In reply to Will Legon:
Health warning. The following comments are from experience NOT having been on the fells during the last week.
I would suspect Jacks Rake will be largely stripped as its low and south facing.
There will be snow on north through to east facing aspects - the view from Ambleside of Fairfield can often be deceiving as you are looking at a southerly aspect - it's not unusual to find good winter nick in the Lakes when there is no snow on theses slopes.
In your situation I'd go for the Helvellyn edges - Saturday looks good.
http://www.lakedistrictweatherline.co.uk/