February/March 2020 Winter's Last Chance Thread

[Carvers Gap]

21 minutes ago, nrgjeff said:

Weekend snow north of I-40 (and perhaps along parts of I-40) looks decent this morning. Euro remains on board, and even ticked south overnight. Still awaiting 12Z Euro.

I still think snow will not make it south to the 540 thickness line / 0C at 850 line. Low levels look warm and much of the event is Saturday daytime. 500/700 mb vort max still along/north of I-40. Finally, who believes Chattanooga will get snow? Shows 540/0C over town, but nah.

OK, serious again, the more reliable output still keeps snow an elevation event for the Plateau and Mountains. However snow levels are a touch lower, and accumulation at elevation a bit higher. Surface HP comes in behind the system. Might get some cold enough air for BNA/TYS/MRX but it's tough w/o HP already in place and/or dropping from the N/NE. Tri Cities has a slightly better shot at snow, esp if some wrap-around.

While it's a little early to drill down partial thicknesses, they are not as bullish as the total 1,000-500 mb thickness. They are almost as far south, but not quite. The 1,000-850 mb hints at warm boundary layer. The 850-700 mb hints at the vort max a bit north. Again it's early for that tool, and I only have it on the GFS. 

Looking ahead. Carvers offers a path to a nice encore. It could happen given IO Pac convection. Some is in a decent spot. However the IO is firing too. Depends when/how long that meanders over warmer phases of Indonesia. Also if any northern stream TPV energy fails to catch the West trough, SER will be stubborn. Euro is with Carvers. Fingers crossed.

Thanks for the great commentary.  Yeah, I am not sold on the Euro solution...just noting there is some uncertainty after the 15th or so.  I am actually not convinced any model has the actual pattern evolution nailed down yet, and that is understandable at this range.  Just looking for a window of 2-3 days at a time.  The base-warm pattern is unlikely to be broken prior to the end of winter unless the TPV, as you note, gets involved.  Interesting to watch for sure.  But no matter how Feb goes, you have the Chiefs to get you through and then it is March Madness!

[Holston_River_Rambler]

Euro, Euro, come getcha Euro, get it while its hot:

 

[Carvers Gap]

Unless I am wrong, the AO on the Euro run is going to go from near record positive values and then crash into the negative range.  

[Holston_River_Rambler]

Just saw the EPS posted in the mountains and foothills over in the SE forum. It has upped the ante:

best look I feel like we've seen all year

[Holston_River_Rambler]

Check out how the 3k NAM sees the 3rd wave going down:

Looks to me like it wants to keep the upper low back long enough to allow some return flow after the front:

 

[AMZ8990]

20 minutes ago, Holston_River_Rambler said:

Check out how the 3k NAM sees the 3rd wave going down:

Looks to me like it wants to keep the upper low back long enough to allow some return flow after the front:

 

Dad gummit, I hate when the NAM showing snow for me .  Lol.  It’s very much like swallowing a double edge sword 

[jaxjagman]

3 hours ago, nrgjeff said:

Weekend snow north of I-40 (and perhaps along parts of I-40) looks decent this morning. Euro remains on board, and even ticked south overnight. Still awaiting 12Z Euro.

I still think snow will not make it south to the 540 thickness line / 0C at 850 line. Low levels look warm and much of the event is Saturday daytime. 500/700 mb vort max still along/north of I-40. Finally, who believes Chattanooga will get snow? Shows 540/0C over town, but nah.

OK, serious again, the more reliable output still keeps snow an elevation event for the Plateau and Mountains. However snow levels are a touch lower, and accumulation at elevation a bit higher. Surface HP comes in behind the system. Might get some cold enough air for BNA/TYS/MRX but it's tough w/o HP already in place and/or dropping from the N/NE. Tri Cities has a slightly better shot at snow, esp if some wrap-around.

While it's a little early to drill down partial thicknesses, they are not as bullish as the total 1,000-500 mb thickness. They are almost as far south, but not quite. The 1,000-850 mb hints at warm boundary layer. The 850-700 mb hints at the vort max a bit north. Again it's early for that tool, and I only have it on the GFS. 

Looking ahead. Carvers offers a path to a nice encore. It could happen given IO Pac convection. Some is in a decent spot. However the IO is firing too. Depends when/how long that meanders over warmer phases of Indonesia. Also if any northern stream TPV energy fails to catch the West trough, SER will be stubborn. Euro is with Carvers. Fingers crossed.

Over 3" for you

 

ECMWF Deterministic FORECAST FOR: CHA LAT= 35.03 LON= -85.20 ELE= 689 12Z FEB04 2 M 850 1000 FZING SFC SFC 6 HR SNCVR TMP TMP 850 HGT WIND PCP QPF LIQ (C) (C) THK (FT) (KTS) TYPES (IN) (IN) TUE 12Z 04-FEB 11.8 11.1 136 10758 21007 TUE 18Z 04-FEB 14.3 9.8 136 10518 19007 WED 00Z 05-FEB 14.8 10.0 137 10805 18007 0.06 WED 06Z 05-FEB 15.1 11.4 137 10955 19008 0.11 WED 12Z 05-FEB 15.0 12.0 137 10344 19005 0.23 WED 18Z 05-FEB 16.9 11.4 137 10166 18006 0.43 THU 00Z 06-FEB 16.3 11.9 138 10356 17007 0.23 THU 06Z 06-FEB 16.7 12.7 138 11091 18011 0.35 THU 12Z 06-FEB 16.5 12.2 138 9869 19007 0.25 THU 18Z 06-FEB 13.7 9.2 136 9821 29005 0.17 FRI 00Z 07-FEB 11.0 5.6 135 7743 26005 0.20 FRI 06Z 07-FEB 6.2 -2.5 131 2167 28009 0.02 FRI 12Z 07-FEB 2.6 -6.6 130 849 27008 0.01 FRI 18Z 07-FEB 4.9 -6.8 130 1237 27010 0.00 SAT 00Z 08-FEB 3.2 -4.3 131 2091 30003 0.00 SAT 06Z 08-FEB 0.9 -1.0 131 2833 17003 0.00 SAT 12Z 08-FEB 2.3 0.3 131 3925 15005 0.00 SAT 18Z 08-FEB 2.4 -0.9 130 1937 17007 0.42 SUN 00Z 09-FEB 3.8 -2.7 131 2454 25002 0.14 SUN 06Z 09-FEB 0.5 -4.0 130 1776 30003 0.00 SUN 12Z 09-FEB -1.0 -0.7 130 7530 02003 0.00

