forecast for temperature and rainfall anomalies in May and you can see a large area of warm (orange and reds on the left-hand map) and dry (browns on the right-hand map) weather for much of continental Europe including the British Isles.
With high pressure nearby or overhead, we can expect a lot of sunny, warm days with below-normal winds and rainfall for much of the UK. Afternoons in mid and late May are likely to feel more summer-like than spring-like. However, Scotland and Northern Ireland may see some cloudier weather with weak weather fronts able to get into northern Europe.
That’s not to say the entire month of May will be sunny and warm. Occasionally we expect high pressure to weaken and let low pressure systems in from the northwest for a few days. These will make for some slightly cooler, wetter spells to break up the summer-like weather. Two are on the cards so far for the first half of May, and there are some signs we might see a third one near the end of the month as well. At any rate, these wetter spells are unlikely to last longer than three or four days.