January 17th-18th Winter Storm Discussion

[burgertime]

I think it's an improvement but wont know until the soundings come in.

 

Def. looks colder to me. This should be a good run. 

[tnweathernut]

Looks to me like the GFS is still trending toward the NAM. Sounds like game on for northeast TN and western NC (especially the mtns) to me.  Also confirms the possibilities of snow east into NC and VA too.

[BullCityWx]

Date: 48 hour AVN valid 0Z FRI 18 JAN 13

Station: KHKY

Latitude: 35.73

Longitude: -81.38

-------------------------------------------------------------------------------

LEV PRES HGHT TEMP DEWP RH DD WETB DIR SPD THETA THE-V THE-W THE-E W

mb m C C % C C deg knt K K K K g/kg

-------------------------------------------------------------------------------

0 1000 115

SFC 964 412 2.2 0.7 90 1.5 1.5 344 14 278.2 278.9 276.5 289.7 4.17

2 950 530 1.3 -0.5 88 1.8 0.5 351 24 278.5 279.2 276.2 289.2 3.88

3 900 963 -0.8 -1.9 92 1.1 -1.3 355 39 280.7 281.3 277.2 291.0 3.69

4 850 1421 -0.1 -1.8 89 1.6 -0.9 3 46 286.0 286.7 280.1 297.2 3.94

5 800 1906 -0.9 -1.8 94 0.9 -1.3 11 41 290.1 290.9 282.3 302.2 4.18

6 750 2420 -2.3 -2.9 96 0.6 -2.6 16 34 294.1 294.8 283.8 306.2 4.11

7 700 2966 -4.1 -4.4 98 0.3 -4.2 20 26 298.0 298.7 285.2 309.8 3.95

8 650 3548 -6.8 -7.2 97 0.4 -7.0 45 14 301.2 301.9 285.9 311.7 3.42

9 600 4170 -9.7 -10.2 96 0.5 -9.9 175 3 304.9 305.4 286.8 314.0 2.94

10 550 4838 -13.3 -13.8 96 0.5 -13.5 207 17 308.3 308.8 287.4 316.0 2.40

11 500 5557 -18.0 -18.6 95 0.6 -18.1 181 31 311.1 311.4 287.7 316.9 1.77

12 450 6337 -22.7 -24.3 87 1.6 -23.1 154 41 314.7 314.9 288.3 318.7 1.19

13 400 7190 -29.1 -31.6 79 2.5 -29.5 144 43 317.1 317.2 288.6 319.5 0.68

14 350 8131 -35.4 -40.4 60 5.0 -35.8 163 50 321.1 321.1 289.5 322.2 0.32

15 300 9195 -39.5 -66.7 4 27.1 -40.5 182 67 329.7 329.7 291.6 329.7 0.02

16 250 10425 -45.8 -66.9 7 21.1 -46.4 193 74 337.9 337.9 293.8 338.0 0.02

17 200 11890 -51.6 -67.3 14 15.7 -52.0 214 68 351.1 351.1 296.9 351.2 0.02

18 150 13723 -57.4 -70.9 16 13.5 -57.6 229 83 371.3 371.3 300.8 371.3 0.02

19 100 16239 -63.8 -79.4 10 15.6 -64.0 241 81 404.5 404.5 305.8 404.5 0.01

TRP 0

WND 0

[burgertime]

This looks more reasonable...

 

[deltadog03]

If we somehow get dry slotted down here, I am gonna be PISSED!!  (for rain that is)

[RaleighWx]

Looks similar to NAM. Storm deepens with a nice 3-5 hour period or so where the rain changes to snow and a good deformation band sets up. Again thiss would be a few inches of snow with it as it passes eastward.

 

Good Signs! May have to make a map in the morning.

[chapelhillwx]

One disturbing trend is that the 00z GFS continues the warmth on the lee side of the Apps. This means CAE gets snow while GSP gets none.

[wncsnow]

Maps still showing the downsloping effect for the foothills   little to no snow accumulations... but almost 2 inches of qpf..

[tnweathernut]

Burger, do you have the text output for KTRI?  Just curious.

[BullCityWx]

Burger, do you have the text output for KTRI?  Just curious.

 

I'd say at least 6" for KTRI

[Blue_Ridge_Escarpment]

This shows us a little love wncsnow.  Easier to see the counties on this map.

 

[burgertime]

Burger, do you have the text output for KTRI?  Just curious.

 

To be honest I never really look at text output. So Jeremy how much for CLT ?

[nrhardin]

Looks RDU could get smacked pretty good if this is right!

