This is the outlook for the next four weeks using the JMA model issued from the Japanese Met Agency. It is not a forecast but a general outlook.. I have pasted the images together, rotated them and added a red line so you can see the UK. Blue colours is low pressure and orange colour is high pressures.
Week 1 27th to 2nd August.
High pressure to the South of the UK with low pressure across the Atlantic and over the UK and into Scandinavia. This period will see some mixed weather. A few showers with some longer spells of rain at times. Temperatures just around 1 centigrade below average for end of July early August.
Week 2 from 3rd August to 9th.
High pressure ridge in the Atlantic and over central mainland Europe with low pressure to the North of Scotland. This will bring a wet start to this period with some heavy rain around. Becoming drier with a few showers later during this period. Temperatures are set to be slightly below average for the time of the year.
Week 3 and 4 9th August to 22nd.
This is a two week period but it looks like overall low pressure trough is over the UK. This looks like it will be a wet period with some prolonged rain at times. Temperature again slightly below average for mid August.