December 8-10, 2018 Winter Storm

[SouthCentralWakeCo]

 

[Orangeburgwx]

Just now, sarcean said:

I am just waiting for the rug to be pulled out from under this storm but model after model keeps showing the same (more or less). I can't recall this level of model consistently from this far out possibly ever.

Not only that it keeps bobbing between north one run and south the next... Someone (I'm thinking the I85 corridor around Atlanta) is going to be drilled by a nasty ice storm

[SnowDawg]

Wow, the EPS means went up and expanded even more than the GEFS did!

[snowlover91]

1 minute ago, Orangeburgwx said:

I believe it is the ensembles of the CMC

RGEM is a high resolution version of the CMC, similar to how you have the 32km NAM, 12km and 3km versions. The RGEM ensembles go out to 72 hours and can be useful for trends in track but that's about it. Inside 48 they are excellent.

[donsutherland1]

8 minutes ago, NCWX said:

Wondering if ILM will get enough rain to break 100 inches of rain for the year. It’s at 95.82 right now. 

95.83", not that 0.01" makes much of a difference. ILM will probably need one or two additional storms beyond the weekend event with moderate or greater precipitation to get to 100".

[Amos83]

Just now, DopplerWx said:

i know we keep saying it but jan 2017 has the ensembles showing insane totals just like these and the waa screwed many of us.  expecting a loooot of sleet with this one.

yep for sure.... that one really hacked me off and why I'm so gun shy with this one. the type of snow being shown on the models is rare for around here so our caution should be even more warranted this go around. Although which each passing model run it is getting hard to contain the excitement for sure

[DopplerWx]

1 minute ago, Amos83 said:

yep for sure.... that one really hacked me off and why I'm so gun shy with this one. the type of snow being shown on the models is rare for around here so our caution should be even more warranted this go around. Although which each passing model run it is getting hard to contain the excitement for sure

to me it seems likely we see initial snow sat night into sunday morning before a changeover, no matter what that is a win this early in december.  give me an inch or 2 and i will be more than happy.

[sarcean]

Just now, Orangeburgwx said:

Not only that it keeps bobbing between north one run and south the next... Someone (I'm thinking the I85 corridor around Atlanta) is going to be drilled by a nasty ice storm

I know there is a question of how far south and east the snow will get (and how cold it will be) but here in the triad (Greensboro) up to  the high country in Boone have been in a great spot nearly every model run by every model .

NWS is still calling it conservative with lots of mixed precip in the forecast

[Cincy12]

Just now, Amos83 said:

yep for sure.... that one really hacked me off and why I'm so gun shy with this one. the type of snow being shown on the models is rare for around here so our caution should be even more warranted this go around. Although which each passing model run it is getting hard to contain the excitement for sure

lol Hopefully the ole yard stick is buried. Until then... I wouldn't feel comfortable. Personally, I hate being the "target location" outside of 48 hours.  

[BooneWX]

9 minutes ago, kelani said:

Why is Lenoir/central Caldwell county always a lone dead zone in these guys?  (Ok, dead-ish in this one, but you get my point). 

I’ll take a stab at this one. Growing up in Mount Airy, I always had the same question, because you’d frequently see the same thing modeled for that area. I believe (and someone with a legit background feel free to correct me), the models always try to predict lee side sinking. I’ve found that in these particular systems, coming up from the south, it rarely happens. Usually I just ignore the hole’s. 

[Orangeburgwx]

7 minutes ago, SouthCentralWakeCo said:

 

You should not have shown me that bottom chart... Time to be a silent cheering weenie for that 4%

[burgertime]

1 minute ago, DopplerWx said:

to me it seems likely we see initial snow sat night into sunday morning before a changeover, no matter what that is a win this early in december.  give me an inch or 2 and i will be more than happy.

I also like the idea of a thump at the end with a nice deform band setting up. To me that's where there could be a lot of potential. I'm worried about that WAA though, it always always always gets CLT. Hope it's a sleetfest for you guys but if say the Euro is right with how it gets you there, I still think there's a good chance of 3-5 inches before a switch over then another 4-6 with the aftershot...IF the Euro were to come to reality. 

[ILMRoss]

Wouldn't be surprised if there's a diminished gradient because more members are throwing some of that front end thump further east. that initial finger of precip extending ahead of the storm can be a doozy. I would still expect the main rain/sleet line to developed somewhere along RDU/CLT during warmest portion of storm

[Pilotwx]

2 minutes ago, BooneWX said:

I’ll take a stab at this one. Growing up in Mount Airy, I always had the same question, because you’d frequently see the same thing modeled for that area. I believe (and someone with a legit background feel free to correct me), the models always try to predict lee side sinking. I’ve found that in these particular systems, coming up from the south, it rarely happens. Usually I just ignore the hole’s. 

I'M with ya as well I  call it,  Mountain Shadow effect.

