UPDATE... This article is outdated...

For the latest winter storm forecast information, please refer to my newest weather blog post.


UPDATE as of 3:45 p.m. Friday...


ORIGINAL POST from 6:14 a.m. Friday...

The Bottom Line

We have two big headlines to talk about in your weather forecast, and they’re both quite wintry.

First, a blast of arctic air is set to arrive Thursday, leading to some of New Jersey's coldest temperatures in almost two years. And the wind chill in particular will approach the “danger zone”.

Meanwhile, our next winter storm looks like a "hit". It is becoming abundantly clear that a powerful coastal storm will indeed impact New Jersey early next week, in the Sunday-Monday-Tuesday time frame. There are a number of big question marks surrounding the track, type of precipitation, and totals. We’ll slowly and carefully piece together those details over the next 72 to 96 hours before the storm arrives.

The Cold

Thursday is a transition day. Early morning temperatures are holding near 30 degrees, with a little breeze. Light snow is just barely clipping southern New Jersey, staying mainly in the southern half of Cape May County. Otherwise, look for early clouds clearing to sunshine in the afternoon.

We’ll hit a high temperature in the lower to mid 30s around midday Thursday. Then, 30+ mph wind gusts will start to push thermometers down, leading to a frigid Thursday night.

I often refer to the wind chill as the “feels like temperature”. But it’s much more than that. Also known as the “apparent temperature,” it is an important measure of human health. It approximates the effect of both cold and wind on the body. And when the wind chill approaches zero and below, things like hypothermia and frostbite become increasing concerns.

Friday morning, low temperatures will be in the teens across most of the state. (Single digit temps in NW NJ.). Because of the continued brisk wind, the wind chill will be close to zero. (My math actually shows the WC ranging from -18 to +5 degrees.)

We won’t do much better through the rest of Friday. Despite sunshine, it’s going to stay windy (gusts to 35 mph) and very cold. Highs will only reach the mid 20s — likely to be New Jersey’s coldest day since February 2019.

I wouldn’t rule out a late-effect snow shower or squall creeping into NW NJ at some point Friday too.

Saturday looks better, thanks largely to lighter winds and bright sunshine. High temperatures in the lower 30s are still 5 to 10 degrees below seasonal normals.

The Storm

Let’s call this a “potential high-impact winter storm”. We’ve been watching its development for several days. Now, the culprit storm system is crashing into the U.S. West Coast and all forecast models are showing wintry precipitation in New Jersey. So we can now confidently declare this storm a “hit” and start taking it more seriously.

Big forecast challenge #1 is the timeline. We’ll likely have wintry precipitation falling over New Jersey for a period of about 48 hours, from Sunday to Monday to Tuesday.

Big forecast challenge #2 is precipitation type, which (as always) will be heavily impacted by the precise storm track. There is zero chance this is going to be an “all snow” event for the entire state.

With 72 to 96 hours to go before first flakes, it’s still too early to dig into details. But I can think outloud about possible storm scenarios.

Worst-case? Raw forecast model output suggests snowfall up to 16 inches. Alongside rainfall up to 2 inches. Wind gusts over 40 mph. Moderate coastal flooding. Yes, we could have a real winter storm in the works here.

At the moment, a plurality of model guidance shows the storm tracking along a sweet spot, with significant snowfall in North Jersey. Meanwhile, South Jersey would see a flip from snow to rain, leading to much lower accumulations (possibly even zero).

Where will the line between big snow and mainly rain end up? Good question. Likely somewhere between I-195 and I-78, but I wouldn’t bet on it just yet.

If the storm track wiggles north… More of the state will end up on the warm side of the storm. Accumulations and overall impacts go down.

If the storm track shifts south… NW NJ gets shafted from big totals, but we’d fall into a colder and snowier solution across the heart of New Jersey (the Turnpike corridor).

However… I don’t think there’s an opportunity for this storm system to completely escape and become a “miss” for New Jersey.

Next Steps?

So how do we go about forecasting such a long-duration, complicated, potentially high-impact storm? Very slowly and carefully.

Over the next 24 hours (by Friday morning), I hope forecast models will come into better agreement regarding the storm’s overall timeline (start, brunt, end).

Over the subsequent 24 hours (by Saturday morning), we’ll start nailing down potential accumulations. This will largely hinge on when and where snow-mix-rain changeovers happen. At this point, 72-hour tidal guidance will also confirm the magnitude of any coastal flooding.

Then we’ll continue to refine and revise the forecast until the flakes start to fly on Sunday.

So for now, bundle up, stay warm, and be patient. The grand finale of January looks active, to say the least!

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

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