Adam Cairns, the Chief Executive of Cardiff and Vale University Health Board - which runs the University Hospital of Wales - spoke to ITV News this evening.
He told Jonathan Hill that the findings of the report by the Royal College of Surgeons are "troubling, worrying and unacceptable".
He said the primary problem - of getting patients into the hospital - caused cancellations of planned procedures, and needs to be tackled with a "much more resilient plan" in future.
More top news
The heaviest bursts are expected in the south and east, with some western areas either remaining dry or becoming dry by dawn.
Many places will start dry, but rain in the southeast will spread to most for a time overnight.
The family of Isaac Nash who went missing after being swept out to sea last summer have presented a cheque for £10,000 to the RNLI.