December 2020 Medium/Long Term Pattern Discussion.

[Carvers Gap]

1 minute ago, Holston_River_Rambler said:

18z RGEM plows the surface low right up the TN/ NC border. 

 

 

Definitely jog SE over the past couple of days and with this past run...but can it get east of the mountains?  Just seems to me like a track between Asheville and Charlotte makes the most sense with maybe a some energy running up the eastern valley(aka the warm nose).  Pretty crazy to see that type of move this late in the game.  Think it is a testament to how tough this phase is to model.

NAM is definitely northwest of its previous run as you all have noted.  The storm right after this also has my attention.  Looks like it will be further east with enough separation and maybe storm 1 providing a bit of a block to slow it down so it can phase.  Really like the energy coming across the TN Valley feeding into that coastal.  Chance for a really big storm for eastern sections IF it were to phase earlier.

[Holston_River_Rambler]

 

Just now, Carvers Gap said:

Just seems to me like a track between Asheville and Charlotte makes the most sense with maybe a some energy running up the eastern valley(aka the warm nose).

The WRF NMM showed a similar solution at 12z:

That would be as much of a  run for my location as I can probably hope for. 

 

 

[Carvers Gap]

3 minutes ago, Holston_River_Rambler said:

 

The WRF NMM showed a similar solution at 12z:

That would be as much of a  run for my location as I can probably hope for. 

 

 

There is no shame in hoping for a solution that hammers your local...same goes for everyone else.  LOL.  If we had that run in January, all of the northwest quadrant would be snow.

[BhamParker]

I’m hugging the RGEM. MRX saying 1-2 for elevations between 2000-3000 feet and that seems a little conservative to me after seeing the RGEM, Euro, and GFS. Even the 18z NAM seemed to have some nice totals even around gatlinburg. 

[Holston_River_Rambler]

Yeah, their 1 -2 for Roan Mountain seemed a little low to me, but maybe they mean the town of Roan Mountain and not the 5500 - 6000 peak. 

Did I read earlier that you were getting a cabin near Gatlinburg @BhamParker? 

[Holston_River_Rambler]

18z GFS looks like it almost wanted to run the SLP from Macon, GA to Charlotte, NC, but randomly jumps at hour 36 back to the TN/ NC border:

 

I guess we're just at "see what happens time" now. One thing I did notice today was that there was a stronger wedge (from obs at southerwx) and a little bit of a leeside low near Asheville:

 

That's now transitioned to a more of a diffuse area of lower pressure and the WPC even has a couple of what I think are inverted surface troughs and a Low hanging out in the piedmont. This may play a role in how the surface low behaves too, but honestly I'm not sure:

 

[Carvers Gap]

9 minutes ago, Holston_River_Rambler said:

18z GFS looks like it almost wanted to run the SLP from Macon, GA to Charlotte, NC, but randomly jumps at hour 36 back to the TN/ NC border:

 

I guess we're just at "see what happens time" now. One thing I did notice today was that there was a stronger wedge (from obs at southerwx) and a little bit of a leeside low near Asheville:

 

That's now transitioned to a more of a diffuse area of lower pressure and the WPC even has a couple of what I think are inverted surface troughs and a Low hanging out in the piedmont. This may play a role in how the surface low behaves too, but honestly I'm not sure:

 

Good stuff.  Yeah, 18zGFS is west a hair though the slp is a bit strung out between two pieces of energy.  I am just now resigned to following the dry slot to see if the system is moving east or west.  The precip shield is a hair west in west TN.  Definitely worth trying to see the 0z runs.  Just let me see some snow in early Dec, and I am ready to roll.  LR ensembles still look good through mid December.  Am watching to see what happens on the GFS after 120 on this run...

[Carvers Gap]

That is a massive vort coming out of the Plains at 132...going to have to be reckoned with.

[BhamParker]

38 minutes ago, Holston_River_Rambler said:

Yeah, their 1 -2 for Roan Mountain seemed a little low to me, but maybe they mean the town of Roan Mountain and not the 5500 - 6000 peak. 

Did I read earlier that you were getting a cabin near Gatlinburg @BhamParker? 

