Winter Storm 1/6 - 1/8, 2017

[griteater]

2 minutes ago, Queencitywx said:

Enhanced frontogenesis should help with higher rates and cooler temps aloft, correct?

Yes, should help with all of that...though it would be better to have it over a deeper layer...say up through the 700mb layer as well....others can comment on it maybe

[phishbfm]

Allan Huffman ‏@RaleighWx  6m6 minutes ago

The GFS bufkit soundings for RDU airport was all snow after brief rain to begin. 10-12 inches.

[Brick Tamland]

6 minutes ago, Cary_Snow95 said:

My guess for us is 3-4" sleet and snow combined

 

3 minutes ago, POWERSTROKE said:

I am only a contractor but have seen over the past 25 years of plowing that when sleet starts alot of times it never goes back to snow.  Hopefully this is not the case.

The NAM is the worst case scenario for RDU, so I don't think it will just be 3 to 4 inches combined.

And even if it doesn't change back over to snow, 7 inches of snow and sleet would be a big deal and a big mess. That's still more than the average we get all winter.

[Cary_Snow95]

1 minute ago, Brick Tamland said:

 

The NAM is the worst case scenario for RDU, so I don't think it will just be 3 to 4 inches combined.

And even if it doesn't change back over to snow, 7 inches of snow and sleet would be a big deal and a big mess. That's still more than the average we get all winter.

Brick I want higher numbers just as much as you but the GEM and the RGEM and HRRR are shifting us to a majority sleet. You have a little advantage over me though since your further north. I am right below the Airport

[phishbfm]

1 minute ago, fritschy said:

What about Asheville

StnID: kavl    Profile Thermal Adjust:  0.0       Cloud RH threshold:  85%    Average Hourly Sounding: NO

 Date/hour    FHr  Wind    SfcT   Ptype   SR |Snow||Sleet|| FZRA|| QPF    CumSR|TotSN||TotPL||TotZR|| TQPF   S%| I%| L%
============================================================================================================================
170106/1500Z   3  35003KT  36.4F          0:1| 0.0|| 0.00|| 0.00|| 0.000    0:1|  0.0|| 0.00|| 0.00|| 0.00    0|  0|  0
170106/1800Z   6  VRB02KT  42.9F          0:1| 0.0|| 0.00|| 0.00|| 0.000    0:1|  0.0|| 0.00|| 0.00|| 0.00    0|  0|  0
170106/2100Z   9  VRB02KT  36.0F  RASN    0:1| 0.0|| 0.00|| 0.00|| 0.059    0:1|  0.0|| 0.00|| 0.00|| 0.06   26|  0| 74
170107/0000Z  12  04003KT  31.9F  SNOW    7:1| 0.3|| 0.00|| 0.00|| 0.046    7:1|  0.3|| 0.00|| 0.00|| 0.10  100|  0|  0
----------------------------------------------+----++-----+-------------++--------------++-------------++-----------+---+---
170107/0300Z  15  VRB02KT  30.3F  SNOW    6:1| 0.9|| 0.00|| 0.00|| 0.152    6:1|  1.2|| 0.00|| 0.00|| 0.26  100|  0|  0
170107/0600Z  18  VRB02KT  28.5F  SNOW    8:1| 1.4|| 0.00|| 0.00|| 0.169    7:1|  2.6|| 0.00|| 0.00|| 0.43  100|  0|  0
170107/0900Z  21  34004KT  25.1F  SNOW   11:1| 1.5|| 0.00|| 0.00|| 0.139    8:1|  4.1|| 0.00|| 0.00|| 0.56  100|  0|  0
170107/1200Z  24  33007KT  19.8F  SNOW   13:1| 0.5|| 0.00|| 0.00|| 0.040    8:1|  4.6|| 0.00|| 0.00|| 0.60  100|  0|  0
----------------------------------------------+----++-----+-------------++--------------++-------------++-----------+---+---
170107/1500Z  27  33008KT  19.1F  SNOW   23:1| 0.3|| 0.00|| 0.00|| 0.013    9:1|  4.9|| 0.00|| 0.00|| 0.62  100|  0|  0

[Brick Tamland]

2 minutes ago, Cary_Snow95 said:

Brick I want higher numbers just as much as you but the GEM and the RGEM and HRRR are shifting us to a majority sleet

And other models aren't. 

[Cary_Snow95]

2 minutes ago, Brick Tamland said:

And other models aren't. 