Interesting changes indeed. I'd love to see the rdu soundings if anyone has them, as I'm on the iPad tonight. If this run holds serve and the surface looks reasonable, I need to go kill a crow or two.

Still am a bit weary, but more encouraged with the 16/00z GFS runs when coupled with the NAM

[RaleighWx]

[BullCityWx]

Of note, this run is much better for KAVL. I'd reckon around half a foot, even for the airport.

[BullCityWx]

Interesting changes indeed. I'd love to see the rdu soundings if anyone has them, as I'm on the iPad tonight. If this run holds serve and the surface looks reasonable, I need to go kill a crow or two.

Still am a bit weary, but more encouraged with the 16/00z GFS runs when coupled with the NAM

 

Date: 48 hour AVN valid 0Z FRI 18 JAN 13Station: KRDULatitude:   35.87Longitude: -78.78-------------------------------------------------------------------------------LEV PRES  HGHT  TEMP  DEWP  RH  DD   WETB DIR SPD THETA THE-V THE-W THE-E   W     mb     m     C     C    %   C     C  deg knt   K     K     K     K    g/kg-------------------------------------------------------------------------------  0 1000    93                                                                 SFC  998   105   3.9   3.0  94  0.9   3.4  18  17 277.1 277.9 276.7 290.0  4.74  2  950   507   0.7   0.5  99  0.2   0.6  23  41 277.9 278.6 276.3 289.4  4.18  3  900   941  -0.0  -0.3  98  0.2  -0.2  28  44 281.5 282.2 278.2 293.1  4.16  4  850  1400   1.1   0.9  98  0.2   1.0  46  31 287.3 288.2 281.8 301.0  4.81  5  800  1890   2.8   2.5  98  0.3   2.7 103  22 294.1 295.2 285.6 310.8  5.75  6  750  2414   2.9   2.6  98  0.4   2.8 153  31 299.8 300.9 288.1 318.1  6.16  7  700  2972   1.3   0.9  98  0.3   1.1 170  41 303.9 305.0 289.2 321.6  5.86  8  650  3566  -1.6  -1.7  99  0.1  -1.7 179  51 307.1 308.1 289.7 323.1  5.20  9  600  4201  -4.5  -4.7  99  0.2  -4.6 187  61 310.9 311.7 290.3 324.9  4.49 10  550  4881  -8.5  -8.8  98  0.2  -8.7 193  66 314.0 314.7 290.4 325.5  3.59 11  500  5613 -14.2 -14.6  97  0.4 -14.3 197  66 315.7 316.2 289.9 323.8  2.47 12  450  6403 -20.5 -20.7  98  0.2 -20.5 197  73 317.5 317.8 289.7 323.0  1.63 13  400  7264 -26.3 -30.5  68  4.2 -27.1 197  89 320.7 320.9 289.8 323.4  0.75 14  350  8218 -32.0 -44.9  27 12.9 -33.3 201 101 325.5 325.6 290.6 326.3  0.20 15  300  9289 -39.7 -57.5  13 17.9 -40.5 208 104 329.5 329.5 291.6 329.7  0.05 16  250 10512 -48.2 -63.6  15 15.4 -48.6 211 105 334.5 334.5 292.9 334.6  0.03 17  200 11950 -57.0 -67.8  24 10.8 -57.2 215 107 342.5 342.5 295.0 342.6  0.02 18  150 13760 -58.3 -70.1  21 11.8 -58.5 228 103 369.6 369.6 300.5 369.6  0.02 19  100 16280 -64.7 -80.1  10 15.5 -64.8 236  76 402.8 402.8 305.6 402.8  0.01TRP                                             0                              WND                                             0                              

 

