Depends on the plume type. If it's water vapor, we might have additional warming. If it's SO2, then cooling. However, the plume type might not mean much if the eruption is weak. Also, the effects aren't definitive either.
One thing that caught my attention was that the 06Z NAM had a closed-off H5 Low at Delaware's Latitude. That's probably why the snowfall pushed further inland this time.
The 06Z GFS really wanted to rush the storm. The H5 vort closed off over NJ while remaining Positive tilted. This would benefit the coast quite a bit, but alas the amount of snowfall would be cut down further inland (Southern NY and NE PA) vs 00Z. Seems like EPA will get the goods on this run.
If there are disruptions on the stratospheric and tropospheric levels of the PV up north through late December, then there should be a window of opportunity through mid January into mid February.
Yeah. I'd be cautious about this one for the coast. The primary low not transferring quick enough is one scenario that's glaringly bad for the coast. Another problem is dry-slotting.
We really dodged a bullet. If Sub-Tropical Storm Melissa was 350 miles further west, we'd be talking about heavy rain and high winds with insane wave heights.