lastVisualChange and fullyLoaded are spiking up and down significantly for the Barack Obama article around Nov 4:
A similar issue is present on mobile for visualComplete99 around Nov 2:
A very modest increase to CSS has occurred on Nov 5 but hopefully it's independent of these spikes:
A select comparison on wpt.wmftest.org doesn't seem to show significant differences for these dates. Have there been recent changes to our WebpageTest instance?