RU848789

Surprised nobody posted the updated maps and advisories as the NWS-Philly finally dropped snowfall amounts considerably north of 195/276, dropped the warning for Monmouth and considered dropping the advisories for near/north of 80, but also expanded the warnings well down into SNJ, reflecting the shift in the snow axis the last day or so; NWS-NYC also dropped snowfall amounts some, but did retain their 2-3" advisories. Like many of you, it's odd that it took this long. The AFD from Mt. Holly is below. .NEAR TERM /THROUGH TONIGHT/... One area of low pressure is tracking eastward across Virginia early this morning, while a stronger coastal low is lifting northeastward off Cape Hatteras. Light snow is breaking out ahead and to the north of the former low and that snow will quickly spread across our region from west to east through 8 AM this morning. While the snow is initially fighting some lower level dry air, and will not begin really picking up in intensity until mid to late morning, travel conditions during the morning commute will become slick, especially on untreated roads. Leave early, or telework if you can. Overall, the forecast looks on track; there is some rain mixing in along portions of the NJ shore and southern Delaware, but that was expected. Areas just inland are all snow at the moment, and temperatures/dewpoints across the area suggest that the cold air in place is as-advertised. Aloft, an initial shortwave bringing vorticity advection with mid- level forcing for the initial batch of snow heading in. This is also supported by some weak lower-level isentropic lift, and aided by diffluence farther aloft from the left-exit region of a strong upper- level jet streak. That shortwave will pass by to our northeast this afternoon, while the two areas of low pressure merge and intensify well offshore. However, another more potent shortwave and vorticity maximum will approach from the west this afternoon, with vorticity and much colder air aloft phasing in from the upper-low over the Great Lakes. As a result, a mid-level low will attempt to close off, off the southern NJ coast this afternoon, after passing across the Delmarva. That will support an inverted trough extending back from the strengthening storm offshore. Frontogenetic forcing and lower- level convergence associated with the low aloft and the surface trough respectively will be the key for focusing steadier and heavier snow today. Since Thursday afternoon, the last couple runs of various model guidance has made a distinct shift south with the axis of heavier snow amounts, focusing the inverted trough extending westward from Friday`s coastal low back closer to the Delaware coast rather than southern NJ. The initial steadier snow may set-up near the urban corridor from Trenton southwest later this morning. Much of the guidance suggests that the steadier snow will focus more on southern NJ into Delaware at it`s peak this afternoon, and linger there longest as the coastal low pulls away, dragging the inverted trough behind it. While higher snow ratios may make up the difference for a bit less liquid equivalent precipitation along the northern edge of the steadier snow, with the southerly shift in the guidance, we had to lower amounts by an inch or two across the northern half of our area. Considered dropping Advisory around Morris and Sussex Co NJ, but given some fairly rough conditions for the evening commute as colder air work in, it can be justified from an impacts standpoint. Did drop the Warning for Monmouth County, as amounts look to fall short of the 6" threshold there. Considered dropping Bucks to an Advisory as well, but amounts are near enough to 5" criteria to let it ride a this point. Meanwhile, farther south along the NJ shore and into the Delmarva, with winds expected to stay more northeasterly (rather than SE as earlier models projected), any initial rain may shift over to snow more quickly with less marine influence. Additionally, the axis of stronger forcing shifted south there as well. Added Kent County (both MD and DE) along with inland Atlantic and Cumberland County NJ to the Winter Storm Warning. Latest snow amounts in the warning area are somewhat marginal for reaching criteria, right around 5". However, given the tendency for higher ratios, the possibility that models are underdoing some mesoscale lifting mechanisms (coastal convergence, low-level convergence along the inverted trough, and mid-level frontogenesis), we expect some localized amounts near or even over 6 inches. Sometimes we expect too much accuracy from the model guidance QPF; it would only take another `surprise` 0.10-0.20 inches to exceed snowfall amounts by a few inches. While the snow may have a tendency to linger into this evening right where the inverted trough sets up, probably near Delaware Bay, forcing aloft will start to quickly diminish and progressively drier air will filter in. Just about all guidance suggests any last bit of snow will push off the coast by 9 PM.

Middlesex, Somerset, Hunterdon, and Morris, at a minimum, need to be split in half, like so many other counties in the NWS CWA system already have been. If they can split tiny Essex and Union, surely they can do these - that would likely put you in a warning as the areas on both sides of the border are forecast to get 3-7"...

