December 8-10, 2018 Winter Storm

[nwupstatewx]

9 minutes ago, drfranklin said:

interesting, I'm at 38.5/37 - temp very dependent on rates - 2 miles north of I-85 near DT Greenville - mixing occurs with higher precip rates - precip lightens and the temp can rise 1/2 degree and mixing stops

I can also verify this - 5-6 miles NNW of I-85 in the Upstate west of GVL the way the crow flies, sitting at 37 and mixing when precip gets heavy, all rain when it lightens up.  It is trying...

[Poimen]

Top image is the last frame from the most recent HRRR at 700mb. You can see the warm nose very clearly. Bottom image is from the 12Z NAM at the same time. Both models have it, but the NAM is more pronounced. 

 

[Cornsnow]

Is this really any different than any other storm. We really do not know. It is rinse and repeat. Eroding CAD, rain/snow/sleet/ice line setting up somewhere along the 85 corridor. Climatology always wins here except for every once a decade it seems. It all depends on the track of the low and strength of the CAD and we really do not know how it sets up until go time!

[Poimen]

Same as above, this time at 850mb: 

 

[PackWxMan]

12 minutes ago, ryan1234 said:

"If you haven't prepared for this winter storm, your window is closing rapidly. Driving will be dangerous AT LEAST tonight through tomorrow PM and many folks will lose power. A bunch of us at the office at GSP are even planning to sleep here tonight. This is one to take seriously."

 

This just came in from GSP's Facebook page. Despite some of the newer globals, I am not quite ready to call this a "bust" yet and go cliff diving. Yet, it seems like a lot of you have already jumped and are plummeting to the ground.  

Nobody is “jumping off a cliff” - people are consuming the data. Right now it follows what most expected. A warm nose eroding cad. 

 

 

[NC_hailstorm]

Right now I'd say the Euro and the FV3 look pretty close with the cutoff line somewhere along highway 73 in the southern piedmont of NC.

Sleet will probably mix in everywhere time to time with warm pockets coming through but more south of there.

Carry on.

 

[blueheronNC]

18 minutes ago, Cornsnow said:

Is this really any different than any other storm. We really do not know. It is rinse and repeat. Eroding CAD, rain/snow/sleet/ice line setting up somewhere along the 85 corridor. Climatology always wins here except for every once a decade it seems. It all depends on the track of the low and strength of the CAD and we really do not know how it sets up until go time!

Pretty much this.  I’d say it’s classic climatology with a few things working AGAINST it.  Source air region isn’t that cold.  Antecedent in situ air isn’t that dry (dewpoints in the 20s, not 0s/teens).  Early season warmer inshore waters promoting closer-in energy handoff and coastal low track (watch Southport, NC climb into the 60s during the event as the low passes nearshore). 

[Cornsnow]

Just now, blueheronNC said:

Pretty much this.  I’d sat it’s classic climatology with a few things working AGAINST it.  Source air region isn’t that cold.  Antecedent in situ air isn’t that dry (dewpoints in the 20s, not 0s/teens).  Early season warmer inshore waters promoting closer-in energy handoff and coastal low track (watch Southport, NC climb into the 60s during the event as the low passes nearshore). 

Still not completely over. We really do not know what the complete outcome will be. Sure if you are further south on the normal battleground it could be worse but there is no guarantee. We still need to see how it plays out. I would not be surprised either way at this point.

[PackWxMan]

1 minute ago, Cornsnow said:

Still not completely over. We really do not know what the complete outcome will be. Sure if you are further south on the normal battleground it could be worse but there is no guarantee. We still need to see how it plays out. I would not be surprised either way at this point.

The HRRR is holding on - its historically good with eroding CAD on model verification scores. It's still looking good. 

However, there is a 50+KT SWly jet aloft, that doesn't bode well. 

[Poimen]

The RAP...FWIW...through 15Z tomorrow has nearly 1" qpf in the Triad, all of which should be snow per model soundings. It does have the 700 and 850 mb warm nose, but it keeps it confined to the SW Mountains, over to Charlotte, and then NE toward the Triangle.

[insipidlight]

Yes. 56"

[beanskip]

Anybody have the Kuchera maps for Euro? 

[insipidlight]

Mmmmm yes totally

[Brick Tamland]

41 minutes ago, SnowNiner said:

HRRR still looks good.  For some reason in my mind, it's always been the harbinger of the dreaded warm nose, not the NAM.  I'm happy it's on my side.  We'll see. 

 

41 minutes ago, GunBlade said:

17z HRRR holding on to keeping rain much further south. 

It does look great. I am sure there will be ice mixed in, but I think the majority of the models are showing a good hit of snow before changing to ice up my way. I'll take the majority instead of seeking out the one or two that show the worst case scenario.

[Nraleigh]

[Brick Tamland]

RAP looks good, too.

[CaryWx]

Is that forecast call taking in the 12z suite?

[Nraleigh]

Just now, CaryWx said:

Is that forecast call taking in the 12z suite?

I believe so because he had an earlier post referencing the 12z.

[GunBlade]

18z HRRR still bringing the goods.  LOTS of mixing but holding strong with colder air out to 21. 

[superjames1992]

1 hour ago, Poimen said:

Bet it was the 700mb temps on the EURO. 

 

1 hour ago, Blue_Ridge_Escarpment said:

 

Probably 750 mb or so, assuming it's on the same wavelength as some of the other modeling.  There's not any good (public) charts at that level aside from soundings, though, generally.  But the WB and SV clown maps won't pick up on this and show it as snow.

On the flip side, I wouldn't be surprised if BL temps verify colder than predicted as CAD at ground level often takes longer to erode than expected.

[BIG FROSTY]

49 minutes ago, Cold Rain said:

At this point, I’m just hoping for some sleet.

I really hope you get in of some form of winter precip!! You contribute a lot to the board and I appreciate it. So I'm pulling for to get some sleet maybe a touch of snow?!! 

[Poimen]

Literally, the 18Z HRRR is snow from the Triad to RDU from roughly 1am to 10am. After 10, it transitions to sleet at RDU before rain around noon. It does bring sleet into the Triad by 11-noon,but by then 12 or more inches of snow has fallen. 

[Brick Tamland]

1 minute ago, Poimen said:

Literally, the 18Z HRRR is snow from the Triad to RDU from roughly 1am to 10am. After 10, it transitions to sleet at RDU before rain around noon. It does bring sleet into the Triad by 11-noon,but by then 12 or more inches of snow has fallen. 

So, maybe 1 to 2 less hours of snow here. That does not sound bad at all if the Triad gets a foot.

[PackWxMan]

FWIW

[beanskip]

Just now, PackWxMan said:

FWIW

Can’t see model name??

[Wow]

18z HRRR :  Thru noon Sunday.. 12" line up to I-77, N of 85

[CaryWx]

4 minutes ago, Brick Tamland said:

So, maybe 1 to 2 less hours of snow here. That does not sound bad at all if the Triad gets a foot.

Keep in mind the HRRR because of the rapidity of its cycle, it's discovery can be progressive.   Let's hope it holds where it is.

[ryan1234]

I would gladly take 7-8 inches, on top of what I'm assuming will be an IP or ZR mix.

[WidreMann]

18z NAM is coming in warmer and further north.

[Cornsnow]

1 minute ago, WidreMann said:

18z NAM is coming in warmer and further north.

When do we start using much shorter range models like the HRRR, RAP and others? I thought lots of models like the NAM, GFS, Euro are not as accurate when you are literally inside 12 hours or less from go time?