Look at the GEFS. Every panel has us as rain/mix thru 10 am tomorrow

[Regan]

2 minutes ago, Brick Tamland said:

And other models aren't. 

Yesterday here was crying about the NAM and today it's not the NAM, it's crying over the RGEM. Not all models are going to be right and each has their own problems. The GFS has been consistent. Naive?  Maybe. But I'm not ready to jump ship and go RGEM etc. 

[GlaringSun]

Could anyone inform me on when it looks like ATL will switch over completely to any frozen precipitation?

[weatherbubba]

25 minutes ago, uncjibble said:

I've lurked here for years and hardly ever post, but this post is my thoughts exactly! I'm in that little yellow dot too, maybe a hair north. Just once, it would be nice for Wake county to not be the dividing line. I feel like South/East Wake is always on the wrong side. I have completely lowered my expectations and would be thrilled to just get enough of anything to cover the grass and go sledding! This feels so much like the one last year where there was so much potential at the beginning and all we ended up with was rain. 

Add another person who lives in that general vicinity to that list!  I'm praying that the GFS will verify

even though it comes in warmer with each run.  At least the latest run of the NAM was a little better.

King Euros last run before the storm hits our area should be interesting.  I would love to see something

in the 6+ inch range but expectations are that 2 inches and a lot of sleet are what I'm going to see.

[toxictwister00]

1 minute ago, GlaringSun said:

Could anyone inform me on when it looks like ATL will switch over completely to any frozen precipitation?

It should be frozen (sleet, possibly freezing rain) as soon as the first batch of precip moves in over the next couple of hours. 

[strongwxnc]

The foothills WX network has put out their final call map. 

Great group of guys that cover the foothill counties in NC. 

http://www.foothillsweathernetwork.com/weatherdiscussion/

 

[Brick Tamland]

5 minutes ago, Cary_Snow95 said:

Look at the GEFS. Every panel has us as rain/mix thru 10 am tomorrow

And look what Huffman said about the NAM and GFS bufkit. Still lots of possibilities for more snow than sleet. But the thing is, either way it's going to be a mess and a big deal, whether it be more snow or a mix of snow and sleet.

[beanskip]

Hard to keep up on the board, but I assume everyone saw much of southern Mississippi upgraded to Winter Storm Warning about an hour ago. http://www.weather.gov/jan/

It's raining and 34 all the way down in Hattiesburg.

[Cary_Snow95]

5 minutes ago, Brick Tamland said:

And look what Huffman said about the NAM and GFS bufkit. Still lots of possibilities for more snow than sleet. But the thing is, either way it's going to be a mess and a big deal, whether it be more snow or a mix of snow and sleet.

Yeah I am anxious for the 18z NAM. It took a step in the right direction at 12z, needs to do it once more

[DopplerWx]

1 minute ago, Cary_Snow95 said:

Yeah I am anxious for the 18z NAM. It took a step in the right direction at 12z, needs to do it once more

1am tonight on the latest hrrr, snow line right over wake but those in the all snow band will be getting absolutely crushed.

[packbacker]

Just now, Cary_Snow95 said:

Yeah I am anxious for the 18z NAM. It took a step in the right direction at 12z, needs to do it once more

I am worried about all sleet event too....we never post mortem a winter event and say the models over estimated warm nose.  I think we get a 1-2" snow then flip to a lot of sleet (1.5" accum) then maybe flip back to snow for 1-2" more.  That's my hope but I may be a little high.  Wouldn't be surprised if we sleet the whole time and we end up 2" block of ice.  To be honest with miller a like this I am surprised there is such an IP zone, would think it would be rain or snow for the most part.   That would be funny if we rained.  

[ryan1234]

Does anyone have or know where I can find the soundings for Charlotte per the latest CMC run? Curious to see what they look like.

[mackerel_sky]

4 minutes ago, DopplerWx said:

1am tonight on the latest hrrr, snow line right over wake but those in the all snow band will be getting absolutely crushed.

So HRRR, is bad with temps??

[phil882]

50 minutes ago, localyokelweather said:

I dont have the ability to screenshot his post, but our boy Philippe is weighing in on the thermal issue with his technical prowess... 

Worth a look: 

 

43 minutes ago, griteater said:

And to the earlier question on FGEN, Phillppe also has detailed HRRR model images centered over our area (at bottom of his page) - http://www.atmos.albany.edu/student/ppapin/hrrr.php

I thought I heard my ears ringing! Hope everyone is excited for the event :D. I'll have to live vicariously though you guys (I was GSP over the holidays with family but just flew back up yesterday since I'm trying to finish up my PhD at UAlbany.) 

