December 8-10, 2018 Winter Storm

[Buddy1987]

Just now, SimeonNC said:

Rock Hill, Ballantyne, Pineville, etc. all get clobbered with ice. 

Ice is def nuts this go around down that way. Stay safe if it comes to fruition.

[olafminesaw]

Mid levels are significantly better on the 3km NAM in the Triad than the 12km. Impressive banding too.

[packfan98]

The hi-res Nam is much less ominous with the freezing rain.

[CADEffect]

1 minute ago, SimeonNC said:

Rock Hill, Ballantyne, Pineville, etc. all get clobbered with ice. 

GSP just as bad if not worse

[beanskip]

Just now, packfan98 said:

The hi-res Nam is much less ominous with the freezing rain.

The hi-res NAM and the other NAMs need to huddle up and get on the same page!

[Buddy1987]

The low on 3k is jumping around like crazy between hr37-40. I’m guessing it has to do with the convection and dynamics and what not. 

Hr 42 has the low over Tallahassee, whereas 12z had it southeast of MYR

[SnowDeac]

1 minute ago, packfan98 said:

The hi-res Nam is much less ominous with the freezing rain.

 

Must be more in the way of sleet or just plain rain. I assume the former? Do the Kuchera maps account for sleet?

[packfan98]

The hi-res Nam is also more West to East oriented like the Euro.  More friendly to the I-40 corridor than the 12z run.

[sarcean]

2 minutes ago, beanskip said:

The hi-res NAM and the other NAMs need to huddle up and get on the same page!

at this point I would trust the NAM-3k on precip type!

[nchighcountrywx]

I think someone else posted it, but this is what the HRRR does to temperatures mid afternoon Saturday

Reason for concern:  Yes

 

 

 

[ryan1234]

If the NAM keeps showing these ice totals, this area will be a disaster area. However, it's only 1 run and things will continue to change. There is no need for cliff diving or hugging one particular model. That will only cause pain. I am curious to see what the FV3 does for its next run. It has been the most consistent thus far and I wouldn't completely discount those higher snowfall amounts.  

[olafminesaw]

3 minutes ago, Buddy1987 said:

The low on 3k is jumping around like crazy between hr37-40. I’m guessing it has to do with the convection and dynamics and what not. 

It's just the arbitrary point where the absolute center is moving around in the broad area where the center is. Look at the mslp lines, they don't move around much.

[PackGrad05]

Southern Wake looks like it will get blanked...  or less than 1".  I'm just hoping the freezing rain stays away!

[beanskip]

1 minute ago, packfan98 said:

The hi-res Nam is also more West to East oriented like the Euro.  More friendly to the I-40 corridor than the 12z run.

QUestion -- so how do you reconcile these maps in Gaston County, NC? There is no ice AND no snow? All sleet? 

[JoshWeather]

Just now, PackGrad05 said:

Southern Wake looks like it will get blanked...  or less than 1".  I'm just hoping the freezing rain stays away!

Same here in south Charlotte.  Ill be happy with a cold rain at this point

[tamarack]

6 minutes ago, Dunkman said:

Yeah 1.39 ZR = be prepared to not have power for a week. There's going to be an unlucky ice zone it seems, just hope it isn't that large and doesn't last that long.

21 years ago we had 2-3" qpf of ZR with some IP in central Maine, and some folks went 3-4 weeks without power, including the VP of Central Maine Power.  Signs of that disaster are still visible if one knows what to look for.

[lilj4425]

3 minutes ago, nchighcountrywx said:

I think someone else posted it, but this is what the HRRR does to temperatures mid afternoon Saturday

Reason for concern:  Yes

 

 

I would rather have this then 1.39 inches of ZR. Give me 33 and rain. 

[burgertime]

1 minute ago, beanskip said:

QUestion -- so how do you reconcile these maps in Gaston County, NC? There is no ice AND no snow? All sleet? 

3KM is pretty much all sleet for the duration of the storm there so totally possible. 

[Poimen]

4 minutes ago, packfan98 said:

The hi-res Nam is also more West to East oriented like the Euro.  More friendly to the I-40 corridor than the 12z run.

It's a beaut, Clark!

[beanskip]

1 minute ago, burgertime said:

3KM is pretty much all sleet for the duration of the storm there so totally possible. 

Wow 2.2 inches of QPF, all sleet -- that's what, 5-6 inches of sleet? Surely that would be some sort of a record. 

[packfan98]

Well, scratch my earlier freezing rain graphic with the 3k nam.  It got icy over the last few panels.

[mwp1023]

Just now, beanskip said:

Wow 2.2 inches of QPF, all sleet -- that's what, 5-6 inches of sleet? Surely that would be some sort of a record. 

