Winter Storm Warning: 9 things to know about Thursday-Friday snow and ice
1.) The bottom line?
While I have tweaked my snow map, leaning toward more snow and less ice for the northern half of the state, the general impacts forecast remain unchanged. New Jersey's next winter storm is going to roll in fast and hard, with messy conditions during the daytime hours. Wintry mix will continue until sometime Friday.
2.) How much snow and ice?
My latest snow and impacts map neatly breaks down the state into major (6-10"), moderate (3-6"), and minor (1-3") impact snowfall. Keep in mind, sleet and freezing rain will be pervasive in the "orange" and "light blue" regions, which could lead to a glaze of ice along the way.
I'm feeling better about this accumulation forecast than I was earlier. Let me give you a peek inside my head — here are some things I'll be watching as the final model runs come in and the storm arrives:
—Will far northern New Jersey miss out on the heaviest snow bands, and therefore underperform the 6-10? (I almost called it 6-8 or 6-9 instead. But it is going to be snowing there for almost 36 hours straight, so in the end I'm not that concerned about mischaracterizing some pretty wintry weather conditions.)
—Will the initial snow band be so hard and so prolonged that SW NJ overperforms the 3-6? (Once it goes to sleet, accumulation is pretty much all over.)
—Could the far southern coast (i.e. Cape May) see zero snow accumulation, therefore underperforming my 1-3? (I almost put 0-3, but wanted to accentuate that things will turn pretty wintry at onset Thursday morning.)
3.) When will it start?
Precursor snow showers are possible between 2 a.m. and 6 a.m. Thursday. Don't worry too much about these — they could drop a dusting in spots, but there won't be any travel impacts yet.
Steady snow will move into the state between about 6 a.m. and 10 a.m. Thursday. All snow to start, and pretty heavy too. I expect road conditions to deteriorate rapidly as precipitation begins.
4.) When will the storm peak?
The brunt of the storm will come between 8 a.m. and 4 p.m. Thursday. This is when snow will pile up the fastest, as bands of heavy 1+ inch an hour snowfall cause quick accumulation.
In addition, during this time period, warmer air will intrude the middle layers of the atmosphere (about a mile overhead). That will force a transition from snow to icy mix (mainly sleet) across the southern half of the state Thursday afternoon.
By 4 p.m. Thursday, I expect the "dark blue" zone on my impacts map to still be mainly snow, the "orange" zone to be mainly sleet, and the "light blue" zone to be rain (possibly some freezing rain for inland areas).
5.) When will it lighten up?
As we move into the Thursday evening rush hour, after 4 p.m., precipitation intensity should decrease noticeably. Precipitation types (as described above) should generally hold steady through the overnight hours — light snow to the north, light wintry mix central and inland south, light rain southern coast.
6.) When will it end?
A surge of cold air will arrive early Friday morning. So, between about 6 a.m. and 10 a.m. Friday, the sleety and rainy areas of the state should flip back to mainly snow. Some models do show another little "thumping" of moderate to heavy snow in the Friday morning time frame, which could lead to some additional accumulation. (Especially in North Jersey, where snow cover will be largely unaffected by sleet and rain.)
Snowfall will become more scattered (broken apart) by Friday afternoon. I think we could legitimately have snow showers over New Jersey through about 8 p.m. Friday evening.
7.) What about coastal flooding?
Tidal guidance has wavered back and forth between "hardly any" and "a foot" of storm surge from this coastal storm. The on-shore wind really won't be ferocious. But because the storm system is more prolonged, as the low hangs out just off the coast into Friday, I still think we could see 1 or 2 rounds of minor coastal flooding. Those Jersey Shore residents who live in especially vulnerable areas should expect some water inundation issues.
8.) Warnings and advisories?
The National Weather Service has issued a Winter Storm Warning (pink), from 4 a.m. Thursday to 10 a.m. Friday, for NW Burlington, Camden, Gloucester, Hunterdon, Mercer, Middlesex, inland Monmouth, Morris, Salem, Somerset, Sussex, and Warren counties.
In weather, a "warning" means it's time to take action. If you live within the warning area, travel from Thursday through early Friday will become very challenging. This is the area where school districts will be strongly leaning toward a snow day (or going all virtual).
A less-severe Winter Weather Advisory (purple) covers almost the rest of the state:
—4 a.m. Thursday to 10 a.m. Friday... Atlantic, inland Cape May, Cumberland, coastal Monmouth, and Ocean counties.
—4 a.m. Thursday to 7 p.m. Friday... Bergen, Essex, Hudson, Passaic, and Union counties.
Poor coastal Cape May County, left out of the advisory fun, as usual.
The advisory vs. warning call in NE NJ is somewhat puzzling. (Those five counties are handled by the NWS office in Upton, N.Y.) I have that corner of the state firmly in the 6 to 10 inch snowfall forecast. Their advisory calls for 5 to 9, plus a light glaze of ice. Let's see if conditions warrant an upgrade to a warning as the storm arrives Thursday morning.
9.) What's next?
Hopefully this breakdown of the timing, accumulations, and impacts help you to plan your Thursday for maximum safety and minimum headaches. I'll push out one more weather blog update Thursday morning (by 7 a.m.), just as the heavy snow bands are approaching New Jersey. That article will offer one more detailed overview of this 36-hour winter storm.
Our news, digital, programming, and engineering teams are making their plans too. We'll be on-air and online with you until the final flakes fall.