Monthly Outlook

The second half of the week will initially be changeable and cool, but temperatures will gradually rise at the weekend. The beginning of May could be generally warmer, but perhaps remain wetter than normal.

The high pressure ridge tends to shift towards Iceland and Greenland, causing the low pressure over the North Sea to sink with an initially northerly current from Scandinavia. At the same time, an area of low pressure approaches from the west with its frontal system.

The result is a persistent, mainly blocked North Atlantic flow with slightly wetter but generally cooler conditions for the UK and chilly and even frosty nights more widely, at least until Friday night.

A deepening low pressure system will approach the UK from the south and south-west over the weekend, leading to heavy rain at times, particularly in the south of the country, as well as quite windy conditions in places. This heavier rain will move towards northern Scotland on Saturday night, with snow still possible on the highest ground.

However, a further rise in temperature is expected on Sunday, reaching seasonal levels, with frequent, sometimes thundery showers in the south and south-east and heavy and persistent rain in the north.

The timing and some details are still uncertain.

Early next week, temperatures will start to recover across the UK following the recent chilly conditions. This will be due to a change in wind direction, as low pressure takes a southward track to the west of the country.

Although there will still be some rain or showers around in association with the new low, temperatures will rise to near or even a little above average due to the flow off the continent.

From midweek, a ridge of high pressure may extend from the Azores towards the UK and connect with another ridge of high pressure over southern Scandinavia. Increased high pressure influence will mean drier conditions for many, although still the potential for some wetter weather to hold on across the south for a time.

It may turn a little cooler as north-easterly flows develop, but temperatures should still be higher than of late.

Into next weekend there are some signals from the models that high pressure could migrate further west and introduce a chillier and more showery north to north-westerly flow, but confidence is low at present.

According to global weather models, high pressure may remain close to the UK in the second week of May, while areas of low pressure will affect mainly southern and possibly eastern parts of the country at times. Temperatures will be slightly above average.

Stronger winds and wetter conditions are expected, particularly in southern and perhaps eastern parts of the country. Scotland and Northern Ireland could remain drier and calmer.

However, there is the chance that the ridge of high pressure will re-establish itself further west or even north-west of the UK, with a wetter, north-westerly flow bringing cooler conditions for a while. This risk could increase, especially towards the end of the second week of May and going into the third week. Confidence remains quite low at this stage.

Recently, the likelihood of cooler and wetter conditions returning later in the forecast has increased.

We'll see which trend continues into mid to late May and whether above average temperatures manage to win out.