Extreme Cold, Snow & Sleet: SECS 1/25 - 1/26

[psv88]

2 minutes ago, WeatherGeek2025 said:

look at this map it shows 850's below freezing that shows snow all around south of long island and nyc could be sleet but nyc and north is all snow on the euro. its a great run!

Still a lot of time for details. There is no doubt in my mind that we mix here. I am ok with laying down some taundra before the next storm

[NJwx85]

Can we get a separate banter thread please? Too much nonsense here the last few hours.

[NEG NAO]

4 minutes ago, WeatherGeek2025 said:

look at this map it shows 850's below freezing that shows snow all around south of long island and nyc could be sleet but nyc and north is all snow on the euro. its a great run!

first of all we are right on the edge of the mixing line and its still 4 days away - so this is not set in stone

[allgame830]

1 minute ago, NJwx85 said:

Can we get a separate banter thread please? Too much nonsense here the last few hours.

Its the same with every storm, nothing is going to change this go around! 

[SACRUS]

18z

[Winterweatherlover]

9 minutes ago, WeatherGeek2025 said:

look at this map it shows 850's below freezing that shows snow all around south of long island and nyc could be sleet but nyc and north is all snow on the euro. its a great run!

If the 0 degree line is hugging LI like that very good chance some sleet makes it up to about 30 miles north of that line. The nam will sniff this out. 

[eduggs]

8 minutes ago, WeatherGeek2025 said:

if it's GFS wins this one for sure 12-24 there

The GFS has not been good lately relative to the Euro, CMC, and UKMET. I don't trust it at all, especially when it's an outlier. I like the ECM-AI as a model - it's a little less amped than the other 3 so it gives me some encouragement. 

[allgame830]

Just now, NEG NAO said:

first of all we are right on the edge of the mixing line and its still 4 days away - so this is not set in stone

Who's right on the edge.... central NJ or the city or LI..... I'm 30 miles north of the CITY. So explain who you mean by WE ARE?

[NEG NAO]

2 minutes ago, NJwx85 said:

Can we get a separate banter thread please? Too much nonsense here the last few hours.

there is a banter thread and I think debating opinions is fine - but draw the line at trying to bully someone telling them to stop posting or name calling

[NEG NAO]

4 minutes ago, allgame830 said:

Who's right on the edge.... central NJ or the city or LI..... I'm 30 miles north of the CITY. So explain who you mean by WE ARE?

thats another problem here because the forum apparently extends from Ocean County all the way up to lower  New York State and into eastern PA and CT., Long Island - so sorry I don't know how to rephrase what I said

[Wannabehippie]

12 minutes ago, NEG NAO said:

Agreed and I wouldn't commit to any accumulation amount right now until all the players are on the field and moving - at first I thought we would have high ratio's but now that is in doubt also.

I think the cold air will be stubborn to get out. That is a strong high pressure system, with damn low temps at all levels of the atmosphere, at least for most of the storm. GFS and Euro soundings both show temps in the teens or maybe low 20s at most thru the storm in the NYC tri-state area. It looks like on the Euro you would have to get to around the same latitude as Philly before being concerned about any mixing issues. Canadian looks to be the warmest solution, with the rain/snow line getting as far north as the south shore of LI.

 

[SACRUS]

 

Just for reference and no stick should be put in this range of the NAM

 

84H

[Big Jims Videos]

We mixed along the beach during the infamous January 2016 blizzard and still had well over a foot. 

[Franklin0529]

The nam, "yes I know" is not as amped as the CMC or Euro an more confluence up top as well. Would be all snow I'd imagine 

[Nibor]

Was just looking at the EPS. Looks like a decently large spread on where the primary low is.

[NEG NAO]

2 minutes ago, SACRUS said:

 

Just for reference and no stick should be put in this range of the NAM

 

84H

 

timing wise it might be closer to the GFS -PLUS consider there may be some front end virga involved here which delays the onset of the precip that reaches the ground - we have seen that before

[Winterweatherlover]

2 minutes ago, SACRUS said:

 

Just for reference and no stick should be put in this range of the NAM

 

84H

NAM at 84 hours is about as useful as me trying to draw a random map but given it tends to overamp the fact it's flat in the long range is probably a good sign if you're concerned about mixing.

[wishcast_hater]

Excuse my ignorance but what are the chances this falls as virga since I am assuming the air will be bone dry?  I can remember a storm or two where we had the precip overhead but never made it to the ground for the duration.

[Wannabehippie]

2 minutes ago, Nibor said:

Was just looking at the EPS. Looks like a decently large spread on where the primary low is.

The secondary low has a fairly tight spread. What is the timing for the secondary low to take over?

[NEG NAO]

Just now, wishcast_hater said:

Excuse my ignorance but what are the chances this falls as virga since I am assuming the air will be bone dry?  I can remember a storm or two where we had the precip overhead but never made it to the ground.

I just mentiond that a few minutes ago and with this arctic airmass I would suspect there will be virga

[TriPol]

From H5 (500 mb) height, we are looking at exactly the setup that has a high potential (high ceiling) for the NYC area for a major winter weather event.

