Major Nor'easter snow storm (possible top 20) Noon Wednesday-Noon Thursday Dec 16-17, 2020

[MJO812]

[weatherpruf]

3 minutes ago, MJO812 said:

Doesn't it count sleet as snow though....

[MJO812]

4 minutes ago, weatherpruf said:

Doesn't it count sleet as snow though....

All snow on the gfs

[weatherpruf]

5 minutes ago, MJO812 said:

All snow on the gfs

Interesting. Would be something to get get those amounts in Dec, but I've seen it before, in Dec 2003, 14 inches, but it was all snow, no mix. Heard high will be 34 tomorrow, but that may be before the storm arrives.

[SnoSki14]

19 minutes ago, MJO812 said:

It did well with the last storm in New England while the Euro was too amped.

Gfs is your hail mary with this storm. 

12z runs will probably be the final nail in the coffin regarding track and amounts.

If you want that 6" front-end dump then you better hope that don't keep trending inland. 

[wdrag]

Good Tuesday morning, Dec 15.  I have no change in my previously expressed opinions regarding what I think is coming. Not the worst ever, by far, but this will alter pandemic normal lives.  If you have plans Wednesday and Thursday across parts of WV, western VA, PA, NJ along and northwest of I95 as well as NYS and all of southern New England, I would think twice (and probably change plans) about traveling there (especially 4PM Wednesday to 10AM Thursday).  Follow local NWS Warnings/Statements/ forecasts and that of local government officials. 

Other than e LI and portions of coastal NJ near and s of Toms River,  where an uncertain less than 6" of snow-sleet should occur, this will be a widespread 6"+ snow storm with a period of sleet possible in the overnight hours up to I80. The 45-50 MPH wind gusts are still expected on the coasts 9P Wednesday to 6A Thursday, This with the periods of heavy wet snow changing to sleet and/or rain should  result in extensive power outages, somewhere near or just east of the NJT, or on LI.  

Moderate coastal flooding is probable along the coasts-inlets for the Thursday morning high tide (follow local NWS guidance).

With a likely 10-20" of powdery snow from I80 (or I78?)  northward through the I84 corridor, it will be time to sit back and sip hot cocoa and get into the Holiday Spirit. 

Those with heart conditions, be careful...the snow will be wetter and heavier as you get close to NYC.  Otherwise removing a batch of snow around 9PM Wednesday will make it easier not to break overwhelmed with snow removal Thursday morning. 

My guess for CP is 6-10"--it will be wetter snow there and I think sleet mixes in and I could see 2-4" of snow on the ground there by 7PM. 

Top 20 snowfall potential exists for MPO, POU, BDR.  

Banding will be big and may overcome some slightly above freezing layers aloft to keep snow going over w LI and I80. The banding could yield isolated 2 foot snowfall somewhere near I84. These storms have suppressed areas and enhanced areas of snowfall and I've no way to predict where. So while you see the base snow amounts in the EC ensemble graphic... snow ratios will possibly add 10" to this in a few spots of ne PA or NYS, CT?  Then there are snow measuring guidelines, and the 30 MPH gusty wind fracture of dendrites overnight Wednesday as well as drifting that will make it a bit more difficult to figure out the amounts. You may want to regionalize your post-storm assessment (the mean of multiple snowfall abs within a 15 mile radius?)

Graphics are: NWS office collaborated impact product-please use as an experimental guidance.  WPC 304AM  QPF assessment. The EC EPS ensemble baseline 10 to 1 snow ratio snowfall (be careful southeast edge where sleet is treated as snow), the WPC probability of 6"+ and 18+". This gives a feel for confidence by the NWS and axis of concern. Added SPC Short Range Ensemble Forecast (SREF) plumes for snowfall amounts at LGA, AVP, POU, IJD. We see the spread in the members and mean (Bold line).  Then close with the two day top 20 snow accumulations - Note the shorter Period Of Record (POR) at some stations.  Sussex is in there to show that we have quite a hurdle to exceed here, but MPO, POU (valley shadow lower amounts??) and BDR are vulnerable for top 20. Follow local NWS products and the advice of officials. My posts do not represent the NWS, only utilizing all the available models-tools to the public including NWS generated products. I may be off-line many hours today and probably won't have a comment on whether I overdid this, until about 6PM tonight or 6AM Wednesday.  Have at it and do the downside checks to help keep perception of future reality, realistic, with hopefully few disappointments Thursday. 533A/15

