Tennessee Valley Winter Storm March 2-3

[Carvers Gap]

Boys...somebody needs to go look at the RGEM. Just saw the B/W maps.

[Stovepipe]

Boys...somebody needs to go look at the RGEM. Just saw the B/W maps.

 

I'm out to hour 18 on AmWx.  Don't tell me, it's crashing the 850s like the Euro?

 

(ok tell me)

[jaxjagman]

Northwestern TN is 'bout to get buried under a pile of frozen mess. Pretty epic maps. Man! The trend is amazing.

Exactly.Definite trend to the S and E though,if this thing could trend S more the NW of the valley would have a snow storm they never seen in quite sometime

[valkhorn]

That heavy band is just 5 or 6 counties away from Knoxville. It's starting to get too close for comfort.

[Stovepipe]

What's amazing when you look at the NAM and RGEM is just how much friggin QPF it's laying down and how slow it's moving.  Despite the insane NAM snow map it still looks like a metric crap ton of ice to me, with NW areas getting snow on top of it.  The trend is indeed nuts.

[tnweathernut]

The RGEM is WAY north with accumulating snow. Like northern flippin Kentucky.......

Sent from my iPhone using Tapatalk

[Carvers Gap]

What's amazing when you look at the NAM and RGEM is just how much friggin QPF it's laying down and how slow it's moving.  Despite the insane NAM snow map it still looks like a metric crap ton of ice to me, with NW areas getting snow on top of it.  The trend is indeed nuts.

 

If someone can get the total qpf for the RGEM run and compare the 18z to the 0z for the state.  Which way does the shield move and are amounts higher or lower?  The 6 hr increments are a pain because you can only compare them to the run 12 hrs before...see what I mean.  Looks like the NAM, Stove.  That is basically what I am saying.  I am like, tnweathernut.  I doubt ZR in March but that high to the west is a monster.  It could do it. 

[Stovepipe]

The RGEM is WAY north with accumulating snow. Like northern flippin Kentucky.......

Sent from my iPhone using Tapatalk

 

Yep, but areas in TN with up to 1.75 inches of ice AND 2 to 3 inches of sleet lol.

[jaxjagman]

Yep, but areas in TN with up to 1.75 inches of ice AND 2 to 3 inches of sleet lol.

 

[Carvers Gap]

1040 high parked over Iowa @ 36 on the RGEM B/W maps.  At this point, I am just looking where the precip shield is.  Looks to me like the cold air is going to funnel south.  Wherever the moisture is, it is going to be frozen.  The cold air is going to get trapped up against the Cumberlands and funnel south and then do the same w/ the Smokies.  What are the model tendencies for the NAM and RGEM? 

[Carvers Gap]

This is a big time ice storm coming to middle and west TN.  Right now appears to me that the 0z RGEM is a tad slower w/ the cold front and does not go as far south w/ the cold front.  The 0z NAM just rams it right to the Apps.  Not sure which horse to ride at this point so split the difference.  The RAP ought to be getting this into its wheelhouse about now.

[Stovepipe]

If someone can get the total qpf for the RGEM run and compare the 18z to the 0z for the state.  Which way does the shield move and are amounts higher or lower?  The 6 hr increments are a pain because you can only compare them to the run 12 hrs before...see what I mean.  Looks like the NAM, Stove.  That is basically what I am saying.  I am like, tnweathernut.  I doubt ZR in March but that high to the west is a monster.  It could do it. 

 

From the AmWx maps, comparing 18z to 0z, it looks like 18z had WAY more QPF.  Hard to say how the shield shifted, it just looks wetter.  0z manages to crank out more ice and sleet but less snow, kind of odd.  It is impressive how the frozen precip has moved eastward over time.  Still not much of any significance yet east of the plateau in TN but if it keeps trending... who knows.  I guess that high pressure means business.

 

Edit:  I had a caching problem with my maps, the 18z RGEM is not WAY more QPF, just a fair amount more.  0z has it more concentrated on NW TN as opposed to spreading it out across middle.

[tnweathernut]

The RGEM is actually a little drier for east TN. 0z first, 18z second.

Sent from my iPhone using Tapatalk

[tnweathernut]

Unfortunately, east TN may only have time for a little bit more trending. Middle TN looks to get hammered with zr and sleet. Big question in my mind is how much snow to cap it off??

