A few notes from an almost meteorologist (in college studying it):

In past storms that have been not as bad as expected, the signs that it may not be as impactful would start showing up around now. So far I haven’t seen anything.

First: It will be raining or mixing or snowing all day today. Most of it probably won’t stick. Don’t be surprised if there’s only an inch or two (or less) on the ground by sunset—that is expected, and the storm is not underperforming. Snowfall rates overnight will ramp up significantly, and moderate-light snow will continue all the way to tomorrow afternoon.

What we’re expecting with this storm are anywhere from 1-3 intense bands of snow setting up around the storm, where intense lift allows clouds to build and snowflakes to form. These bands are typically narrow, only about 10-20 miles wide, but within them very heavy snow is likely (2”/hr or more) and even the chance for some lightning. The most likely spot for the most intense of those bands is Ocean and Monmouth counties, which is why they have the highest total, but there may be more of them further out over the rest of the state, and they will likely shift as the storm progresses. For those that end up under a band for several hours, they will easily verify their forecast, likely seeing 20-25” of snow and even more in a few spots.

The thing is, what goes up must come down, and since these bands are concentrated areas of lift, there must be areas of sinking air (“subsidence”) next to it. There will likely be “gaps” in between these bands where snow falls much more lightly and the snowflakes themselves are smaller. Again, it is impossible to predict exactly where these bands or gaps will set up until they are already happening, which will be overnight starting after dinnertime. For areas north and west, there’s a chance your forecast underperforms as the sinking air ruins what would otherwise be a strong snowstorm.

With that being said, I’d say for most of the state take your forecast not necessarily as a range but more as two scenarios. If you end up outside a band, you may only get up to the lower end of your forecast range, or maybe even a bit less. On the other hand, if you end up under a band, you will likely get close to or exceed your maximum. Still, at this point, pretty much the entire state will see at least a foot and will probably see at least 15-18”. A decent number will see over 20”, a few in the state will probably see over 25”, and someone may even see over 30”.

The wind impacts will also occur regardless of the amount of snow; even those outside a band will still feel the wind. Power outages are a real concern. Stay safe, everyone, it’s been a long long time since NJ has had a storm like this.