We’ve got a fascinating weekend of weather ahead with big contrasts now underway between Northwest Scotland and Southeast England. In between, a seemingly innocuous stalled front draped from Cornwall to Northumberland is now lighting up as the thermal gradient over the UK increases.

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Hot, humid air lifting out of France and bumping up against the boundary is triggering heavy rain and embedded thunderstorms. Through the course of today, rainfall picks up and becomes more widespread, pushing northwards as pressure falls out over the Irish Sea.

Through tonight into tomorrow, low pressure forms out over the Irish Sea. As the energy lifts north, heavy, perhaps torrential rains and thunderstorms could become problematic as the front over Scotland becomes a warm front, being pulled west around the developing low. Expect to see waves or pulses of intense rain and storms through this evening, spreading into southern and central Scotland.

Even within the hot sunshine over Southeast England where temps will surpass 30C, possibly 32C, thunderstorm cells are likely to pop.

As the low spins, so it will pull the warm front westwards and so through the course of Sunday morning, rains should clear western Scotland, allowing sunshine to return and some very warm, humid air to pull in from the east while the cold front pivots northwards back into southern England and Wales where further outbreaks of heavy rain and embedded thunderstorms are likely.

Here’s how the GFS sees this weekend playing out.

Hot, humid and stormy Saturday PM for the Southeast.

Front lights up later today and particularly tonight.

Notice above how as the low forms and isobars begin to turn in from the ESE how the rain shield pushes west whereas the cold front lifts back up into southern England and Wales.

Tomorrow will be a very warm, humid day across Scotland with a stiff ESE wind.

That low eventually lifts out towards the NE Atlantic while another, potent low moves into southern UK bringing wind, rain and thunderstorms. As pointed out in recent days, these lows are simply circling a large upper low over the NE Atlantic, surrounded by high pressure.

See this morning’s video for the discussion. Will have more tomorrow!

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