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Wintry Dec 8-10th Winter Storm

Hard to believe that the set up shown is still not quite going to be cold enough...I guess early December is early December. Hopefully this afternoon things will be get more suppressed and colder. If not, this one may be slipping away.
Yeah it's a fine line. Need a strong hp and low dewpoints to keep that cold air locked in.
 
Hard to believe that the set up shown is still not quite going to be cold enough...I guess early December is early December. Hopefully this afternoon things will be get more suppressed and colder. If not, this one may be slipping away.

I don't see anything slipping away on the models yet for NC. If anything, they have gotten better the last two days.
 
If the trends don’t look better tmrw or Wednesday then I’ll be worried. My gut tells me GA shouldn’t be worried
Georgia shouldn't be worried if they are expecting a cold rain in most places. Expecting freezing or frozen at this point is not realistic unless you are in the NE section (north of Gainesville). We may have some flooding issues to address. We've had close to 3" of rain widespread. This one looks like another shot at 2" or so.
 
Just to give people an idea on how much things can change over the course of 2-3 days, the clipper moving through Wednesday is a good example.

Here's the GFS 138 hours out for the clipper system, notice the 528dm line is up in VA with a nice low off the coast.
gfs_mslp_pcpn_frzn_us_23.png


Now 60 hours out here is the setup. Notice the 528dm line actually pushed into northern NC and overall things are a bit colder and there is no strong LP off the coast at this same time. This goes to show how much things can change in just a few days and why no one should be accepting one model solution or set of runs this far out.
gfs_mslp_pcpn_frzn_us_10.png
 
Georgia shouldn't be worried if they are expecting a cold rain in most places. Expecting freezing or frozen at this point is not realistic unless you are in the NE section (north of Gainesville). We may have some flooding issues to address. We've had close to 3" of rain widespread. This one looks like another shot at 2" or so.
I still don’t know about that the FV3 pushed frozen precip nicely into GA. The Euro 12z and last nights gefs theirs still to many cards in the table
 
I know it's the NAM and pretty far out but it is worth noting that it has the energy entering California a bit weaker than the GFS and slightly further south as well. A weaker and further south system would be beneficial for snow across the SE. I always like to see them enter around the upper Baja and that's what the NAM is showing.
nam_z500_vort_us_29.png


gfs_z500_vort_us_16.png
 
An interesting tidbit from one of the most respected posters on AW, donsutherland1:

The best match for the forecast 500 mb height anomalies is the December 2-3, 1896 snowstorm.

The following snowstorms dumped 6" or more snow at Raleigh prior to December 20:

December 2-3, 1896: 7.5"
December 12-13, 1917: 7.1"
December 17, 1930: 7.0"
December 11, 1958: 9.1"

Snowfall for select cities from those storms was as follows:

December 2-3, 1896:
Greenville-Spartanburg, SC: 10.5"
New York City: None
Philadelphia: None
Washington, DC: None
 
I don't see anything slipping away on the models yet for NC. If anything, they have gotten better the last two days.
Yeah, at this time, there aren't really any trends. There are oscillations. There are several key features that have the potential to interact in various ways. We've seen some favorable interactions (depending on where you are), and we've seen some unfavorable scenarios (also depending on where you are). Observe output over the next 3 days to determine legitimate trends. We'll be getting into the window where data is better sampled, model skill goes up, and trends will show themselves more reliably.

My guess, based on time of year, availability of cold air, and complexity of the setup is that the best chance for snow will be over the mountains and foothills into western VA and down into NW SC. I favor more of a mixy, icy scenario into the upstate of SC through the Triad of NC and potentially into central VA. The Triangle and down into north-central SC are in the game for some snow/mix before changing to rain cold. That is my favored scenario, but of course it is not set in stone.

We will need to see models lock into a strong high building in ahead of or in tandem with the storm (and not hauling arse OTS), the storm not getting too amped (we don't want early Miller B-ing or Apps Rubbering), and the storm not moving up the coast (at least not along the immediate coastline), if we want the more wintry scenarios farther south and east to pan out. This will be the harder road, but it is doable. Pay attention to how the models and ensembles trend over the next 3 days -- not 2 runs in a row, but over the longer period.
 
