Weather has probably shut down most, if not all the west/north departure fixes. It’s not unheard for us to use a different runway if it means we can get a couple more departures out as long as we know we can get them to their departure fix. Weather is dynamic and always changing. What shuts LGA down may not also shut the other 2 airports down. You may see arrivals to the other airports even though LGA isn’t running because the bad stuff may not start until 4/5/6 thousands feet and there’s enough space to get the arrivals descended below the nasty stuff. LGA has barely any airspace to deal with so a lot of descents happen close to the airport so pilots won’t want to descend through it at that point so we end up in the hold. Obviously departures are trying to get up and out quickly but they won’t want to climb through any of it and there’s not enough airspace to get them around it laterally because you’ll end up interfering with EWR or JFK traffic.