1/23/26-1/25/26 Winter Storm Thread

[jaxjagman]

4 minutes ago, Holston_River_Rambler said:

wow.

If y'all haven't had the front pass by in East TN yet, get ready. That N/NW wind has a bite. 

Definite got colder,CF is already trough Tn per RAOBS

[dwagner88]

2 minutes ago, jaxjagman said:

Definite got colder,CF is already trough Tn per RAOBS

Is that an official product? Because it looks like I drew it in MS Paint.

[Carvers Gap]

5 minutes ago, Holston_River_Rambler said:

wow.

If y'all haven't had the front pass by in East TN yet, get ready. That N/NW wind has a bite. 

Send it, man.  Bring on the 1050hp...or 1040...or 1030...or 1028....or just send a slp right up the Valley instead.

[Daniel Boone]

6 minutes ago, Carvers Gap said:

FWIW...I think the 3K NAM has this nailed.

Agree. Might even go a bit further South. Probably be more Snow particularly in northern areas than what is being forecast barring much of it doesn't fall as Virga.

[jaxjagman]

5 minutes ago, dwagner88 said:

Is that an official product? Because it looks like I drew it in MS Paint.

Seriously?

Its public info

https://www.spc.noaa.gov/exper/compmap/

[Carvers Gap]

1 minute ago, Daniel Boone said:

Agree. Might even go a bit further South. Probably be more Snow particularly in northern areas than what is being forecast barring much of it doesn't fall as Virga.

The HRRR looks like it is over-doing the downslope, but I never, ever discount that model.  If one model can see downslope, it is that one.  The 3k NAM basically got rid of the downslope - not sure if it is a hiccup or if the mountain wave was less.  The HRRR is basically showing that NE TN is going to takes its time getting precip in here.  As you know, not uncommon.  The 12z Euro, 18z NAM(southward jog), 12z GFS, 12z RGEM....take some time to get precip, but then they just overwhelm the dry air, and send it.  Ice is so difficult to forecast in the Tennessee Valley.  I have seen cold get trapped and never leave until the event is over.  I have seen it scoured immediately.  My experience says this cold air erodes pretty quickly.  But........this hp setup is different than most other events.  It is strong.  If I was just looking at a map and scientifically had to make a call...I would say that big high is gonna pour cold air down the west slopes of the Apps and hold onto frozen precip just a bit longer.

[dwagner88]

2 minutes ago, jaxjagman said:

Seriously?

Its public info

https://www.spc.noaa.gov/exper/compmap/

Oh I saw that. It just looks really off to me for some reason. Way different than WPC maps I'm used to. Like all the overlays are shaky. 

[Carvers Gap]

As @Holston_River_Ramblernoted, you have to watch the first part of the storm.  If everything is colder and south, that tells us something.  We need to start watching numbers for verification purposes.  The 18z RFSS has ice to the Ohio River.  The 18z 3k NAM(which has been good for E TN forecast purposes) has the ice several counties south of the Ohio River.  BIG differences in short range models.  The interesting thing is how much precip gets out in front of this?  Do we get a lot of virga or does this go from the jump?

Houston, what were your ideas on the southward verification?

[Holston_River_Rambler]

I am wrong to say the RGEM is usually a colder (biased) model? It just surprises me that it has continuously ticked S. 

Is it slower, colder, south? All of the above? 

Don't get me wrong, I'm don't see su dodging the ice bullet completely, but it does look like the HP is bullying things a bit.

[Carvers Gap]

4 minutes ago, Holston_River_Rambler said:

I am wrong to say the RGEM is usually a colder (biased) model? It just surprises me that it has continuously ticked S. 

Is it slower, colder, south? All of the above? 

Don't get me wrong, I'm don't see su dodging the ice bullet completely, but it does look like the HP is bullying things a bit.

The RGEM is usually money.  The GEM is biased cold.  The RGEM is usually a strong model for this area, and my favorite.  3k NAM is a close second.

[TellicoWx]

3 minutes ago, Carvers Gap said:

The RGEM is usually money.  The GEM is biased cold.  The RGEM is usually a strong model for this are, and my favorite.  3k NAM is a close second.

