I was just looking at last night’s ascent from Watnall to gauge the size of the inversion that’s trapping the SC sheet beneath it across the eastern regions of the UK. The inversion is quite sharp, at 2,615 feet the temperature is just above freezing 0.3°C, but by the time you ascend to 2,841 feet it’s shot up to +6.8°C and the humidity as fallen to just 4% (fig 1). If the Pennines where a little bit higher they would stand clear of this particular inversion, and it would have been a lovely scene last night as the radiosonde balloon pushed through the inversion, with a lovely moonlit sea of SC beneath it, some patches of the SC sheet bright from the lights shining up from the city lights beneath it. Anyway enough of waxing lyrical, here are the results when the sun came up from a little higher even than the radiosonde balloon can reach (fig 2).
The SC sheet can’t be particularly thick, maybe no more than a thousand feet or less, so it may fragment as it tries to push further southwestward (fig 3), helped by the rise in temperature in western areas (I notice that we are already up to 13°C in Devon), we shall see.
Figure 1 – Courtesy of the Met Office and EUMETSAT
A lovely sunny morning down here in Devon after a sharp overnight frost, the 18-06 minimum at Exeter Airport was -3.4°C. But I notice that the edge of the SC sheet has just taken Yeovilton out, and a few bits of cloud have appeared on the eastern horizon as I type, so the sunshine might not last the morning out. The SC sheet itself looks very uniform across the country, with a base of 3,000 feet and tops of around 5,000 feet if the Herstmonceux midnight ascent is anything to go by.
Figure 2 – Data courtesy of OGIMET
Figure 3 – Data courtesy of OGIMET
Yet another news item in the Guardian and other similar media outlets about more scientists doing some airy-fairy research this time into what role the jet stream plays in the winters of the UK and the eastern United States. Of course it’s only available to download and read from the Journal Nature Climate Change for the sum of $32. Why, if the research is so important does it cost so much, or cost anything for that matter? I know a couple of outfits that will buy it, and they are the Daily Mail and the Daily Express, and they’ll make good use of the research and build a story of an impending snowmageddon around it that’s soon to be on its way to the UK.
As regards the research who would have credited it, the more zonal the jet stream the milder the winter, the more meridional the jet stream the more blocked and colder the winter will be. I would have never guessed that the researchers would have come to these mind-blowing conclusions. I will admit that the reduction in sea ice and hence the warmer temperatures in the Arctic over the last 20 years does have a role to play in this.
Courtesy of the University of Sheffield