December 8-10, 2018 Winter Storm

[CentralNC]

Just now, PackWxMan said:

GSP busting big on this one. CLT is not getting a foot. It’s Thursday and 12in on Sunday/Monday is being tossed around ?!?

Not sure I agree or not but this time GSP seems a little too overconfident and RAH underconfident.

[Cold Rain]

1 minute ago, Brick Tamland said:

 

Okay, so where is the info that shows they could be wrong? What is the other info that RAH is basing their forecast on right now?

You will know they are wrong when ice is forming on the trees in your yard.

[DopplerWx]

1 minute ago, Brick Tamland said:

 

Okay, so where is the info that shows they could be wrong? What is the other info that RAH is basing their forecast on right now?

just go look through the soundings for clt and rdu over the past 3-4 runs and the trend will be evident.  in our locations you just can't hang your hat on a razor thin snow sounding, because it hardly (if ever) works out for us.

[FallsLake]

6 minutes ago, Brick Tamland said:

It been is just hard for me to ignore the consistency and agreement with the various models. I know what has happened in the past, but we also don't usually have this much consistency and agreement with the models. They would all have to be wrong or start to do a complete 180 now.

Not sure if it was last year or the year before that, we had a storm modeled with high amounts throughout the Triangle (and down east). The models failed to see the warm nose and many folks SE of our location saw a lot of rain mixture. The NAM did see this late in the game but most folks ignored it. **I think we need to pay more attention to the short term models from this point on. 

[Cornsnow]

1 minute ago, Brick Tamland said:

 

Okay, so where is the info that shows they could be wrong? What is the other info that RAH is basing their forecast on right now?

I think at this point you have to look at climatology and the past storms and I am sure that is what they are doing. There are many more cases of a warm nose busting these model totals than there are of them actually verifying. Not saying it cannot happen but they are just being ultra conservative probably from past experiences.

[BlueRidgeFolklore]

6 minutes ago, GunBlade said:

I have seen it a few times but not often.  Nice thing is they aren’t pressured in a news room environment so they can put out what models show (conservatively still).  Difference here is normally we don’t have so much model agreement so early.  The storms normally gone until the day before.  GSP is always on top of storms though and not afraid to show the possibilities.  Always big kudos to them. 

They were bullish for WNC in January 2016 storm but even then the totals crept up as we got closer. I don't think it's wishcasting to say these totals will go up when the Euro is showing 12" probabilities for KAVL at 100%. My gut just tells me based off experience, that these (for the Mountains only) are their conservative numbers.

[Amos83]

1 minute ago, PackWxMan said:

GSP busting big on this one. CLT is not getting a foot. It’s Thursday and 12in on Sunday/Monday is being tossed around ?!?

you seem pretty confident in that. As unlikely as it may seem I think they are honking the horn to grab the general public's attention that a potentially serious winter storm is headed this way. If they are wrong and it ends up being more ice the public will hopefully still be prepared. People tend to understand the seriousness of large snow accums better than ice accrual forecasts in my opinion. just my two cents

[Justicebork]

As per usual, Wake and Mecklenburg Counties are your battlefields.  Any forecaster who is bullish or bearish on either metro area is putting up a front.

[BlueRidgeFolklore]

5 minutes ago, McDowell_Weather said:

The mix line will be closer to hwy 64 imho guna be a sleetfest for elevations below 2500 feet.

I'm going with 2000', right along the escarpment.

[McDowell_Weather]

Just now, burrel2 said:

06z CMC trended the mix line further south in to the upstate Sunday morning compared to 00z. Still has mostly sleet/zr all the way to the nc/va border though.

Need stronger hp this is why i haven't jumped on those big totals feb 2014 was a lesson learned this storm reminds me alot of it got 3in of sleet ughh. Until the nam trends colder my expectations are in check like the ole vern gosdin song this aint my first rodeo lol

[QC_Halo]

14 minutes ago, Queencitywx said:

I think 485 is going to be the dividing line, again. Maybe up to 73. 

Lol...485 is a loop. I’m inside it.

[Cornsnow]

Just now, QC_Halo said:

Lol...485 is a loop. I’m inside it.

Probably means the north side just south of Huntersville....

[BullCityWx]

4 minutes ago, QC_Halo said:

Lol...485 is a loop. I’m inside it.

and the dividing line is either going to be the south or north end of it. Just not clear on which side. 

[McDowell_Weather]

I guess well see but im along the escapement and im worried about mixing if i was south of 40 id be buying a generator....

[Brick Tamland]

7 minutes ago, Cornsnow said:

I think at this point you have to look at climatology and the past storms and I am sure that is what they are doing. There are many more cases of a warm nose busting these model totals than there are of them actually verifying. Not saying it cannot happen but they are just being ultra conservative probably from past experiences.

That is what I was wondering, if it was based on any other data they have right now, or if it is just based on what has happened in the past. 

[Shane]

Since we're in Storm Mode, can posters be more specific about what geography they are referring to when making observations? It's a big storm. "The foothills and mountains" can be anywhere from NE Georgia to Northern Virginia. On some devices, your avatars are not visible, so it's hard to decipher where you're from and where you're talking about. Also, some are more interested in a meta view of the whole event, not just what's happening in your town.

Kthxbai

[FallsLake]

6z NAM freezing rain. And this only goes to hr 84. Lots of precip still occurring and I would think this ice would move up towards central/east NC.

