Winter returns to NJ: Accumulating snow likely this weekend
UPDATE as of 9:15 a.m. Friday...
Here are a few nuggets of wisdom I forgot to mention in my weather blog post early this morning:
--Refreeze: Friday will be rainy, then temperatures will rapidly fall into the 20s overnight. Although the accompanying brisk wind will help to evaporate some of the rain puddles, icy spots are still possible (even likely) for Saturday morning.
--Snow Character: Because temperatures are going to be close to the freezing mark during Saturday night's winter storm, any snow is likely to be heavy and wet. While it might take a couple of hours for snow to "stick" to road surfaces, things could get quite slushy and icy in a hurry.
--Forecast Range: The snowfall forecast I've embedded in this article serves as my "best guess" at how this storm will play out. The general trend is pretty clear: interior northern and central NJ get thumped, while the south coast gets mostly rain. However, the exact numbers are really hard to pinpoint, even now. I'm comfortable with my current forecast, with the caveat that it may need to be adjusted before the storm arrives. Just to give you a sense of the entire range of possibilities, I've seen forecast snow totals for this storm ranging from 0 to 9 inches.
ORIGINAL POST from 6:30 a.m. Friday...
From sixties to sogginess to sunshine to snow! It's a wild forecast over the next three days, as February-esque weather is about to return with a vengeance.
Here are your weather headlines for Friday, February 16, 2018...
Bands of steady rain have been traversing the Garden State on this Friday morning. The rest of the day looks pretty wet too, with showers (at least) through Friday afternoon. These are the first effects of a slow-moving cold front.
That front won't really arrive until late Friday (as early as about 3 p.m.) That means we'll maintain above-normal temperatures in the upper 50s to around 60 degrees — still toasty warm for mid-February.
As that front drives in a brisk northwest wind (gusting over 25 mph), colder air will begin flowing into the Garden State. Rain will end by about 8 p.m. Winds will calm after about Midnight. And by Saturday morning, it's going to be pretty frigid across New Jersey, with low temperatures mostly in the mid 20s.
The daytime hours on Saturday will be quiet, although chilly. Look for high temperatures to get stuck in the upper 30s to around 40 degrees, just below normal for this time of year.
The Winter Storm
Believe it or not, we are about 36 hours away from our next shot at accumulating snow — Saturday evening through early Sunday morning. And this forecast is still a low-confidence, complicated mess.
In Thursday morning's weather blog post, I presented three scenarios for our impending winter storm. As usual, the most likely result is trending toward a blend of these three situations: Rainy along the immediate coast, Snowy for most of the state, and possibly Very Snowy for part of interior New Jersey.
As usual with coastal storms, the biggest forecast issue is temperature. At storm time, temperatures are expected to range from 27 to 34 degrees across New Jersey(from north to south). A pretty small range — but included in those seven measly degrees is a huge range of potential weather conditions, from snow to sleet to freezing rain to rain.
The second biggest issue is where the greatest forcing happens — in other words, who will see the heaviest precipitation. I suspect this will occur along and just northwest of the NJ Turnpike. That means interior New Jersey will probably experience a quick "thumping" of heavy snow accumulation.
Here's the latest breakdown of this wintry forecast:
--Timing: First flakes will enter New Jersey around sunset Saturday (5 p.m. hour). Heaviest snow/rain is expected starting around 10 p.m. Saturday. All precipitation should wrap up completely by 8 a.m. Sunday.
--Winter Storm Watch: Early Friday morning, the National Weather Service issued a Winter Storm Watch for 13 counties in northern and central New Jersey: from Mercer and Middlesex counties northward. If the going forecast holds, this watch will likely become a warning either late Friday or early Saturday. I expect an advisory for the rest of the state (except, perhaps, for coastal zones).
--Biggest Snow: As my snowfall forecast map illustrates, I believe the biggest totals will occur in interior sections of northern and central New Jersey. (This geography matches well with the NWS watch.) That is the segment of the state that I expect to 1.) see all snow, and 2.) fall within the heaviest snow bands. I realize there's a somewhat significant different between the end points of 3 and 7 inches. But due to forecast uncertainty I believe either outcome is a distinct possibility. Literally a coin flip. Still, regardless of how much snow accumulates on the ground, travel will be quite difficult during the height of the storm.
--Snow/Mix: In the corridor from Monmouth to Salem counties, we'll be right on the line between "mostly snow" and "mostly rain". This mix will limit accumulations to about the 1 to 3 inch range.
--Mostly Rain: Along the Jersey Shore, especially for coastal Ocean, Atlantic, Cape May, and Cumberland counties, just-above-freezing temperatures will keep precipitation as mostly (but not exclusively) rain. There may very well be some sleet and freezing rain, so travel conditions could be messy at times.
--Confidence: For being only a day and a half away from storm onset, model consensus and forecast confidence are pretty poor. To call this forecast tricky would be a gross understatement. The NAM model shows 9 inches. Meanwhile, the GFS shows no more than an inch. The Euro has resolved to a middle-ground solution, pretty close to what I've presented here. I highly recommend you keep a close eye on the forecast over the next day, as last-minute changes may be necessary.
The Long-Term Forecast
Warmth returns as early as Sunday, with sunshine and high temperatures on either side of 50 degrees. We'll see some good snow melt by Sunday afternoon, although any spot with snow on the ground will be several degrees colder than the rest of the state.
Next week will be warm and somewhat unsettled, with a daily chance for at least an isolated shower. By Tuesday and Wednesday, we might see temperatures spikes to around 70 degrees!
I plan to publish two more full winter storm forecast updates: Friday afternoon/evening and Saturday morning.
Yes, that means the start of my paternity leave has been postponed until the final snowflakes fly this weekend. Part of the job.