Yea my personal opinion, shared by many met forecasts I've seen here and elsewhere, is that it's really unlikely to get more than 3" N of 78 and especially N of 80. Lee Goldberg, for example, has N of 78 only getting 1-3", but does have 3-6" south of 78. That's why I'll stick with my forecast of 3.3" for my house in Metuchen. The higher amounts south of 78, especially near 195 and south of there make sense assuming that's where the best inverted trough banding sets up. Would love to be wrong and get 4"+ and have everyone north of 78 joining in in the fun.

And here's the map for NWS-Philly, as well as the latest NBM. Still no real support for more than 3" from any of the globals. I hope the NWS and others predicting more than that have it right.

Wow, Lee Goldberg, who's usually fairly conservative, just called for 3-6" for much of CNJ, all of SNJ (except the SE coast) and a big chunk of EPA/northern DE, with the 3" line running very close to 78 from about Allentown to Elizabeth and then to the Southern Parkway on LI, with 3-6" south of that line and 1-3" north of that line. South of that line is where he and many other pros are thinking the Norlun Trough sets up and focuses the most lift and snow. Hopefully I can get a screen grab of his map once they put the forecast up. I have to say, I'm still concerned that all of the current global models (and their ensembles) are showing basically 1-3" but yet many forecasters are going with 3-5" in much of CNJ/SNJ/EPA. Is that mostly based on the NAMs? As an aside, I'm also surprised (but comforted) the NBM is showing so much snow - figured the blend would be heavier on the globals and not show much over 3"

NWS -Philly isn't the only bullish one, as Mike Masco just came out with his first call and it's pretty bullish, especially from about 10 miles N of 195/276 and southward almost to Delaware Bay, where he has a 4-6" swath from the inverted trough, mainly, as per the tweet, below.

I'm actually astounded at this, as the Euro, UK, and GFS generally have 1-2" for this storm (even using Kuchera), while only the NAM, CMC and SREFs have more than 3" anywhere. Maybe they're going with the ICON...

The last 2 years (20.2") rank as the 4th worst 2-year period in NYC snowfall history, so bad, but not unprecedented. 96/97-97/98 was 15.5", 30/31-31/32 was 16.9" and 97/98-98/99 was 18.2". And this winter, while off to a crappy start, is nowhere near over. https://www.weather.gov/media/okx/Climate/CentralPark/monthlyseasonalsnowfall.pdf

And here's the NWS Philly updated snowfall map. We do have an obvious discontinuity between the offices from Union up through Passaic, where the NWS-NYC has 1-2" while the NWS-Philly has adjacent Middlesex, Somerset, and Morris at 2-3". This often happens this far in advance and the offices should address this in future updates. It's also worth noting that the NWS-Philly is a bit more bullish than the NBM, while the NWS-NYC is in line with the NBM.

Ice accreting on all untreated surfaces here at 29F right now. The treated street in front of my house is ok, but the untreated street perpendicular to it is slushy from snow/sleet/rain and getting icy from the freezing rain.

It's a win because it's already verified for much of the area with every untreated surface around here covered in a glaze of ice and we're very likely to continue to see ZR for awhile anywhere along/close to the 95 corridor.

Score a huge win for the NAM and the RGEM the two major mesoscale/regional models, as both models have been calling for significant freezing rain (ZR) since Sunday morning and generally weren't joined by the global models in predicting appreciable ZR until Monday morning or afternoon.

Well, we flipped to freezing rain a little while ago, but it did sleet pretty decently for 30-45 minutes, which put down 0.1" of sleet before the ZR, so our final total for the storm is 2.4", which is a bit of a bust vs. the NWS advisory for 3-5" and my prediction of 3.2", but still a nice storm if you like snow and it'll be around to enjoy for at least a week and might even be topped off on Friday. I recall being excited, but a bit skeptical when the NWS-Philly bumped up their forecast yesterday afternoon; in hindsight their 2-4" forecast for 95 and most of CNJ/NNJ/NEPA would've been better. I cleared a small paved area when it changed to sleet and yes, it's now covered with the 0.1" of sleet and a glaze of ice on top, which will likely get worse for untreated paved surfaces, as temps are still only 29F and freezing rain continues to fall until early afternoon here with temps only forecast to reach 32F. Time for some sleep, then some shoveling...

Well, we flipped to freezing rain a little while ago, but it did sleet pretty decently for 30-45 minutes, which put down 0.1" of sleet before the ZR, so our final total for the storm is 2.4", which is a bit of a bust vs. the NWS advisory for 3-5" and my prediction of 3.2", but still a nice storm if you like snow and it'll be around to enjoy for at least a week and might even be topped off on Friday. I recall being excited, but a bit skeptical when the NWS bumped up their forecast yesterday afternoon; in hindsight their 2-4" forecast for 95 and most of CNJ/NNJ would've been better. I cleared a small paved area when it changed to sleet and yes, it's now covered with the 0.1" of sleet and a glaze of ice on top, which will likely get worse for untreated paved surfaces, as temps are still only 29F and freezing rain continues to fall until early afternoon here with temps only forecast to reach 32F. Time for some sleep, then some shoveling...

