This is the latest outlook for the next four weeks from the Japanese Met Agency the JMA. It is not meant to be a forecast but a general outlook. I have added the 3 images together and rotated them and added a red line so you can see the UK. Blue colours are low pressure area’s and oranges high pressure area’s.
Week 1, 16th May to 22nd.
During this period it looks like high pressure will be over the northern parts of the UK with low pressure over southern parts. It looks like the midlands is where the high and low pressure area meets. This looks like rainfall will be around average so we can expect some showers with temperatures around average, around the mid teens.
Week 2, 23rd May to 29th.
Low pressure looks to be over, England, Scotland and Wales stretching over Scandinavia and most of Europe. Rainfall will be around average so we can expect some showers. It looks like we will be in a northerly airflow so we can expect a cool feel with temperatures around 1 or 2 degrees below average for the end of May.
Week 3-4, 30th May to 12 June.
A slack air pressure period looks to bring rainfall around average so any rain will be in the form of showers. Again temperatures will be around average if not slightly cooler than you would expect.