Heavy rain warning updated

I notice that the yellow warning for heavy rain has been updated by the Met Office to cover the north and west of Scotland. Wise move, as it’s already been bucketing down here in the strath for the last few hours. It does make you wonder why possible totals of 90 to 120 mm in 33 hours in places only merits a yellow warning? How much more rain would have to fall to make that yellow an amber warning? Yes I know, under the impact method they employ – a lot more people, but surely Glasgow must count for more people? The rainfall accumulations from 18 UTC yesterday also suggest, if persistence has any part to play in this current rainfall event, that the warning might have included the northwest of Wales too.