A warning for severe thunderstorms and locally heavy rain, extending up to Haparanda, is in effect from 4 p.m. to 11 p.m. on Saturday.
According to SMHI, it is difficult to specify where the storms will be strongest, but across the warned area a warm, humid air mass is sweeping in from the south.
In this warm and humid air mass, there is a risk that thunderclouds can develop quite easily. Locally, they can cause torrential rain and lightning strikes, says Erik Höjgård-Olsen, meteorologist at SMHI.
SMHI warns, among other things, of the risk of flooding and disruptions to electricity and telecommunications networks.
A yellow warning has previously been issued for thunderstorms on Midsummer's Day for Götaland, large parts of Svealand and southeastern Norrland.