[John1122]

WVLT is already saying 2-4 inches for the Plateau in Friday. 3-5 plus eastern areas.  Even with multi model consensus at this point it feels early. 

 

 

[Holston_River_Rambler]

29 minutes ago, John1122 said:

WVLT is already saying 2-4 inches for the Plateau in Friday. 3-5 plus eastern areas.  Even with multi model consensus at this point it feels early. 

I'm superstitious and it makes me nervous when news outlets latch on this far out. Gotta sneak up for full effect. 

[Holston_River_Rambler]

oooh 18z GFS gets the purple colors into Cumberland county:

[Carvers Gap]

And the GFS isn't done yet.  LOL

[Carvers Gap]

Is it that feature at 300 over MS/AL moving westward...like to New Mexico?

[Holston_River_Rambler]

10 minutes ago, Carvers Gap said:

Is it that feature at 300 over MS/AL moving westward...like to New Mexico?

It forgot to get a running start to help it cut, lol!

[Holston_River_Rambler]

GEFS looks fairly steady too:

[Holston_River_Rambler]

Steady uptick on the mean over the last 5 runs, with Knoxville snow hole in effect:

[Carvers Gap]

20 minutes ago, Holston_River_Rambler said:

It forgot to get a running start to help it cut, lol!

I have sometimes seen something back into the front range In Colorado.  But E TX/Lousiana to New Mexico is a first.  Add in two ice storms to go with our snow this weekend, and Happy Hour has yet again lived up to its name yet again.

[Holston_River_Rambler]

Happy hour also delivers on the strat:

[Carvers Gap]

The 18z GEFS at 500 is much different at 500 that it was at 0z.  For all intents and purposes it has removed the western trough by the end of the run.  We talked this morning about the how modeling is all over the place with the MJO.  Makes since that there is some movement on the GEFS which was on its own.  By no means is that discussion a success based on the 18z GEFS.  I don't trust that model.  However, the GEPS at 12z was nearly there, and the EPS is showing cold pressing.  Now, not entirely sure that the new look is better as the trough retreats into Canada.  However, with cold in eastern Canada, it may press with cold high pressure at the surface.  I still don't think that pattern is done adjusting after the 10th.

[Mr. Kevin]

Dr. Amy Butler posted this image and tweet earlier today. 

[Holston_River_Rambler]

NAM keeps doing NAM things. A sub 995 low over Cloumbia, SC ain't nothing to sneeze at:

To paraphrase a Met from the MA forum, "now if we can just get one of the good models to follow suite..." 

[John1122]

I'll credit the NAM with schooling the other models on the snow system last week in South and North Carolina. It was the first by far to latch onto snow that far north and west when the other model suites were dry or rain. As usual it was over amped though. So I usually shave 35-40 percent off NAM snow maps. 

[John1122]

Another good run of the GFS for most people from the Eastern rim and eastward. Solid 2-4 inches in most of those areas. 

[Icy Hot]

Too bad that snow isn't coming predominantly at night. We will take whatever we can get.

[John1122]

1 minute ago, Icy Hot said:

Too bad that snow isn't coming predominantly at night. We will take whatever we can get.

Granted it's usually easier at night but as long as it comes as snow and we get good rates,  day vs night isn't a huge deal, especially in early February. 

[Stovepipe]

I'll take the dusting the GFS is showing here.  Need something to sweeten up my turnip greens.  

[John1122]

Probably wrong as it often is, but the GFS is unleashing a massive Arctic blast. Has rain here at 240 but a monster HP at 1049 with temps in the -30 range are in the upper midwest. That arctic air would undercut the system that comes by south of here and probably have freezing precip. Especially western Valley. The SE ridge is often vastly over modeled in the face of that kind of Arctic air mass. 

[John1122]

1 minute ago, Stovepipe said:

I'll take the dusting the GFS is showing here.  Need something to sweeten up my turnip greens.  

It looks like its throwing out about 3-4 inches in West Knoxville. 

[Stovepipe]

3 minutes ago, John1122 said:

It looks like its throwing out about 3-4 inches in West Knoxville. 

I initially was looking at tropical tidbits, looked like an inch or less, but pivotal does indeed show more.  

[John1122]

As I figured, the Euro goes from major winter storm to nothing burger. Snow modeling doesn't work in this area. Don't know why, it just doesn't.

Meanwhile the massive winter storm it forecast in Texas and Oklahoma a week ago is unfolding as expected.  

[weathertree4u]

2 hours ago, John1122 said:

As I figured, the Euro goes from major winter storm to nothing burger. Snow modeling doesn't work in this area. Don't know why, it just doesn't.

Meanwhile the massive winter storm it forecast in Texas and Oklahoma a week ago is unfolding as expected.  

Like your post not because I like it but because you are spot on! Everywhere else modeling seems to know well in advance at least the generalities of what is going to fall from the sky and will depict the same thing in multiple consecutive runs. In the TN Valley, forget it.