Our wave is verifying weaker than progged in the Pacific . Pretty good placement/position on the NAM but it's been constantly playing catch up with regards to strength.

nam-z500-vort-namer-fh0-trend.gif

nam-mslp-uv850-namer-fh0-trend-1.gif

That's certainly good news in the long run if you're hoping for a weaker/flatter wave to traverse across the southern tier of the country, again worth re-iterating that the strength of the s/w and its forward movement are intrinsically linked, a less meridional extensive, and weaker wave will propagate more quickly towards the east
 
I don't see anything slipping away on the models yet for NC. If anything, they have gotten better the last two days.
I don't think I'd say it's slipping away just yet, it is concerning to be in best possible position 5-6 days out and Grits comments don't help.... he knows his stuff and he even states it could change but right now some of the trends are in the wrong direction. Not jumping ship, not complaining just toss out the possibility

I didn’t think it was that bad


Sent from my iPhone using Tapatalk

His write up? Or the models overnight? His words aren't doom and gloom necessarily but they do cause pause...
 
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Ultimately what we want here in the SE is a bit of a weaker wave coming onshore that stays suppressed and keeps the 850 low south. We also want the confluence over the NE US to hold our HP in place. I wouldn't start taking model solutions, whether rain or wintry, seriously until 12z Wednesday.
 
An interesting tidbit from one of the most respected posters on AW, donsutherland1:

The best match for the forecast 500 mb height anomalies is the December 2-3, 1896 snowstorm.

The following snowstorms dumped 6" or more snow at Raleigh prior to December 20:

December 2-3, 1896: 7.5"
December 12-13, 1917: 7.1"
December 17, 1930: 7.0"
December 11, 1958: 9.1"

Snowfall for select cities from those storms was as follows:

December 2-3, 1896:
Greenville-Spartanburg, SC: 10.5"
New York City: None
Philadelphia: None
Washington, DC: None

Nice, I'd take just about all of these storms.
December 2-3 1896 NC Snowmap.png

December 12-13 1917 NC Snowmap.png
December 15-18 1930 NC Snowmap.png
December 11-12 1958 NC Snowmap.png
 
Yeah, at this time, there aren't really any trends. There are oscillations. There are several key features that have the potential to interact in various ways. We've seen some favorable interactions (depending on where you are), and we've seen some unfavorable scenarios (also depending on where you are). Observe output over the next 3 days to determine legitimate trends. We'll be getting into the window where data is better sampled, model skill goes up, and trends will show themselves more reliably.

My guess, based on time of year, availability of cold air, and complexity of the setup is that the best chance for snow will be over the mountains and foothills into western VA and down into NW SC. I favor more of a mixy, icy scenario into the upstate of SC through the Triad of NC and potentially into central VA. The Triangle and down into north-central SC are in the game for some snow/mix before changing to rain cold. That is my favored scenario, but of course it is not set in stone.

We will need to see models lock into a strong high building in ahead of or in tandem with the storm (and not hauling arse OTS), the storm not getting too amped (we don't want early Miller B-ing or Apps Rubbering), and the storm not moving up the coast (at least not along the immediate coastline), if we want the more wintry scenarios farther south and east to pan out. This will be the harder road, but it is doable. Pay attention to how the models and ensembles trend over the next 3 days -- not 2 runs in a row, but over the longer period.

Well, if you go back a few days, the GFS and FV3 have shown the big storm before that they are showing now for NC. So, it really isn't just the last two days. I think the Euro even showed it once or twice a few days back, too.
 
Yeah, at this time, there aren't really any trends. There are oscillations. There are several key features that have the potential to interact in various ways. We've seen some favorable interactions (depending on where you are), and we've seen some unfavorable scenarios (also depending on where you are). Observe output over the next 3 days to determine legitimate trends. We'll be getting into the window where data is better sampled, model skill goes up, and trends will show themselves more reliably.

