It's a fascinating landscape out there these days. There are many fields containing substantial bodies of surface water, and often there are waterbirds taking up residence. That could lead to some chaotic times as and when those water bodies dry out...
...which doesn't look to be any time soon. For England, 5-15mm looks likely from the Tuesday-Wednesday rain, with more than that falling in regions that catch any showers.
Then Friday-Sunday could deliver 20-30mm widely, with 40mm+ probable when factoring in showers.
For Wales, the figures are similar for the first event but are as high as 45-50mm for the second event.
For Scotland, the upper range for event one is higher, at 30mm or so (considering showers), while the second dumps 10-20mm in the east and some 80mm+ in the west - one to keep an eye on there! 
This is all based on a rather uncertain intense storm system that slowly decays while sliding south. It's positioning could change, along with the zone of highest rainfall totals. Let's hope it doesn't shift notably south, else some of the worst hit regions in terms of flooding will come into the firing liine for totals similar to those currently projected for the NW (but not as high due to the lack of orographic - i.e. mountain - effects).
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[email protected] https://twitter.com/peacockreports 2023's Homeland Extremes:
T-Max: 30.2°C 9th Sep (...!) | T-Min: -7.1°C 22nd & 23rd Jan | Wettest Day: 25.9mm 2nd Nov | Ice Days: 1 (2nd Dec -1.3°C in freezing fog)
Keep Calm and Forecast On