Snapshot foretells Heeley Festival cold snap

Posted on June 23, 2010 by


I’m not a great photographer, but I noticed this view of ‘contrails’ over Albert Road Tram-sheds the evening before Heeley Festival.  I don’t often notice ‘contrails’ (short for ‘condensation trails’ or also known as ‘vapour trails’), but these lasted so long that they all start to criss-cross.  I wondered what it meant for the weather at Heeley Festival the next day.  According to an article in Scientific American:

‘A thin, short-lived contrail indicates low-humidity air at high altitude, a sign of fair weather, whereas a thick, long-lasting contrail reflects humid air at high altitudes and can be an early indicator of a storm.’

Well, thankfully there was no storm, but it was pretty fresh out there on Saturday.

If you’re interested in finding out more about ‘contrails’, they’re mentioned in a couple of Met Office documents: Factsheet1 on Clouds (basic information – good homework source); and ‘Science: driving our response to climate change‘ (bit more technical!).

I thought the photo was striking enough to share so I’ve added it to the Meersbrook & Heeley group pool of photographs on Flickr. There’s a permanent link to this group’s collection of photos if you scroll down the green panel to the right of Heeley Online’s main page.  If you get a Flickr account, or have one already, you can join the group and add your own pictures.  If you’re happy for other people to use your photos, you can give them a ‘Creative Commons’ licence.  Flickr explain the different aspects of Creative Commons licences fairly simply here.