The weather forecast for this weekend has changed dramatically.

It looks as if the forecasters were just toying with us earlier this week.

The prediction for Welwyn Hatfield and Potters Bar had been nearly universally sunshine from Saturday morning onwards, with mild temperatures.

However, as of today, a yellow weather warning for rain has been issued for all of Saturday and Sunday.

The warning states: “Heavy showers and thunderstorms will affect parts of Southern Britain this weekend.”

This means that there is a small chance that buildings could be flooded quickly or damaged by lightning, hail or strong winds.

There’s also a small chance of fast-flowing floodwater, as well as possible travel delay both on the road and on public transport services.

Friday’s overcast weather may mellow into some breaking sunshine by evening, with temperatures of 15 to 18° C.

Despite the yellow rain warning, by mid-morning on Saturday there’s a good chance of some sunshine breaking through the clouds and brightening up the rest of the day.

Sunday and Monday will return to mostly cloud cover, with some sunny intervals by mid-afternon.

Daytime temperatures all weekend are predicted to reach a high of 23°C or a low of 15°C.