Date: 54 hour AVN valid 6Z FRI 18 JAN 13Station: KRDULatitude:   35.87Longitude: -78.78-------------------------------------------------------------------------------LEV PRES  HGHT  TEMP  DEWP  RH  DD   WETB DIR SPD THETA THE-V THE-W THE-E   W     mb     m     C     C    %   C     C  deg knt   K     K     K     K    g/kg-------------------------------------------------------------------------------SFC 1007   105   0.9   0.8  99  0.2   0.8 336   8 273.5 274.2 273.6 284.3  4.01  1 1000   163   0.9   0.3  96  0.5   0.7 340  12 274.0 274.7 273.8 284.6  3.92  2  950   574  -1.4  -2.6  91  1.3  -1.9 355  27 275.8 276.4 274.0 284.9  3.31  3  900  1003  -3.8  -5.9  85  2.2  -4.6 348  32 277.6 278.1 274.1 285.2  2.72  4  850  1454  -3.2 -15.9  37 12.7  -6.8 348  40 282.8 283.0 274.9 286.7  1.30  5  800  1933  -3.8 -17.0  35 13.3  -7.5 347  41 287.1 287.3 277.1 290.9  1.26  6  750  2441  -4.7 -15.5  42 10.9  -7.9 341  41 291.5 291.8 279.6 296.1  1.52  7  700  2984  -5.2 -13.5  52  8.3  -7.9 330  36 296.7 297.0 282.4 302.6  1.92  8  650  3564  -7.3 -11.5  72  4.2  -8.8 317  28 300.7 301.2 284.7 308.3  2.44  9  600  4184 -10.5 -12.0  89  1.5 -11.1 304  27 303.9 304.4 286.0 311.8  2.53 10  550  4849 -14.5 -16.1  88  1.5 -15.0 299  36 306.9 307.2 286.5 313.2  1.99 11  500  5565 -18.0 -21.6  74  3.5 -18.9 291  59 311.1 311.3 287.3 315.6  1.36 12  450  6345 -23.4 -24.2  93  0.9 -23.6 295  56 313.8 314.1 288.1 317.9  1.19 13  400  7196 -29.3 -31.8  79  2.4 -29.7 293  59 316.9 317.0 288.5 319.2  0.67 14  350  8138 -34.3 -43.7  38  9.4 -35.1 294  70 322.4 322.5 289.8 323.3  0.23 15  300  9208 -37.8 -62.0   6 24.2 -38.9 275  74 332.1 332.1 292.3 332.2  0.03 16  250 10440 -46.6 -66.8   8 20.2 -47.1 258  77 336.8 336.8 293.5 336.8  0.02 17  200 11892 -54.6 -69.6  14 15.0 -54.8 246  78 346.4 346.4 295.8 346.4  0.02 18  150 13709 -58.6 -71.4  18 12.7 -58.8 240  81 369.1 369.1 300.4 369.2  0.02 19  100 16223 -64.5 -77.5  15 13.0 -64.6 240  81 403.2 403.2 305.6 403.2  0.01TRP                                             0                              WND                                             0                              

[wncsnow]

This shows us a little love wncsnow.  Easier to see the counties on this map.

 

 

Looks like a general 3-5 across the western part of the county, thanks foothillsweather, living next to the Catawba River usually doesnt do me any favors, but i would be extremely disappointed to get dryslopped with that much QPF

[HKY_WX]

Looks like a general 3-5 across the western part of the county, thanks foothillsweather, living next to the Catawba River usually doesnt do me any favors, but i would be extremely disappointed to get dryslopped with that much QPF

I'm not sure I completely buy the scenario of the foothills getting shafted(to a degree the models are still showing a couple inches). The main reason being I've seen these setups a million times and an upper low with a 850mb closed low over eastern NC is generally a great sign for us. There is normally a dryslot over the eastern carolinas when the SLP is this close to the coastline.  The deformation zone will eventually pivot east, but there's generally a solid timeframe for western NC to get several inches.

[jrips27]

Any sounding info for the North Georgia area? Allan's map shows an inch or so but I'm wondering if it would actually be snow.

[calculus1]

Brandon, you mentioned this was similar to the March 09 event.  I just went and took a look at that event on the past events page that the Raleigh NWS site puts up.  The minimum snowfall in the lee of the mountains was quite astounding.  Caldwell county with basically nothing, while even Hickory on the extreme NW side of Catawba county experienced ~6 inches.  The recent model outputs of the NAM and GFS suggest a similar outcome Thursday night.  What's your general feeling for this system for our shared backyard of HKY?  Do you think this snow shadow (as modeled) is quite likely?  Or are the models missing something?  It seems like the low is taking a perfect track to dump snow on all of WNC.  Am I missing something?

 

Edit:  I see I just wasn't patient enough, and you answered this question above.  Thanks! 

[HKY_WX]

Brandon, you mentioned this was similar to the March 09 event.  I just went and took a look at that event on the past events page that the Raleigh NWS site puts up.  The minimum snowfall in the lee of the mountains was quite astounding.  Caldwell county with basically nothing, while even Hickory on the extreme NW side of Catawba county experienced ~6 inches.  The recent model outputs of the NAM and GFS suggest a similar outcome Thursday night.  What's your general feeling for this system for our shared backyard of HKY?  Do you think this snow shadow (as modeled) is quite likely?  Or are the models missing something?  It seems like the low is taking a perfect track to dump snow on all of WNC.  Am I missing something?