Yes we are. We are staying in a cabin that is about 2800 feet up in elevation outside of gatlinburg. It’s off of ski mountain road. We are so close to that 3000 feet threshold that I hope it really helps us out. 
 

We came up for a storm back in early February of 2018 that produced an inch or two but it was a quick hit. The models to me see to paint a pretty prolonged period of snowfall for our area, at least I’m hoping so.

[John1122]

4 minutes ago, BhamParker said:

Yes we are. We are staying in a cabin that is about 2800 feet up in elevation outside of gatlinburg. It’s off of ski mountain road. We are so close to that 3000 feet threshold that I hope it really helps us out. 
 

We came up for a storm back in early February of 2018 that produced an inch or two but it was a quick hit. The models to me see to paint a pretty prolonged period of snowfall for our area, at least I’m hoping so.

Elevation makes massive differences across the area. 2800 should see accumulation for sure. Even 2 or 3 hundred feet is night and day at times though.  3000 is a magic number there it seems because MRX uses it frequently.   I know that above 3000 in my area sees a significant amount more than 2500. There are also places that are much better for upslope than others and those even vary based on the angle of the wind. Hopefully your cabin is located in a favorable spot.

[Daniel Boone]

2 hours ago, BhamParker said:

I’m hugging the RGEM. MRX saying 1-2 for elevations between 2000-3000 feet and that seems a little conservative to me after seeing the RGEM, Euro, and GFS. Even the 18z NAM seemed to have some nice totals even around gatlinburg. 

They're pretty much always conservative.  I'll say this, IF there's strong nw flow off the lakes and enuff steep lapse rates, I guarantee much more than they're showing. NW flow alone would yield more than 2 inches in places like Wise, Va for example..

[Carvers Gap]

18z GEFS low locations.  Still quite a bit of spread even at this range.  Again, I think this goes up east of the Apps with some energy going up west as it usually does during events from the GOM(aka the warm nose).  

Great conversation by John above about elevation.  I am at 1,300'.  However, about a mile behind my house there is a ridge which reaches 2,400'.  You can actually see the snow line for most elevation dependent storms.  

 

 

[Carvers Gap]

Will try to save this.  This is the 90hr GFS 500 map.  When we look back on this thread, this is the set-up.  Looks like the crazy type of block(which has been forecast and not come to fruition during past winters), might actually verify.

[Carvers Gap]

@Holston_River_Rambler, I am dropping my SREF plume in the main thread.  LOL.  1" mean for reference after I have to delete this image later for space.

[Holston_River_Rambler]

They've been pretty consistent for both our areas with a one inch mean and no members showing 0. 

[Holston_River_Rambler]

18z Euro mighty close to making the jump across the Apps:

 

[Daniel Boone]

1 hour ago, Carvers Gap said:

Will try to save this.  This is the 90hr GFS 500 map.  When we look back on this thread, this is the set-up.  Looks like the crazy type of block(which has been forecast and not come to fruition during past winters), might actually verify.

What a boobyful Map !

[Carvers Gap]

32k 0z NAM is further south than 18z through 11 hours.  Will update in this post....just hit refresh in a minute.

Through 18 slp over the panhandle of Florida.  

Through 27, south and east of 18z.

Switched back to 3k NAM as it is populating more quickly:

Through 38, very similar but a hair quicker and maybe a bit more robust to the NW in Indiana.

@44 down to 990mb...quite a bit stronger than 18z.  Wrap around moving in.

 

[Holston_River_Rambler]

'Twere pretty @Daniel Boone 

but surely no match for SREF plumes:

 

[Olhausen]

5 hours ago, Blue Moon said:

Were you not in Nashville in 2016? Jonas was an overachiever for your area IIRC

Yes I was in White House. Got 12 inches from that storm but the night before they were calling for 6 plus with localized areas of 8 or more. In other words it was very clear there was good possibility for a big snow. I believe the 2003 storm was calling for an inch maybe two in Nashville. Anyways I don’t want to clutter the thread up with this but hopefully someone in Tennessee gets a surprise out of this one coming up.

[John1122]

00z hi-res, the 3K NAM and RGEM looked better for more of us than the 12K NAM. The 3k is down right aggressive in some areas even outside of elevation. I assume it's trying to guess as mesoscale bands that drop heavier stuff. 