 

I'

[RU848789]

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

 

[sussexcountyobs]

46 minutes ago, SnoSki14 said:

Gfs is your hail mary with this storm. 

12z runs will probably be the final nail in the coffin regarding track and amounts.

If you want that 6" front-end dump then you better hope that don't keep trending inland. 

What area are you talking about?

[tim]

...just a simple observation..temp here this morning 30.3*..it was suppose

to get into the mid 20's as a low...NG !...just sayin'..

[nycsnow]

This has 100% trended towards a lower end event in NYC compared to what could’ve been. Need some big changes by tonight otherwise double digits looking less and less likely

[HVSnowLover]

Models still showing over a foot equivalent of snow falling for the city however snow depth maps lower. Mixing and dry slotting don’t help in terms of that but if temps stay below freezing at surface it would help prevent too much melting, maybe it ticks back south maybe not either way it’ll still be more snow than all of last winter. 

[nycsnow]

1 minute ago, Torch said:

So you think the nws has it wrong at the moment with their totals? Predicting a change by 1pm?

If these models don’t back down with showing a dry slot abs or mixing over nyc I don’t think we break double digits probably 5-10 maybe 

[sussexcountyobs]

15 minutes ago, nycsnow said:

This has 100% trended towards a lower end event in NYC compared to what could’ve been. Need some big changes by tonight otherwise double digits looking less and less likely

NWS forecast for Queens is 1-2" Wednesday 

9-13" Wednesday night 

1-3" Thursday

[Northof78]

[jbenedet]

I think you’re going to see a correction back southeast today as the arctic airmass that’s building into the region throughout the day begins to get ingested into the models. 

The temp drops throughout the day today....

This airmass is very cold and dry as the storm approaches...DENSE.  

The orientation of the high is a classic CAD over performing location for northeast/mid Atlantic...

I would strongly hedge higher than current guidance for snowfall amounts in LI/NYC area...

 

 

[TJW014]

Nothing is more miserable than a 34° rainstorm. Looks like that's what it's going to be down here. Doubt it at this range, but hoping for ticks SE. 

[Hoth]

3 minutes ago, jbenedet said:

I think you’re going to see a correction back southeast today as the arctic airmass that’s building into the region throughout the day begins to get ingested into the models. 

The temp drops throughout the day today....

This airmass is very cold and dry as the storm approaches...DENSE.  

The orientation of the high is a classic CAD over performing location for northeast/mid Atlantic...

I would strongly hedge higher than current guidance for snowfall amounts in LI/NYC area...

 

 

I like the cut of your jib, Pope!

[lee59]

At this point in my area, I am expecting a good front end thumping and then a mix or change to sleet, drizzle, freezing rain and so on. Probably 6-10 inches.

[jbenedet]

2 minutes ago, Hoth said:

I like the cut of your jib, Pope!

Attitudes will shift when they start feeling the cold overhead...

The warm bias will fade in the models and in the minds of weenies...

We are all at our high temps for the day..

[weatherpruf]

9 minutes ago, jbenedet said:

I think you’re going to see a correction back southeast today as the arctic airmass that’s building into the region throughout the day begins to get ingested into the models. 

The temp drops throughout the day today....

This airmass is very cold and dry as the storm approaches...DENSE.  

The orientation of the high is a classic CAD over performing location for northeast/mid Atlantic...

I would strongly hedge higher than current guidance for snowfall amounts in LI/NYC area...