1" of QPF -= 2.5-3" sleet

[SnowDawg]

Pretty big reduction in snow over N GA Mtns. though after a pretty long trend in the other direction. Substantially more ice and sleet. I’d rather miss completely than have anywhere near the ice that 12k NAM put out. Our forests would be devastated with that and the gusty winds expected.

[beanskip]

1 minute ago, mwp1023 said:

1" of QPF -= 2.5-3" sleet

Thanks for confirming my math! Need all the editing I can get!

[wxduncan]

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/... As of 220 PM Friday: Confidence remains high on winter storm reaching peak intensity late Saturday night and Sunday morning, with the 12z guidance cycle having changed little in terms of the general setup for CAD interacting with coastal low pressure. At the start of the period Saturday evening, low-level warm advection will be starting to set up, but not yet having warmed temps in the midlevels. Therefore a relatively straightforward rain-snow split is expected initially, based on sfc temp. Nonetheless, used the Top-Down technique to produce the p-type trends throughout the period. Profiles aloft are already expected to be nearly isothermal, and near 0C, over a fairly deep layer. Slight warming occurs overnight which will introduce enough of a warm nose to permit sleet to mix in by daybreak, if not sooner, across the periphery of the colder air. The deepest forcing and moisture is expected to occur early Sunday, with precip rates peaking to match. For most of western NC this still looks to translate into heavy snow. Even using relatively low SLRs to account for the isothermal profiles, rates meeting or exceeding 2 inches in 3 hours are expected throughout the morning. Sfc temps remain very important as the warm nose continues to strengthen. The raw models, which normally are the best choice during a wedge, mostly depict temperatures staying above freezing in the areas where the warm nose strengthens enough to support a change from snow to sleet or FZRA. So while temps were initially populated with raw values, they were adjusted down closer to wet-bulb temps. While the NAM has trended somewhat warmer at the surface, its warm nose is not nearly as strong as it previously progged. This puts it in line with the GFS/EC/Canadian at the sites where we were able to sample vertical profiles. The consensus still does support the warming later in the day, so the pure-snow area shrinks to the northern NC mtns/Piedmont as we progress through Sunday. Some areas of GA and the Upstate are even expected to warm slightly above freezing, which should result in precip changing over to rain again. The warming is expected to continue into Sunday evening as the sfc low pushes offshore and the wedge weakens a tad--while the pressure pattern reflects less wedging we will still have some weak WAA in place. As previously advertised, precip chances diminish only to the chance range, as a upper-level deformation zone begins to cross the area. The models continue to depict spotty (but appreciable) QPF lasting through Monday, and the GFS/EC both now depict yet another cutoff 500mb low swinging into the Southeast on the heels of the first wave. PoPs decline gradually Monday night but this may eventually prove too fast in light of the trends with that next wave. Heavy snow and/or sleet accumulation is still forecast in our western North Carolina zones north of the Black Mountains and east of the Blue Ridge Escarpment, plus the adjacent SC zones--i.e., the areas that were already in a Winter Storm Watch. Therefore all of these zones will be upgraded to a Winter Storm Warning effective 00z Sunday. We dicussed the possibility of hoisting a Winter Weather Advisory for the rest of the CWFA, given sleet/ice accums that end up below warning criteria, but certainly enough to have impact. However, with the temps aloft and at the sfc being especially critical, even a slight increase in QPF or warming of profiles could result in some of these areas reaching warning criteria on tonight`s forecast package. Thus we will give the next shift the option of upgrading these areas to warning instead of advisory. Even after the current warning expires at noon Monday, an eventual Winter Weather Advisory likely will be needed for some or all of the area on account of poor road conditions likely lingering into Tuesday. &&

[olafminesaw]

When you get heavy freezing rain a good portion doesn't actually accreate. You can cut those totals on those maps by at least half.

[CADEffect]

It’s possible the surface temps are not cooling as fast on 3knam over the upstate SC area. Compared to 32k nam. As mention earlier by another poster. The NAMs need to get on the same page. FAST. 

[ryan1234]

Well, GSP pulled the trigger. Winter Storm Warnings out for most of my area. 

[Buddy1987]

Just now, olafminesaw said:

When you get heavy freezing rain a good portion doesn't actually accreate. You can cut those totals on those maps by at least half.

Yup. Plus to maximize accrual you’d want to have temps in the upper 20s to have it stick to everything. Antecedent conditions will obv help as well with the cold weather of late. 

[mwp1023]

Just now, olafminesaw said:

When you get heavy freezing rain a good portion doesn't actually accreate. You can cut those totals on those maps by at least half.

Freezing rain is awful.  Had to go through one in the late 90's and lost power for three weeks.  Even if you have a wood fireplace, cold showers in January are not fun....