1/10-1/12 Southern Slider

[John1122]

2 minutes ago, Holston_River_Rambler said:

What time will get an AFD? Will this be one of those after 4 days? I’m goin for 3:34 PM unless they’re waiting on a WPC product like Jeff mentioned. 

Always late when snow is possible. 4:21 is my guess. 

[TellicoWx]

Anything outside of 24hr on short range models..12hr on hrrr, take with a grain of salt verbatim. Used for trends outside that range, but are lightly weighted. Global Ops still have the weight until the 24-36hr range. 

[Jed33]

1 minute ago, John1122 said:

Always late when snow is possible. 4:21 is my guess. 

I was going to say I’ve seen NWS offices wait till 5 or later, with complicated forecasts, but that was usually back years ago. Normally I don’t think they’re that late anymore. 4:21 is a great guess John. I’ll roll with that time as well.

[Reb]

7 minutes ago, Jed33 said:

I was going to say I’ve seen NWS offices wait till 5 or later, with complicated forecasts, but that was usually back years ago. Normally I don’t think they’re that late anymore. 4:21 is a great guess John. I’ll roll with that time as well.

@Stovepipe would take just short of that, if I had to guess.

[ShawnEastTN]

Also I thought they bumped Tri-Cities area down to advisory mid day?  Am I losing my mind, back to watch now.

[Jed33]

1 minute ago, ShawnEastTN said:

Also I thought they bumped Tri-Cities area down to advisory mid day?  Am I losing my mind, back to watch now.

No, it was mentioned earlier that they have had snow showers with heavy enough accumulation that they needed an advisory for today. So they issued one for immediate effect. Then they canceled it when the new watch came out around 1:30. Not sure why they canceled it or if it just got bumped with the new watch issuance 

[dwagner88]

Lol. MRX grids have rain Friday afternoon now for here. Lucy is coming for the football.

[bearman]

20 minutes ago, Reb said:

I’ve seen MRX lower snow totals only for the actual accumulation to be twice what they originally predicted. 3-6” is still a nice snowstorm for East Tennessee though.

I have seen this as well and to be honest it always seems that the average reported totals are always more than the official total that MRX comes out with at McGhee Tyson.  It is very odd.

[John1122]

NAM is often on the amped side of things. I hope the rain/Mix in the far SE areas are not on any other models. 

[midwoodian]

I expect MRX to continue to trend down for the area south of I81. Even with the newest HRRR in range, it shows a brutal snow hole over parts of Greene and Washington Co. Mixing issues. Just unbelievable the luck. We've not had a 6"+ snow since 2014. Last decent snow was the Christmas Eve fun 2020  

When you’re saying 81, do you mean I-40? 81 ends northeast of Knoxville and is a north south artery.


.

[TellicoWx]

Think they covered everything in the updated watch.....2-4 up to 6..with snow, sleet, freezing rain, rain...yep they fit everything to be covered in it lol.

[bearman]

In the grid forecast MRX now has Rain snow for Friday in Knoxville.  That way they can't be blamed for hype. Or is it time to get out the towel?

[Carvers Gap]

18z NAM is a beaut for NE TN folks (both 3k and 12k).

[John1122]

The NAM had slightly lower snow totals in the East 40 and north with about .05 less qpf. Just in the small run to run variation window. 

[Hurricaneguy]

6 minutes ago, midwoodian said:

When you’re saying 81, do you mean I-40? 81 ends northeast of Knoxville and is a north south artery.


.

More areas south of 81 until it meets the split at 40. Specially Cocke, Greene, Washington, etc

[Bigbald]

12/18z Nam and 12z gfs killer runs for east tn.  Hopefully happy hour gfs agrees

[Silas Lang]

3 minutes ago, bearman said:

In the grid forecast MRX now has Rain snow for Friday in Knoxville.  That way they can't be blamed for hype. Or is it time to get out the towel?

Nah man, it is going to snow. Feeling pretty good about it, though the NAM and GFS was throwing in some sleet for Knox.  

[fountainguy97]

3KM picking up on my concern for myself and fellow border counties. Very obvious moisture/downslope issues. NW may bail myself out but verbatim the 3km would make for a long Saturday for me watching it snow across the mountain.

 

 

[Vol4Life]

4 minutes ago, John1122 said:

The NAM had slightly lower snow totals in the East 40 and north with about .05 less qpf. Just in the small run to run variation window. 

Any issues of mixing near Knoxville?

[John1122]

1 minute ago, Vol4Life said:

Any issues of mixing near Knoxville?

Verbatim, Knoxville is right on the edge that run. Sevier county is freezing rain, Loudon sleet. 

[TellicoWx]

Questions I have about the system are:

1) How quickly can the column moisten? (Virga Monster eating initial QPF)

2) exact path of the trowal feature? If it passes to the west, East gets into the dry slot coming from SW. (Think middle/west TN are OK there). Column starts drying quickly, Def could be some mixing concerns as DGZ dries out.

3) Does any other model have the amping compared to the NAM? (Still TBD)

[ChattZ]

Downgrade?

[jaxjagman]

Not sure why it made it small,heres the linkhttps://www.wpc.ncep.noaa.gov/discussions/hpcdiscussions.php?disc=qpfhsd

[Holston_River_Rambler]

Hey I almost nailed the WPC disco release time lol. Nice that they want to keep mention of mixing around and south of I 20

[ShawnEastTN]

42 minutes ago, Jed33 said:

No, it was mentioned earlier that they have had snow showers with heavy enough accumulation that they needed an advisory for today. So they issued one for immediate effect. Then they canceled it when the new watch came out around 1:30. Not sure why they canceled it or if it just got bumped with the new watch issuance 

Gotcha I was confused by that.  Ok good!

[John1122]

Nice pass by the ICON. 0 mixing in Tennessee that I saw. 

[dwagner88]

I could be totally off base here, but my gut tells me the dynamics at play are going to keep TN all snow for this event. If you look at the 850 temps on the NAM, you can see them sneak above 0 south of I-40, then as the levels saturate they quickly cool below freezing starting in Northern MS and AL and spreading northward. The wetbulbs are well below freezing. I don't see enough warming to actually cause a changeover. Might see lowered ratios and sloppy wet snow though.

[John1122]

 

[tnweathernut]

If this is how it plays out with a healthy system west that weakens as it comes east I'd have to give a hat tip to the EURO.  It was showing this as a possibility when other modeling wasn't several days out (5-6).  Still uncertainty with how the mountains will affect the mountain counties, but as Fountain points out, the mesoscale modeling is picking up on impacts.  Usually when we see this it's not wrong.  Just have to see how much of an impact comes with it.  Minor differences in the next 24-36 hours can mean the difference in a couple of inches of snow for these areas.  Hopefully, the NAM is overdoing these issues.  

[Holston_River_Rambler]

RGEM has only a small amount of sleet near the GA border and has upped .qpf a small amount.