The 2015 ice storm at one point the RGEM was only one that showed the threat. That storm was when I started following it with the other runs

[Carvers Gap]

Again, we really need to watch trends to our West.  We have lost storms at this range in the past...and usually we see it immediately when everything verifies northward.  If modeling is shifting south (to our west), we need to watch that closely.  The RGEM trend southward(past several runs) is noteworthy.

[Carvers Gap]

Just now, TellicoWx said:

The 2015 ice storm at one point the RGEM was only one that showed the threat. That storm was when I started following it with the other runs

It is a great model.  The 3k NAM is giving it a run for resolution IMBY.  I like the HRRR and RAP, but they move around a lot during the storm as I think that have radar data included.  As Holston noted...if it is adjusting the start point in Arkansas southward....I am somewhat interested in that.

[John1122]

Cold rush is happening here. Very gusty and cold N winds have started. 

[Save the itchy algae!]

I am wrong to say the RGEM is usually a colder (biased) model? It just surprises me that it has continuously ticked S. 

Is it slower, colder, south? All of the above? 
Don't get me wrong, I'm don't see su dodging the ice bullet completely, but it does look like the HP is bullying things a bit.

From what I can tell, it might be a little slower but it seems the valley is mainly where it’s trending more south. The 546 line has been pretty consistent east of the apps and west of the valley, just seems to be our area with any real changing trends from a thermal perspective.

[Holston_River_Rambler]

2 minutes ago, Carvers Gap said:

Houston, what were your ideas on the southward verification?

Best guess I have is that the HP is bullying the system a bit. The real challenge to the HP comes when the Baja low fully ejects and starts to interact with the n. stream shortwave dropping in now through NW Canada. 

I guess we could look at the confluence over the NE to see if that has trended stronger? There is a touch more confluence on the RGEM over NE and I do mean just a touch. 

 

Most of the early precip. on the first wave is driven  by frotogenesis, isentropic upglide (presumably not unrelated), and jet dynamics over the upper OH Valley.

LLJ doesn't really hit TN until after 3 tomorrow (eastern time),

So I guess there is some scenario where this first wave overperforms wrt frozen as opposed to freezing for favored areas. 

But I don't see much of a window outside of TN and VA/KY border counties (eastern areas only here since out west TN it is a different story) past maybe dark tomorrow when that LLJ gets cranking. 

 

[ShawnEastTN]

Cold rush is happening here. Very gusty and cold N winds have started. 

Yeah same here front appears to have passed me just before 2pm, wind shifted out of N and NW and since 2 pm my weather station has had steady falling temp.

Sent from my Pixel 10 Pro XL using Tapatalk

[Holston_River_Rambler]

One other thing to consider especially north of I-40. When the transition happens, there is usually an area with humongo snowflakes (fatties, as it were) just on the leading edge of that warm nose.

 

[jaxjagman]

[brewman22001]

Loudon and knox County bullseye for ice

That’s us . We will make the best of it, we’re as prepared as we can get!


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[Holston_River_Rambler]

15 minutes ago, Carvers Gap said:

 As Holston noted...if it is adjusting the start point in Arkansas southward....I am somewhat interested in that.

Here is the trend centered on 0z this evening, def slower moving out of TX. Heights have also been creeping south out that way. 

[Holston_River_Rambler]

Might as well throw of Cranky/ contentwxguy out against the wall too, and see if anything sticks:

 

 

 

Since he originally posted a gif, here is one showing the wavebreak he drew in

 

[Tucker1027]

GFS is running.. already a tick south 

 

[Holston_River_Rambler]

Now to be totally fair, the HP has weakened some (based on SPC mesoanalysis) since contentwx posted the above:

[Matthew70]

 

[Tucker1027]

5 minutes ago, Matthew70 said:

Anyone got pics of the 3K NAM?

 

So the regular name is still out to lunch?

[Scottie16]

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[Tucker1027]

[Scottie16]

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Still funneling down, I see nothing to suggest a break yet.


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[Matthew70]

1 minute ago, Tucker1027 said:

Ouch