 

 

You give good reasons for your thoughts and I appreciate your input. Remember, some people have to plan appropriately, it's not just about watching totals. Now is the time to clear the driveway of obstructions ( like my hoses, stray pieces of gravel ) get snow equipment and generators ready. If you don't end up needing it, so be it. 

[HVSnowLover]

1 minute ago, jbenedet said:

Attitudes will shift when they start feeling the cold overhead...

The warm bias will fade in the models and in the minds of weenies...

We are all at our high temps for the day..

The issue is more about dry slotting and possible mid level warming depending on the track of the 700 low more so than surface temps. Either way I agree the freaking out right now is overboard. When it’s pouring snow tomorrow night after last winter it’s going to feel nice. 

[Allsnow]

6 minutes ago, JoshSnow said:

Euro ?

 

[jm1220]

15 minutes ago, jbenedet said:

Attitudes will shift when they start feeling the cold overhead...

The warm bias will fade in the models and in the minds of weenies...

We are all at our high temps for the day..

Certainly hope you're right. We definitely could see a tick back SE today hopefully for the reasons you mention. 

But even the amped models aren't all that bad for the NYC area especially. 6z NAM is about 12" in NYC (which actually is more snow than 0z run had), but the 700mb low goes north which means a huge initial thump to a dryslot. Much of the period that would coincide with mixing would be light precip in the dryslot, and then some snow as the low leaves. 6z RGEM also about a foot in NYC, 6z Euro about the same? The cold dry air should be our savior for at least that heavy initial thump, and the mid levels don't look horrible unless the WAA there is being underdone (which is possible). 

The big winner though is shaping up to be central PA to perhaps the I-84 corridor where that 700 low track means a heavy high ratio snow band forms and pivots there. Trying to think of the last time State College PA had over 20" in a storm-may have been March 3, 1994. 

[Franklin0529]

2 minutes ago, Allsnow said:

 

Looks like a tick se

[lee59]

With such short distances between areas that get crushed and those that lose out, it should be an interesting storm to watch unfold. There may be a lot of disappointed people and or a lot of very happy people.

[jm1220]

31 minutes ago, CarLover014 said:

Nothing is more miserable than a 34° rainstorm. Looks like that's what it's going to be down here. Doubt it at this range, but hoping for ticks SE. 

Unfortunately I don't see much to help your area if you're in Toms River. Even a trend SE would mean lots of onshore wind and warm air coming off the water. 

[Brian5671]

11 minutes ago, jm1220 said:

Certainly hope you're right. We definitely could see a tick back SE today hopefully for the reasons you mention. 

But even the amped models aren't all that bad for the NYC area especially. 6z NAM is about 12" in NYC (which actually is more snow than 0z run had), but the 700mb low goes north which means a huge initial thump to a dryslot. Much of the period that would coincide with mixing would be light precip in the dryslot, and then some snow as the low leaves. 6z RGEM also about a foot in NYC, 6z Euro about the same? The cold dry air should be our savior for at least that heavy initial thump, and the mid levels don't look horrible unless the WAA there is being underdone (which is possible). 

The big winner though is shaping up to be central PA to perhaps the I-84 corridor where that 700 low track means a heavy high ratio snow band forms and pivots there. Trying to think of the last time State College PA had over 20" in a storm-may have been March 3, 1994. 

OR March 93

[Allsnow]

26 minutes ago, jbenedet said:

Attitudes will shift when they start feeling the cold overhead...

The warm bias will fade in the models and in the minds of weenies...

We are all at our high temps for the day..

They better pray for high ratios in sne because that gradient is going to be sharp 

[Yanksfan]

18 minutes ago, Franklin0529 said:

Looks like a tick se

Can anyone confirm this???

[mulen]

Tough forecast haven’t been here for a while living in s. Florida now the one overlooked fly in the ointment is sst temp and how far the low is off the coast .watch buoy readings it’s fun and could give a good indicator on the coast for mixing issues .