January 2026 Medium/Long Range Discussion

[Maestrobjwa]

13 minutes ago, SnowenOutThere said:

I dunno man you should consult the big ones are locked in early chart.

This is fantastic, lolol

[Weather Will]

WB latest GEFS extended showing a snowy look for the last week of January. 

[mitchnick]

23 minutes ago, Terpeast said:

I imagine that’d be like PD1 in ‘79. It’s famous for its rates. I hope I see this in my lifetime. 

Oh those rates were unbelievable once 2 or 3am hit with these huge flakes and several inches/hour for 2+ hours. But being out in the Megalopolis storm in 2/83, pushing my uncle's car out of the snow during the hour when BWI reported 4" of snow with repetitive lightning strikes and claps of thunder was probably better!

[Solution Man]

7 minutes ago, Weather Will said:

WB latest GEFS extended showing a snowy look for the last week of January. 

That looks great

[Scarlet Pimpernel]

Wow, that 18Z GFS was smoking something!!  I want what it's having!!  Even here in metro DC, a ton of sleet followed by 6-10" snow with temps in the teens or 20s??  Gimme that!

But in all seriousness, I don't quite get a lot of the cynicism here.  OK, ignoring what the GFS shows verbatim at this point (which on its face is ridiculous amounts)...the fact is, there has been indication of that type of setup over the past few days for that time frame across different models and ensembles.  Hell, even the venerated Euro a couple of days ago showed basically double the amount of PD-2!!  I know these are extremes unless this really starts showing up across all guidance and it gets closer.  Again though, that time period around Jan. 23-26 has shown several possibilities now for a potential moderate-major overrunning event with cold air pressing in up top and then behind the system.  That's my takeaway right now.

[winter_warlock]

1 hour ago, SnowenOutThere said:

I think this is the single most ridiculous snow map I have seen for pretty much anywhere nearby. Would need to make a drive up to see 90 inches of snow. 

Never gonna happen lol

[MillvilleWx]

The 18z GFS output verbatim is an extreme fantasy. However, the pattern shaping up around that time absolutely screams some type of SWFE type event that could involve a large areal coverage. Something we are keeping an eye on at range. For now, it's not real life, it's just fant-....oh, you get it. 

[adelphi_sky]

7 minutes ago, winter_warlock said:

Never gonna happen lol

Looks like a weenie hacked into the models. 

[aldie 22]

1 minute ago, MillvilleWx said:

The 18z GFS output verbatim is an extreme fantasy. However, the pattern shaping up around that time absolutely screams some type of SWFE type event that could involve a large areal coverage. Something we are keeping an eye on at range. For now, it's not real life, it's just fant-....oh, you get it. 

Exactly...what if

[snowmagnet]

1 hour ago, SnowenOutThere said:

I think this is the single most ridiculous snow map I have seen for pretty much anywhere nearby. Would need to make a drive up to see 90 inches of snow. 

Now I know why the digital snow thread is making a comback. 

[JenkinsJinkies]

15 minutes ago, winter_warlock said:

Never gonna happen lol

Unless it’s a Modoki Niño

[Terpeast]

10 minutes ago, MillvilleWx said:

The 18z GFS output verbatim is an extreme fantasy. However, the pattern shaping up around that time absolutely screams some type of SWFE type event that could involve a large areal coverage. Something we are keeping an eye on at range. For now, it's not real life, it's just fant-....oh, you get it. 

I hope it trends in our favor in the coming days. Because right now even though the ensembles look cold, that system looks like it wants to cut as the PNA dips well into negative territory. Maybe the PNA will trend toward neutral and we get better cold press to keep the wave just south of us. 

[SnowenOutThere]

3 minutes ago, Terpeast said:

I hope it trends in our favor in the coming days. Because right now even though the ensembles look cold, that system looks like it wants to cut as the PNA dips well into negative territory. Maybe the PNA will trend toward neutral and we get better cold press to keep the wave just south of us. 

Pardon my ignorance but to get such an overrunning event don't we need a negative (or neutral) PNA since the wave is from the southern stream and tracks eastward across the country? Wouldn't a positive PNA block it's path or force it to be significantly weaker/disjointed as part of it goes over the ridge and part goes under? 

[Imgoinhungry]

Why do the models always spit out ridiculous snowfall amounts? 95% of the time the depicted snow amounts disappear. The models are dreadful in this regard.


.

[Chris78]

9 minutes ago, Terpeast said:

I hope it trends in our favor in the coming days. Because right now even though the ensembles look cold, that system looks like it wants to cut as the PNA dips well into negative territory. Maybe the PNA will trend toward neutral and we get better cold press to keep the wave just south of us. 

I like the trends for temps for next weekend.

[baltosquid]

I mean given the tendency to over-model the SE ridge this winter, I think the 23-26 period definitely deserves cautious attention. Even for a storm that ultimately is gonna go too far north, fight off the ridge a little and I could imagine getting a frontend thump out of a nice shot of gulf moisture while we still have some cold. Or honestly, just imagine the setup as depicted on the GEFS right now just moves east some. It has trended eastward since this morning. That could put us much closer to the bullseye.

Besides, this is real Gulf moisture. Not ready to be pessimistic about it!

[Chris78]

With this moisture during the time frame shown above.

 

[Terpeast]

13 minutes ago, SnowenOutThere said:

Pardon my ignorance but to get such an overrunning event don't we need a negative (or neutral) PNA since the wave is from the southern stream and tracks eastward across the country? Wouldn't a positive PNA block it's path or force it to be significantly weaker/disjointed as part of it goes over the ridge and part goes under? 

Normally a negative PNA would dump the cold west of us causing storms to cut, pumping the SER.