Sent from my iPhone using Tapatalk

[Carvers Gap]

From the AmWx maps, comparing 18z to 0z, it looks like 18z had WAY more QPF.  Hard to say how the shield shifted, it just looks wetter.  0z manages to crank out more ice and sleet but less snow, kind of odd.  It is impressive how the frozen precip has moved eastward over time.  Still not much of any significance yet east of the plateau in TN but if it keeps trending... who knows.  I guess that high pressure means business.

 

Seems like the NAM has a tendency to overdo things as we get closer to the event.  Does anyone know if it is a bit cold w/ these types of evens or the RGEM too warm.  The RAP will nail this I bet.  I think the northern border counties w/ VA and KY need to really keep a close eye on this.  MRX was less guarded than normal w/ their afternoon update.  You could tell they were concerned.  Looks to me like the models are struggling w/ how far south the cold front drives.  I think it is a done deal that middle and west get socked.  I-40(Knoxville and points northward) is a crap shoot.  This is a rare set-up for the Valley, and I don't know jack about how this will unfold! LOL.  I-40 north(in the eastern valley) looks like a cold rain but a close call...this system may have a trick up its sleeve.  It slides the low pressure(if you really want to call it that...more like a wave) through central GA and then through western NC.  If it strengthens a bit...who knows.  Quickly evolving system on the models. 

[Stovepipe]

Unfortunately, east TN may only have time for a little bit more trending. Middle TN looks to get hammered with zr and sleet. Big question in my mind is how much snow to cap it off??

Sent from my iPhone using Tapatalk

 

That's my question as well.  Based on this winter, it's impossible for me to write off the Euro.  I believe a good chunk of this progged ice on the other models will fall as snow.  Might be mostly northwest TN areas, but I believe someone is going to be shoveling.

[tnweathernut]

Hi-res 0z NAM

Sent from my iPhone using Tapatalk

[Carvers Gap]

The RGEM is actually a little drier for east TN. 0z first, 18z second.

Sent from my iPhone using Tapatalk

 

 

For sure...So, the 0z NAM trends southeast and the RGEM northwest(a hair).  Looks like it is seeing some downsloping in addition to the northwest jog.  Also, looked a hair warmer.  Right now, a hiccup's difference.  We will know tomorrow night how quickly that cold air is approaching.  Again, the RGEM has a 1040 hp over Iowa on the black and white maps.  It is such a rare set-up, has the look of ice further south than is being modeled.  I think it will depend on where that precip shield sets-up. 

[tnweathernut]

From DT on Facebook.

Sent from my iPhone using Tapatalk

[Carvers Gap]

That's my question as well.  Based on this winter, it's impossible for me to write off the Euro.  I believe a good chunk of this progged ice on the other models will fall as snow.  Might be mostly northwest TN areas, but I believe someone is going to be shoveling.

 

The Euro has been king this winter.  The models, in all fairness, are clustered pretty well.  200 miles is not a big difference in the model world.  So, even if the Euro jogs a tad north at 0z...it still nailed this.  If that is truly a 1040 parked over the plains, it will bring some surprises.  It is one of the few times that I would even think ice.  I am not really thinking snow.  Won't take a lot of ice to make a mess.

[Stovepipe]

Seems like the NAM has a tendency to overdo things as we get closer to the event.  Does anyone know if it is a bit cold w/ these types of evens or the RGEM too warm.  The RAP will nail this I bet.  I think the northern border counties w/ VA and KY need to really keep a close eye on this.  MRX was less guarded than normal w/ their afternoon update.  You could tell they were concerned.  Looks to me like the models are struggling w/ how far south the cold front drives.  I think it is a done deal that middle and west get socked.  I-40(Knoxville and points northward) is a crap shoot.  This is a rare set-up for the Valley, and I don't know jack about how this will unfold! LOL.  I-40 north(in the eastern valley) looks like a cold rain but a close call...this system may have a trick up its sleeve.  It slides the low pressure(if you really want to call it that...more like a wave) through central GA and then through western NC.  If it strengthens a bit...who knows.  Quickly evolving system on the models. 

