Flood warning issued for Gwynedd and Conwy by Natural Resources Wales
Heavy rain could bring flooding to roads and low-lying land north west Wales on Thursday night, Natural Resources Wales (NRW) warns.
The Met Office says higher ground in Snowdonia could see up to 80mm (over 3 inches) falling over a 12 hour period.
NRW warned driving conditions could be difficult with blocked drains and overflowing streams the main concern.
Holidaymakers in tents and caravans have been told to take advice from site owners.
The yellow "be aware" warning is valid from 15:00 to 23:59 BST on Thursday.