Possible Record Breaking Cold + Snow Sunday 1/25 - Tuesday 1/27

[jm1220]

Just now, Stormlover74 said:

Its about 30 miles further north which is a huge difference since that encompasses most of the metro

If the primary hangs on longer and we have a sharper western trough, more warm air gets pulled north and we flip sooner/more of us flip. Also if it’s drier with that setup we’re screwed two ways since a broken/lighter precip shield will allow warm air to take over sooner. It’s that simple. Hopefully it’s wrong. 

[Stormlover74]

Just now, jm1220 said:

If the primary hangs on longer and we have a sharper western trough, more warm air gets pulled north and we flip sooner/more of us flip. Also if it’s drier with that setup we’re screwed two ways since a broken/lighter precip shield will allow warm air to take over sooner. It’s that simple. Hopefully it’s wrong. 

Yeah we need that thump to perform if we're getting anywhere near double digits

[SACRUS]

 

1/23 18z NAM total qpf storm

 

 

Total snow/ sleet  / frz rain (10:1)

[jm1220]

1 minute ago, psv88 said:

Jesus NAM! God awful...

Yep pretty much back to 6z where mixing gets to almost all of CT and RI. Thankfully it’s on its own pretty much and other models got colder at 12z but a SWFE like system such as this will take any chance it can get to nudge north unless confluence stops it. 

[psv88]

Just now, jm1220 said:

Yep pretty much back to 6z where mixing gets to almost all of CT and RI. Thankfully it’s on its own pretty much and other models got colder at 12z but a SWFE like system such as this will take any chance it can get to nudge north unless confluence stops it. 

Flips us to plain rain! Awful. 

[mikem81]

Just now, jm1220 said:

Yep pretty much back to 6z where mixing gets to almost all of CT and RI. Thankfully it’s on its own pretty much and other models got colder at 12z but a SWFE like system such as this will take any chance it can get to nudge north unless confluence stops it. 

The NAM will change every single run to something else. That is what is does. Period. 

[SHELEG]

1 minute ago, mikem81 said:

The NAM will change every single run to something else. That is what is does. Period. 

You would not say that if it showed want you want.

[eduggs]

The NAM is irritating and somehow predictable. Meaningful QPF lost to sleet and then pronounced dryslot with little lingering wraparound. It's also totally believable. We really need to see a meaningful shift south in some guidance tonight - not just holds - to give us room to think the sleet line won't zoom north Sunday afternoon.

[Lucy Pull]

Nam 12z and 18z weren’t much different until about hour 30. Then it just went ballistic with the southern vort. Need it more shredded like 12z.

Could be the nam just being amp happy but driving that strong of a primary west isn’t gonna do it. 

[nycwinter]

throw nam run out not believable..

[MarcmmKU]

Ugly looking NAM

[eduggs]

From the clown maps it looks like the City south gets more QPF as sleet than as snow.

[Brian5671]

2 minutes ago, nycwinter said:

throw nam run out not believable..

NAM is good with thermals so can't throw it out-but if nothing else moves towards it-then I'd be skeptical

[Stormlover74]

Just now, eduggs said:

From the clown maps it looks like the City south gets more QPF as sleet than as snow.

That would be .7 as snow and. 7 as sleet. Would still be like 8 or 9 total since sleet will still add up

[jm1220]

4 minutes ago, eduggs said:

The NAM is irritating and somehow predictable. Meaningful QPF lost to sleet and then pronounced dryslot with little lingering wraparound. It's also totally believable. We really need to see a meaningful shift south in some guidance tonight - not just holds - to give us room to think the sleet line won't zoom north Sunday afternoon.

I’m not very concerned about it on its own but there’s definitely still time for late north bumps. The confluence needs to hold to force it south. We’re also definitely getting sleet at least up to I-80 and maybe even up to the CT coast eventually, it’s just a matter of how big the initial thump is and how long it can hold back the sleet line. 

