Does anyone know what criteria is used for deciding on red warnings. The pictures of flooding in Wales and subsequent damage and destruction seem to appear to have warranted a red warning yet only reached Orange Status.

I find it a bit confusing. I guess there is a desire not to overuse that status to avoid being caught out; but none the less I suppose little comfort to those whose lives have been washed away.

Check out this link. It explains the difference between medium and high impacts for each type of weather. One of the main criteria for the high impact classification is that the impacts will last for a prolonged period (days not hours) and will also be widespread. While there were some serious impacts in Wales yesterday they were relatively localised and are unlikely to last for days. Hence why the warning stayed at Amber.

https://www.metoffice.gov.uk/guide/weather/severe-weather-advice