Cascade Pastaza-Familiar with this yarn?

[Rennagayle]

I'm wanting to knit a winter hat, and the pattern says she used two skeins of Cascade Pastaza. She doesn't state what weight yarn to use if substituting, so I googled and found a couple of sites which sell this particular kind, to see if I could find out what weight it is. Each of the two sites where I looked give the exact same specifications for the yarn, except one classifies it as a "chunky", and one classifies it as a "worsted".

I'm wanting to use a yarn I have on hand, but am not sure what weight to use. Can anyone advise me on this, that is familiar with that yarn?