1-30/2-1-26 Arctic Blast, ULL Snow Event

[John1122]

Figured we may as well have a thread for this. All modeling except the Ukie and ICON have basically 2+ inches of snow from the Western side of the Plateau and points east. With several being more wide spread and much heavier. 

Extreme cold is also a story. We could have 20-1 or even higher ratios. The Euro has Saturday afternoon temps 30 to 35 degrees BN across the state. We could have snow falling with wind chills below 0, and if the GFS is to be believed, incredible snowfall totals, especially for NC border counties. 

The event is basically 3 days away from beginning. Let's reel something in! 

[John1122]

The trend map for the Euro is west, west, west, west. I'm not sure if it can go much further west or not. 

[John1122]

The Euro went from barely touching the Eastern mountains to this. 

 

 

[John1122]

Granted, I should probably look to my avatar. 

[John1122]

The NAM is winding our energy up over Eastern Kansas/Western Missouri at 06z, 72hrs, at 78 at 0z it wasn't quite wound yet and was over SE Missouri.

[John1122]

In response, we are getting nammed, almost state wide by 78. Looks like the RGEM.

[John1122]

Ratios are 17 to 20:1 on the NAM across the state as snow is falling.  Just south of Nashville, and in NE Tn from earlier snow, 4-6 inches have fallen at 84 and it's still snowing over the eastern 2/3rds of the forum area. Alabama and Georgia are in the game.

[John1122]

RGEM looks like it's winding the vort up tighter further NW as well vs 0z.

The ICON, while not quite enough for most of us, jumped west 200 miles.

[John1122]

RGEM takes the ULL from Memphis to North Alabama, and it's stronger than it was at 0z. Still snowing over the eastern half of the state with 1-3 inches down from Nashville to Cookeville, and 3-5 inches down from Cookeville eastward.

[Windspeed]

I feel completely opposite versus last weekend's lead time into the event for a snow storm. Obviously, that transitioned into worry for the ice storm. But with respect to all snow, perhaps even significant totals, my confidence is growing. Got to love recent trends with a stronger and slower mid-to-upper low versus the coastal surface low. If the moisture feed is there, that ULL will eat. Very cold column and high ratios. I guess if I get my heart broken, so be it. I am all in on this system.

[John1122]

The GFS has a 986 low bombing just inside Hatteras or over it. 4-12 inches has fallen over East Tennessee by that point. Looks like it pulls away NE rather than heading up the coast.

[John1122]

The AI GFS QPF totals, .14 in Nashville, with generally 17:1 to 20:1 ratios.  .20 the next tier of counties eastward, trailing SE towards Chattanooga. Around .30 in Cookeville to McMinn Co. .40 in counties along the 75 corridor from my area down to Knoxville. .5 around Morristown. .5 to .7 along the NC border areas into SW VA. The DGZ in nearly to the surface with -12c being around 2400 feet and high humidity from there to 700mb.

[John1122]

Weather Next 00z has the .25-.50 line back to my area with .50 creeping into NE Tn. The 18z crapped out and never finished. That is a big improvement west over 12z yesterday, which barely had the .25-.50 in far NE Tn.

[fountainguy97]

Models are in pretty good agreement with regards to the ULL energy diving a precip maxima from ETN down into SC/NC.  The main question continues to be the coastal.

 

ON euro/gfs/nam our starting ratios are 15:1 and peak at 24:1 toward the end of the event. It won't take much qpf at all. 
 

.5 qpf at 15:1 is 7.5" 

[fountainguy97]

Here are the latest models. 7 of them.  All of them in agreement about the ULL sliding moisture. Vary degrees of intensity.  
 

and then the GFS with the coastal lol

[fountainguy97]

Euro ticked west a bit. But mostly the same. AIFS very close to the same

[GBOVolz]

That cutoff through Knox co sucks. 10 miles one way or the other is a lot of people.


