THE UK’S leading tornado research organisation has issued a severe weather forecast with the risk of “isolated tornadoes”.

The warning from Tornado & Storm Research Organisation (TORRO) is valid until 8pm tonight, March 28.

The affected area covers the entirety of Gwent - including Blaenau Gwent, Caerphilly, Monmouthshire, Newport and Torfaen - as well as Powys, the Midlands, parts of London and the south west of England.

Among the potential hazards, TORRO includes wind gusts of 50 to 70mph, hail and occasional cloud-to-ground lightning, also known as forked lightning.

There is also a risk of isolated tornadoes forming in the affected area.

They said: “An area of low pressure will move NNE to the west of the area today. To the east of this, a slightly unstable airmass will be present.

“Several bands of showery rain are expected to move NNE across the discussion area, and lightning is already present within this to the south of SW England.

South Wales Argus:

“Strong deep-layer shear coupled with upper forcing will likely cause the precipitation to align into lines. Strong low-level shear will be present too.

“Heavier cores within the lines will be able to mix-down stronger flow from just above the boundary layer, bringing the risk of gusts of 50-60mph, perhaps locally 70mph in the most extreme cases.

“Hail is possible in the stronger cores too, as well as a few CG lightning strikes.

“Finally, whilst the overall tornado threat is low, given the linear nature of much of the activity, there is a low-end chance of one or two developing, especially within a core of stronger 850 hPa flow, from parts of SW England into Cent S England and the southern Midlands.”

A tornado is a violent rotating column of air that reaches to the ground from a storm cloud.

When the humidity is high enough, the tornado funnel is visible.