DONALD Trump, having started his UK visit by brewing a political tempest, could face thunder, lightning and heavy rain as a physical storm brews.

After savaging Theresa May's Brexit plans and praising her rival Boris Johnson's leadership abilities, the US President will visit Sandhurst and Chequers with the Prime Minister today.

The Met Office issued a yellow weather warning for thunderstorms over much of the south, which could bring up to 1.2in (30mm) of rain while temperatures hit 28C (82.4F).

Met Office forecaster Sarah Kent confirmed the patchy showers could hit the military academy in Camberley and the Prime Minister's Buckinghamshire retreat, giving a description sounding somewhat like the presidential visit itself.

"They're going to be generated by the rising temperatures through the day," she said.

"So it's a little bit like putting a pan on the oven where you turn the heat up and you know it's going to start bubbling but you don't know where those first bubbles are going to appear."

Mr Trump, and the protesters who will march through London in opposition to him, could be spared by the erratic nature of the storms, however.

"They will be very hit-and-miss but you will certainly know about them if you are underneath one," Ms Kent added.

The second day of the controversial leader's visit to the UK comes after the Sun published an interview with him where he said Mrs May's Brexit plan could "kill" any UK-US trade deal because it would keep Britain closely aligned with the European Union.

He also said Mr Johnson, who dramatically quit as foreign secretary on Monday over the Brexit proposals, has "got what it takes" to be prime minister.

The weather warning last from 11am to 8pm and covers Exeter and Swansea to London and Folkestone and stretches up to Bradford, though much of the east is spared.