December 8-10, 2018 Winter Storm

[ajr]

 

[msuwx]

Well, been pouring through all available data for hours now, and it all depends on the temperatures 5-9k feet aloft for much of the region tonight into Sunday morning.

NAM really warms temps in those layers later tonight....some other models do not. 

The NAM often does well in this situation, but I'm more hesitant than normal this time. Makes a massive difference in ground accumulations, especially around CLT-RDU corridor. 

 

[griteater]

1 hour ago, nchighcountrywx said:

HRRR for Sunday 4am

 

Well it's kind of impressive to see the HRRR be this cold to the south

[CaryWx]

Just now, griteater said:

Well it's kind of impressive to see the HRRR be this cold to the south

Didn't the HRRR also pick up on the warm nose around RDU in the Jan 2017 storm. I know that whole thing was a late discovery but thought the HRRR saw it as well as the NAM around this time before things began.

[msuwx]

7 minutes ago, CaryWx said:

Thanks Matt.  Does that mean more zr in your view for CLT to RDU or just plain cold rain?

If the warmer temps aloft are correct, I think CLT stays sub-freezing at the SFC longer than RDU, at least a by a bit. 

However, I am not totally sold on the warmer aloft solution. Couple of normally-reliable tools aren't in that camp. 

[Poimen]

How does the HRRR compare to other Hi-Res models, specifically in regards to thermals? Edit: @griteater just answered above lol

[griteater]

2 minutes ago, CaryWx said:

Didn't the HRRR also pick up on the warm nose around RDU in the Jan 2017 storm. I know that whole thing was a late discovery but thought the HRRR saw it as well as the NAM around this time before things began.

I would just say that it's always a plus to see it on the cold side because if any model is going to be warm in the mid levels it's the HRRR and NAM

[FallsLake]

3 minutes ago, CaryWx said:

Didn't the HRRR also pick up on the warm nose around RDU in the Jan 2017 storm. I know that whole thing was a late discovery but thought the HRRR saw it as well as the NAM around this time before things began.

Looking at my grid forecast, they're giving me 7-13". I'll still call this a win with 5" with a little sleet and freezing rain. That initial snow is going to be everything. As others have stated once you get snow and if it's heavy, it many times overcomes slightly above freezing mid level temps to stay all snow.  

[CaryWx]

4 minutes ago, griteater said:

I would just say that it's always a plus to see it on the cold side because if any model is going to be warm in the mid levels it's the HRRR and NAM

It bears watching for sure every hour now.

Will be praying for sleet to hang on longer and not change to zr unless ground temps can go above 32.

[packfan98]

@griteater have you had a chance to look at the 6z euro?  I’m curious if there were any changes, especially with the transition lines. Thanks!

[CaryWx]

1 minute ago, FallsLake said:

Looking at my grid forecast, they're giving me 7-13". I'll still call this a win with 5" with a little sleet and freezing rain. That initial snow is going to be everything. As others have stated once you get snow and if it's heavy, it many times overcomes slightly above freezing mid level temps to stay all snow.  

NWS calling for .20 ice accrual as well around Wake in their latest graphic and also mention "up to a quarter inch" in their text product. 

As Seinfeld's dad said-"I don't like the sound of that."

[SnowDawg]

Weather channel saying Lubbock, TX just reached 6 inches of snow and still snowing. Went back and looked and even at the 10 pm last night they weren’t calling for more than 4 there. Definitely juicy.

[fountainguy97]

Nice trend for increased CAD.  Pretty large trend to be so close.

 

[SnowDawg]

2 minutes ago, fountainguy97 said:

Nice trend for increased CAD.  Pretty large trend to be so close.

 

Probably just the HRRR getting a grip in its short term. Pretty sure it has a known warm bias in CAD events, so it’s correcting as it gets closer.

[SnowNiner]

1 hour ago, griteater said:

I would just say that it's always a plus to see it on the cold side because if any model is going to be warm in the mid levels it's the HRRR and NAM

Hrrr is usually the crusher of my dreams. Nice to have it wintry for once. Who knows at this point though.

[Solak]

Under a WWA for 1"-3" snow and ice; point forecast calls for 2"-4". Confusing.

[Berlin1926]

1 hour ago, FallsLake said:

Looking at my grid forecast, they're giving me 7-13". I'll still call this a win with 5" with a little sleet and freezing rain. That initial snow is going to be everything. As others have stated once you get snow and if it's heavy, it many times overcomes slightly above freezing mid level temps to stay all snow.  

I was genuinely surprised to see 7 - 13 for us as well.  Consistency between Blacksburg and RAH is unusual.  We are at the point where RNK, AKQ, and RAH meet.  AKQ has 3- 5.

[Lookout]

1 hour ago, msuwx said:

Well, been pouring through all available data for hours now, and it all depends on the temperatures 5-9k feet aloft for much of the region tonight into Sunday morning.

NAM really warms temps in those layers later tonight....some other models do not. 

The NAM often does well in this situation, but I'm more hesitant than normal this time. Makes a massive difference in ground accumulations, especially around CLT-RDU corridor. 

 

I wonder if the intense precip rates   could offset that warming somewhat or delay it? 

Speaking of those intense rates, most of the models are now  showing enough heavy precip/cooling for a several window of very heavy snow or sleet across ne ga...maybe as far south as athens, before going back to sleet/freezing rain (mainly north of 85 until after 09z) overnight tonight as the warm nose aloft moves in. (just for reference it's all snow/subfreezing at 06z but warms to  plus 3c at 750mb on the fv3 near cornelia at 09z). There does appear to be some dynamical cooling at play here with very intense precip rates and cooling occuring at the same time. ...in fact the 06z run  it keeps it as sleet for areas like gainesville to hartwell for the duration of the storm after 03z.  Would be quite the accumulation of it if that happens. 

 i sure envy the upstate/western nc. The rates are going to be insane. 

