Another nor’easter, another threat of significant snow for NJ
As many New Jerseyans continue to suffer the power outages and flooding impacts of last Friday's powerful winter storm, bad news looms on the horizon. Yes, another coastal storm system is aiming for the Garden State for the middle of this week.
There's still a tremendous amount of uncertainty regarding this new storm's exact track, which will have a tremendous impact on the geography and magnitude of snow totals. I can't ignore the fact that there's a real potential for a heavy "snow dump" over New Jersey.
Monday & Tuesday
Let me start with the short-term forecast which, thankfully, looks quiet. Both Monday and Tuesday will feature a mix of sun and clouds, dry weather, and light winds. Monday's high temperature looks to get stuck just below seasonal normals, in the 35 to 40 degree range. Tuesday should be a bit warmer, around 40 to 45 degrees.
Precipitation from this next nor'easter looks to start late Tuesday night (after 10 p.m.) Initially, we'd probably see scattered areas of rain for most of the state, with the potential for all snow north of Interstate 78.
The raindrops and snowflakes would spread across the entire state by sunrise Wednesday morning (7 a.m.) The morning commute through lunchtime Wednesday looks manageable — there may be slick spots, but roads would mostly just be wet.
All bets are off starting Wednesday afternoon (after 2 p.m.), as the heaviest precipitation arrives. In addition, falling temperatures by Wednesday evening (5 p.m.) would force a transition from rain to snow for most.
Bands of heavy snow would exit the state late Wednesday evening (10 p.m.), with lingering showers potentially continuing through early Thursday morning (8 a.m.)
This is going to be a pretty classic nor'easter setup, which will basically play out as follows:
1.) Area of low pressure (storm system) moves in from the west.
2.) Secondary low forms off the Carolina coast and moves north-northeast, paralleling the coast.
3.) These two low pressures "phase" or "merge".
4.) Coastal low becomes the primary, strengthening dramatically.
This setup is renowned for producing big snow somewhere between the mid-Atlantic and New England. Truly a "feast or famine" forecast, I've seen model snow solutions for New Jersey ranging from 0 to 18 inches.
Scenario #1: Too Far West
This is the forecast currently depicted by the GFS model.
In this instance, the center of the coastal low rides right along the Atlantic seaboard. As the storm system carries warmer (read: above-freezing) air with it, the Jersey Shore in particular would struggle to transition from rain to snow. New Jersey's highest snow totals would likely occur in the western part of the state (which would see the heaviest precipitation) and to the north (where it would likely remain cold enough for the duration of the storm to stay all snow).
The latest GFS model snowfall estimate calls for about 6 inches of snow in that target area.
Scenario #2: Too Far East
This is the forecast track currently favored by the European model.
Here, the center of the coastal low would end up well off the coast of New Jersey. While that puts us on the colder side of the storm (thanks to northerly winds), the truly heavy snowfall bands would be limited to the coast. Therefore, the highest snowfall totals in this scenario would occur along the eastern edge of New Jersey.
The Euro currently paints a swath of 6 inches of snow accumulation along the Garden State Parkway corridor.
Scenario #3: Sweet Spot
This forecast track is the current solution of the NAM model.
It's a Goldilocks forecast. Not too far west. Not too far east. Just the right combination of heavy precipitation and cold temperatures.
Sometimes it's easy to discard such an outlier forecast, but I believe the potential for heavy snow from this nor'easter is very real.
The NAM's latest solution shows most of New Jersey receiving significant snow accumulation (6+ inches) with a large bullseye of a foot-plus of snow along the NJ Turnpike corridor.
Winter Storm Watch
There's one area of New Jersey that at least partially falls into the snow bullseye in all three of these scenarios: North Jersey, specifically along and north of Interstate 78. That's where temperatures will likely remain cold enough for this storm to output all snow.
Since the start of snowfall is less than 48 hours away, the National Weather Service has issued a Winter Storm Watch for 10 counties in northern New Jersey:
--From 9 p.m. Tuesday to 3 a.m. Thursday for Hunterdon, Morris, Somerset, Sussex, and Warren counties (4 to 8 inches, with locally higher amounts).
--From Midnight Wednesday to 6 a.m. Thursday for Bergen, Essex, Hudson, Passaic, and Union counties (6 to 9 inches, with localized amounts to 12 inches).
For those who do not fall under the watch, don't let your guard down and/or don't get too disappointed. As I mentioned in Scenario #3, there's still a reasonably good chance we'll see plowable snow for most of NJ.
Wind & Flooding
Yes, this storm could carry some strong wind gusts. But rest assured, I don't see anything near the intensity of last week's storm. Best guess would be 30 mph gusts inland, and up to 40 mph along the coast.
Similarly, there could be a coastal flooding component. As we've discussed endlessly, that forecast is highly dependent on the precise speed and direction of the wind. (We were actually spared from truly catastrophic tidal flooding last week thanks to the strong northwesterly wind counteracting the surf and surge action.)
The latest guidance shows a foot or two of surge on Wednesday and Thursday. That's would push tidal waterways into the "minor flooding" category — enough to force road closures, but generally not so much water inundation to cause significant property damage.
So... What's the Forecast?
Honestly, I believe it's impossible make a definitive deterministic call at this time. While it's probably safe to say that someone in New Jersey will receive several inches of snow on Wednesday, I don't think we have enough model consensus to make a reasonably confident forecast yet. That's why I have opted not to draw a snowfall forecast map at this time — I'd rather be right than first.
Hopefully, those details will come into better focus within the next 12 to 24 hours. I'll be spending my final day of paternity leave patiently awaiting the afternoon model suite, and analyzing the ensemble model runs for additional insight. Look for a weather blog update Monday afternoon.
In the meantime, I'd keep any plans for late-day Wednesday as flexible as possible.
You know, when we experienced near-record warmth in mid-February, the public clamoring that "winter is over" was deafening. I said it then, I'll say it again: March is notorious for big storms and big snows.