[burgertime]

Just now, ILMRoss said:

Wouldn't be surprised if there's a diminished gradient because more members are throwing some of that front end thump further east. that initial finger of precip extending ahead of the storm can be a doozy. I would still expect the main rain/sleet line to developed somewhere along RDU/CLT during warmest portion of storm

Def agreed. My money would be somewhere between Concord and Charlotte is where that sleet/snow line sets and then probably between Rock Hill and CLT is the sleet/rain line. That's usually where it always sets up there. Whoever is on the sleet side of the snow sleet line is going to have a long weekend. 

[WinstonSalemArlington]

7 minutes ago, sarcean said:

I know there is a question of how far south and east the snow will get (and how cold it will be) but here in the triad (Greensboro) up to  the high country in Boone have been in a great spot nearly every model run by every model .

NWS is still calling it conservative with lots of mixed precip in the forecast

Yep, the models almost all agree with every run that the Triad and Northwest NC will have a major winter event.

[WinstonSalemArlington]

Tim Buckley:  

 

[burrel2]

I'm getting pretty dang excited here. Keeping my expectations tempered that the upstate will undoubtedly be sleet for the majority of the storm, I'm going to say any snowfall accumulation will be a bonus in my book.  The sleet may really pile up though as I expect us to go from 33/34 Saturday evening quickly down in to the upper 20's as the heaviest precip moves in.

Get your popcorn ready for the 18z NAM, i'm betting it's going to be a doozy. 

[CentralNC]

3 minutes ago, WinstonSalemArlington said:

Tim Buckley:  

 

At least Tim will hype when it's time to hype...unlike Lanie Pope...

[griteater]

Just think, we have basically 48 hours of modeling left....that's an eternity for how things can change.  We have a system that is going to bring a lot of warmth and juice out of the gulf into an airmass that is marginal aloft overall.  Outside of the central and northern mountains, northern foothills, into SW VA, confidence should be tempered IMO for a big event.  I post the snow maps like others, but I feel a little slimy doing it because heavy support for cold temperatures isn't there....and those maps are much heavier with snow than they should be along the edges.  Wonder if anyone has the Eurowx site access...seems like they used to have much more tempered snow maps, etc.

[PackGrad05]

Surface temps in Wake during the event do not look that great to me...  I think we will see a lot of melting of anything that falls.

With that said, the time frame between Monday-Wednesday is super cold.  So anything on the ground have a hard time melting and thawing until Wednesday/Thursday.

[CentralNC]

1 minute ago, griteater said:

Just think, we have basically 48 hours of modeling left....that's an eternity for how things can change.  We have a system that is going to bring a lot of warmth and juice out of the gulf into an airmass that is marginal aloft overall.  Outside of the central and northern mountains, northern foothills, into SW VA, confidence should be tempered IMO for a big event.  I post the snow maps like others, but I feel a little slimy doing it because heavy support for cold temperatures isn't there....and those maps are much heavier with snow than they should be along the edges.  Wonder if anyone has the Eurowx site access...seems like they used to have much more tempered snow maps, etc.

Thank you voice of reason...

[burrel2]

Just now, griteater said:

Just think, we have basically 48 hours of modeling left....that's an eternity for how things can change.  We have a system that is going to bring a lot of warmth and juice out of the gulf into an airmass that is marginal aloft overall.  Outside of the central and northern mountains, northern foothills, into SW VA, confidence should be tempered IMO for a big event.  I post the snow maps like others, but I feel a little slimy doing it because heavy support for cold temperatures isn't there....and those maps are much heavier with snow than they should be along the edges.  Wonder if anyone has the Eurowx site access...seems like they used to have much more tempered snow maps, etc.

Absolutely.  I don't think anyone stays snow for the whole storm outside of the mountains and maybe the northern foothills.  I would guess 6 to 10 inch amounts in the foothills to greensboro, with one to two feet totals confined to the mountains.

The snow maps,(IMO), are an excellent tool for tracking trends in the models, not so much for showing where snow will actually fall. 

[sarcean]

when does the 3K NAM window come into play? isn't it suppose to be quite accurate sniffing our precip types

[kelani]

8 minutes ago, BooneWX said:

I’ll take a stab at this one. Growing up in Mount Airy, I always had the same question, because you’d frequently see the same thing modeled for that area. I believe (and someone with a legit background feel free to correct me), the models always try to predict lee side sinking. I’ve found that in these particular systems, coming up from the south, it rarely happens. Usually I just ignore the hole’s. 

Thanks for the reply. That would make sense.  I also tend to ignore the holes (and always did when I lived in Charlotte, Cary, Wilmington, and Wilkesboro), but those holes actually seem to happen here for pretty much every storm from any direction --albeit less so for these southern storms.  No matter whether it's a line of thunderstorms or snow, there always seems to be a 5-10-mile wide swath across central Caldwell that receives far less precip than the surrounding areas.  The last time it didn't happen that I can recall was 1993.  It's an odd thing, for sure. 