[NEG NAO]

NAM is a warning to stay up later Sunday night and remove the accumulated snow from your driveway and sidewalks before the sleetfest and or freezing rain starts.

[NJwx85]

That NAM run wasn’t great but we’re still 36hrs out and things are going to continue to fluctuate. Any further North and there’s going to be some serious ZR issues for Southern parts of the area. Even as is, the NAM has about a 30 mile swath of 0.10 to 0.20 more or less over 95 with closer to a half inch South of Philly and into DC.

[eduggs]

1 minute ago, jm1220 said:

I’m not very concerned about it on its own but there’s definitely still time for late north bumps. The confluence needs to hold to force it south. 

But haven't we heard this dozens of times before marginal events?... but it's almost always correct with mix lines being further north than the consensus of other guidance.

[Nibor]

1 hour ago, donsutherland1 said:

Yes. And because Microsoft no longer supports Windows 95, each frame needs to be scanned independently for viruses. And then it has to be double authenticated.

I’m not gonna lie, because of how knowledgeable you are when I read that first line, for a half second, I thought you were confirming the NAM was run on a windows 95 computer. 

[MJO812]

1 minute ago, eduggs said:

But haven't we heard this dozens of times before marginal events?... but it's almost always correct with mix lines being further north than the consensus of other guidance.

Its not a marginal event. Temps are frigid. Models are most likely too warm.

[David-LI]

Is Mt Holly map still 12-14 for the area?

[psv88]

1 minute ago, eduggs said:

But haven't we heard this dozens of times before marginal events?... but it's almost always correct with mix lines being further north than the consensus of other guidance.

It's just one more model. Still a long way to go. It's been wrong plenty of times with mix lines. Let's see what the rest of the suite brings before pulling the plug on the event.

[Lucy Pull]

Like the Nam for picking up on warm layers but would like to see it consistent with vort handling two runs in a row before basing anything off its thermals…

[mob1]

1 minute ago, MJO812 said:

Its not a marginal event. Temps are frigid. Models are most likely too warm.

NAM gets you to 32 for a bit, and if it's right about the primary being that strong and holding on for so long, it can be even warmer. Still snow and sleet with frigid temperatures to start, but when you can't just say it's cold when the entire dynamics change and it's entirely possible that a large chunk of coastal areas get to or above freezing. 

[BoulderWX]

3 minutes ago, Tar Heel Snow said:

FWIW, on RRFS, the sleet line only barely brushes LI but keeps the city all snow

Compare totals from 18z to 12z - this was a huge step back in accumulation. Went from 15 to 9 IMBY as an example for the drop. That’s now NAM, 3k, and RRFS with pronounced warm nose. Not a good sign

[WeatherGeek2025]

is this slowly becoming a 4-6 inch snow event for the city? NAM always does this not sure if it's right or wrong!

[mob1]

2 minutes ago, Tar Heel Snow said:

FWIW, on RRFS, the sleet line only barely brushes LI but keeps the city all snow

That's 12Z, the new run is a lot further north. 

[Bxstormwatcher360]

Just now, Tar Heel Snow said:

FWIW, on RRFS, the sleet line only barely brushes LI but keeps the city all snow

Ive seen storms here literally cut in half,raining in soundview,the bx,snowing in Riverdale,the bx. This storm might be one of those. Southern parts of the city a bit diff then northern manhattan,the bronx.

[psv88]

2 minutes ago, Tar Heel Snow said:

FWIW, on RRFS, the sleet line only barely brushes LI but keeps the city all snow

This model has been pretty solid this winter. 

Do we have a comparison with the prior run?

[weatherpruf]

1 minute ago, jm1220 said:

I’m not very concerned about it on its own but there’s definitely still time for late north bumps. The confluence needs to hold to force it south. 

just read the updates for upton and mt holly and they see a northern trend, esp on the gfs. uncertain about how much mixing but mt holly flat out says the I 95 corridor is gonna ping, and there will be rain south. still going 8-12 but keeping cards close to the chest.