[Carvers Gap]

Looks like the eastward jog has stopped with the 0z suit as the NAM and GFS have either similar tracks or are slightly west and/or stronger.   Time to start watching the one behind this for MBY.  Maybe our folks at elevation and middle TN can score some accumulating snow.

[John1122]

10 minutes ago, Carvers Gap said:

Looks like the eastward jog has stopped with the 0z suit as the NAM and GFS have either similar tracks or are slightly west and/or stronger.   Time to start watching the one behind this for MBY.  Maybe our folks at elevation and middle TN can score some accumulating snow.

The 12z Euro Control dropped the hammer with that wave. 

[John1122]

Everything is pretty consistent across modeling with this one now. I'd say the MRX map looks pretty good.  Less than an inch below 3000 and 6+ at LeConte.  

For my area I'm going to go with 1/2-3/4ths inch on decks and car tops and a dusting on grassy areas as far as the ground goes depending on time of day. 

[jaxjagman]

I swear this has typical strong NINA sig all over it,we get the early cold and we will bake around X-Mas onwards.Nice cold spell tho in the long range showing up.

 

ECMWF Deterministic FORECAST FOR: BNA    LAT=  36.12 LON=  -86.68 ELE=   591

                                            00Z NOV29
                 2 M     2 M     2 M     SFC     SFC    6 HR    FROZN   TOTAL
                 MXT     MNT     TMP     DEW     WIND    QPF     PCP    CLOUD
                 (F)     (F)     (F)     (F)    (KTS)   (IN)    (IN)    (PCT)
SUN 00Z 29-NOV                  44.9    35.9    01005                     72    
SUN 06Z 29-NOV  45.0    37.4    39.4    34.2    05003                     98    
SUN 12Z 29-NOV  39.7    36.6    37.1    34.8    11003   0.00    0.00      99    
SUN 18Z 29-NOV  56.2    37.0    56.5    43.3    18004   0.00    0.00     100    
MON 00Z 30-NOV  57.6    50.5    50.4    50.0    35004   0.17    0.00     100    
MON 06Z 30-NOV  50.4    41.9    41.8    41.5    34012   0.51    0.00     100    
MON 12Z 30-NOV  41.8    36.5    38.9    38.4    31011   0.49    0.03     100    
MON 18Z 30-NOV  39.0    35.5    35.7    24.6    30011   0.02    0.00     100    
TUE 00Z 01-DEC  35.7    32.9    32.8    22.8    31009   0.02    0.02      94    
TUE 06Z 01-DEC  32.9    28.7    28.6    19.1    30006   0.02    0.02      25    
TUE 12Z 01-DEC  28.5    25.5    25.5    19.7    27006   0.00    0.00       2    
TUE 18Z 01-DEC  36.3    24.9    36.4    19.0    28007   0.00    0.00      11    
WED 00Z 02-DEC  38.7    31.6    31.4    20.5    27005   0.00    0.00       0    
WED 06Z 02-DEC  31.5    26.0    25.9    19.8    27004   0.00    0.00       0    
WED 12Z 02-DEC  27.4    24.7    25.0    21.3    24002   0.00    0.00      30    
WED 18Z 02-DEC  44.7    24.4    45.0    25.7    30001   0.00    0.00      35    
THU 00Z 03-DEC  46.8    36.6    36.1    29.8    10004   0.00    0.00       0    
THU 06Z 03-DEC  36.1    27.8    27.9    23.7    15002   0.00    0.00     100    
THU 12Z 03-DEC  30.5    27.4    28.4    24.4    11004   0.00    0.00      69    
THU 18Z 03-DEC  50.7    28.4    51.0    29.3    17003   0.00    0.00      33    
FRI 00Z 04-DEC  53.0    44.4    44.7    35.0    18004   0.01    0.00      95    
FRI 06Z 04-DEC  46.5    43.0    43.3    40.9    20005   0.04    0.00     100    
FRI 12Z 04-DEC  43.4    42.6    42.7    42.5    17002   0.20    0.00     100    
FRI 18Z 04-DEC  44.8    42.7    44.8    43.9    24001   0.24    0.00     100    
SAT 00Z 05-DEC  45.8    43.8    43.7    42.4    36003   0.02    0.00      98    
SAT 06Z 05-DEC  43.7    39.9    39.8    36.8    35007   0.00    0.00      94    
SAT 12Z 05-DEC  39.8    35.9    35.9    32.7    35007   0.00    0.00      86    
SAT 18Z 05-DEC  45.8    34.7    46.0    30.4    33008   0.00    0.00       0    
SUN 00Z 06-DEC  47.9    39.6    39.4    30.7    33006   0.00    0.00       0    
SUN 06Z 06-DEC  39.4    32.7    32.4    29.8    30004   0.00    0.00       0    
SUN 12Z 06-DEC  32.4    30.2    31.1    28.9    22004   0.00    0.00       0    
SUN 18Z 06-DEC  50.9    31.1    51.1    34.1    28007   0.00    0.00       0    
MON 00Z 07-DEC  52.8    43.4    43.3    34.1    27007   0.00    0.00       0    
MON 06Z 07-DEC  43.3    40.3    40.2    33.3    32008   0.00    0.00      40    
MON 12Z 07-DEC  40.2    34.5    34.5    23.0    32008   0.00    0.00      46    
MON 18Z 07-DEC  37.9    33.5    37.9    19.3    33010   0.00    0.00      16    
TUE 00Z 08-DEC  38.4    31.4    31.2    16.0    34006   0.00    0.00       0    
TUE 06Z 08-DEC  31.2    25.4    25.3    17.7    33003   0.00    0.00       0    
TUE 12Z 08-DEC  26.1    22.9    22.9    17.5    24003   0.00    0.00       0    
TUE 18Z 08-DEC  37.4    22.8    37.6    15.2    19002   0.00    0.00      81    
WED 00Z 09-DEC  38.3    32.8    33.4    20.2    16005   0.00    0.00       5    