In this case, hopefully its more transient but atm we may have temp/mixing issues as storms attempt to cut while cold air presses it south. We can hope it continues to trend in our favor as @Chris78 just showed a few posts above. A mildly negative or neutral PNA shouldn’t hurt in our case. 

[SnowenOutThere]

2 minutes ago, Terpeast said:

Normally a negative PNA would dump the cold west of us causing storms to cut, pumping the SER.

In this case, hopefully its more transient but atm we may have temp/mixing issues as storms attempt to cut while cold air presses it south. We can hope it continues to trend in our favor as @Chris78 just showed a few posts above. A mildly negative or neutral PNA shouldn’t hurt in our case. 

I understand how a neg pna typically hurts us but I'm wondering how else we get a wave to track like the 18z shows. 

I understand that this is a traditionally -pna with a low in the southwest. However, like you said it is progressive so this low moves eastward and throws moisture up in front of it (alongside the WAA and ridging as a result of it impacting the flow). So to my (flawed) understanding wouldn't having higher heights in the pna region basically mean our storm doesn't exist/is far weaker? Or alternatively the pna is more positive which results in the storm rolling off the ridge at a higher latitude before dipping eastward in a trough, which seems like it would cause even worse thermal issues. I guess I'm just struggling to see how else we get a SWFL event without a negative or neutral PNA. 

[mattie g]

2 hours ago, VA Mad Man said:

67" at Deep Creek? Jesus.

That’d be a fun drive out to a long weekend at Wisp with the wife and kids in the family truckster. I’m in.

[LP08]

ICON trying to be frisky for the 18th. Sorry don’t know whose storm that one is. Lol

[Terpeast]

28 minutes ago, SnowenOutThere said:

I understand how a neg pna typically hurts us but I'm wondering how else we get a wave to track like the 18z shows. 

I understand that this is a traditionally -pna with a low in the southwest. However, like you said it is progressive so this low moves eastward and throws moisture up in front of it (alongside the WAA and ridging as a result of it impacting the flow). So to my (flawed) understanding wouldn't having higher heights in the pna region basically mean our storm doesn't exist/is far weaker? Or alternatively the pna is more positive which results in the storm rolling off the ridge at a higher latitude before dipping eastward in a trough, which seems like it would cause even worse thermal issues. I guess I'm just struggling to see how else we get a SWFL event without a negative or neutral PNA. 

The map you just posted isn’t actually a “traditionally” neg PNA, but a transient gradient pattern where the index “computes” negative for a few days. More like a bootleg -PNA. However, I would feel better if we didn’t have troughing in the pac NW. We’d want ridging there to maintain the cold supply as the storm approaches here (even as a cut off low or energy undercutting the +pna ridge). I do like the atlantic side, we have a PV pressing down south towards us with confluence.

The biggest failure risk is that the western trough gets stronger, the TPV retreats north or NW, and the eastern ridge pumps, and the storm cuts. So far we haven’t been trending in that direction, though. 

The other end of the spectrum is where the PNA is so positive (with -EPO) that it suppresses the storm south. Right now that is the most unlikely scenario for that window.

In short, with -EPO and a strong TPV in SE canada, we’d root for a neutral PNA if not slightly positive. In this case, too much -PNA, cutter. Too much +PNA, suppression. But generally, we get our best snows snowstorms when the PNA is positive. 

btw this is why we like El Ninos. STJ undercuts the +PNA, which delivers the cold while we get gulf moisture from a STJ wave. Way simpler than trying to thread the needle during a Nina. 

[bncho]

3 minutes ago, Terpeast said:

The map you just posted isn’t actually a “traditionally” neg PNA, but a transient gradient pattern where the index “computes” negative for a few days. Mote like a bootleg -PNA. However, I would feel better if we didn’t have troughing in the pac NW. We’d want ridging there to maintain the cold supply as the storm approaches here (even as a cut off low or energy undercutting the +pna ridge). I do like the atlantic side, we have a PV pressing down south towards us with confluence.

The biggest failure risk is that the western trough gets stronger, the TPV retreats north or NW, and the eastern ridge pumps, and the storm cuts. So far we haven’t been trending in that direction, though. 

The other end of the spectrum is where the PNA is so positive (with -EPO) that it suppresses the storm south. Right now that is the most unlikely scenario for that window.

In short, with -EPO and a strong TPV in SE canada, we’d root for a neutral PNA if not slightly positive. In this case, too much -PNA, cutter. Too much +PNA, suppression. But generally, we get our best snows snowstorms when the PNA is positive. 

I would agree. With a -PNA the GFS is the best scenario for our area. There are literally two 1045 arctic highs keeping that storm down. I'd like to see a neutral PNA such that our margin for error is more.

[Terpeast]

13 minutes ago, LP08 said:

ICON trying to be frisky for the 18th. Sorry don’t know whose storm that one is. Lol

Love how it skips the exact panels we want to see. (At least on TT)

[LP08]

3 minutes ago, Terpeast said:

Love how it skips the exact panels we want to see. (At least on TT)

Saw this and it perked my interest.

[Maestrobjwa]

9 minutes ago, Terpeast said:

Love how it skips the exact panels we want to see. (At least on TT)

TT Icon does that all the time and I have no idea why, lol

[Ralph Wiggum]

AI GFS is decent for the 18th. We continue seeing some positive trends.

[SnowenOutThere]

I think this latest GFS will be significantly better for us from how the H5 is looking out over the plains. Still probably a bit too broad though. 

[NorthArlington101]

6 minutes ago, Ralph Wiggum said:

AI GFS is decent for the 18th. We continue seeing some positive trends.

Slightly better map, but yeah, this is a 1-2”+ storm for many of us. 
 

[Ralph Wiggum]

1 minute ago, NorthArlington101 said:

Slightly better map, but yeah, this is a 1-2”+ storm for many of us. 
 

I accept. Where do I sign?