Weekend winter storm update: Nasty weather likely for NJ
While timing, precipitation type, and accumulations are still in question, confidence is increasing that a significant winter storm will impact New Jersey this weekend.
The Bottom Line
The threat of a significant winter storm is increasing for New Jersey, between Friday afternoon and Saturday evening. Some combination of heavy snow, heavy rain, damaging winds, and moderate to major coastal flooding will make for prolonged nasty conditions in New Jersey. It is still too early to produce a detailed forecast, as significant questions have yet to be resolved regarding the exact storm track, timing, temperature profile, and snow accumulation potential.
Yes, everyone is thinking about and talking about this weekend's storm. And researching this forecast has literally taken up about 95% of my life over the past few days. However, it's in my job description that I have to include some sort of short-range forecast in my daily blog. So here you go...
It's cold! Tuesday will be similar to Monday overall. Morning wind chills are near zero, and will only improve to the teens by this afternoon. Thermometers will only climb to the 26 to 32 degree range across the state today.
Winds finally calm down on Wednesday, under partly sunny skies. Highs will bump into the mid 30s - still a bit below normal for mid-to-late January.
On Thursday morning, we could see a few light snow showers as a weak wave pushes through New Jersey. (Although this morning's models show these showers to be a fizzle.) Skies will become sunny again on Thursday, with highs again in the mid 30s.
And then clouds increase on Friday ahead of a strong low pressure approaching from the southwest. That's the system that will probably bring nasty weather to the Garden State starting Friday afternoon and through most/all of the day on Saturday.
Why Can't You Just Tell Me the Forecast?
In yesterday's blog, I joked that the forecast called for anywhere from 0 to 25 inches of snow. That example illustrated the challenges and inconsistencies surrounding this forecast. There is still little model-to-model consistency at this time, so it is still impossible to give a definitive, detailed forecast. Here are some of the biggest reasons why:
Sampling. The low pressure system behind our winter weather threat is still thousands of miles away, over the Pacific Ocean. That's a problem. Our computer forecast models are hungry for data specifically from the upper atmosphere to make a weather forecast. Most of the highest quality data input into these models come from the twice-daily weather balloon launches at about 100 National Weather Service locations across the country. Unfortunately, there are no weather balloon launch sites over the ocean. So the quality of the forecast model output for this storm is currently fairly weak. Once we have a better sampling of the energy swirling around in this system, we can present a more confident and accurate forecast.
Storm Track. The exact track the storm takes up the Atlantic coast is everything in this forecast. If New Jersey ends up on the left side of the storm, our precipitation will be mostly snow. If we end up right under the center of the track, our forecast will include a complicated mix of heavy snow and rain. If the storm tracks further out to sea, it would turn into a mostly wet forecast. If the track of the storm leads to prevailing northerly winds, the coastal flooding threat will be minimized. But if winds are out of the northeast or east (from the ocean), the Jersey Shore may be in trouble. This is a perfect example of The Butterfly Effect - a great movie, by the way - and an illustration of the chaos theory that dictates the workings of our atmosphere. The closer the storm gets, the fewer potential paths it may ultimately take. And therefore, the more confident we are that any "wiggle" in the storm track will be insignificant.
Temperatures. Among the major long-range models, the European has consistently shown a colder forecast than the GFS and Canadian. That would, of course, lead to a snowier forecast with higher accumulations. However, during the storm on Saturday, our official high temperature forecast for New Jersey ranges from 28 to 40 degrees. Yes, 40 degrees... too warm to support all-snow! In fact, coastal and southern New Jersey in particular are prone to see a period of rain or wintry mix at some point. That would, of course, lead to dramatically lower snow totals. Forecasting the location of the rain-snow line at any given time during this storm's evolution is going to be tricky (actually, almost impossible). The difference of just a few degrees over just a few miles could lead to a snowfall difference of many inches (or even feet).