I'll check in throughout the day to provide some commentary if I see fit. But some preliminary things from what I've seen so far:

1) As alluded by my tweet above, I am pretty worried about the thermal ridge that is showing up in a lot of the mesoscale guidance for Northeast GA. It's been a pretty consistent feature that needs to be looked as closely as the event gets underway this evening. 

2) WATCH THE WARM NOSE! Already there have been some upstream obs that suggest a pretty potent warm nose 

One thing the global model almost all universally do is that they are bad with vertical gradients. In this context, that oftentimes mean they underforecast the intensity of the cold air damming at the surface AND they also underforecast the intensity of the warm nose aloft. It would not surprise me if there is a lot more sleet/freezing rain than initially projected in SC/NC... so keep that in the back of your mind. 

3) Mesoscale banding will certainly enhance rates, however, these are also likely to be present near transition zones where the temperature gradient is strongest. Thus, the best snowfall accumulation might actually be on the north end of locations where strong frontogenesis occurs (to ensure you stay all snow). My frontogenesis maps hopefully will be helpful, but there are a number of other sites that are helpful for showing frontogenesis (some have already have the college of dupage which is another excellent resource).

I have all my HRRR maps over KGSP which you can access here. I have also moved my other floater domain to Virginia Beach to cover the rest of NC/VA.

KGSP Maps:

15min-resolution maps: http://www.atmos.albany.edu/student/ppapin/hrrr.php#flt

1hr-resolution frontogenesis maps: http://www.atmos.albany.edu/student/ppapin/hrrr.php#diag

KEMV Maps: For ENC/VA

15min resolution maps: http://www.atmos.albany.edu/student/ppapin/hrrr.php#wxch

If you guys have any requests or questions... holler away! I'll be checking in every so often! Hope everyone gets some nice accumulation

[Jenkins]

Probably getting outside it's scope of usefulness but is anyone doing PBP for 12z ECMWF?

[burrel2]

Sitting in savannah deciding whether or not to haul tail to the house. Hrr appears to drop about 6 inches on my house with -1 temps through the column and a surface temp of 33. 10 miles to my south it's showing all rain. I know if I make the 5 hr drive it'll shift north. If I don't my house will get plastered.  Decisions decisions!

[PackGrad05]

That HRRR image that shows the line right over wake at 1AM.  That should start moving south after 1AM and changing areas south to snow right?

[DopplerWx]

fwiw, 12z euro looks identical to the gfs/rgem/nam. splits wake cty. northern wake from raleigh upwards looks all snow, southern is a sleet/snow mix.

[Dunkman]

9 minutes ago, packbacker said:

I am worried about all sleet event too....we never post mortem a winter event and say the models over estimated warm nose.  I think we get a 1-2" snow then flip to a lot of sleet (1.5" accum) then maybe flip back to snow for 1-2" more.  That's my hope but I may be a little high.  Wouldn't be surprised if we sleet the whole time and we end up 2" block of ice.  To be honest with miller a like this I am surprised there is such an IP zone, would think it would be rain or snow for the most part.   That would be funny if we rained.  

I've seen the warm nose delayed but never denied, at least not here in the last decade (how long I've been in the triad). For instance I can remember a couple storms in which we were forecast to get ~"1 of snow before changing and ended up with ~4-5" before the switch. But you're right, it was never a case of there not being one.

[Cold Rain]

5 minutes ago, BFF said:

Probably getting outside it's scope of usefulness but is anyone doing PBP for 12z ECMWF?

 Be nice to know, but I'm sure it's north and west again with its snow max.

[strongwxnc]

3 minutes ago, burrel2 said:

Sitting in savannah deciding whether or not to haul tail to the house. Hrr appears to drop about 6 inches on my house with -1 temps through the column and a surface temp of 33. 10 miles to my south it's showing all rain. I know if I make the 5 hr drive it'll shift north. If I don't my house will get plastered.  Decisions decisions!

 

DO IT! Drive home..

[DopplerWx]

12" for rdu on the euro. sharp cutoff with 2" on the southern portion of the county.

[packfan98]

Just now, DopplerWx said:

12" for rdu on the euro. sharp cutoff with 2" on the southern portion of the county.

Can you post a map for the rest of the areas, or comment on CLT, Triad, Foothills, Upstate, etc.... please?  Thanks!

[DopplerWx]

nc snow totals