Starting data

[in the vale]

I did check briefly if there was already a guide to this so, if this has been answered many times, please forgive me and please point me in the right direction. As usual, I have been watching the models this winter and it seems, to my amateur eyes, that the hi-res models have struggled far more than I have seen in many recent winters in getting 144, or even well before, remotely right. I know, for my location, all the super-hi-res views have been dreadful (even the NW-48 and others) - often by 6 or 7 degrees for days at a time. I have a VP2 so I reckon the 48-hr forecasts have frequently been several degrees out - which is unusual. It feels, as a result, that our low-res views have consequently sprayed around like an out of control fire hose. My question is whether all the big three share the same starting data - do they share? Or is there somewhere that shows the geo-density of data that each starts with. I just wonder whether there is something actually happening right now that the physics in the big three is not resolving well, and perhaps a data dark spot may help pinpoint roughly where this may be. Thanks smart people!