January 2026 Medium/Long Range Discussion

[stormtracker]

Trying to see some encouraging changes and so far I cannot.  Doesn't mean it's going to be bad, but not seeing anything to be excited about thus far

[stormtracker]

Yeah, precip breaking out is a bit further s and E than it was at 18z.

[stormtracker]

 

[stormtracker]

See yall in the AM!

[bncho]

Everything is more east on this Euro run

[bncho]

Remember that the Euro AI trended south before trending back north for the last storm

[Nomz]

1 minute ago, bncho said:

Remember that the Euro AI trended south before trending back north for the last storm

It's ok to say a model run is bad lmao

[Maestrobjwa]

Well that's unfortunate. Everything trended west except the most important one and it's AI counterpart...and you know how slow it is to change! If it doesn't change by 0z tomorrow it may be right, smh

[wxmeddler]

If the weenies want a bit of a glimmer of hope to hold onto, climatology does not support a surface low that OTS. Pretty rare.

[midatlanticweather]

Eps? 

[bncho]

Upgraded CMC shift SE

[EHoffman]

1 minute ago, bncho said:

Upgraded CMC shift SE

The only shred of hope I have is it actually gonna snow 30" on the Delmarva?

[wasnow215]

Ensembles?

[Nomz]

2 minutes ago, wasnow215 said:

Ensembles?

All the rich folk with pivotal and wxbell subs are asleep lol

[bncho]

EPS-AI tick SE
(these just came out on WxBELL, btw)

[bncho]

EPS is a more major tick SE
(these ALSO just came out on WxBELL)

 

[Jebman]

It's SE BUT this is pretty early

[bncho]

2 minutes ago, Jebman said:

It's SE BUT this is pretty early

If it's like this on 12z Wednesday then it's probably cooked, but I want to see how the recon data affects the modeling output.

[wasnow215]

7 minutes ago, bncho said:

EPS is a more major tick SE
(these ALSO just came out on WxBELL)

 

Temps teens and low 20's Sat could be 20:1 ratios no?

[Jebman]

22 minutes ago, wasnow215 said:

Temps teens and low 20's Sat could be 20:1 ratios no?

2m temps means something but it is much more about what goes on upstairs. Need Bob Chill or one of the Mets to explain this better than I could, lol. It's something about the DGZ, Dendritic Growth Zone or something like that.

 

Remember the last storm in Virginia? Ground temps in the low teens? Sleet falling in 13 degree temperatures and people saying this is so ridiculous? It was all about what was happening upstairs. I think it was because of a strong warm layer at about 700mb or something like that over top of the incredibly frigid airmass over the Mid Atlantic that caused the warm layer to dump rainfall that froze into sleet pellets because it was so damn COLD in the boundary layer.

Or something like that. I really should leave this to degreed Mets or qualified hobbyists like Bob Chill or PSU or even SnowinOutThere. He needs a red tag stat. I sure don't. All I am, is an old man, all played out, can't even dig snow anymore, can hardly walk on ice down here in Texas without falling and smashing my low back to smithereens, snow weenie lmao.

[bncho]

35 minutes ago, Jebman said:

2m temps means something but it is much more about what goes on upstairs. Need Bob Chill or one of the Mets to explain this better than I could, lol. It's something about the DGZ, Dendritic Growth Zone or something like that.

 

Remember the last storm in Virginia? Ground temps in the low teens? Sleet falling in 13 degree temperatures and people saying this is so ridiculous? It was all about what was happening upstairs. I think it was because of a strong warm layer at about 700mb or something like that over top of the incredibly frigid airmass over the Mid Atlantic that caused the warm layer to dump rainfall that froze into sleet pellets because it was so damn COLD in the boundary layer.

Or something like that. I really should leave this to degreed Mets or qualified hobbyists like Bob Chill or PSU or even SnowinOutThere. He needs a red tag stat. I sure don't. All I am, is an old man, all played out, can't even dig snow anymore, can hardly walk on ice down here in Texas without falling and smashing my low back to smithereens, snow weenie lmao.

Here's my two cents.

Yes, the storm two days ago featured sleet falling at 13 degrees due to the warm nose at ~750-800mb. Snow formed high up in the atmosphere and fell out of it, but when those falling snowflakes ran into that warm nose, they melted and turned into raindrops. After they exited that warm nose, they eventually refroze into sleet pellets.

I'm actually not entirely sure how a snowflake forms, but what I do know is that snowfall efficiency is determined by two things: temperature (amount of cold) and lift (which brings in the moisture and determines where snow grows). These two things are linked. Moist air is lifted high up into the atmosphere, and the cold temperature allows moist air to grow onto ice crystals (I think this is called deposition?). We don't want too little cold air where the lift sets up (-5 to -10°C) where snow forms because everything about snow growth is generally slower. The moist air doesn't grow onto the ice crystals quickly enough to turn into snowflakes. This causes a domino effect: ice crystal growth is slower so the "snowflakes" don't have time to really grow before they fall out of the snow growth zone, which also makes it harder for them to stick together, and what you see is usually more needle like. No dendrites. We also don't want too much cold air where the lift sets up (-20 to -25°C) because that'll mean there won't be enough moisture to grow snowflakes efficiently, so you'll see pixie dust. If, however, if lift sets up at the DGZ (-12 to -18°C), for some reason ice crystal formation is quickest (I have no idea why). This leads to bigger snowflakes in a shorter amount of time, which induces dendritic growth, or where snowflakes start clinging together. That's why you see those baseball sized beauties fall from the sky.

So generally, where lift sets up is where the snow growth zone sets up. Where lift sets up is where the temperature matters most for snow growth. Afterwards, temps below the snow growth zone shouldn't matter much unless it's above freezing (then we might talk about sleet/freezing rain). Hoped this helps. And if I'm wrong anywhere, let me know!