January Pattern and Storm Discussion

[Jonesing for a chase]

Doesn't the Euro usually stop some of its holding back SW energy around 120-144hrs ? if so 12z today might be telling

[CAD_Wedge_NC]

This sounding would argue that Hickory stays snow for at while, at least:

Date: 5 day AVN valid 12Z THU 3 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 210

SFC 975 411 1.4 -1.5 81 2.8 0.2 59 6 276.5 277.1 274.6 286.1 3.51

2 950 623 0.8 -5.9 61 6.7 -1.7 68 12 278.0 278.4 274.1 285.2 2.58

3 900 1055 -1.7 -6.0 73 4.3 -3.3 81 9 279.8 280.2 275.3 287.4 2.72

4 850 1512 0.0 -5.0 69 5.0 -2.0 151 4 286.2 286.7 279.1 295.1 3.10

5 800 1999 1.9 -9.2 43 11.1 -2.3 260 5 293.2 293.6 281.5 300.3 2.37

6 750 2519 0.6 -5.0 66 5.6 -1.8 279 11 297.3 297.9 284.5 307.8 3.51

7 700 3070 -2.4 -3.5 92 1.2 -2.9 263 13 299.9 300.6 286.2 312.6 4.21

8 650 3657 -4.2 -5.0 94 0.8 -4.6 237 17 304.2 304.9 287.6 316.6 4.04

9 600 4285 -7.1 -7.5 97 0.4 -7.2 226 27 307.9 308.6 288.5 319.3 3.63

10 550 4960 -10.4 -10.6 98 0.2 -10.5 218 39 311.8 312.4 289.3 321.7 3.10

11 500 5690 -13.0 -13.2 98 0.2 -13.0 231 56 317.2 317.8 290.6 326.3 2.77

12 450 6489 -16.5 -16.6 99 0.1 -16.6 236 72 322.5 323.0 291.8 330.3 2.32

13 400 7367 -21.2 -21.3 99 0.1 -21.2 237 85 327.4 327.8 292.7 333.5 1.75

14 350 8340 -27.4 -27.6 99 0.1 -27.5 240 96 331.8 332.0 293.3 335.8 1.13

15 300 9429 -36.8 -37.0 98 0.2 -36.8 243 96 333.5 333.6 293.2 335.5 0.53

16 250 10662 -47.2 -47.3 99 0.1 -47.1 245 114 336.0 336.0 293.5 336.8 0.22

17 200 12101 -57.9 -58.1 97 0.3 -57.9 252 131 341.1 341.2 294.7 341.5 0.07

18 150 13879 -63.3 -66.1 69 2.7 -63.4 259 112 360.9 361.0 298.9 361.1 0.04

19 100 16358 -69.1 -79.7 20 10.6 -69.2 244 65 394.2 394.2 304.4 394.3 0.01

TRP 0

WND 0

Yeah, and once the lower layers reach wetbulb, the atmosphere will be saturated all the way up to 250mb. That would be absolutely perfect for snow growth. With super-saturation at those temps it would produce mostly sectored plates and dendrites.

[packbacker]

rest of 12z very odd- much wamer after storm but then pops a coastal and nearly another winter storm at truncation

Yeah, the cutoff that formed over CO finally starts to move east on day 8, very similar to the 0z Euro, too warm for us though by that time, we need it to move out sooner.

[calculus1]

This sounding would argue that Hickory stays snow for at while, at least:

Date: 5 day AVN valid 12Z THU 3 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 210

