Winter Storm Watch: Less than 48 hours away from a nasty nor’easter
The Bottom Line
One storm system (almost) down, one to go this week.
With snow, ice, rain, wind, and coastal flooding still very much on the table, Wednesday-Thursday will easily be New Jersey's most significant winter storm in several years. Peak impacts will be Wednesday night through early Thursday morning. While confidence remains high that the storm will "hit" here, specific details (like timing and accumulation) remain uncomfortably uncertain.
Not much. It's actually remarkable how consistent forecast models have been for this storm since Thursday. There are some things that still make me hesitate in going all-in on the heavy snow forecast. For instance, the NAM model continues to paint a period of sleet and freezing rain in west-central NJ (Mercer/Somerset/Hunterdon counties) Wednesday evening. And there's also the "boom or bust" factor — there will likely be a very tight gradient (a few miles) between double-digit snowfall and a puddle of slush. If the storm track wobbles even 50 miles in either direction, it would lead to drastically different conditions.
Given the (ahem) feedback from my early Monday morning forecast, I have tweaked my snow accumulation map to offer a slightly clearer (although still uncertain) picture of how I believe the nor'easter will play out. It is based on the latest data and guidance. And those snowfall ranges are still pretty wide. But hopefully that gives a more effective picture of where we're expecting high, medium, and low snow impacts. This map will update at least three more times before the storm arrives — that's just how the inexact science of weather forecasting works.
A Winter Storm Watch continues for most of inland New Jersey, technically in effect from 10 a.m. Wednesday to 10 a.m. Thursday. (That's a smidge later than the initial watch issuance — a good change, in my opinion.)
A watch means that hazardous winter weather conditions, including snow, ice, and reduced visibility are possible within 24 to 48 hours. Sometime Tuesday, warnings will be issued where snowfall is expected to hit 6+ inches. Advisories will be issued cover the rest.
In addition, we now have a Coastal Flood Watch for the Jersey Shore, effective from 7 a.m. to 3 p.m. Thursday. That morning high tide cycle looks to cause widespread moderate category flooding, with just over 2 feet of surge.
—Wednesday morning looks fine. Mostly cloudy to overcast. Quite cold in North Jersey, starting the day in the 20s.
—Wednesday midday to afternoon, things start to go downhill as initial showers arrive. Snow to the north and west, rain to the south and east.
—Wednesday evening's commute could get tricky as heavier precipitation bands become more likely and more wintry.
—Wednesday late evening, we'll be in the brunt of the storm with the heaviest snow (rain along the immediate coast) and strongest wind gusts.
—Thursday morning after sunrise, things will start to taper off. Storm surge and coastal flooding issues likely at high tide.
—Thursday mid-morning, the sun emerges but it will remain cold.
I have previously referred to this as a "classic nor'easter". And the anticipated impacts and biggest concerns will match a typical northeast coastal storm. In order of my biggest to least concern:
—Obviously, 6 or 12 or 18 inches of snow is a lot. Potentially crippling travel for at least a day, if not more. It's very important to note that NOT everyone in New Jersey will see such big totals. But I'm pretty confident a wide area of the state will get buried.
—Ice is way worse than snow. And we could see a warm layer less than a mile above the surface and/or some really heavy convective precipitation toward the tail-end of the storm Thursday morning. That would force a transition to more sleet and freezing rain, rather than straight snowfall. Icing would obliterate our snowfall forecast, and make for even more challenging travel conditions and even more difficult clean-up.
—Some of the Jersey Shore's record tidal floods have been from wintertime nor'easters. 2 to 3 feet of extra water barreling toward our beaches could cause inundation issues, road closures, and possibly even property damage.
—Wind gusts up to 55 mph is sufficient to cause minor damage — especially when combined with heavy snow, ice, and rain. Scattered power outages seem likely during the height of the storm Wednesday night. Bad news for heaters, work-from-homers, and remote-learners.
—Heavy rain, on the order of 1 to 2 inches along the coast, would lead to visibility, traction, and ponding problems.
I think we now have a pretty good idea of how this storm system will play out over time (see the Timeline section above). My goal for my next blog posting Tuesday morning will be to add more specific times to that outline, including some sort of region-by-region or even county-by-county breakdown.
We'll also continue to refine our sense of snow vs. ice vs. rain, and consequently potential accumulations across the state. We're getting there.
And I think we also have to start really hammering home the wind and storm surge threats. I'm still worried we're facing significant flooding problems along the Jersey Shore. So far, the peak push of water looks to be during low tide along the oceanfront. But what about back bays? How many high tide cycles will be precarious? Could we approach major flood stage in spots?
And while there are no more significant storms on the horizon (thankfully), the post-nor'easter cold air will be quite uncomfortable. Especially for those who lose power, or for those with huge snow drifts on the ground.
Next weather blog update should be posted by 7 a.m. Tuesday. Until then, make it a great night.