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, 10th May to 16th.
High pressure will be in control over the UK, but with high pressure in this location it will bring a more northerly airflow, so the temperatures will be slightly below what you would expect for early May. It is looking to become dry from late weekend onwards.
Week 2, 17th May to 23rd.
Low pressure is out to the West of the UK over the Atlantic. I expect to see rainfall around average for mid May, so we will see some dry periods. Temperatures will be around mid the teens.
Week 3-4, 24th May to 6th June.
This setup will bring little change, rainfall may be slightly above average and temperature again cool for the end of May early June. Scotland is looking to be fairly wet with above average rainfall.