1/10-1/12 Southern Slider

[Carvers Gap]

The 12z ARW is having none(and I mean none) of what the NAM is having.  Ice doesn't even reach the southern TN state line on that model so far....and it is about halfway across the state so far.

[Kasper]

8 minutes ago, Carvers Gap said:

12z 3K NAM and 12z 12k NAM:

 

Correct me if I’m wrong but if that verified, that would be the worst ice storm since what the mid 80s?

[Carvers Gap]

NE TN peeps, the storm isn't even too our area on this model.  Just to illustrate the 12z ARW run that is underway.

[Carvers Gap]

The 12z ARW is rock solid compared to its 0z run...remarkably similar.

[Wurbus]

What is the difference between the ARW & NSSL on the HRW model? NSSL does have some WAA entering the valley toward the end of the run.

[Carvers Gap]

4 minutes ago, Kasper said:

Correct me if I’m wrong but if that verified, that would be the worst ice storm since what the mid 80s?

It is kind of pick your poison at this juncture.  Ice or snow.  Could all of that change?  Sure.  I would think by 18z, we have a much better picture.  I hope so, because that is only 12 hours before the event starts in E TN(southern Plateau).

[Math/Met]

10 minutes ago, Carvers Gap said:

I think we wait to see the rest of the 12z suite before passing a verdict.  To me, it looks too wound up.  It looks like feedback.  That is a bias of that model.   

That's my thought at the moment as well. I've seen the NAM go crazy with bringing the LLJ too far north and too strong many time while looking at wind events. It tends to hold on to that look until the last minute. Hopefully that's the case this time.

[AMZ8990]

3 minutes ago, Carvers Gap said:

The 12z ARW is rock solid compared to its 0z run...remarkably similar.

 Great run for sure, that’s what we’re looking for.  

[TellicoWx]

NAM is trying to split and go around the HP to its east. You can tell by the iso bars forming a backward moon as it is over southern MS

[Carvers Gap]

So, the ARW is at 43(out of 48 hours).  NE TN folks add a tenth or two more to your run(edi...full run shown).  Now, take this model and compare it to what we have seen so far, and what is still to run.  So far(with the notable exception of the NAM), this looks very similar. 

Now, I have seen one storm go horribly, epically wrong in terms of modeling.  Charlotte was once forecast to get 4 feet of snow.  Short range modeling got all sorts of feedback going as it turned the corner.  They got nothing.  I made the mistake of sharing that forecast with a friend of mine who works for ESPN.  He wasn't happy when that didn't verify.  I was scared to death(still am!) I was going to end up on his show for sending him that!!!  LOL!!!

[tnweathernut]

12z RGEM ticked up in total QPF for most along I-40 that run.  looks like it added about a tenth, no mixing issues.

Nice mid-south snow  3-5" (pockets of 6) across the state, verbatim

[TellicoWx]

Oklahoma already seeing Half Dollars

[tnweathernut]

5 minutes ago, TellicoWx said:

Oklahoma already seeing Half Dollars

https://www.colgate.edu/about/campus-facilities/webcams-around-colgate/seven-oaks-webcam  yep

[Carvers Gap]

17 minutes ago, Carvers Gap said:

12 RGEM for comparison....

[Wurbus]

ICON hammered the valley

[Carvers Gap]

Just now, Wurbus said:

ICON hammered the valley

ARW, RGEM, ICON...almost identical at 12z.  Let's see if the pattern continues. 

[Carvers Gap]

12z NBM

[Grothar of Herndon]

So far so good with other 12z models. NAM standing alone...

[ShawnEastTN]

8 minutes ago, Grothar of Herndon said:

So far so good with other 12z models. NAM standing alone...

MRX will stand with NAM and die on that hill regardless of consequences for the public.  Though with 12z NAM technically a worse outcome in terms of threat to life and property for the MRX CWA it will be interesting to see if MRX tries to wiggle a bit and side with previous runs of the NAM and claim 12z is an outlier.  I should get about 3 inches of sleet according to the 12z NAM if that happens will be the deepest sleet I've ever seen imby.  Previously I've seen a bit more than an inch.

[Carvers Gap]

12z GFS holds.

[Hurricaneguy]

7 minutes ago, Carvers Gap said:

12z NBM

That scenario is identical to last year's event for Greene Co. Sharp cutoff mid county due to mixing issues. We've on average had less than most places in East TN but the last few years have been worse than normal. New normal I suppose. 

[ShawnEastTN]

2 minutes ago, Hurricaneguy said:

That scenario is identical to last year's event for Greene Co. Sharp cutoff mid county due to mixing issues. We've on average had less than most places in East TN but the last few years have been worse than normal. New normal I suppose. 

Because it's a blend of models that include those models with downslope holes.

[Carvers Gap]

1 minute ago, Hurricaneguy said:

That scenario is identical to last year's event for Greene Co. Sharp cutoff mid county due to mixing issues. We've on average had less than most places in East TN but the last few years have been worse than normal. New normal I suppose. 

It could happen.  Hi res models are definitely showing that potential.  I don't think that is written in stone at the moment though.

[Math/Met]

3 minutes ago, Hurricaneguy said:

That scenario is identical to last year's event for Greene Co. Sharp cutoff mid county due to mixing issues. We've on average had less than most places in East TN but the last few years have been worse than normal. New normal I suppose. 

When 850mb winds are southerly, there will be some negative effects for areas adjacent mountains. That's the unfortunate reality. (Its also why parts of Greene Co do well in NW flow events). However, how the 850 LLJ develops makes a huge difference. If the stronger winds develop to the west and move into the mountains, that is more of a true downslope wind. When the core of the LLJ stays to the south or builds in from the south, low level convergence can offset the downslope effects and there's only small decrease in precip amounts. Small changes in the evolution make a very significant difference.

[Carvers Gap]

12 GFS, ICON, RGEM, ARW on board.  Dr No is up next.  My guess is similar but with lighter precip. 

12z GFS vs 6z GFS:

[dwagner88]

GFS is a big improvement down here. Way less mixing over northern GA.

[tnweathernut]

12 minutes ago, Hurricaneguy said:

That scenario is identical to last year's event for Greene Co. Sharp cutoff mid county due to mixing issues. We've on average had less than most places in East TN but the last few years have been worse than normal. New normal I suppose. 

Those downslope holes are still around 2 inches, FWIW.

[Reb]

CMC still looking good

[Hurricaneguy]

1 minute ago, tnweathernut said:

Those downslope holes are still around 2 inches, FWIW.

True, but when you've been deprived seeing a good >5" snow event at your house in over ten years it gets old. Last year broke me lol

[Carvers Gap]

Here is a more zoomed in version of the gfs: