January 2026 Short/Medium Range Thread

[WintryMixmaster]

3 hours ago, Holston_River_Rambler said:

What the Euro is spitting out is extremely anomalous. I don't think I've seen a cutoff with this wrapped up at our latitude since I've been watching weather...let's say...enthusiastically enough to participate.

Some observations though:

Only 30+ hours later the situation has chnanged a lot:

 

what is now essentially a TPV vort says: "TPV eat shortwaves!!! YUM!!!!!"

 

But look at this, hour 126:

 

That's so wild I'm not really sure what options are on the table. 

These kinds of posts are great for people like me (I only have a vague idea of how to interpret the 500 mb maps, I never know what the important features are on these). Thank you!

[Icy Hot]

1 hour ago, Kasper said:

Need that to tick west a 100 miles and we’re in business 

NOAA says dry weather for the next 7 days. They aren’t buying stock in this. Perhaps that will change.

[Holston_River_Rambler]

7 minutes ago, Icy Hot said:

NOAA says dry weather for the next 7 days. They aren’t buying stock in this. Perhaps that will change.

Probably what I'd go with too for now if I had to make and official forecast for 5-7 days out. As modeled, this is a highly anomalous system with extremely high end potential for someone in the eastern US.

Highly anomalous things are just that, very uncommon.  N. stream has been favoring cold and dry and at this range, so I'd go with the trend and only start to introduce some pops (20%) tomorrow if this holds. 

 

[Holston_River_Rambler]

Just as an example, look at this sigma anomaly (standard deviation from the norm). 

[Bigbald]

Just glancing at the 6z and 12z runs, there appears to be good agreement on a 2nd system 200-230 hrs euro ai, gfs, cmc

[Holston_River_Rambler]

16 minutes ago, Bigbald said:

Just glancing at the 6z and 12z runs, there appears to be good agreement on a 2nd system 200-230 hrs euro ai, gfs, cmc

There was a time late last week when the EPS actually liked the 4-6th window better than this weekend. 

[John1122]

SE shift by the Euro AI, I expect the Euro will follow.  Hopefully it can work back this way but not holding my breath.

[tnweathernut]

7 minutes ago, John1122 said:

SE shift by the Euro AI, I expect the Euro will follow.  Hopefully it can work back this way but not holding my breath.

This type of setup is more likely to whiff, IMO.  It's funny, the last system we went so far west the phase started in the 4 corners region of the southwest...............  This time we need it further west and the likely result will probably be a further east phase than is needed to snow on parts of the mid-south.

[Carvers Gap]

12z Euro might be interesting per 500 vort maps.

[John1122]

The Euro is a whiff that run except for the Smokies/NE mountains.

[Carvers Gap]

Negative tilt vort over South Carolina at 141.

[Carvers Gap]

Just now, John1122 said:

The Euro is a whiff that run except for the Smokies/NE mountains.

It might be a whiff on the surface...it is not a whiff on the vort maps.  Looks similar to 6z. 

[John1122]

Just now, Carvers Gap said:

It might be a whiff on the surface...it is not a whiff on the vort maps.  Looks similar to 6z. 

It's weaker and further east than 06z, so we end up dry.

[Carvers Gap]

The 12z Euro slp is further west w/ a negative tilt trough.  For whatever reason, the surface doesn't respond as strongly.  They synoptics are better w/ 12z.  I don't think that means much for the western 2/3 of the forum area.  This is probably something the eastern 1/3 of the valley maybe has a 30-40% chance of sneaking into the game - if that.  12z left.  6z right.

 

[John1122]

The Canadian run that did so well for us, the vort is probably 75-100 miles SW of the Euro and it's stronger than the Euro. That little bit was the difference between 4-8 inches for most of East Tennessee and a couple of snow showers. It's a fine line. Hopefully everything is too far east currently, because if we needed it to be east it would truck west.

[Carvers Gap]

I think when we see partial phases...they just don't get worked out really well until inside of 3-4 days.  I do think this looks more like a Carolina special.  My investment level is low, but think light snow is possible with this for NE TN and SW VA.  I am not even sure the northern stream energy is even being modeled correctly.  Preferably, we would like that negative tilt maybe 150 miles further west in Georgia.  But that phase is so finesse...just tough to know.  I would feel good if I lived in the Piedmont, and keep an eye on it if in NE TN.  NE TN may well score w/ the northern stream energy before it phases, catch a little bit of backing, and see some light snow as a result.  But as we have seen this winter...these things do change quickly from time to time.

Of note, there are a lot of small pieces of energy directly behind this.  JB noted last night, and I tend to agree, this looks like a lot of lighter events until after Feb 10, and then the STJ fires again w/ cold in place.  

[John1122]

I'm hoping the Google AI model doesn't move SE. It's been steady with at least 2-4 inches for more of the area, and 4-8 for parts.

[Vol4Life]

7 minutes ago, John1122 said:

I'm hoping the Google AI model doesn't move SE. It's been steady with at least 2-4 inches for more of the area, and 4-8 for parts.

Where do you find access to that? And how often does it run?

[John1122]

3 minutes ago, Vol4Life said:

Where do you find access to that? And how often does it run?

It's on StormVista and I believe 12z comes out at 2pm.

[tnweathernut]

With high ratios .15-.2 would be a nice 3-5 inch snow.  Even a glancing blow would be fairly significant for our area.  Just something to keep in mind.

[Carvers Gap]

The following evolution looks reasonable to be.  Both the 12z GEPS-par and 12z Euro are very similar.  The Euro was missing some juice.  The 12z GFS, Euro, and GEPS-para are slightly west of their previous positions with the slp.  Below is a 12z comparison (not comparing to 6z runs) of the GEPS-para and Euro.  Left is GEFS-para and right is Euro.  Generally, that is pretty good agreement for low placement.  Per the GEPS-para, I tend to think the northern stream system will be stronger over the eastern Tenn Valley than the Euro has.  The Euro tends to be a little biased towards drier systems.  The GEPS-para was the first to nail mixing issues over NE TN with this last system.

Can it trend west to northwest?  Sure, but that is a tighter window with each passing run.  

Hour 114

Hour 128

 

[Carvers Gap]

The 12z GEPS is further back w/ the surface high pressure over TX than it was at 12z.  The 12z Euro is further east w/ the surface high pressure over TX than it was at 6z.  That seems to be a pretty significant difference.  The amount of hp over the top in New England is also important.  The 12z Euro had more there than compared to 6z...and that may well have shunted the moisture to the coast.