Every storm is different, so i can't say who will get shafted. But I think the overall setup is a good one for a few inches in the foothills. Maybe more depending on how quickly we changeover. I love the fact that the GFS is showing an 850mb low setting up to the east of us. That's all that matters to me. That pretty much ensures a period of deformation snow.

[1234snow]

Looks to me like the GFS is still trending toward the NAM. Sounds like game on for northeast TN and western NC (especially the mtns) to me. Also confirms the possibilities of snow east into NC and VA too.

This was a great trend for us, I was waiting for the GFS to trend northwest with the QPF. Hopefully this will hold serve. This would be very bad to have a heavy wet snow just right after all the flooding NE TN/SW VA has had today and tonight.

[valkhorn]

GFS snow maps put down almost a foot around RDU. If Brick gets a foot of snow out of this I'm never coming back to the boards. 

No it doesn't. Brick doesn't get but 3" or so according to this:

 

The mountains along TN/NC may approach or exceed a foot, but I doubt the Piedmont or anywhere near RDU will exceed 3".

[beanskip]

I know we are all hoping for white precip, but the QPF the 0z GFS lays down is pretty stunning -- 2+" for areas of WNC with at least 1.5 inches for the western half of the state.

 

The lee "warm bubble" being depicted reminds me of the big March 09 snow when I was literally the last place within a 100 miles to see snow -- north, south, east and westof me it's snowing and that bubble shrunk 'til it was right over my head.

[valkhorn]

Looks like the clear winners from the 00z NAM and 00z GFS are the Smoky Mountains through the spine of the apps through SW Virginia. The middle of Virginia might do well, but I don't think NC will do well overall except for the far western mountains and the north central part of the state.

 

As far as East TN goes, looks like Bristol and Kingsport will get 4-6", Morristown 3", Knoxville maybe 1", and Chattanooga nothing according to this.

[burgertime]

No it doesn't. Brick doesn't get but 3" or so according to this:

 

The mountains along TN/NC may approach or exceed a foot, but I doubt the Piedmont or anywhere near RDU will exceed 3".

 

SV snow map certainly does. Thus why I posted that exact same map and said, "this seems more reasonable". 

[Disc]

Any sounding info for the North Georgia area? Allan's map shows an inch or so but I'm wondering if it would actually be snow.

 

They look too warm for your area, but it's close. You could possibly see a small amount of some kind of mixed frozen precip.

[valkhorn]

I know we are all hoping for white precip, but the QPF the 0z GFS lays down is pretty stunning -- 2+" for areas of WNC with at least 1.5 inches for the western half of the state.

 

The lee "warm bubble" being depicted reminds me of the big March 09 snow when I was literally the last place within a 100 miles to see snow -- north, south, east and westof me it's snowing and that bubble shrunk 'til it was right over my head.

 

But it won't be all snow in the mountains. It'll probably start as rain until the cold air can bleed in on the backside. Then the precip on the NW side will likely form a deformation band. On the far right side of the low the precip might arrive in north central NC to start as snow but could easily switch over to rain before the low moves through - cutting down significantly on accumulations.

 

The sweet spot is going to likely be the Appalachians and high elevations along the TN/NC border into VA. Leconte will likely get about 14" with this considering the short duration plus the heavy snow and possible brief start as rain. It will be VERY heavy snow for a few hours but anything over a foot is pushing it, and Leconte is 6600'. The deformation band could elevate snow totals for the foothills from Cosby to Maryville and into NE TN into Johnson City to Greeneville and Bristol. Once the elevation is above 2000' overall, there probably won't be much of a start as rain if at all in northeast TN.

 

With warm ground temps, a quick moving system, and the soundings, I don't see anything more than a 1-3" storm for parts of lower NC as of now.

[nrhardin]

Thanks queencitywx. While I'd like to see it a little colder, obviously heavier precip could overcome a 0.9 layer to make it isothermal. This also overlaps with when the triangle would experience the best lift/deformation. Physically, if the layer that is above freezing is about 550 meters thick, and heavy aggregates fall about 2 m/s, then we are talking about 4 minutes for snow to fall through the layer. This would result in probably very wet snow for a period of a few hours as mentioned by Allan. Also,the timing of this event for the triangle is much better than points west, although it would be great a few hours later.

[The Alchemist]

I wouldn't mind a repeat of march '09... I got almost a foot here in Saluda... I think Andy said it had to do with the up sloping winds...