A spokesperson for the Essex County Education Coalition has confirmed that a number of schools in the county will be closed on Monday due to the ‘thunderfog’ that arrived late on Sunday afternoon.  

The weather phenomenon is caused by one area of cold fog colliding with another area of even colder fog, and air conditions across Essex have been described as ‘treacherous.’

Edmund Brouillard of the ECEC said: ‘We have been contacting head teachers all over Essex to ensure that their premises are safe for pupils and staff on Monday morning.’

‘One of the biggest problems with thunderfog is that it is powerful enough to permeate the inside of buildings, and we have already heard reports that some classrooms in Southend have visibility as low as three rows.’

‘Corridors are also a concern as we are aware that a yellow wet floor sign has to be visible from at least 10 metres away. At present, we simply don’t have the resources to add flashing lights to them.’

‘We also need to consider the surrounding areas and entrances. If some 33-year-old Leigh mum with humongous rubber tatas parks her 4×4 on zig zags, it is a road safety hazard for people who are trying to cross.’

‘Factor the thunderfog into the equation and it is a recipe for disaster. She’ll probably have very little on even though it is freezing, and you can imagine how close you will have to get before you can get a good look because of the mist.’

At around 7.30pm on Sunday, it was reported that heavy fog in Southend had led to the collapse of a classroom building at the Woodgrange Drive Primary Narcotics Academy. 

Headteacher Walter White said: ‘As the fog froze it solidified and made the roof collapse. Thank heavens that there were no kids inside. The lab equipment is replaceable, but it could have been so much worse.’