In reply to climber_Ken:
Hi Ken,
For the avvy forecast for Picos de Europa head here:
http://www.proyectoenacc.com/meteo-nieve/bpa Usually there's a link to the PDF at the bottom, so that you can get a nicer, coloured version that can help if you don't speak Spanish.
As for the traverse itself, the December 2014 issue of Desnivel had a description of what you might be looking for:
http://desnivel.com/revistas/especiales/desnivel-342
However, I didn't see it, so I cannot tell if it would be helpful in terms of maps, difficulty etc. I am guessing it shouldn't be too bad as Desnivel prepares their articles well. You may buy this issue on Zinio platform in digital form, so worst case you'll shell out 5EUR for nothing... The issue contains both the Picos Traverse and the Circular route - so perhaps this will give you some inspiration.
HTH
RS
PS: The avvy info is normally issued for weekends only, so take a look at the issue date when consulting the forecast.
Post edited at 10:48