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

[nycsnow]

1 minute ago, billgwx said:

Blizzard watches got discontinued, just because of that one March bust a few years ago. When we've issued them otherwise they worked out quite nicely.

I think the rationale was that we all freak out when the S word is mentioned, throwing the B word in there too early gets everyone jacked up way too much too soon.

Could go winter storm watch to blizzard warning, also winter storm watch to winter storm warning and then issue a shorter fused blizzard warning. We don't typically do that, the Sterling office has.

Awesome thanks... seems like the winds have been the most consistent aspect on all models with this storm

[NJwx85]

3 minutes ago, HVSnowLover said:

January 2010 was a memorable time this happened (I think I have the year right, i know it was a storm that went snow to sleet/rain and then dumped like 15 inches of snow in 4 hours at night). I believe Nemo also went like this with snow to mix to snow. Agree it's sort of rare but does happen.    

We had a storm on Christmas Day, I think it was 2002 where we had a thunderstorm come through with heavy rain, lightning and dime sized hail at my parents house in Northern, NJ. After the storm passed it changed over to snow and I think we finished with around 8". One of the few storms that I remember that started as rain and ended as significant snow.

[friedmators]

Blizzard Warnings give me PTSD.


.

[weatherbear5]

12z NAM 500mb.

Through 21z the shortwave is in virtually the same position as the 6z, maybe a hair weaker. In addition, heights over the NE seem to be more compressed, a sign which could mean confluence is stronger

[wdrag]

54 minutes ago, LibertyBell said:

question about the snowfall gradient is this based on the idea that long island will mix or change to rain or more because of the temps involved mean lower ratios and wetter snow?

On this it looks like snowfall gets less at Scranton and points north and once east of Morristown?

 

Hi!  Gradient collaborated grids that see adjacent offices and work with together with WPC. So qpf, whether its all snow and the associated mixing ratios dictate snow amounts. These are put together sometimes before new guidance that you and i see and sometimes hastily because of the eastern time zone and 330-4PM/AM deadlines (deadline office dependent).  I'd take the lower numbers of the range as a start, and focus on the axis.   I want to reserve comment on anything beyond what we see here, til 430 or 5P.  Too many models and interps... 

[NJwx85]

4 minutes ago, billgwx said:

Blizzard watches got discontinued, just because of that one March bust a few years ago. When we've issued them otherwise they worked out quite nicely.

I think the rationale was that we all freak out when the S word is mentioned, throwing the B word in there too early gets everyone jacked up way too much too soon.

Could go winter storm watch to blizzard warning, also winter storm watch to winter storm warning and then issue a shorter fused blizzard warning. We don't typically do that, the Sterling office has.

Most of the general public doesn't even understand the difference between an advisory, watch or warning. It should be self explanatory that a warning would be the highest level of concern but it doesn't register.

[wdrag]

1 hour ago, LibertyBell said:

an excellent list! Thanks Walt!  I cant wait to see your two day lists for the above locations plus MPO, NYC and EWR.  A couple of notes - the number of 20" snowfalls will increase since these are the ones most affected by two day totals.

That will put both Feb 1961 and Feb 1969 over the 20 inch mark at both JFK and LGA.   Jan 1996 and Feb 1983 will also go over the 20 inch mark (the latter at JFK at least.)  Boxing Day 2010 should be close to 20 inches at both.  I'm also curious to see what the full storm total was from Feb 1978 at MPO.  And I didn't know that JFK got 9.6 inches in one day in 1/88, I'd be curious to see if they hit double digits for that storm total as that was an era with few or no double digit snowstorms.

 

 

Let's wait this out...  I need to NAM to be more realistically south and closer to EC or GFS.  It cant keep trying to drill big snow into the southern Adirondacks. 

[mweisenfeld]

It's Monday morning and the storm isn't supposed to start until late Wednesday afternoon. Watches typically aren't hoisted until 36-48 hours prior to the start. I'm sure if everything holds you will see watches with the afternoon update. 

In the disco nwsny specifically notes not posting a watch in part to avoid confusion with current conditions

Sent from my SM-T510 using Tapatalk

[weatherbear5]

12z NAM 500mb through 45 hours-

definitely more confluence over the NE this run, heights are noticeably lower in the NE quadrant of the country vs 6z

Interestingly enough, the ridge moving onshore to the west coast is coming in significantly stronger as well. I wonder if this will help the shortwave to dig a bit more. With any luck the 500mb feature would end up passing south of LI

we shall see

[weatherbear5]

The NAM SHOULD be at least a little south of 6z, based on the 500mb setup. Haven’t looked at the surface, and I don’t until I get through the 500mb stuff

[Nibor]

40 minutes ago, NJwx85 said:

I'm pumped, kind of wish I was still living in Mahwah for this one.

