January 19 RGEM leeside Apps low and following arctic blast tracking and obs

[Holston_River_Rambler]

At least it's something

[Holston_River_Rambler]

seems like two jets streaks will have some sort of a say over this one:

[Carvers Gap]

The trend is our friend.

[John1122]

RGEM/Canadian for Sunday, Canadian Tuesday, (though the deep south would cease to function for a week or two) and the GFS later in the week. That's not too much to ask for. 

[matt9697]

27 minutes ago, John1122 said:

RGEM/Canadian for Sunday, Canadian Tuesday, (though the deep south would cease to function for a week or two) and the GFS later in the week. That's not too much to ask for. 

The models are crazy! I mean, all of the stuff I have ever read about historical cold, for example, the 1899 outbreak when it snowed in New Orleans, we were really cold here in the TN Valley. From what I have seen, we are now where near that kind of cold, how is everything being depicted so far south? 

[John1122]

I see the big system that was set for late week just went poof on the GFS. It's folding to the Canadian on the Tuesday system and now on that system as well. Hopefully everything folds to the Canadian on the Sunday system, but so far none are.

[bearman]

4 hours ago, matt9697 said:

The models are crazy! I mean, all of the stuff I have ever read about historical cold, for example, the 1899 outbreak when it snowed in New Orleans, we were really cold here in the TN Valley. From what I have seen, we are now where near that kind of cold, how is everything being depicted so far south? 

Yeh,  I don't buy it.  I think there is going to be some very disappointed people in the deep south.  I would like them to score but many times these setups say snow and that far south they end up with ice.  Like you say our temps don't add up to what is being forecast.  We will see.

[John1122]

After looking, and it's still the 00z run because it's always behind everyone else, the GFS Graphicast is not far off the Canadian. We get generally .1 to .15 qpf as frozen on it. The 06Z Euro AI is very close to the Graphicast with QPF for Sunday.

[*Flash*]

How accurate has the RAP performed in the short term this year?

[Carvers Gap]

The 12z GEFS has a trailing system like the 12z Euro deterministic does later in the week....something to watch and makes a lot of sense.

[Carvers Gap]

Just now, *Flash* said:

How accurate has the RAP performed in the short term this year?

I got about 25% of the RAP snow forecast last weekend.  LOL.  Maybe not even that.  Looks like the RGEM though!

[John1122]

19 minutes ago, *Flash* said:

How accurate has the RAP performed in the short term this year?

It was kinda bad with the last event. Way too much QPF imby and I think way too warm down towards Chattanooga.

[Daniel Boone]

For the Sunday System, we either want ana development sooner and a bit east to put us in the eastern KY zone showing now or cold to slam in quicker and result in faster turnover. It looks as though the latter is what some Models are seeing as the problem east of the KY line.

[John1122]

It should snow most of the night Sunday if there's any moisture at all around still. It will fall from lower levels as the DGZ will be down to probably 3000-4000 feet. Monday morning  at 1am the 850 RH is depicted between 85 percent and 100 percent from the Plateau east. 850s are -16c to -19c. (DGZ is -12c to -19c if I recall correctly) the 925 is -14c to around -10c with the colder 925s on the Plateau and the -10s to the east. 925 rh is 80-85 percent.  So the snow growth zone will be as low as 925 or about 2500 feet. I suspect there will be small flake pixie dust falling even during the time the models show the precip as over, as it wrings out the lingering lower level moisture in the DGZ.

Looking at my sounding on the GFS, it shows me at 8f at 1am Monday, and the green RH line and red temp line are touching at 850. That's why there's usually at least a trace of snow with big Arctic outbreaks. It happened during the Christmas 2022 cold.

[*Flash*]

10 minutes ago, John1122 said:

It should snow most of the night Sunday if there's any moisture at all around still. It will fall from lower levels as the DGZ will be down to probably 3000-4000 feet. Monday morning  at 1am the 850 RH is depicted between 85 percent and 100 percent from the Plateau east. 850s are -16c to -19c. (DGZ is -12c to -19c if I recall correctly) the 925 is -14c to around -10c with the colder 925s on the Plateau and the -10s to the east. 925 rh is 80-85 percent.  So the snow growth zone will be as low as 925 or about 2500 feet. I suspect there will be small flake pixie dust falling even during the time the models show the precip as over, as it wrings out the lingering lower level moisture in the DGZ.

