RU848789

So, same question I asked 3 hours ago...can this happen still?

As of 9 pm we have 5.75" OTG - slowed down a bit the last 30 min with the radar break; hoping it picks back up soon. Pretty happy so far. Would love to get to 10". 26F now.

is this possible that the HRRR has 5 or more inches left?

As of 8 pm, we have 5.0" OTG which is 1.5" the last hour - that's pretty heavy snow. Pounding here now. Still 25F. Very heavy band on our doorstep.

As of 7 pm, we have 3.75" OTG which is 1.5" the last hour - that's pretty heavy snow. Pounding here now. Still 25F. Very heavy band on our doorstep.

SIAP, but here's the latest from the NWS...if the underlined part about the snow/sleet/rain transition line being further SE than expected comes true, folks from Trenton to NYC will likely see mostly or all snow (and at least 8" and up to 12" and maybe more if the back end delivers), but that's certainly not a given. At current rates, we'll have 6" by 10 pm, the earliest any models showed sleet. We'll see... Area Forecast Discussion National Weather Service Mount Holly NJ 555 PM EST Wed Dec 16 2020 NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... Evening Update... The storm is well underway now, with steady to heavy snow, sleet, and rain having overspread all areas. Made a few tweaks to the snow amounts to reflect some observations, but we`re well past the point for any meaningful changes. In general the onset and ptype transition have gone about as expected and the forecast continues to track well for such a big event. If anything the cold air has held on a little longer than expected and certainly longer than a lot of this morning`s hi res guidance indicated, leading to some higher totals across portions of southern New Jersey. This includes here at the office where some massive snowflakes and snowfall rates of 2 to 3 inches per hour have been observed leading into the transition, which was happening here around 5:30 PM after about 4 inches of snow. That transition line continues to march north and there have been no changes to headlines or the overall forecast philosophy, with the sharp gradient appearing it will end up just slightly southeast of forecast especially in New Jersey. In addition to the ptype transition, satellite and radar also show the dry slot rapidly approaching from the southwest. This should lead to precipitation rates falling off significantly or precipitation ending completely for areas such as Delmarva and parts of southern New Jersey over the next few hours. Further north, snow rates are starting to come up significantly, and these areas remain in line for the highest totals. No noteworthy changes to the forecast to the north and west with a widespread 10 to 20 inches of snow still expected. Dry slotting should be less of a factor to the north, but banding will produce local variations in totals. Late tonight as the low starts to pull away, a final wrap-around band of precipitation may bring some additional snow to many areas, especially towards central and northern New Jersey. This could add on an inch or two of accumulation within a couple of hours during the predawn hours. In addition, falling temperatures later tonight could lead to a refreeze of any water or slush, yielding continued treacherous conditions into the morning. No changes to the wind forecast either, with winds steadily ramping up from south to north. A 60 to 70 kt easterly LLJ will continue to bring a lengthy period of gusty winds as it partially mixes down to the surface, especially along the coast and within the heavier precipitation. Gusts up to 60mph remain possible along the immediate coast this evening and into tonight, with 45 to 55mph gusts possible in the coastal plain and 35 to 45 mph gusts elsewhere. Storm total QPF continues to look mainly at or below 2 inches, possibly a bit higher along the New Jersey coast and towards the Poconos. Dry slotting should help keep liquid totals manageable in most areas. Outside of nuisance/poor drainage flooding, no hydro issues are anticipated. Marine and coastal flood headlines remain in effect, and are covered in their respective sections below.

Just got in from a wonderful Jebwalk with my wife, our son and his girlfriend. As of 6 pm we have 2.25" OTG (was only about 1" at 5 pm, so it's coming down) and it's 25/23F. Heavy snow right now with 1/4 mile visibiilty. Gorgeous out there - don't forget to get out in this stuff - snow angel time soon, lol.

Nice! That's where I grew up - WTHS Class of 80. Hated being on the wrong side of the rain/snow line growing up, relative to Philly and NW suburbs, but good to see it's overperforming for you already, as you're on the NWS ~1" line.

Hey @SACRUS - always loved this resource, but looks like a lot of links don't work anymore (most of the radars)...