[Holston_River_Rambler]

In terms of the long range pattern, the battle of wits ensembles continues:

GEFS

 

EPS:

 

GEPS:

 

[fountainguy97]

Our system is well on its way this morning! 
 

everything looks right on track using the upper air WV loops. Going to be a beautiful phase later during this storms life.
the darker and light yellow dry air trough over the Dakotas is our northern stream energy. 
 

hoping for 1-2 inches here at 2000ft in Erwin! Small potential to bust higher than that I think in this setup.

[Daniel Boone]

7 hours ago, jaxjagman said:

I swear this has typical strong NINA sig all over it,we get the early cold and we will bake around X-Mas onwards.Nice cold spell tho in the long range showing up.

 

ECMWF Deterministic FORECAST FOR: BNA    LAT=  36.12 LON=  -86.68 ELE=   591

                                            00Z NOV29
                 2 M     2 M     2 M     SFC     SFC    6 HR    FROZN   TOTAL
                 MXT     MNT     TMP     DEW     WIND    QPF     PCP    CLOUD
                 (F)     (F)     (F)     (F)    (KTS)   (IN)    (IN)    (PCT)
SUN 00Z 29-NOV                  44.9    35.9    01005                     72    
SUN 06Z 29-NOV  45.0    37.4    39.4    34.2    05003                     98    
SUN 12Z 29-NOV  39.7    36.6    37.1    34.8    11003   0.00    0.00      99    
SUN 18Z 29-NOV  56.2    37.0    56.5    43.3    18004   0.00    0.00     100    
MON 00Z 30-NOV  57.6    50.5    50.4    50.0    35004   0.17    0.00     100    
MON 06Z 30-NOV  50.4    41.9    41.8    41.5    34012   0.51    0.00     100    
MON 12Z 30-NOV  41.8    36.5    38.9    38.4    31011   0.49    0.03     100    
MON 18Z 30-NOV  39.0    35.5    35.7    24.6    30011   0.02    0.00     100    
TUE 00Z 01-DEC  35.7    32.9    32.8    22.8    31009   0.02    0.02      94    
TUE 06Z 01-DEC  32.9    28.7    28.6    19.1    30006   0.02    0.02      25    
TUE 12Z 01-DEC  28.5    25.5    25.5    19.7    27006   0.00    0.00       2    
TUE 18Z 01-DEC  36.3    24.9    36.4    19.0    28007   0.00    0.00      11    
WED 00Z 02-DEC  38.7    31.6    31.4    20.5    27005   0.00    0.00       0    
WED 06Z 02-DEC  31.5    26.0    25.9    19.8    27004   0.00    0.00       0    
WED 12Z 02-DEC  27.4    24.7    25.0    21.3    24002   0.00    0.00      30    
WED 18Z 02-DEC  44.7    24.4    45.0    25.7    30001   0.00    0.00      35    
THU 00Z 03-DEC  46.8    36.6    36.1    29.8    10004   0.00    0.00       0    
THU 06Z 03-DEC  36.1    27.8    27.9    23.7    15002   0.00    0.00     100    
THU 12Z 03-DEC  30.5    27.4    28.4    24.4    11004   0.00    0.00      69    