 

Regarding the RGEM and anecdotal evidence, I followed two of the west TN ice events very closely this winter, both the modeling beforehand and the boots on the ground obs via my folks in Paris.  The RGEM was surprisingly good at nailing the setup, precip type (including sleet), and generally did well on the areas affected.  On one storm it over did the ice a tad and was a little south of reality.  BUT, that was a storm where 1 or 2 degrees made all the difference.  Also the freezing lines setup oddly where Union City and Clarksville (and points north into KY) got substantial ice and some sleet but Paris was in a warm pocket getting only trees and powerlines involved but no road accum.  All in all, I was impressed with the RGEM on both of those icy situations.  I was also very impressed with how it handled the two biggish snow events here in my area. 

[tnweathernut]

RGEM has been more than solid this winter and I'd put it up against the king anytime inside of 48 hours.

Sent from my iPhone using Tapatalk

[Carvers Gap]

Regarding the RGEM and anecdotal evidence, I followed two of the west TN ice events very closely this winter, both the modeling beforehand and the boots on the ground obs via my folks in Paris.  The RGEM was surprisingly good at nailing the setup, precip type (including sleet), and generally did well on the areas affected.  On one storm it over did the ice a tad and was a little south of reality.  BUT, that was a storm where 1 or 2 degrees made all the difference.  Also the freezing lines setup oddly where Union City and Clarksville (and points north into KY) got substantial ice and some sleet but Paris was in a warm pocket getting only trees and powerlines involved but no road accum.  All in all, I was impressed with the RGEM on both of those icy situations.  I was also very impressed with how it handled the two biggish snow events here in my area. 

 

The RGEM is on a hot streak this winter.  Did very well w/ the last system.  Was the first to project heavier amounts west of the Apps even though all eyes were on North Carolina.  So, if I were guessing, I would go 60/40, RGEM and NAM blend.  Again, I think it is a done deal that northwest TN and Nashville metro(especially northern sections) go bullseye.  I am most interested, mainly from a hobbyist perspective, what will happen east of the Plateau and on the Plateau itself.  Also, Memphis is riding the southern edge of this.  GFS is rolling and looks almost identical to the 18z GFS and is similar to the 0z NAM.  Goodness.  Close call north of I-40 in the east.

[Stovepipe]

I have family in Dekalb county that are hoping for a school closure (teachers lol), so I'm watching the eastern highland rim very closely.  I believe there is enough of a threat even that far east that schools closing is pretty much a lock.  It's still up in the air as to what will actually end up on the ground there though.

[tnweathernut]

Robert at WxSouth thinks Nashville and west is a big problem, but east of will largely miss. Looks that way to me as well with the best lift and cold just north of us.

Sent from my iPhone using Tapatalk

[jaxjagman]