It's fascinating really: we have we have the Euro/GFS (snowy) vs. CMC/UK (snow/sleet) on the globals and HRRR (snowy) vs. NAM (snow/sleet) on the mesoscale models - almost 50/50 to me. Anyway, 18Z HRRR ftw! Or 18Z NAM for the...sleet, I guess (still way better than rain) - posted both the Pivotal/Tidbits maps so people could see the difference (sleet counted as snow by TT, which is ok if one uses both, as per below). Also, I've posted about sleet in models and sleet impact in depth before, but worth a repost, IMO (this is from last night, elsewhere, but applies still). Briefly, Pivotal only reports pure snow and TT reports snow + sleet, but all counted as snow. One can't figure out how much of the TT frozen equivalent is snow vs. sleet directly, but you can if you compare the Pivotal and TT maps, as long as you use the 10:1, snow:liquid outputs. Pick a spot like Philly, which shows 4.4" of snow on Pivotal and 13.4" of "snow" on TT. Since both are reporting the amount as 10:1 that means the Pivotal LE is 0.44", while the TT LE is 1.34". If you then subtract out the snow from Pivotal from the TT total, that means that 0.90" of that LE is sleet and if one assumes that the sleet has a snow:liquid ratio of 3:1, then that is 2.70" of sleet by depth. In theory, that that 4.4" of 10:1 snow and the 2.70" of 3:1 sleet would equal 7.1" on the ground, but often sleet falling on top of snow will compact the far less dense snow underneath it (I measured that effect in the linked post) by 25-50%, so one might get a snow/sleet depth of 5-6" and not 7.1". The opposite is not true, i.e., snow falling on top of sleet will not change the depth of the sleet, so you'd see 7.1" on the ground for this case. Given my long history in emergency preparedness, including being in charge of snow removal crews for the site where I worked for 30+ years (5000 person site in Rahway - Merck), that's why I like the TT maps better from that perspective, since frozen mass and not depth is far more important with regard to plowing/shoveling/snow removal, as well as with regard to impacts on the road, meaning 1.34" of frozen LE mass is just as impactful whether it's 13.4" of 10:1 snow or 4.5" of 3:1 sleet or anything in-between. The one exception to this is visibility, as sleet barely affects visibility. That's why, to me, the Pivotal map of 4.4" does not tell me at all what the impact really is going to be, while the 13.4" of "snow" (which is really a snow/sleet mix) from TT tells me what the impact will be. I get the aesthetics part of it, but from a meteorology perspective, since so much is based on preparing the public for impacts, I've always been surprised and disappointed that mets don't report total frozen mass at least alongside frozen depth. Maybe more than folks bargained for, lol, but hope it's useful.

Started snowing lightly here around 2:40 pm - nice dusting...Will be on the knife's edge late this evening into Thursday on whether we get sleet and how much - will possibly be the difference between 6" snow/2" sleet vs. 12" snow (same frozen mass though!) - I'm fine with either - the thing I hate is rain in a winter storm.

Just posted elsewhere that we need to see if this is "real" or not vs. the other models, i.e., whether there's some heretofore unseen parameter leading to all models trending this way or if it's just some flaw in the data input or model physics with the NAM. We'll know in a couple of hours. Just like one shouldn't overreact to a huge jump up in snowfall for one model (like the 40" RGEM the other day), one shouldn't overreact to one model slashing snowfall. Also, at this point, the NAM is often pretty good, so even if it's an outlier it can't be discounted. As I said this morning, I did think Mt. Holly was too bullish on total snowfall, especially for the 95 corridor (12-18") and NWS-NYC was likely a better call with 8-14" of snow/sleet for NYC/95 corridor.

NWS just put out their regional snowfall map, below, and the NWS-Philly is staying fairly aggressive - a bit moreso than me, with 12-18" of snow (with some sleet) predicted for most of Middlesex, Mercer, Somerset, Bucks, Montgomery, Chester, Delaware and Philadelphia counties and all of Somerset, Hunterdon, and Morris and even a bit more than that NW of there with 20-24" predicted for the Poconos, Sussex/Warren, and Lehigh Valley.Warnings are up for all of these counties and watches, still for the counties on the NJ side of the Delaware in SNJ, and Monmouth, since sleet/rain may hold accumulations down there. Monmouth might see the biggest gradient of any county, with only a few inches along the coast but possibly 12" or more close to Middlesex and Mercer counties.And the NWS-NYC is similarly aggressive with 12-17" predicted for NE NJ (Union up to Bergen) and the Hudson Valley and CT, but a little less aggressive with only 8-14" for NYC and most of LI, as they think sleet will hold accumulations down a bit - this is what I would expect for Middlesex, Mercer, Philly and its close suburbs in PA. It's why my guess for my house in Metuchen is for 14" of snow/sleet (the point/click forecast is for 17" in case anyone thinks I'm bullish, lol).The NWS also put out their regional max wind gust map, below, and it shows the coastal counties in NJ/NY with up to 60 mph gusts possible and 40-50 mph inland (this would be mostly after 11 pm Wednesday, through 7 am Thursday). Where this coincides with heavy snowfall, we'll likely see occasional blizzard conditions, although my guess is we'll only see blizzard warnings for LI and maybe NYC.https://www.weather.gov/erh/gis_wfo?id=PHI