SFC 975 411 1.4 -1.5 81 2.8 0.2 59 6 276.5 277.1 274.6 286.1 3.51

2 950 623 0.8 -5.9 61 6.7 -1.7 68 12 278.0 278.4 274.1 285.2 2.58

3 900 1055 -1.7 -6.0 73 4.3 -3.3 81 9 279.8 280.2 275.3 287.4 2.72

4 850 1512 0.0 -5.0 69 5.0 -2.0 151 4 286.2 286.7 279.1 295.1 3.10

5 800 1999 1.9 -9.2 43 11.1 -2.3 260 5 293.2 293.6 281.5 300.3 2.37

6 750 2519 0.6 -5.0 66 5.6 -1.8 279 11 297.3 297.9 284.5 307.8 3.51

7 700 3070 -2.4 -3.5 92 1.2 -2.9 263 13 299.9 300.6 286.2 312.6 4.21

8 650 3657 -4.2 -5.0 94 0.8 -4.6 237 17 304.2 304.9 287.6 316.6 4.04

9 600 4285 -7.1 -7.5 97 0.4 -7.2 226 27 307.9 308.6 288.5 319.3 3.63

10 550 4960 -10.4 -10.6 98 0.2 -10.5 218 39 311.8 312.4 289.3 321.7 3.10

11 500 5690 -13.0 -13.2 98 0.2 -13.0 231 56 317.2 317.8 290.6 326.3 2.77

12 450 6489 -16.5 -16.6 99 0.1 -16.6 236 72 322.5 323.0 291.8 330.3 2.32

13 400 7367 -21.2 -21.3 99 0.1 -21.2 237 85 327.4 327.8 292.7 333.5 1.75

14 350 8340 -27.4 -27.6 99 0.1 -27.5 240 96 331.8 332.0 293.3 335.8 1.13

15 300 9429 -36.8 -37.0 98 0.2 -36.8 243 96 333.5 333.6 293.2 335.5 0.53

16 250 10662 -47.2 -47.3 99 0.1 -47.1 245 114 336.0 336.0 293.5 336.8 0.22

17 200 12101 -57.9 -58.1 97 0.3 -57.9 252 131 341.1 341.2 294.7 341.5 0.07

18 150 13879 -63.3 -66.1 69 2.7 -63.4 259 112 360.9 361.0 298.9 361.1 0.04

19 100 16358 -69.1 -79.7 20 10.6 -69.2 244 65 394.2 394.2 304.4 394.3 0.01

TRP 0

WND 0

Trying to learn to read these soundings properly. Is your statement based off the fact that the wet bulb temp is below zero all the way down to 950 mb? Thus, once precip begins to fall it would cool the atmosphere and allow flakes to make it all the way to the surface even though the final 25 mb are slightly above freezing?

Also, from site do you get these soundings from?

Thanks

[Wow]

Models in disarray!

Yesterday's 18z run at 138hrs:

Today's 12z run valid for the same time

[FallsLake]

Yeah, the cutoff that formed over CO finally starts to move east on day 8, very similar to the 0z Euro, too warm for us though by that time, we need it to move out sooner.

I think we all know that this storm is going to be our best chance at a winter storm and then it should warm for at least 10 days. After that it should start to to more favorable (again) by the end of January. **So the GFS might be correct showing the warm-up.

[packbacker]

Models in disarray!

Yesterday's 18z run at 138hrs:

Today's 12z run valid for the same time

Euro at simliar time...

[BullCityWx]

Trying to learn to read these soundings properly. Is your statement based off the fact that the wet bulb temp is below zero all the way down to 950 mb? Thus, once precip begins to fall it would cool the atmosphere and allow flakes to make it all the way to the surface even though the final 25 mb are slightly above freezing?

Also, from site do you get these soundings from?

Thanks

Yep, you've got it. It's kinda like how the best winter storms start with temperatures right at freezing with a large dewpoint depression at the surface. There's also a little bit of interpretation in there(the storm is headed to the south so less WAA and the deep moisture penetration in the atmosphere).

The soundings come from this website: http://vortex.plymouth.edu/grbsnd.html

[burgertime]

Models in disarray!

Yesterday's 18z run at 138hrs:

Today's 12z run valid for the same time

6z to 12z even crazier. 6z literally had nothing for the same time frame.

[burgertime]

The event modeled by the 12z GFS reminds me just a little bit of the Jan 29-30 2010 storm.

That's probably a pretty good observation. I remember that one looking like a zR storm...then a snow storm but it was just slightly too warm and it ended up snow on the front with heavy sleet during the middle and end.

[packbacker]

ENS mean matches up fairly well with Op, a little warmer so I imagine there are some amped up ones or the high is not getting over in a favorable spot soon enough.

[franklin NCwx]

Cmc valid same time.

[strongwxnc]

No doubt..

http://www4.ncsu.edu/~nwsfo/storage/cases/20100129/

That's probably a pretty good observation. I remember that one looking like a zR storm...then a snow storm but it was just slightly too warm and it ended up snow on the front with heavy sleet during the middle and end.

[burgertime]

GFS ENS Mean seems to hold serve with the placement of the low. Looks like temps are in the 30 - 40 range at the SFC with 850's in the 0 - 5 range for most of NC....of course it's the ENS Mean...so it should be interesting to see what individual members look like.

[franklin NCwx]

GFS ENS Mean seems to hold serve with the placement of the low. Looks like temps are in the 30 - 40 range at the SFC with 850's in the 0 - 5 range for most of NC....of course it's the ENS Mean...so it should be interesting to see what individual members look like.

