A strong solar storm headed towards Earth could allow parts of the UK the chance to see the Northern lights this weekend. The Met Office said space weather experts had issued a rare severe geomagnetic storm (G4) warning for this weekend, the first in nearly 20 years. The storm, caused by powerful eruptions known as coronal mass ejections, could trigger spectacular displays of aurora. They could be visible across Scotland, Northern Ireland and parts of northern England and Wales, the Met Office said. Krista Hammond, the Met Office’s space weather manager, said: “Multiple coronal mass ejections from the sun are expected to reach Earth in the coming days bringing the potential for aurora visibility over the UK, particularly on Friday night. “While short nights at this time of year will limit the visibility window, if conditions are right there’s a good chance of sightings on Friday night. “Aurora visibility may persist through Saturday night, but as it stands this is likely to be less widespread than on Friday night with northern parts of the UK most likely to continue to have the best viewing potential.” Stephen Dixon, a Met Office spokesperson, added that the combination of enhanced activity from the sun reaching Earth and clear skies would improve the chances of seeing the display. He said: “There could even be [aurora] visibility further south if you have the right equipment.” He added that the vast majority of the UK is expected to see sunny and dry weather on Saturday, with highs of 26C predicted for the south-east. Temperatures could rise to 27C on Sunday, which could also bring intense rainfall and thunderstorms. Two yellow weather warnings are in place for thunderstorms on Sunday – one for western parts of Northern Ireland from 11am until 7pm and the other covering a large part of England and Wales from noon until 10pm. On Thursday, the US National Oceanic and Atmospheric Administration (NOAA) issued a G4 geomagnetic storm watch for this weekend, the second highest on its scale. It last issued a G4 warning in 2005. It said the sun produced strong solar flares beginning Wednesday, resulting in five outbursts of plasma capable of disrupting satellites in orbit and power grids here on Earth. An extreme G5 geomagnetic storm in 2003 took out power in Sweden and damaged power transformers in South Africa. NOAA said that the latest storm could produce northern lights in the US as far south as Alabama and northern California.