Of course that band is sleet, damn - best looking band of the storm lost to sleet. The dual pol looked like it and verified. Final (I think) snow measurement as of 8:30 am was 2.3" and I cleared the board to measure the sleet (which does get added to the snow, although sleet is much more dense than snow - typically 1" of liquid translates to 3" of sleet and 10" of snow). Hopefully the freezing rain holds off for awhile, although the temp has jumped up to 28F...

Of course that band is sleet, damn - best looking band of the storm lost to sleet. The dual pol looked like it and verified. Final (I think) snow measurement as of 8:30 am was 2.3" and I cleared the board to measure the sleet (which does get added to the snow, although sleet is much more dense than snow - typically 1" of liquid translates to 3" of sleet and 10" of snow). Hopefully the freezing rain holds off for awhile, although the temp has jumped up to 28F...

Anyone SW of me (New Brunswick to Princeton) know if that nice band heading NE towards me is still snow? Anyone?

As of 8 am we're up to 2.2" and still snowing at 26F, so temps are on the increase as the mix line gets closer (looks to be 15-20 miles SE of me). Looks like another decent band is to our SW from Philly to Trenton and will hopefully hit us (as snow).

As of 8 am we're up to 2.2" and still snowing at 26F, so temps are on the increase as the mix line gets closer (looks to be 15-20 miles SE of me). Looks like another decent band is to our SW from Philly to Trenton and will hopefully hit us (as snow).

Brief moderate to heavy snow band right now - maybe best snow of the event...

Had 1.5" at 4:30 am and just had our best 30 min of the storm and as of 7 am, we're at 2.0". Starting to doubt we get to 3" here (my prediction was 3.2"), as the radar has been much spottier over the last several hours than forecasted and the short term models right now aren't showing more than another inch falling along/SE of 95, if that, especially if mixing reaches 95 later this morning when precip rates are expected to increase, at least for areas NW of 95 and N of 78, where the storm has underperformed significantly with only about 1-2" for much of NWNJ/NEPA/NENJ/NYC. Huge doubts over whether the coastal is going to deliver as much snow/precip as was modeled even a few hours ago. Forecast was good for SNJ and CNJ SE of 95 with 3.5" in South River, 2.5" in Howell and 2.5" in Toms River.

Just had our best 30 min of the storm and as of 7 am, we're at 2.0". Starting to doubt we get to 3" here (my prediction was 3.2"), as the radar has been much spottier over the last several hours than forecasted and the short term models right now aren't showing more than another inch falling along/SE of 95, if that, especially if mixing reaches 95 later this morning when precip rates are expected to increase, at least for areas NW of 95 and N of 78, where the storm has underperformed significantly with only about 1-2" for much of NWNJ/NEPA/NENJ/NYC. Huge doubts over whether the coastal is going to deliver as much snow/precip as was modeled even a few hours ago. Forecast was good for SNJ and CNJ SE of 95 with 3.5" in South River, 2.5" in Howell and 2.5" in Toms River.

After a snooze, just checked the radar history and after an hour of nearly nothing, snow picked back up around 2:30 pm and then became moderate around 3:30 pm and I went out in it around 4:30 pm and measured 1.6" with the temp now at 25F. It is really pretty out there with moderately falling beautiful dendrites and nearly no wind. Had a nice little walk in the silent snow. The NWS cut back on snowfall a bit for the 95 corridor from Philly to NYC, down to 3-4" and SE of 95 to 2-3", as per the maps. Not a surprise with a bit less snow falling overnight vs. the forecast and with a mix (and maybe plain rain) probably occurring SE of 95 by 7-9 am and a mix by 9-11 am for 95 (based on a few point/click forecasts I looked at - the AFD wasn't very helpful). When any changeover to non-snow occurs will be critical in whether the 95 corridor gets to 3-4", as we're going to need to get a few hours of at least moderate snowfall to get there after the coastal starts to crank by 6-7 am, according to the discussion. Pretty sure most of the area SE of 95 already has their 2-3" or will by 6-7 am, based on posts I've seen on the weather boards.

Colonia? Rahway? I worked in Rahway for 31 years, at Merck...

As of 1 am, we're up to 1.1", so we had about another 1/4" last hour, but the radar has dried up to our SW and it's heading here, so expecting less this next hour, unless that fairly large hole closes up. Still 24F. Probably going to nap for a few hours...