Burger storm!

[HKY_WX]

I think the odds are much greater this trends into a high qpf event vs an out to sea suppressed solution. It just has that icestorm miller b look to me.

[WXinCanton]

CAD is very likely underdone. That HP is in a great position. It always seems the models struggle CAD and how strong it is.

[burgertime]

No doubt..

http://www4.ncsu.edu...cases/20100129/

Thanks, great read and just to get it out of the way now...

First note that this winter storm was preceded by a few mild days with temperatures reaching the 50s and 60s on January 24th and 25th and again on January 28th when max temperatures reached the upper 50s to lower 60s across central North Carolina. During this warm period the 0.1m (4 inch) soil temperatures reached the mid 40s to around 50 during the late afternoon hours. The amount of diurnal and spatial variability in the data is impressive with diurnal spreads of nearly 10 degrees F during the sunny milder days.

Past experience has shown that when max soil temperatures during the day preceding a snow fall are in the lower 40s or colder and given modest snow rates with surface temperatures at or near freezing, the snow can be expected to accumulate. Max soil temperatures in most of central North Carolina were in the lower to mid 40s with the mid 40 temperatures confined to the southern Coastal Plain (GOLD) and location near the South Carolina border (HAML and LILE).

[RaleighWx]

As you guys said ENS is wetter. Compare 12 ENS 72 hour precip

vs 6z similar time frame

[bhamwx205]

Does allens site show each member?

[rduwx]

The event modeled by the 12z GFS reminds me just a little bit of the Jan 29-30 2010 storm.

I could see that. The Jan 29-30 2010 storm was modeled to be a good storm but we always new it was going to be close between sn and ip. The one thing about that storm is that it really turned cold during the storm. I remember it in the 20's on the 30th. I didn't think my kids were ever going to go back to school. I just don't see this storm as being that cold. I also remember convection in the gulf robbing a lot of the moisture.

[franklin NCwx]

CMC says around I-20 north. Here is the link. Moto, this looks good for you.http://www.meteo.psu.edu/~fxg1/CMC_12z/cmcloop.html

[Poimen]

126 HR GGEM is colder than the GFS....would imply a snow/ice threat to upstate SC as well.

[BullCityWx]

12z GGEM has heavy snow across the 85 corridor from Charlotte all the way to very close to ATL.

[burgertime]

CMC is not bad...

Hr. 132

[ILMRoss]

CMC says around I-20 north. Here is the link. Moto, this looks good for you.http://www.meteo.psu.edu/~fxg1/CMC_12z/cmcloop.html

The CMC also has that quick little coastal storm the GFS had about 8 days out. Both models had a pretty small yet surprisingly cold pocket of cool air associated with it.

[BIG FROSTY]

CMC @ 120.. Looks like southern NC in to Ga. snow! The heaviest looks like it will stay south of frosty land!

[franklin NCwx]

Ukie

[RaleighWx]

Canadian meteograms look like snow for RDU

http://meteocentre.com/models/get_mgram.php?stn=Raleigh&mod=gemglb&run=12&var=prcp〈=en&map=us

[calculus1]

Yep, you've got it. It's kinda like how the best winter storms start with temperatures right at freezing with a large dewpoint depression at the surface. There's also a little bit of interpretation in there(the storm is headed to the south so less WAA and the deep moisture penetration in the atmosphere).

The soundings come from this website: http://vortex.plymouth.edu/grbsnd.html

Thanks for the confirmation and the link. Good to know I was on the right track.

Thanks, great read and just to get it out of the way now...

First note that this winter storm was preceded by a few mild days with temperatures reaching the 50s and 60s on January 24th and 25th and again on January 28th when max temperatures reached the upper 50s to lower 60s across central North Carolina. During this warm period the 0.1m (4 inch) soil temperatures reached the mid 40s to around 50 during the late afternoon hours. The amount of diurnal and spatial variability in the data is impressive with diurnal spreads of nearly 10 degrees F during the sunny milder days.

Past experience has shown that when max soil temperatures during the day preceding a snow fall are in the lower 40s or colder and given modest snow rates with surface temperatures at or near freezing, the snow can be expected to accumulate. Max soil temperatures in most of central North Carolina were in the lower to mid 40s with the mid 40 temperatures confined to the southern Coastal Plain (GOLD) and location near the South Carolina border (HAML and LILE).

I loved this! Even before the warm soil temp advocates make their appearances...