THU 18Z 03-DEC  50.7    28.4    51.0    29.3    17003   0.00    0.00      33    
FRI 00Z 04-DEC  53.0    44.4    44.7    35.0    18004   0.01    0.00      95    
FRI 06Z 04-DEC  46.5    43.0    43.3    40.9    20005   0.04    0.00     100    
FRI 12Z 04-DEC  43.4    42.6    42.7    42.5    17002   0.20    0.00     100    
FRI 18Z 04-DEC  44.8    42.7    44.8    43.9    24001   0.24    0.00     100    
SAT 00Z 05-DEC  45.8    43.8    43.7    42.4    36003   0.02    0.00      98    
SAT 06Z 05-DEC  43.7    39.9    39.8    36.8    35007   0.00    0.00      94    
SAT 12Z 05-DEC  39.8    35.9    35.9    32.7    35007   0.00    0.00      86    
SAT 18Z 05-DEC  45.8    34.7    46.0    30.4    33008   0.00    0.00       0    
SUN 00Z 06-DEC  47.9    39.6    39.4    30.7    33006   0.00    0.00       0    
SUN 06Z 06-DEC  39.4    32.7    32.4    29.8    30004   0.00    0.00       0    
SUN 12Z 06-DEC  32.4    30.2    31.1    28.9    22004   0.00    0.00       0    
SUN 18Z 06-DEC  50.9    31.1    51.1    34.1    28007   0.00    0.00       0    
MON 00Z 07-DEC  52.8    43.4    43.3    34.1    27007   0.00    0.00       0    
MON 06Z 07-DEC  43.3    40.3    40.2    33.3    32008   0.00    0.00      40    
MON 12Z 07-DEC  40.2    34.5    34.5    23.0    32008   0.00    0.00      46    
MON 18Z 07-DEC  37.9    33.5    37.9    19.3    33010   0.00    0.00      16    
TUE 00Z 08-DEC  38.4    31.4    31.2    16.0    34006   0.00    0.00       0    
TUE 06Z 08-DEC  31.2    25.4    25.3    17.7    33003   0.00    0.00       0    
TUE 12Z 08-DEC  26.1    22.9    22.9    17.5    24003   0.00    0.00       0    
TUE 18Z 08-DEC  37.4    22.8    37.6    15.2    19002   0.00    0.00      81    
WED 00Z 09-DEC  38.3    32.8    33.4    20.2    16005   0.00    0.00       5    


Yeah, however, there are  a couple drivers that may change the typical Nina pattern. The NPAC SST's,and the NAO . Of course we all know about 95-96 and 10-11. 

      Early on those years the same thing was touted. La Niña pattern will take over and we go mild.

         Odds ,as we all know, do favor the stereotypical Niña and pretty strong at that but, there is some hope; a couple things that can war against that. 

      Just some encouraging thoughts for the cold snow lovers.

Y

[fountainguy97]

Models slowly upping my snowfall toward 3-4 inches. Still wary of them as it’s tough to nail down the elevation influence but man this looks promising.

Cautiously optimistic. Although I’ve been burned on NW flow before. 

[Daniel Boone]

If today's GFS Operational comes to fruition, our cold/snow after 2morrow and Tuesdays went in the crapper! Flip flop from last several days.