There has been travel chaos in Watford as flooding cancelled trains and forced police to close roads.

The Met Office had issued a warning for potential heavy showers and thunderstorms from midday to 9pm today (June 12) — and it has been borne out.

Watford Junction was shut for about an hour from around 3.17pm, with disruption and cancellations still impacting commuters.

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Roads including Radlett Road, Bushey Mill Lane, the A41, and Balmoral Road have been shut with Hertfordshire Constabulary warning motorists to generally avoid any large flooded areas.

Watford Observer: The Dome roundaboutThe Dome roundabout (Image: Wai Meng)

The force has apparently been experiencing “a high volume of 999 emergency calls involving cars being stuck in flooded roads in Watford”.

Watford Observer: Balmoral RoadBalmoral Road (Image: Contribution)

Balmoral Road was closed after the flooded road reportedly caused a car crash, requiring an ambulance to be called.

The water has apparently since cleared but the road remains closed as of 5pm.

This morning, Met Office meteorologist Grahame Madge warned people that heat rising from freshly ploughed fields or over a city area could trigger thunderstorms even when nearby areas remain dry and that flash flooding can occur in a few minutes.

He added that urban areas with lots of concrete can be vulnerable to flash flooding as the rain hits surfaces such as pavements which cannot absorb heavy downpours, leaving them to flow into drains or roads.

Watford Observer: Watford High StreetWatford High Street (Image: Stephen Thorp)