Pretty happy with 12Z. My thoughts, for what they're worth... Basically, the Euro, UK and CMC all moved a bit SE with their snow fields, as the confluence was a bit stronger, so the track of the low was a bit further SE, meaning the snow/rain (or snow/sleet) lines moved SE a bit (like 10-20 miles, which isn't a lot, but makes a big difference for some), more towards what the GFS had been showing - and the GFS moved significantly further NW with its track and snow field, meaning the models are closer together than they were the last 2 cycles, but still some differences obviously. Models should in theory converge as one gets closer to an event (every model will show almost the exact same forecast 1 hr into the future), though, but good to see. If you live along or NW of the 95 corridor, prepare for a major (8" or more) snowstorm, with 12" or more possible especially just NW of 95 and anywhere NW of there. Just SE of 95 and towards the coast will likely be the battleground for snow/sleet/rain at times. Also by early Thursday, after about 1 am, most folks should be snowing and the winds will increase to blizzard levels, so it should be pretty wild from maybe 1 am to 7 am. Let's hope for no nasty surprises on this one, especially after last year's fiasco. I think we're good, though, unless you're at the NJ coast and even they'll likely still have some fun on the backend. NWS has 15" at my house - that's about my thinking too. Make it so, lol

Of course the UK is far, far worse than any other model for those SE of 95, with basically only 1-2" from DC to Philly to Asbury Park, whereas 10 miles NW of that line gets 10" and 20 miles NW gets over 15". I can't see the gradient being that steep, but stranger things have happened I guess. Are those locations showing very little snow getting sleet at least? Hard to believe the snow to rain cutoff is that sharp for the whole storm. I'd get incredibly lucky in the Edison area with 18" of snow, while friends 15 miles SE of me in Holmdel would get maybe 3-5" and folks 10-15 miles SE of there would get nada.

That's what the NWS has been saying, given thermal profiles of the column...

D'oh! Fixed it, thanks - sleepy time, lol...

In case people haven't seen the UK - I'll take two please. I assume the Euro will join the GFS/CMC/UK in keeping us in loads of digital snow.

Meh, I'll take it, lol...(have to subtract Monday's few inches of snow from this, along/NW of 95).

Make that GFS/CMC/UK/Euro consensus. Boom! Euro also shows 1-3" along 95 and 3-5" NW of 95 in NJ/EPA/SENY on Monday.

Not sure I can recall such model consensus 5-days out from the GFS/CMC/UK for a major winter storm for the Philly-NYC region. I assume the Euro will still show such a storm too. Let's hope this one isn't only a digital snowstorm.

And it's in the 20s for the 95 corridor and NW of there with temps only getting to 32F at the immediate coast. Would be nice to have enough cold air to not have to worry about p-type...

Just my opinion, but I think we need two separate threads for the 14th and 16th potential events. Way too many posts in this thread where it's difficult to tell which event someone is talking about.

I know it's just one model run and it's 8 days out, but there's at least hope - I could live with this in CNJ (GFS/CMC show snow N of 84).

Interesting to see the moderate weakening observed by the hurricane hunters this evening with winds now down to 130 mph (just barely Cat 4). However, in the last hour or so, there have been indications of an eye trying to form, which is often a sign of intensification. The Yucatan could use a break, although 130 mph is still a big deal. Beyond there, no real change as the forecast is still for a Cat 3 hurricane to strike the central LA coast Friday night (120-125 mph) - the center of the track has landfall near Marsh Island, just south of Lafeyette and about 100 miles west of New Orleans and 90 miles east of Lake Charles. Let's see if tonight's models make any big moves on track or intensity.