[GunBlade]

Kind of reminds me of the Feb 2014 storm we got.  We got nailed with snow from the get go, had wonderful rates and quickly accumulated maybe 4-6”.  But the WAA turned the last few hours into a sleet fest. Really killed the totals we could’ve had here.  Good thing is having lots of snow then sleet didn’t cause the issues like sleet alone would or had it been freezing rain on top of everything.

But like most have said, the transition line almost always sets up around this area, especially with strong systems like this one as the WAA is rarely modeled correctly.  From past storms, the models seem to get a decent idea around 1-2 days out (especially the NAM) of the WAA and transition area but the subsequent runs seem to slowly erode away the WAA and increase QPF and give back hope of big totals.  Only to be smashed once the storms over.  By the time we get close enough to the HRRR etc...being used and they start showing the WAA, ppl then want to assume those models aren’t correct based on the prior global runs not showing it  

I would not disregard any model(s) that start to push that snow line west over the next cpl days, if it happens, as much as I want to bury my head and pretend I don’t see it on the models either. 

I know the info above isn’t very technical in nature, just experience from seeing these storms and models year after year. 

[frazdaddy]

3 minutes ago, sarcean said:

when does the 3K NAM window come into play? isn't it suppose to be quite accurate sniffing our precip types

3K goes out to 60 hrs

[CentralNC]

2 minutes ago, GunBlade said:

Kind of reminds me of the Feb 2014 storm we got.  We got nailed with snow from the get go, had wonderful rates and quickly accumulated maybe 4-6”.  But the WAA turned the last few hours into a sleet fest. Really killed the totals we could’ve had here.  Good thing is having lots of snow then sleet didn’t cause the issues like sleet alone would or had it been freezing rain on top of everything.

But like most have said, the transition line almost always sets up around this area, especially with strong systems like this one as the WAA is rarely modeled correctly.  From past storms, the models seem to get a decent idea around 1-2 days out (especially the NAM) of the WAA and transition area but the subsequent runs seem to slowly erode away the WAA and increase QPF and give back hope of big totals.  Only to be smashed once the storms over.  By the time we get close enough to the HRRR etc...being used and they start showing the WAA, ppl then want to assume those models aren’t correct based on the prior global runs not showing it  

I would not disregard any model(s) that start to push that snow line west over the next cpl days, if it happens, as much as I want to bury my head and pretend I don’t see it on the models either. 

I know the info above isn’t very technical in nature, just experience from seeing these storms and models year after year. 

That deform band with that storm was the heaviest snow I have seen in 28 years at my current location.

[Solak]

RAH:

Sat through Mon night: A significant wintertime storm for NC is 
growing more likely with every model run. Differences among the 
models regarding timing, track, precip amounts, and the vertical 
thermal structure and advection patterns persist, which makes any 
details still difficult to pin down. But the chance of at least some 
wintry precip over the central NC forecast area with this event is 
growing. 

-Synopsis: A potent mid-upper trough/low will cross the S Plains, 
Gulf States, and Southeast during this period, as a surface low 
tracks along the Gulf coast/S GA/FL Panhandle, likely evolving into 
a Miller B configuration as this energy transfers to a deepening low 
just off the Carolinas late Sun. This low should then intensify as 
it tracks NE just off the NC coast through Mon. A second, strong 
polar stream wave will dive through the Midwest Sat night through 
Sun night and into the southern stream wave, prolonging the lift 
over central NC as the column cools further. 

-Timing: Following the slower ECMWF/Canadian/NAM solution over the 
faster GFS, the heaviest precip is expected to fall from early 
morning to late afternoon on Sun, in conjunction with strong upper 
divergence and mid level DPVA. After this time, drying aloft and 
waning forcing for ascent should mean a trend to lower precip rates. 

-Ptype: Still appears to be mostly a rain event through Sun in areas 
from the Triangle to the S and E, albeit with a little wintry precip 
early in the event. For areas N and W of the Triangle, including the 
Triad and most VA border counties, a wintry mix with some 
accumulation is expected for most of the event through Sun, although 
we may see a trend to mostly cold rain Sun afternoon. Some low level 
drying is expected by Mon, but decent moisture and lift in the -12C 
to -18C depth should result in a secondary chance of some light snow 
or a wintry mix associated with the polar wave. It's too early for 
specific amounts, but an inch or two is not out of the question in 
the Triad region, with a non-zero chance of greater amounts. This 
could change, however, especially given the sensitivity of precip 
types to small changes in thermal structure and lift, so stay tuned.

-Temps: Expect highs in the upper 30s to mid 40s Sat and Mon, with 
low 30s to upper 40s on Sun. Again, this is all predicated on 
getting enough warm air into central NC to allow surface temps to 
trend above freezing over the forecast area. Lows in the 30s.

[Shane]

21 minutes ago, Pilotwx said:

I'M with ya as well I  call it,  Mountain Shadow effect.

That hole from MT Airy to GSO up to Roanoke seems to set up when a low transfers to the coast