The ECMWF depicts a then fully closed 500mb low in the Northeast with large negative height anomalies and a slow pivoting flow. It represents a true 500 mb closed low, that is no longer open or progressing as a trough. It is vertically coherent, dynamically mature and no longer associated with the fast zonal flow of upper levels. The closed 500mb low will eventually be around for a period of time, not a question mark of how long.

A compact and centered cold pool aloft is also critical to snow production efficiency. Closed mid-level lows create steep lapse rates, which in turn create significant lift and space throughout the region to support snow band formation, and through the mesoscale process create the large snowfall totals in NYC. Most storms that produce over 18 inches of snow are not continuous, steady snowfall, rather they are created by the time and conditions that create the most snow through banding.

 

[TriPol]

2 minutes ago, wishcast_hater said:

Excuse my ignorance but what are the chances this falls as virga since I am assuming the air will be bone dry?  I can remember a storm or two where we had the precip overhead but never made it to the ground for the duration.

Virga really isn’t a concern in a setup like this. Yes, the antecedent air mass is dry, but this is a deep, dynamically forced system with strong large-scale lift. Once precipitation starts, the column moistens very quickly.

Virga issues tend to happen with weak forcing, shallow lift, or fast-moving systems trying to overcome dry air. A closed H5 low with sustained ascent overwhelms that problem. You might lose the very first echoes to evaporation, but not the storm itself.

[CPcantmeasuresnow]

11 minutes ago, allgame830 said:

Who's right on the edge.... central NJ or the city or LI..... I'm 30 miles north of the CITY. So explain who you mean by WE ARE?

Happens all the time. Everyone acts like where they are is where everyone is. No concept the forum runs a general 75 mile radius north south east and west of Central Park. 

[lee59]

No matter what happens with snow accumulations from this storm, it should stick around a while with all the cold air behind it. Not the case with many big storms we've had.

[NEG NAO]

1 minute ago, CPcantmeasuresnow said:

Happens all the time. Everyone acts like where they are is where everyone is. No concept the forum runs a general 75 mile radius north south east and west of Central Park. 

and a very wide range of weather conditions usually in that 75 mile radius because of the terrain and ocean

[Winterweatherlover]

2 minutes ago, CPcantmeasuresnow said:

Happens all the time. Everyone acts like where they are is where everyone is. No concept the forum runs a general 75 mile radius north south east and west of Central Park. 

For the most part when people refer to us in this forum they are referring to immediate NYC Metro. This storm could be drastically different in Toms River vs Monroe but that's typically the case. 

[Wannabehippie]

4 minutes ago, TriPol said:

From H5 (500 mb) height, we are looking at exactly the setup that has a high potential (high ceiling) for the NYC area for a major winter weather event.

The ECMWF depicts a then fully closed 500mb low in the Northeast with large negative height anomalies and a slow pivoting flow. It represents a true 500 mb closed low, that is no longer open or progressing as a trough. It is vertically coherent, dynamically mature and no longer associated with the fast zonal flow of upper levels. The closed 500mb low will eventually be around for a period of time, not a question mark of how long.

A compact and centered cold pool aloft is also critical to snow production efficiency. Closed mid-level lows create steep lapse rates, which in turn create significant lift and space throughout the region to support snow band formation, and through the mesoscale process create the large snowfall totals in NYC. Most storms that produce over 18 inches of snow are not continuous, steady snowfall, rather they are created by the time and conditions that create the most snow through banding.

 

Would a set up like this cause thundersnow?

[WeatherGeek2025]

5 minutes ago, NEG NAO said:

I just mentiond that a few minutes ago and with this arctic airmass I would suspect there will be virga

not if the precip comes in like a wall like most models are depicting.

[SnowGoose69]

Color me shocked this went that far north but the fact the key southern disturbance was coming in from basically Mars and another piece from NW Canada I guess I should be less shocked.  That said this is still a bit early so there may be corrections back the other way the next 2 days

[TriPol]

10 minutes ago, Nibor said:

Was just looking at the EPS. Looks like a decently large spread on where the primary low is.

According to the EPS mean, there is a definite indication of a MAJOR coastal low pressure center near the latitude of the Mid-Atlantic to Southern New England areas. The evidence that the ensemble members are plotting closely together shows that the group appears willing to evolve toward a coastal redevelopment or borrowed coastal system as opposed to working directionally inland.

The Normalized Spread of the ensemble members indicates a low degree of spread across the Northeast region as indicated by the region of North and Central New Jersey and a decreasing amount of uncertainty narrowing in New York City. The greatest area of spread, i.e., the west and south of the city, indicates the confidence level for the track is very high.

This also indicates mid-level pattern evolution will transfer to the surface of the climate system in an uncomplicated fashion. The ensemble indicates the same path of motion that has been forecasted by the H5 atmosphere since prior to multiple computer models becoming consistent at the H5, including last night's European model update. At this time the only remaining questions are how much water will fall within the axial centerline of maximum impact and when will maximum rainfall occur.

This is why we chase storms all winter. Why we stay up until 3 am refreshing, analyzing. All because of storms like this.