---

Station ID: KBNA Lat:   36.11 Long:  -86.68                                                       

NAM Model Run:  0Z  2MAR 2014
  HR Valid     2m Tmp 2m Dpt 10m Dir 10m Spd TPrcp CPrcp 1000-500 500mb 850mb 500mb MSLP TCC PRS WX   Tot    Snowfall  Vis
                Deg F  Deg F   deg      kt    in.   in.     Thk    GPH   Tmp   Tmp   mb   %  TEXT    Clouds      in    SM
   0 03/02 00Z   54     44     155       3    0.00  0.00    555    573    3.1 -14.0 1020   0          CLR       0.0   15.0
   3 03/02 03Z   49     43     155       6    0.00  0.00    556    574    5.8 -14.6 1021   0          CLR       0.0   15.0
   6 03/02 06Z   48     43     157       6    0.00  0.00    557    573    7.0 -13.2 1019  40       042SCT339    0.0   15.0
   9 03/02 09Z   50     46     178       9    0.00  0.00    558    572    8.6 -14.1 1017  84       046BKN067    0.0   15.0
  12 03/02 12Z   49     48     193       9    0.00  0.00    557    572    9.9 -16.1 1017  55       039BKN089    0.0   14.1
  15 03/02 15Z   54     51     211       9    0.01  0.00    557    573   10.2 -15.7 1018 100       018OVC331    0.0   15.1
  18 03/02 18Z   53     50     299      10    0.01  0.00    557    572   10.3 -15.0 1018 100       016OVC314    0.0   14.9
  21 03/02 21Z   38     35     349      12    0.06  0.04    554    570    9.9 -14.9 1019 100 -TSRA 010OVC351    0.0   15.5
  24 03/03 00Z   35     33       4      10    0.10  0.04    554    569    9.9 -14.7 1019 100 -TSRA 008OVC355    0.0    5.5
  27 03/03 03Z   32     31       4      12    0.34  0.00    552    568    8.3 -14.9 1019 100 -RA   006OVC377    0.0    4.8
  30 03/03 06Z   32     31      27      14    0.43  0.00    552    566    4.8 -14.2 1017 100 +FRZN 005OVC363    0.0    0.4
  33 03/03 09Z   27     26      17      15    0.69  0.01    550    564    3.9 -14.9 1016 100 -TSPL 006OVC267    0.0    1.0
  36 03/03 12Z   21     19       6      18    0.41  0.01    545    560    0.8 -16.0 1019 100 PL    005OVC271    0.0    1.6
  39 03/03 15Z   21     18      22      16    0.04  0.00    540    557   -1.8 -20.1 1022 100       006OVC075    0.0    4.2
  42 03/03 18Z   23     21      11      16    0.02  0.00    537    555   -2.9 -21.3 1024 100 -SN   006OVC108    0.2    2.9
  45 03/03 21Z   26     22      16      13    0.00  0.00    540    559   -1.5 -18.3 1024 100       000OVC029    0.0    7.3
  48 03/04 00Z   23     21      16      11    0.01  0.00    540    560    0.1 -17.4 1025 100       007OVC028    0.0    9.2
  51 03/04 03Z   18     16      17       8    0.00  0.00    541    562    1.6 -16.5 1027  97       007BKN196    0.0   13.7
  54 03/04 06Z   10      8      24       7    0.00  0.00    540    560    2.9 -17.9 1026  83       000BKN200    0.0   12.9
  57 03/04 09Z    4      1      17       6    0.00  0.00    540    559    2.9 -19.1 1025  46       012SCT350    0.0    5.6
  60 03/04 12Z    5      2      19       6    0.00  0.00    539    559    2.2 -20.0 1026  72       012BKN337    0.0    6.2
  63 03/04 15Z   21     18      43       7    0.00  0.00    539    559    1.9 -21.2 1026  83       252BKN333    0.0   15.1
  66 03/04 18Z   28     21       1       5    0.00  0.00    539    558    1.9 -21.3 1024  76       279BKN301    0.0   14.9
  69 03/04 21Z   31     24     356       6    0.00  0.00    540    558    2.4 -21.6 1022  74       303BKN316    0.0   14.9
  72 03/05 00Z   28     25       3       6    0.00  0.00    539    558    2.3 -22.8 1023  66       066BKN073    0.0   15.1
  75 03/05 03Z   23     22      10       6    0.00  0.00    538    558    1.7 -23.4 1024  70       006BKN017    0.0   12.5
  78 03/05 06Z   16     15     350       5    0.00  0.00    537    557    0.1 -23.5 1025  51       020BKN022    0.0    6.1
  81 03/05 09Z   12     11     350       5    0.00  0.00    537    557   -1.4 -21.9 1025  24       069FEW069    0.0    5.6
  84 03/05 12Z   11      9       8       6    0.00  0.00    537    559   -1.8 -21.8 1028  22       117FEW117    0.0    6.8

 

 

 

first time i seen this,thunder pellets

[Stovepipe]

Heh, the NAM has Jackson bottoming out at 13 degrees Monday morning, high of 25, then hitting 0 degrees Tuesday morning. 

[tnweathernut]

My eyes are heavy, but is that around 1/2 inch of zr, and 1.1 inches qpf as sleet for BNA ......!?!? That would be 3+ inches of sleet.

Sent from my iPhone using Tapatalk

[Carvers Gap]

The 0z GFS and 18z GFS are almost mirror images of teach other.  This is such an unusual set-up...the GFS carries a huge high as well over the Plains.  I think we will see cold air begin to ooze out of KY and push SE.  Looks like hour 36 is when the eastern Valley goes cold.  Looks like about 6hrs of light frozen precip north of I-40 east of the Plateau.  Nashville seems to be the dividing line between heavy qpf and lighter amounts. 

[Stovepipe]