There's not much more to say about this powerful coastal storm, that we've been tracking since last Thursday. With a wide variety of "nasty impacts," it is expected to be New Jersey's most significant winter storm system in a couple of years. It will also be our biggest December snow in a decade, since December 26-27, 2010. And I suspect it will be one of our biggest autumn snows of all time.

The center of this "classic nor'easter" is now forecast to pass directly over the southern tip of New Jersey Wednesday evening. That warmer forecast affirms that we're going to see very different weather conditions at opposite ends of the state. To the northwest, 16 inches of snow. To the southeast, 2 inches of rain. In the middle, sleet and wintry mix — a very important piece in the snow accumulation puzzle. Everyone faces howling winds. Which will draw ocean water toward the Jersey Shore, leading to coastal flooding.

Final forecast for Wednesday-Thursday's nasty nor'easter, as of Wednesday morning.

Timeline

—Wednesday Morning... Nothing yet. It's a cold start to the day, with temperatures mainly in the 20s. High temperatures only reach the 30s. Skies will be mostly cloudy, with quiet and dry weather lasting through about lunchtime.

—Wednesday Early to Mid Afternoon (1 p.m. to 4 p.m.)... Initial band of precipitation will push in, from southwest to northeast. Outside of NJ's coastal counties, it's likely to be snow to start. Closer to the coast, probably just rain.

—Wednesday Evening Rush Hour (4 p.m. to 7 p.m.)... Conditions will continue to spiral downhill quickly , with sloppy and slippery roads becoming more and more problematic (especially the farther north and west you are).

—Wednesday Late Evening (7 p.m. to 2 a.m.)... Peak precipitation intensity, lowest visibility, and strongest winds. For all but far northwestern NJ, warming temperatures in the lowest mile of the atmosphere will spark a transition to sleet, icy mix, or straight rain. (At least briefly.) Make or break, boom or bust, right here.

—Early Thursday Morning (2 a.m. to 6 a.m.)... Center of the storm pushes out to sea, and weather starts to calm down. Sleet goes away, transitioning back to snow.

—Thursday Morning (6 a.m. to 11 a.m.)... Storm winds down, with a period of light snow likely for almost everyone (away from the immediate coast).

—The Rest of Thursday... As the sun breaks out, it will be breezy and cold. High temperatures will only reach the lower to mid 30s. There won't be much snow melt, aside from treated and blacktop surfaces.

Totals

You know, if temperatures were cold enough to sustain an "all snow" storm, this would be an easy forecast — 15 to 24 inches statewide. Done and done. But that is not the case.

As you can see on the map above, total snowfall is expected to range from a big fat zero (south and coast) to 16+ inches (northwest). After struggling mightily with forecasting the location of the "boom or bust" transition zone, I'm fairly happy with this final call. (Well, as comfortable as I can be with a complicated storm system like this.) The northern extent of the sleet, icy mix, and rain is absolutely what will "make or break" this forecast.

Unsurprisingly, the biggest snow totals will be found in the coldest corner of the state, approximately north of I-78 and west of I-287. Over a foot of snow is possible. I put an upper bound of 16" on this region, but isolated 18+ isn't completely out of the question (as the National Weather Service is suggesting in their final forecast).

Just south of that, I had previously suggested the likelihood of double-digit snow totals along the Route 1 corridor. But now I'm not so sure, given that (brief) period of sleet creeping in Wednesday evening. It's still going to be very wintry across much of Mercer, Somerset, Middlesex, Union, Hudson, and Bergen counties with about 8 to 12 inches of accumulation.

Farther south, we run into big mixing problems. The "blue" area on my forecast map is probably the most uncertain here, stretching from Sandy Hook to the Delaware Memorial Bridge. There will be snow at the onset, but the changeover Wednesday evening will put a halt to accumulations. What it changes to (mostly sleet vs. mostly rain) will dictate whether we end up on the high or low end of that forecast range. Monmouth County is especially tricky, as my forecast literally includes a range of 0 to 12 inches from one end of the county to the other.

For the southern third of New Jersey, there is no guarantee of any snow at all. But I will leave a glimmer of hope for snow-lovers, as a few models show some snowfall at the very start and very end of this thing. And that could stick to colder surfaces. I do not expect any substantial accumulations or travel problems, other than wet roads.

In addition to the snow, upwards of 2 inches of rain will fall along New Jersey's southern coast.

Top wind gusts should hit 40 mph (inland) to 60 mph (coast).

That wind will drive 2 feet of storm surge toward the Jersey Shore.

Impacts

As you know, driving/traveling is THE most dangerous activity during a winter storm — something like 96% of snow deaths happen in a car. I think my best advice is that if you can be off the roads before the traditional evening commute time, that would be a good idea. Schools and business may consider early dismissals.

Low visibility, ice and slush, and the wind will make for very challenging travel conditions Wednesday night through Thursday morning. In places where it snows hard, it will take crews a while to clear a foot-plus of snow. Schools and business will aim for a delayed opening or (more like) an outright closure due to the wintry conditions. (Again, not everywhere, just in the "snow zone".)

Heavy rain in southern and coastal New Jersey will cause visibility, traction, and ponding issues. The rain is going to be really cold and uncomfortable too.

Power outages will be scattered to widespread, especially in our coastal counties where wind gusts will be highest. Bucket trucks will be grounded until the storm calms down, so it might take a while for restoration.

The ferocious wind will also unhinge Christmas decorations and garbage cans, and also make driving difficult (especially in a high-profile vehicle like a truck, bus, or van).

And the coastal flooding picture is still worrisome too. Widespread moderate flooding will occur along tidal waterways during Thursday morning's high tide cycle, necessitating road closures.

Final Thoughts

It's going to be a nasty 20-hour period of weather, no matter where you live. And our weather, traffic, news, digital, and programming teams are camping out at the radio station to feed you up-to-the-second information before, during, and after the storm.

Be smart, stay safe, and thanks for joining our storm coverage.

Dan Zarrow is Chief Meteorologist for Townsquare Media New Jersey. Follow him on Facebook or Twitter for the latest forecast and realtime weather updates.