The YouGov projection model isn't being updated today because of the tragedy in London, but our regular commenter 'Unknown' pointed out that partial figures for Scotland from yesterday's update were unexpectedly revealed on Twitter a few hours ago. With changes from the last full-scale YouGov Scottish poll, they are -
SNP 42% (n/c)
Conservatives 26% (-3)
Labour 25% (+6)
That's much more encouraging than the Panelbase or Survation polls, because it basically suggests that the SNP haven't taken a hit from the Labour surge, and that the Tories have, thus leaving the SNP with a bigger lead over the Tories by default. A 16% lead is the largest than any of the familiar online firms (YouGov, Panelbase, Survation) have produced during this campaign.
As I understand it, the YouGov model is based on seven days of interviews, so the update these figures are taken from will cover the period between last Saturday and Friday. That means some of the fieldwork is older than Survation's, but some of it took place at the same time. The biggest drawback is that probably none of it (or hardly any of it) took place after Friday's Question Time special, which if we believe the GB-wide Survation poll may have generated an additional surge for Labour. It's certainly hard to see how that programme will have done the SNP any good, given that they weren't involved at all.