Yes, it’s going to snow in NJ this weekend – but not 10+ inches
All week long, I've been promising Thursday, Thursday, Thursday was the day to nail down more precise details on this weekend's potential winter storm. Well, Thursday is here and we find ourselves about 60 hours away from first flakes. Right on schedule, we are indeed getting a clearer picture on how this weekend's weather will play out.
The Short-Term Forecast
It's cold. Bitterly cold, thanks to a brisk northwesterly wind that will stay with us for another day or two. Welcome to January and welcome to wintertime!
We're waking up on this Thursday to temperatures around the freezing mark, in the lower 30s. Alone, that's really not too bad. But the wind chill has fallen into the teens for part of the Garden State. You'll notice the bite to the cold air the instant you walk out the front door.
Some flurries are also still flying around Thursday morning, which will fade away later on. No accumulation or travel issues are expected. Morning clouds will give way to sunshine by Thursday afternoon. Wind gusts over 30 mph will keep the wind chill in the 20s (at best) all day. High temperatures will be at or below seasonal normals, around 35 to 40 degrees.
Surprise, surprise... Thursday night will also be quite cold, with clear skies and a continuing breeze. Low temperatures sink to around 20 degrees. The wind chill will be in the teens, if not single digits. Let's break out our favorite winter cliche once again — bundle up!
Friday will be a very cold, sunny winter day. We'll have to once again battle a chilly breeze (to 20 mph) for the first half of the day (at least). Morning low temperatures will be in the teens, thanks to crystal clear skies, bone-dry air, and calmer winds. High temperatures will only reach the lower 30s. Much of New Jersey may be stuck below freezing all day. That degree of cold only happened on approximately 10 days in all of 2018: the frigid stretch from January 1 to 8, January 14, and November 22 (Thanksgiving).
Clouds will increase rapidly early Saturday. The daytime hours will be quiet, although cold with high temps only in the lower 30s. Snowflakes will arrive in the Garden State starting Saturday evening.
I'm going to break this winter storm forecast in two. First, I'm going to describe how this snow event is most likely going to play out. Then, in the next section, I'll discuss how things might change.
Timing: First snowflakes arrive Saturday evening, in SW NJ around 7 p.m. spreading through the entire state by around Midnight. Bands of moderate snow will be possible through Sunday morning. Most models show snow tapering off by Sunday afternoon around 2 p.m., although there's a chance snow showers linger into Sunday night and Monday morning.
Bullseye: North Jersey, this ain't your storm. The biggest snow accumulations will be found in far southern New Jersey.
Totals: It looks like the blockbuster "foot of snow" level storm that was a possibility early in the week is highly unlikely at this point. Click or tap my forecast map for our latest visualization of snow totals — just keep in mind, this outlook will need to be changed and shifted and adjusted as the storm gets closer and we get a better view of the snowfall potential. On the high side, no major forecast model is painting more than about 7" of snow accumulation in South Jersey, and even that might be a stretch. (My big range of 2 to 6 inches to the south reflects relatively low confidence in which scenario will play out there.) On the other side of the state, even an inch of snowfall in North Jersey might be a stretch.
Impacts: 6 inches is right on the edge of what I'd call a major or heavy snow event. So if that top-end forecast verifies in South Jersey, it will be a pretty snowy scene that could snarl traffic and travel for much of Sunday. Certainly enough to build a snowman or (small) snow fort. One or two inches, on the other hand, I'd consider conversational snow (maybe call it nuisance snow if you have to drive in it). Enough to have a snowball fight perhaps, if it isn't too dry and fluffy. Sure, you can go stock up on bread and milk and toilet paper and spirited beverages, but this level of snow will not strand you at home for days and days.
Questions Remain / The Fudge Factor
With about two and a half days until our first flakes arrive, I'd describe my confidence in this forecast is firmly moderate. Models are starting to agree, and I feel pretty good about the forecast I've presented here — I believe there is an equal chance the final snow amounts will be higher or lower. But remember, there is still plenty of time for the storm to evolve, necessitating a nudge in the totals or timing. However, a massive shift in thinking becomes more and more unlikely as time goes on.
Having said that, there are several possibilities and what if scenarios still running through my head. Here are some questions we have yet to resolve:
Will the storm wiggle north? At this stage, we generally have to consider a margin of error of 50 to 100 miles. The high end of that estimate would drag upwards of 6" of snow accumulation north to about the Driscoll Bridge over the Raritan River in Central Jersey. That would put the entire southern half of the state under pretty healthy snowfall, while northern NJ experiences an inch of two of snow.
Will the storm wiggle south? Well, it certainly could. And, of course, that would lead to even less snow than presented here. I think some snow is pretty much a lock for South Jersey, but there's a non-zero chance that we only end up with only an inch or two on the ground.
Will snow pour from the sky? Forecasting mesoscale banding — isolated pockets of very heavy snowfall — is always a challenge in winter storms. It is impossible to predict exactly where those over-an-inch-an-hour bands may set up, but we can look at the potential. I believe current guidance suggests the greatest convective potential stays south of New Jersey. But this element is still something worth watching as the storm inches closer.
Will it fall apart? Once again, this storm system will be battling a cold and very dry air mass. There's a chance the precipitation shield disintegrates in such an atmosphere. As you might guess, that would lead to snow totals on the low side.
Will there be mixing? New to the forecast models this morning is a splash of wintry mix/rain at the tail end of the precipitation on Sunday. Temperatures will certainly be cold enough to sustain all snow from Saturday night through Sunday morning. But then the precipitation type forecast becomes a bit more complicated, as thermometers climb to 33 to 35 degrees. Such mixing would ultimately 1.) reduce final snow totals slightly, and 2.) potentially lead to a freezing rain and icing situation.
Will it slow down or speed up? Sure, the storm could impact the state a little earlier than expected, say starting Saturday afternoon. As I mentioned above, there is a even better chance that snow showers linger into Sunday night or even Monday morning. The latter scenario could be pretty bad news — at least one model shows some healthy (i.e. accumulating) snow continuing through the Monday morning commute.
The Next Step
Depending on what Thursday afternoon's model run looks like, I may or may not post a weather blog update. Even though this is not looking like a major winter storm for New Jersey, I have canceled my scheduled day off for Friday and plan to work through the weekend to provide regular on-air and online updates.