 

 

[griteater]

1 hour ago, packfan98 said:

@griteater have you had a chance to look at the 6z euro?  I’m curious if there were any changes, especially with the transition lines. Thanks!

For some reason, I don't see the 06z and 18z runs on weathermodels now...not sure what's going on there.

Here's the 06z Euro run on Vista with the 850 low, then the second map is the sfc temps. It's north of an ideal track for northern upstate into CLT but it tries to bring wet snow/sleet in that area with heavy dynamics as it rolls thru.   

[griteater]

Euro Total Precip trend

[UpstateSCGamecock]

I wonder if the intense precip rates   could offset that warming somewhat or delay it? 
Speaking of those intense rates, most of the models are now  showing enough heavy precip/cooling for a several window of very heavy snow or sleet across ne ga...maybe as far south as athens, before going back to sleet/freezing rain (mainly north of 85 until after 09z) overnight tonight as the warm nose aloft moves in. (just for reference it's all snow/subfreezing at 06z but warms to  plus 3c at 750mb on the fv3 near cornelia at 09z). There does appear to be some dynamical cooling at play here with very intense precip rates and cooling occuring at the same time. ...in fact the 06z run  it keeps it as sleet for areas like gainesville to hartwell for the duration of the storm after 03z.  Would be quite the accumulation of it if that happens. 
 i sure envy the upstate/western nc. The rates are going to be insane. 

 
 

GSP’s discussion page doesn’t give much hope for snow south of 85 and they are not sure if frozen gets to advisory criteria. Your post gives me hope. Thanks for the informative posts for your neck of the words. That would bode well for me in S of 85 in SC.


.

[SnowNiner]

4 minutes ago, griteater said:

For some reason, I don't see the 06z and 18z runs on weathermodels now...not sure what's going on there.

Here's the 06z Euro run on Vista with the 850 low, then the second map is the sfc temps. It's north of an ideal track for northern upstate into CLT but it tries to bring wet snow/sleet in that area with heavy dynamics as it rolls thru.   

Thanks grit, to me that looks improved...keeps 850s around clt through most of the storm. Nws still has me over a foot of snow total. Hopefully the colder models win out here.

[Buddy1987]

8 minutes ago, griteater said:

For some reason, I don't see the 06z and 18z runs on weathermodels now...not sure what's going on there.

Here's the 06z Euro run on Vista with the 850 low, then the second map is the sfc temps. It's north of an ideal track for northern upstate into CLT but it tries to bring wet snow/sleet in that area with heavy dynamics as it rolls thru.   

CMC for the win? Looks just like it. LP wise

[Ander]

Hi all, I am more of a lurker here (for a decade or so lol).  I generally keep quiet because my expertise in a far different field and I just enjoy reading.  I did have a noob question, that is both for general knowledge purposes and also with an eye for my personal situation.  As a native New Englander who now lives about ten miles from RDU airport, the only things that really bother me in NC about weather are tornadoes and ice storms.   I have read a good bit about ice storms, but am unsure the extent to which the icing in this storm will have impacts.  From a layman's perspective, I understand snow, sleet, and freezing rain in general.  That being said, I have read estimates from model runs ranging from .10 to .70 inches of icing.  As I understand it, it is when the icing hits .25 the problems start and by .50 there are pretty widespread power outages around here.  Assuming this is correct, why has there been so little said about the icing potential of this storm in the Triangle?  Is there something with the expected mix of snow, sleet, freezing rain and rain in this that would minimize that risk for trees, powerlines etc.  The only thing in 13 years in NC that has caused significant time without power here for us is ice storms.  It is something I never appreciated as a New Englander before moving south.  Thanks in advance for any replies and enjoy the snow :)

[olafminesaw]

The 0z Euro has heaviest snow in Greensboro from 6am to 2pm with snowfall rates in the 1.5-2" per hour range at peak, if we can stay snow until the heaviest banding comes through, I will be more than content.

[SN_Lover]

2 minutes ago, SLAMSTORM22 said:

10-16" is my computer generated forecast in Mooresville, seem legit, or too high? 

 

(it actually shows 9-15" for concord also) 

Sleet line stops at Statesville usually. 4-7" would be a good call. 

[franklin NCwx]

16 minutes ago, griteater said:

For some reason, I don't see the 06z and 18z runs on weathermodels now...not sure what's going on there.

Here's the 06z Euro run on Vista with the 850 low, then the second map is the sfc temps. It's north of an ideal track for northern upstate into CLT but it tries to bring wet snow/sleet in that area with heavy dynamics as it rolls thru.   

Grit, do you have this animation with 850 temps?

Thanks,

[GunBlade]

Just now, franklin NCwx said:

Grit, do you have this animation with 850 temps?

Thanks,

First animation has 850 temps. 

[franklin NCwx]

1 minute ago, GunBlade said:

First animation has 850 temps. 

Correct.  I just rushed and assumed it was heights.

[burrel2]

Hrrr is getting GSP down to 28 degree's by 8am Sunday. That's 4 degree's colder than any other model has showed to this point.  Even more impressive when you consider the Hrrr is typically torching at the end of its run.

It's also flipping the rain over to a major sleet storm by midnight for most of the upstate including hart/anderson/newberry counties. If the wedge can get cranking that quick this could still be quite a winter storm for us.

One concern I have is the backside of the precip looks to fly through here around 3 or 4am; and the development of precip in the dry slot behind that band is usually questionable in coverage and intensity.