A Met Office alert of torrential rain and thunderstorms has been issued for the Helensburgh and Rosneath peninsula area this Saturday (June 7).
The public is being advised to check online before travelling and to be prepared for localised flooding.
A yellow ‘be aware’ warning of ‘heavy, thundery rain’ has been issued by the Met Office for 3am until 11.45pm on Saturday, but forecasters say the location o the worst problems is still uncertain.
A Met Office statement said: “Warm, humid air will be pulled northwards from France and Spain late on Friday and during Saturday.
“Within this air mass, there is an increasing likelihood of heavy, thundery downpours breaking out.
“It is likely that many places within the current broad warning area will miss the worst of the storms, but it will prove difficult to highlight the areas most at risk until nearer the event itself.”