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[GBOVolz]

Put that in your pipe and smoke it


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[Vol4Life]

11 minutes ago, GBOVolz said:

That cutoff through Knox co sucks. 10 miles one way or the other is a lot of people.


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Yes, I guess that’s due to snow downsloping issues maybe. Either way, would love for the precip shield to keep growing back to the west.

[GBOVolz]

Yes, I guess that’s due to snow downsloping issues maybe. Either way, would love for the precip shield to keep growing back to the west.

Not positive but I don’t think downsloping will be an issue here. I think that cut off is the NW shield.


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[Holston_River_Rambler]

Google AI Weathernext 2.2e841369r16r4y1` trend over the past few runs. Ripped from another forum so you may have to look at the time stamps to see, but the current trend is a friend to you TRI folks:

 

that is a 10:1 ratio too

[GBOVolz]

Google AI Weathernext 2.2e841369r16r4y1` trend over the past few runs. Ripped from another forum so you may have to look at the time stamps to see, but the current trend is a friend to you TRI folks:

 
that is a 10:1 ratio too

That’s probably 10/1 also.


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[GBOVolz]

Google AI Weathernext 2.2e841369r16r4y1` trend over the past few runs. Ripped from another forum so you may have to look at the time stamps to see, but the current trend is a friend to you TRI folks:

 
that is a 10:1 ratio too

Somehow i missed your comment lol


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[nrgjeff]

The 06Z NAM is too good to be true. Even a quasi-trowal to help keep snow in Tenn. If that's busts it'll be the biggest NAM job in quite a while. Going high risk 60% hatched of disappointment. Otherwise globals keep light snow and snow showers northeast, Plateau, Mountains, the usual. 

12Z and AI commentary will be in a few hours. My NAM cynicism aside, models overnight look OK. 

[Holston_River_Rambler]

28 minutes ago, GBOVolz said:

Put that in your pipe and smoke it


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If I lived in some place like NYC of Boston, I'd be pretty pissed at that guy for posting something like that. I think 90th percentile means it is higher than 90 percent of all samples in the analog set. 

Here's what the same analog set has for percentage on sites getting greater then 4". I don't mean this in any way as a dig at you Powell, I just think that guy is farming for clicks from high population center snow weenies. 

 

 

[Holston_River_Rambler]

2 minutes ago, nrgjeff said:

Going high risk 60% hatched of disappointment.

Rug pull watch may be warranted later today. 

[GBOVolz]

If I lived in some place like NYC of Boston, I'd be pretty pissed at that guy for posting something like that. I think 90th percentile means it is higher than 90 percent of all samples in the analog set. 
Here's what the same analog set has for percentage on sites getting greater then 4". I don't mean this in any way as a dig at you Powell, I just think that guy is farming for clicks from high population center snow weenies. 

 
 

It’s all good


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[Carvers Gap]

1 minute ago, Holston_River_Rambler said:

Rug pull watch may be warranted later today. 

For sure...This is too finesse for my liking.  It may well work out, but the cutoffs for this are going to be rough for some folks.  Very steep gradient between snow and no snow in some areas.  Just kind of has the feel of one that stops at the NC line w/ some light snow west of the Apps and heavy snow to the East.  DC to NC snow axis is generally good in E TN.  Hatteras to Boston has given me many headaches.

[Carvers Gap]

The closer to the spine of the Apps that one lives and north of I40.....that is the sweet spot for now.  BTW, that is not me.  I am roughly in the same boat as Knoxville in hoping for storm trends.  I am on the far west side of TRI.  

[fountainguy97]

A safe bet right now is the ULL moisture at the start. That's barely 2.5 days out at this point. The bigger question is what interactions happen after that. Everything is still on the table for the eastern valley region.  At the end of the day someone is going to be just too far west and will watch a county over get some snow.  

 

This does remind me a lot of the December 2010 storm. I believe it was also some ULL moisture to start and then the coastal backed another batch over the mountains. It was also a last second thing.