I wish I was still living in Ridgewood for this one. ¯\_(ツ)_/¯ 

[NJsnow89]

2 minutes ago, weatherbear5 said:

The NAM SHOULD be at least a little south of 6z, based on the 500mb setup. Haven’t looked at the surface, and I don’t until I get through the 500mb stuff

Confluence looks a lot better. Hopefully the end result is better

[NJwx85]

1 minute ago, Nibor said:

I wish I was still living in Ridgewood for this one. ¯\_(ツ)_/¯ 

Why would you move from Ridgewood to Astoria?

[NJsnow89]

Nam still gets a ton of mixing at the coast. 

[MJO812]

2 minutes ago, NJsnow89 said:

Nam still gets a ton of mixing at the coast. 

Better than 6z

[NJwx85]

It's the NAM, but it brings mixing issues pretty far inland. Warm punch at 700mb makes it up to about TPZ bridge.
 

[friedmators]

NAM is better but H5 still closes off over PA eventually.

[Neblizzard]

Just now, friedmators said:

NAM is better but H5 still closes off over PA eventually.

It’s a colder solution and a shift south . Onto the GFS...

[SnoSki14]

Nam still out of its best range but it tends to be very amped beyond 48hrs in general. 

[Brian5671]

1 minute ago, Neblizzard said:

It’s a colder solution and a shift south . Onto the GFS...

A great run for most here.   Also may be the end of the north shifts...

[weatherbear5]

5 minutes ago, NJsnow89 said:

Nam still gets a ton of mixing at the coast. 

Honestly, in that look, it looks more like a front-end dump which would be mostly snow and then changing over. Would still be good accumulations even for the coast

A good move from 6z for sure. Hopefully that trend continues for the rest of the 12z suite

[Neblizzard]

Just now, weatherbear5 said:

Honestly, in that look, it looks more like a front-end dump which would be mostly snow and then changing over. Would still be good accumulations even for the coast

A good move from 6z for sure. Hopefully that trend continues for the rest of the 12z suite

Yes it’s much better than 6z.   The high is stronger to the north and trends at H5 were a step in the right direction.  I would take that run as a positive for the metro.   

[Nibor]

9 minutes ago, NJwx85 said:

Why would you move from Ridgewood to Astoria?

Work. 

[Northof78]

1 hour ago, jm1220 said:

RGEM is absolute beauty for this area, but 6z NAM and Euro looked more amped. We really don't want that getting out of hand-this needs to start making a beeline east once it gets to around Cape May. 

NAM is colder and further S/E, but still a very odd solution overall without much precip really anywhere (actually surpressed with northern extent of precip)....would lean heavily away from NAM and towards CMC/Euro combo with a touch of GFS

[snowman19]

4 minutes ago, Brian5671 said:

A great run for most here.   Also may be the end of the north shifts...

 

4 minutes ago, Brian5671 said:

A great run for most here.   Also may be the end of the north shifts...

I think it’s wagons south and east from here on out, the tucked in solutions were bogus all along. You aren’t tucking in a low with a high/confluence that strong and a 50/50 vortex that powerful 

[Brian5671]

Just now, snowman19 said:

 

I think it’s wagons south and east from here on out, the tucked in solutions were bogus all along. You aren’t tucking in a low with a high/confluence that strong and a 50/50 vortex that powerful 

Yeah I'd agree.  I'd say the GFS ends up more along the right idea although probably not that far south

[SnowGoose69]

2 minutes ago, Northof78 said:

NAM is colder and further S/E, but still a very odd solution overall without much precip really anywhere (actually surpressed with northern extent of precip)....would lean heavily away from NAM and towards CMC/Euro combo with a touch of GFS

Yeah the NAM QPF depictions that run were very disjointed and ugly 

[jdj5211]

Can someone give me a current start time for the storm for NNJ on Wednesday? 

[snowman19]

2 minutes ago, Brian5671 said:

Yeah I'd agree.  I'd say the GFS ends up more along the right idea although probably not that far south

IMO the GFS/GEFS end up being the most correct. They have been extremely consistent and unwavering for the last 2 days and make the most sense given the setup over SE Canada and the North Atlantic

[jm1220]

The confluence will cause the low to have to go east after a certain point, but the low itself will want to cut north as much as it can. Confluence does look good, so to me if I had to guess it would cause the turn east in time for us, but I can see how especially with confluence being a little less it cuts into NJ in which case we would mix from the city east. We also don't want the stronger S/W like others have said, that just means it tries to amplify more. This NAM run looks a little better verbatim than 6z but the 700/850 low tracks aren't ideal. 850 low tracks maybe 30 miles SE of LI and the 700 low tracks over E PA into CT. That would mean warm air aloft can make it north for many of us near the coast for a time and the dryslot comes into play. The 700/850 lows should be going SE of you if you want to avoid issues.