I don't post in this subforum much anymore because I moved years ago, but I still "lurk" frequently (split time with the Pittsburgh threads essentially). Though there is a decent chance this will be my home forum again within the next 6 months.
This topic has come up on occasion, maybe once or twice a year. IMHO, I think generally it may make more sense to keep them apart. This forum is certainly plenty active when there is weather to discuss, I think, but the reality is this winter is dead for the time being. Other than the larger "macro" pattern, there's nothing really to talk about. And who knows if we see anything favorable this season. It just doesn't lend itself to great discussion. I'm sure other forums are more active because of more users. I don't know if that matters to others; I can say it doesn't matter to me.
With NYC being as big as it is I can only imagine it swallowing up the Philly folks, perhaps making it difficult to separate the two. Eastern is a distant memory so I can't say I remember much about it and how we coexisted. I suppose if people really don't like it here they can attempt to generate more discussion or visit the other subforums, perhaps even the "new" Philly weather forums (though I haven't been there myself so I can't comment on it further).
When speaking to merging, wouldn't merging with the Mid-Atlantic make just as much sense, if not more? I think Philly and Baltimore's long-term yearly snowfall averages are closer to each other than Philly and New York (though none are very far apart). Though D.C. is quite a drop-off from these three. I suppose an argument could be made either way.
Perhaps we just merge them all and have individual threads for each city. I admit it is somewhat unfortunate the true "weather talent" (actual meteorologists) is spread so thin, having to traverse multiple subforums to access all the different opinions. Then again I understand much of this talent only offers discussion for their individual locales. Not sure if it would change their process if all the locations were merged.
TL;DR: Didn't intend for this to be so long. I'll keep visiting regardless of what happens with the forum configuration. Prefer separate but okay with a merger whether it be NYC or MID-ATL & PHL.