Jetstream currently running across S England, but soon shifting to run across Scotland until Sat 30th when a loop enfolds the UK to generate our own cut-off low by Tue 2nd, which drifts SW to Biscay by Sat 6th at which time the main stream is across Norway.
From GFS, the current deep LP (970mb, unusual for May) moves up to Shetland and fills there by Sun 24th. Warm HP from SW for the following week but the cut-off low referred to above is over Cornwall 1010mb on Tue 2nd. (This feature wasn't showing yesterday). As this low moves away, HP establishes S of Iceland 1035mb Fri 5th with NE-lies setting in.
GEFS temps for S drop on Sun 24th then recover with mean of runs close to seasonal norm through to Sat 6th without too much scatter (no agreement on the warm spells forecast yesterday) Intermittent rain from Fri 29th with a just a few outliers showing big totals later (again, different from yesterday). Scotland & NI, a bigger scatter in temps, and intermittent rain throughout with quite a high chance of rain around Wed 27th. Liverpool on its own for big rainfall spikes in some runs on and after Mon 1st.
ECM like GFS to start with but HP next week is further S so more of a zonal flow, a trough over the UK developing on Fri 29th and the cut-off low is placed further E, over the N Sea Sat 30th
War does not determine who is right, only who is left - Bertrand Russell
Chichester 12m asl