My guess, based on time of year, availability of cold air, and complexity of the setup is that the best chance for snow will be over the mountains and foothills into western VA and down into NW SC. I favor more of a mixy, icy scenario into the upstate of SC through the Triad of NC and potentially into central VA. The Triangle and down into north-central SC are in the game for some snow/mix before changing to rain cold. That is my favored scenario, but of course it is not set in stone.

We will need to see models lock into a strong high building in ahead of or in tandem with the storm (and not hauling arse OTS), the storm not getting too amped (we don't want early Miller B-ing or Apps Rubbering), and the storm not moving up the coast (at least not along the immediate coastline), if we want the more wintry scenarios farther south and east to pan out. This will be the harder road, but it is doable. Pay attention to how the models and ensembles trend over the next 3 days -- not 2 runs in a row, but over the longer period.
I like your assessment very well and most likely scenario imo, I just think some have been seeing these insane absurd clown maps and will be let down if we don't get anything close to that
 
Need more ns confluence. It’s imperative we avoid amplification with our southern wave in order to keep it suppressed. If this trend continues at 12z, abandon ship. I sure hope the 06z FV3 is the correct solution

00z GEFS72D36425-24F1-4EC4-942E-3C728A96B4ED.png

06z GEFS
B25CA8D3-D3BF-4228-98BC-C79C664AD122.png
 
WPC probabilities for exceeding 0.25" of liquid equivalent snow & sleet are fairly realistic imo particularly for CAD favored areas of the Carolinas and far NE GA.
Anywhere at least in the deeper green & blue (>30%) can feel some solace in that it's probable some form of wintry precipitation (whether that be snow, sleet, or freezing rain and/or a combination of these) will at least fall from the sky during this storm. Anywhere within and near the light green is still easily in the hunt and should continue monitoring esp considering we still have several days to go.

Screen Shot 2018-12-03 at 10.04.07 AM.png
 
FFC:
LONG TERM /Tuesday Night through Sunday/...
The main concern in the long term is some potential for a winter
mix over far n GA Friday night into Sunday.

Models are rather consistent with developing a Gulf Coast low
pressure system that will spread deep moisture over the area
with a wet period in store starting Friday night and continuing
into Sunday.

The overall question will be is how cold is the airmass as surface
high pressure noses down the eastern Appalachians and the low pressure
system passes to the south. The lowest forecast temperatures are in
the critical range where a mix of freezing rain, sleet and snow
can not be ruled out over mainly portions of the GA mountains,
where otherwise a cold rain can be expected. This will be a watch and
monitor to see how the entire system develops or is forecast to develop
with future model runs.
 
Dec 2002 sure looks similar to this potential. Upper low ejects from the south west, miller b, cad, snow/ice.
2002120418.gif

GZ_PN_144_0000.gif
 
WPC probabilities for exceeding 0.25" of liquid equivalent snow & sleet are fairly realistic imo particularly for CAD favored areas of the Carolinas and far NE GA.
Anywhere at least in the deeper green & blue (>30%) can feel some solace in that it's probable some form of wintry precipitation (whether that be snow, sleet, or freezing rain and/or a combination of these) will at least fall from the sky during this storm. Anywhere within and near the light green is still easily in the hunt and should continue monitoring esp considering we still have several days to go.

View attachment 8089
Yeh I am a little surprised they moved the light green more South into SC considering the overnight models.
 
This things gonna be a thread the needle no matter where u are the low comes to far north your screwed the high to fast your screwed.
 
Icon is too amp’d. It was looking squashed and then boom it blew up over south Alabama. Not going to cut it
 
I've laughed at the ICON before temp wise, but looking at them, it's a flat out "no" outside of far North NC for anything wintry (and Arkansas on the back end).
 
Icon is too amp’d. It was looking squashed and then boom it blew up over south Alabama. Not going to cut it
I thought it looked better than previous runs, track along southern gulf and over SAV. Probably a big ice storm with that track even though it's showing rain. Does give snow with the 2nd wave that comes through.
 
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