55 ambient is above where you want to be in the initial phase of your lager. Ideally, you want to be at 50-52 fermentation temp for the first few weeks. Wait until you are approaching your FG (typically 2.5-3 weeks for me), then do a diacetyl rest for 2 days, then begin lagering. Under 30 degrees is too cold I believe. I typically lager a week for every 10 gravity points in the OG in the temp range of 35-38F.
Fermenting: Stout, Pumpkin Ale
Drinking: Pale Ale, German Pilsner, Cider
On Deck: Harvest Ale, IPA, Brown Ale