 

[frazdaddy]

9 minutes ago, Brick Tamland said:

 

Okay, so where is the info that shows they could be wrong? What is the other info that RAH is basing their forecast on right now? What other data are they using besides the fact storms as big as the models are showing are rare here?

Brick, remember we are still looking at virtual reality here. A shift in the low track or the WAA that folks have mentioned are very real possibilities. We all want the snow or we wouldn't be here. The reality is there are still things that can keep big accumulation numbers from happening.

[SnowNiner]

21 minutes ago, Wow said:

All GEFS members in general agreement.. 

I don't recall ever having an ensemble suite ALL show a double digit snowfall totals in MBY.  It's always hits/misses.  This is crazy.  I see the EURO/UKMET/FV3/GFS with huge totals, but then there's the latest NAM, with the sleet fest for the southern piedmont.  That's my concern at this point.  Was hoping that the NAM would show a colder solution, not a warmer one in comparison with the global models.  It makes me think the larger scale models may be off.  

However it's the 84 NAM, I know...but I'll be watching that trend today for sure. It is encouraging that the NWS seems to be going with the Miller A pattern for this storm, and specifically call out that the warm nose should be muted, or cool.  

[Cornsnow]

Just now, Brick Tamland said:

That is what I was wondering, if it was based on any other data they have right now, or if it is just based on what has happened in the past. 

Past storms for sure. In our area knowing the past climatology plays a big role in forecasting. Not just spitting out what a model reads. Just go back and look at the Jan 2017 storm.

[QC_Halo]

2 minutes ago, Queencitywx said:

and the dividing line is either going to be the south or north end of it. Just not clear on which side. 

Ballantyne it is...haha. 

Probably a pretty good guess. 

[BullCityWx]

1 minute ago, QC_Halo said:

Ballantyne it is...haha. 

Probably a pretty good guess. 

Ye olde town trash dump is probably a good divding line. 

[ajr]

I went through the big Jan 2017 bust thread, and recurring theme was keep an eye on the NAM and then HRRR for temp profiles... globals don’t have the resolution to sort out in detail factors like CAD.

[frazdaddy]

12z NAM running now

[DopplerWx]

3 minutes ago, ajr said:

I went through the big Jan 2017 bust thread, and recurring theme was keep an eye on the NAM and then HRRR for temp profiles... globals don’t have the resolution to sort out in details factors like CAD.

and that one had the snow line much farther south this far out than this one.  even the day before it had the snow line down into upper sc.  

[Jet Stream Rider]

Our wave just now slowly crawling onshore southern California. The event could be 2 or 3 more-or-less separate periods of precip from Sunday - Tuesday as we get overrunning out ahead of this wave and the slp that will develop ahead of it as well.

https://www.tropicaltidbits.com/sat/satlooper.php?region=atlpac-wide&product=wv-mid

[frazdaddy]

1 minute ago, DopplerWx said:

and that one had the snow line much farther south this far out than this one.  even the day before it had the snow line down into upper sc.  

Agreed, The only difference I remember in that storm was the globals were not near as close in agreement.

[Cornsnow]

Just now, Jet Stream Rider said:

Our wave just now slowly crawling onshore southern California. The event could be 2 or 3 more-or-less separate periods of precip from Sunday - Tuesday as we get overrunning out ahead of this wave and the slp that will develop ahead of it as well.

https://www.tropicaltidbits.com/sat/satlooper.php?region=atlpac-wide&product=wv-mid

I think tonight's and tomorrow mornings runs will be key here. Pieces finally starting to get sampled.

[griteater]

1 hour ago, Queencitywx said:

Looks like steady as she goes on the off hour euro. 

06z Euro ticked south again at 500mb.  Classic slider look.  And it's bringing the backside wave in better as well.  The thing I can't shake here are the mid level temperatures.  One would argue that the models will correct as we get closer and show more cooling on the NW side of the 850mb low track as the cooling from strong ascent offsets warm advection...that's normally how it works...but which one wins the battle, the strong dynamics and cooling that are almost certain to be there, vs. the marginal cold pre-storm airmass.

On the topic of the mid-level drying in the soundings, if you look at relative humidity charts at the 500-600mb levels, you can see the drying (dry slot) working in, but it's obviously after a strong thump on the front side of the storm (think heavy rates).  I will also say that the precip is almost certain to be expanded farther north than what the current QPF shows, especially given how this is going to get wound up into a comma head....so, still looks good to me in SW VA for example.

[BornAgain13]

1 minute ago, griteater said:

06z Euro ticked south again at 500mb.  Classic slider look.  And it's bringing the backside wave in better as well.  The thing I can shake here are the mid level temperatures.  One would argue that the models will correct as we get closer and show more cooling on the NW side of the 850mb low track as strong ascent offsets warm advection...that's normally how it works...but which one wins the battle, the strong dynamics and cooling that are almost certain to be there, vs. the marginal cold pre-storm airmass.

On the topic of the mid-level drying in the soundings, if you look at relative humidity charts at the 500-600mb levels, you can see the drying (dry slot) working in, but it's obviously after a strong thump on the front side of the storm (think heavy rates).  I will also say that the precip is almost certain to be expanded farther north than what the current QPF shows, especially given how this is going to get wound up into a comma head....so, still looks good to me in SW VA for example.

If you keep saying the Euro ticks south each time you do a PBP, it's going to tick all the snow down into Florida lol