Certainly notice that with my heat pump. While it is still cheaper than my old heating in all conditions, the jump in energy usage is enormous when it's subzero, due to the defrost cycles. Now the weather has warmed up a few degrees it is costing less than half what it was a week or two ago.
But I still prefer the frosty weather, and the 00Z GFS has got me a tiny bit interested after what seems to have been weeks of deathly dull model output.
00Z ensembles have quite a few cold options but look less good for prolonged cold than the 18Z set (which I didn't see at the time).
Originally Posted by: Rob K