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Orangeburgwx

December 8-10, 2018 Winter Storm

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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...

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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. 

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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. 

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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. 

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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.

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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.

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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

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2 minutes ago, Solak said:

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.

An inch or two in the triad?  Okay...

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2 minutes ago, Solak said:

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.

They favored the GFS on the 3am discussion. Lol. 

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9 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 storm also dropped a few more inches after an ULL passed by us. IIRC there was a colder airmass to our north but might be mistaken. 

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Seriously RAH?  I get you want to be conservative but 1 inch for the triad looks absurd right now.  

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5 minutes ago, Solak said:

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.

Wow, they poo poo'd the whole thing, didn't they? Even for the Triad.  Cold rain trend for the Triad? I'm lost on that one. :blink:

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2 minutes ago, BIG FROSTY said:


Yup, seen it too many times!! I’m right smack in it also.


Sent from my iPad using Tapatalk

That's why I'm rooting for the slider with some English on it versus the miller B hybrid. Boo coastal low transfer

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NAM out to 54...looks a tad bit colder with more artic air coming south in the NE...if that continues over the next few runs that's a good sign. 

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3 minutes ago, PGAWx said:

Seriously RAH?  I get you want to be conservative but 1 inch for the triad looks absurd right now.  

I'm not going to pretend to have a better feel for this than RAH does but I did find it kind of interesting that they opened saying it looked like a significant winter storm and then proceeded to forecast conditions that are very much not significant for the region.

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It's almost like they don't want snow in the forecast

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.
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Here's my final call.  Ignore areas outside of NC.  Just drew a continuous area for symmetry, such that it is.

139145438_FinalCall.jpg.8d2258ea67279a080c8349f575787ad7.jpg

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2 minutes ago, SnowNiner said:

Wow, they poo poo'd the whole thing, didn't they? Even for the Triad.  Cold rain trend for the Triad? I'm lost on that one. :blink:

Maybe we’re being punk’d. Lol. 

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Here's my forecast in Mooresville.  What warm nose? lol.  I don't know I'm sure I'll probably switch over too, but it's nice at this point that NWS says I may not.  We'll see what tomorrow holds....

 

image.png.f71c28a1f13052f641f1e8d66344a7a1.png

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Just now, Cold Rain said:

Here's my final call.  Ignore areas outside of NC.  Just drew a continuous area for symmetry, such that it is.

 

 

But it's still a few days away? :lmao:

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I'm betting this NAM run is gonna look good at the end. It also isn't looking to far off from the other models as well which is a good sign. 

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Well, if we are within 24 hours and the models are about the same as they are now, and it ends up like RAH says, then the technology really needs to be improved with regards to the models. 

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