Looking at my sounding on the GFS, it shows me at 8f at 1am Monday, and the green RH line and red temp line are touching at 850. That's why there's usually at least a trace of snow with big Arctic outbreaks. It happened during the Christmas 2022 cold.

That was some front! I want to say my area got about 1.5" out of that. Not much...but then again, I would gladly take a repeat. 

[nrgjeff]

Nashville just dropped higher snow probs. Surely this is coming to their public site soon. Ope! I cut off the scale, inch or less.

 

[*Flash*]

This weekend is essentially 'Operation: Can I Buy an Inch?' to go along with my icebox conditions? The 18z HRRR offers some hope... 

[John1122]

MRX just put this out. 

 

[jaxjagman]

[*Flash*]

Per Bobby Boyd: “3 pm Update for snow potential this weekend 1/18-19. I blended several models, including 18Z 12km NAM. It's looking more likely for light accumulating snow in Middle Tennessee Saturday night/very early Sunday as we get into the left exit region of the upper jet. My Tempest blend has it snowing in Nashville from 9 pm Saturday evening 1/18, until 3 am 1/19, Sunday morning. This time frame expanded considerably over the last 3 runs.” 

[Matthew70]

Ole Canada might find a nut for once.

[bearman]

1 hour ago, John1122 said:

MRX just put this out. 

 

Always have to have the cutout for less snow totals for Knox county.  Don't want to have to many people getting excited. Brings to much attention.  I will be happy if we get an inch. Happier if it over performs.  I have now had more than an inch of snow in my front yard for an entire week.  That is very rare.

[nrgjeff]

WPC tease me and maybe even please me. That's moderate impacts. Light impacts probs are likely higher. Fluffy snow doesn't do much except for roads. Reel it in!

Then North Florida Red Alert. Icemageddon!

[jaxjagman]

18 minutes ago, nrgjeff said:

WPC tease me and maybe even please me. That's moderate impacts. Light impacts probs are likely higher. Fluffy snow doesn't do much except for roads. Reel it in!

Then North Florida Red Alert. Icemageddon!

That would be brutal in North Florida,maybe shades like the 2018 storm

[bearman]

 Notice the almost due East-West line that cuts off Knox county right at the county line.  No disruption of daily life for any Knoxvillain.

[jaxjagman]

10 minutes ago, jaxjagman said:

That would be brutal in North Florida,maybe shades like the 2018 storm

Probably not like 2018,that was a wicked storm anyways

[PowellVolz]

1 hour ago, nrgjeff said:

WPC tease me and maybe even please me. That's moderate impacts. Light impacts probs are likely higher. Fluffy snow doesn't do much except for roads. Reel it in!

Then North Florida Red Alert. Icemageddon!

It’s hard for me to see this graph and think that none of the moisture gets funneled up the valley, especially since the precipitation shield has a NE component to the track. 

[tnweathernut]

I mean, it’s not like the last 6 runs of the GFS is staying put…….there is a definite trend at the surface. Looking at 500 there’s a limit how far north and west this can make it, but getting scraped isn’t out of the question for some, IMO.

[Silas Lang]

36 minutes ago, PowellVolz said:

It’s hard for me to see this graph and think that none of the moisture gets funneled up the valley, especially since the precipitation shield has a NE component to the track. 

Kind of where I am. How many times have we seen that finger of moisture pop up on systems like this? Right up the valley and spine of the apps. There upper level moisture doesn't look too bad either or least it didn't yesterday. 

[Silas Lang]

8 minutes ago, Silas Lang said:

Kind of where I am. How many times have we seen that finger of moisture pop up on systems like this? Right up the valley and spine of the apps. There upper level moisture doesn't look too bad either or least it didn't yesterday. 

Upon review, a bit of dry air at the 850 and 925 levels, but looks pretty juiced above that. On the 18z GFS.