The Worst-Case Scenario
I could provide a breakdown of each computer forecast model here... But since there's still considerable inconsistency and uncertainty, that analysis wouldn't provide much useful insight. Instead, let me review a few scenarios that could play out given the current data and information available.
A worst-case scenario would involve double-digit (i.e. 10+ inch) snow totals across most of the Garden State. If temperatures stay below freezing throughout the atmosphere, and if some heavy snow bands set up, snowfall could accumulate at a rate over an inch an hour overnight through Saturday morning. A large swath of the state could experience incredible 18 to 24 inch snow totals. During the peak of the storm, sustained winds of 25 to 35 mph with strong gusts to 60 mph would reduce visibility significantly, potentially producing near-whiteout and/or blizzard conditions. Dangerous wind chills and power outages would exacerbate the wintry weather. Additionally, storm surge of 3+ feet could cause moderate to major flooding up and down the Jersey Shore.
Wow, that's dramatic. Please don't go copying and pasting what I just wrote saying "This is what Dan said is going to happen!!!" It is a realistic interpretation of just how bad this storm could get. It's far from a forecast of what I believe will happen.
If such a worst-case scenario plays out, travel will be nearly impossible, possibly for several days. I suspect some New Jersey schools would still need to close Monday and even beyond, as the cleanup could take a while.
A More Likely Scenario
I am growing increasingly concerned about the wind and coastal flooding threat. No matter which model solution "wins" for this storm... no matter how much snow or rain ultimately falls... northeasterly wind gusts over 60 mph would cause downed trees, power outages, dangerous wind chills, and some pretty significant tidal surge. Tides will already be on the high side this weekend, with a full moon coming up on Saturday... So it won't take much to push gauges above flood stage.
On the precipitation side, I'm honestly leaning toward the GFS solution which shows a "mostly snow-partial rain" solution. As you might guess, the best chance for slightly warmer temperatures and therefore a period of rain or mixing will be along the Jersey Shore and in South Jersey. As I detailed above, that transition would lead to a huge snow gradient even from town to town.
But let's be frank... Forget about the potential for "feet" of snow for a moment... Even a widespread 6 inches of snow would be incredibly disruptive, and would clog even New Jersey's major roadways for at least a day.
Unless there is a significant change to the going model forecasts, someone in New Jersey is going to see big snow from this storm. The question remains... where and how much?
Could It Be a Bust?
Well, I'm not ready to rule out a complete bust (i.e. no big snow totals) from this system... But you can probably tell by the language I'm using on-air and online, a "nothing" scenario is rapidly becoming unlikely.
For several days in a row, every major forecast model has shown this system to have a significant impact on New Jersey. (Again, by significant impact, I mean some combination of heavy snow, heavy rain, strong winds, and/or coastal flooding.) There is a preponderance of evidence suggesting that our weather will probably get downright nasty this weekend. (Hence, the headline of this article.) But because we're still not sure what is going to happen where and to what degree, it's still premature to use hyperbole to describe this storm as "historic" or a "blizzard" or "snowmageddon", etc. (I'm looking at you, "social media-rologists"...)
I laid out several concerns above - specifically, above-freezing temperatures could force a changeover from snow to rain for part of the storm's evolution, and not knowing much about the storm's exact makeup and path across the U.S. yet. Any one of those could still enact dramatic changes to our overall forecast for Friday and Saturday.
More Details Coming Soon
My job is always to provide you with the most honest and accurate forecast I can. I expect that we'll gain some resolution on these forecast issues as the storm draws closer over the next day or two. Be patient - when we know something new, you'll be the first to know!
In the meantime, it would be a good idea to carefully consider your plans for the weekend. If the worst-case scenario forecast plays out, travel will be nearly impossible as power outages and flooding exacerbate any snowy or icy road conditions. You know the stores are going to be packed later this week - it might be wise to get ahead of the crowd, just in case. (I went shopping for my critical storm supplies yesterday.) No need to panic at all, but it would be wise to stay calm and stay informed as this potentially serious weather situation continues to evolve.
Next forecast update planned for Wednesday morning.