I thought one of the changes with FV3 was that the unrealistically deep minimum lows forecast by GFS would be improved. Some have commented that FV3 may have gone too far to the opposite extreme and not allowing enough formation of deep lows. We saw with TC Owen that FV3 deviated significantly from GFS.

Well now look at what FV3 has cooked up in the 20 Dec 12Z run at about 300 hours onwards, a deep low NE of New Caledonia, when the 12Z run and forecast hours from GFS are much more moderated.

Before anybody says it, I do acknowledge that anything beyond about forecast 96-120 hours can often be quite speculative.