The snow, sleet, and freezing rain oh my Dec 27-30 thread

[mackerel_sky]

Euro steady as she goes , supressed. Supposedly, was a little better at H5 and still could be good with a few more changes!?

[snowlover91]

1 minute ago, mackerel_sky said:

Euro steady as she goes , supressed. Supposedly, was a little better at H5 and still could be good with a few more changes!?

Euro looked really close but not quite there. 

[Tar Heel Snow]

18z NAM doesn't develop the coastal low like the 12z did, therefore precip is less far inland on the 29th. Maybe it's just wishful thinking, but it seems like it could easily shift back. 

 

EDIT: It does develop the low, but not until a couple frames later.

[snowlover91]

Some winter weather advisories out for Wednesday morning. Looks like .10-.30 qpf across Eastern NC. 

 

... Winter Weather Advisory in effect from 4 am to 3 PM EST
Wednesday... 

* what... freezing rain expected. The ice will result in very
  slippery conditions on sidewalks, roads and bridges, including
  during the morning commute on Wednesday. Total ice accumulations
  of a light glaze are expected with less than an inch of
  snowfall. 

* Where... Martin, Pitt, Washington, Greene, Beaufort and Lenoir 
  counties.

* When... from 4 am to 3 PM EST Wednesday.


Precautionary/preparedness actions... 

A Winter Weather Advisory means that periods of freezing rain
will cause travel difficulties. Be prepared for slippery roads.
Slow down and use caution while driving. The latest Road
conditions for the state you are calling from can be obtained by
calling 5 1 1.

[Stormsfury]

[tramadoc]

AKQ not too impressed with tomorrow's system.

AFD:

A dampening shortwave trough will push across the Ohio Valley this evening, before sliding across the Carolinas on Wednesday. This feature will interact with the aforementioned cold front, spinning up a weak low/coastal front. 12z/26 NAM/CMC/ECMWF each are a bit wetter with the overrunning moisture, with the GFS lagging behind showing little or nothing. However, much of the deep moisture and lift remains just to our SE. Our official QPF has increased slightly over our SE sections, with precipitation expected in the mid to late morning timeframe across far NE NC and coastal SE VA, and pops have been increased to high end chc/likely during this midday time period. Thermal profiles aloft support light snow at the outset across the entire area. However, warmer air just aloft (H8-85) could allow for some light sleet/graupel mixing in before any mixed precipitation turns over to rain by late morning. PoWT grids do indicate a small chance of some freezing rain along (and mainly S) of the Albemarle sound, and accordingly some FZRA mention was considered. However, given very light QPF and the timing, we have stuck with frozen dominant P-type, and hence no winter wx headlines at this time. Should also note that precipitation could turn back to snow briefly by early afternoon in strong CAA before ending, again with little or no accumulation given relatively warm ground and light QPF. Farther N, highs should only rise into the low/mid 30s under a partly to mostly cloudy sky. Have also allowed for a period of flurries over northern tier, mainly north of a FVX-RIC-WAL line. Even in the dry airmass, northern stream shortwave, ongoing strong CAA and strong upper jetmax crossing could be enough to wring out a few light snow showers. HRRR has begun to catch on to this potential, for what it`s worth...so later shifts will be keeping an eye out for this potential early tomorrow morning. Measuring unlikely, so will hold pops out for now.

[Tar Heel Snow]

Unfortunately, it doesn't seem like the NW trend continued on either the 18z NAM or the GFS . It just doesn't want to develop the coastal low at the right time like the previous run. Hopefully the New Years' storm still looks ok! 

[ragtop50]

If anything, the GFS is a little more suppressed but parts of eastern NC are still brushed on the GFS and NAM. 

[CummingGaSnow]

If nothing else, it will be quite interesting to see how cold the temps can get within the wedge and how far S/W the freezing line can push with little if any wet-bulbing taking place. Any guesses? I will say the freezing line gets possibly to the Atlanta airport but most definitely past Gainesville and Athens, likely to PDK. When is the last time that we had a sfc high that is as strong as this one wedging in?

[Tar Heel Snow]

Well, at least the NY storm's low is further south, pushing snow further south as well. (Still good coverage for us RDU folks!)

[buckeyefan1]

1 hour ago, Stormsfury said:

Nobody cares about us coastal peeps       I've got my fingers crossed for a nice glaze on everything. Should make for beautiful pictures    

[Tar Heel Snow]

[Solak]

Since this thread includes the 27th...

We're under a WWA for a 20% chance of zr overnight/Wed morning

...WINTER WEATHER ADVISORY IN EFFECT FROM MIDNIGHT TONIGHT TO
10 AM EST WEDNESDAY...

* WHAT...Light freezing rain is expected. The ice will result in
  very slippery conditions on elevated road surfaces, such as
  bridges and overpasses. These conditions will affect the morning
  commute on Wednesday. Total ice accumulations will be light,
  ranging from a glaze up to perhaps one tenth of an inch.

* WHERE...I-95 corridor of the NC Sandhills and Southern Coastal
  Plain.

* WHEN...From midnight tonight to 10 AM EST Wednesday.

[Solak]

[Orangeburgwx]

why is the GFS being so suppressed 

[BornAgain13]

Looks like we will get exactly our usual, Cold/Dry

[CummingGaSnow]

1 hour ago, Solak said:

Since this thread includes the 27th...

We're under a WWA for a 20% chance of zr overnight/Wed morning

...WINTER WEATHER ADVISORY IN EFFECT FROM MIDNIGHT TONIGHT TO
10 AM EST WEDNESDAY...

* WHAT...Light freezing rain is expected. The ice will result in
  very slippery conditions on elevated road surfaces, such as
  bridges and overpasses. These conditions will affect the morning
  commute on Wednesday. Total ice accumulations will be light,
  ranging from a glaze up to perhaps one tenth of an inch.

* WHERE...I-95 corridor of the NC Sandhills and Southern Coastal
  Plain.

* WHEN...From midnight tonight to 10 AM EST Wednesday.

I have a gut feeling that even us in North GA will get a little something more than they're advertising right now in the morning. NW trend! Right now I'm 40/20, plenty cold/dry if I can wet-bulb enough.

[Hammer]

37/20 here. Hoping it over performs.


. Pro

[Jonathan]

DT posting the German and Swiss models in which he says contain "cutting edge technology" showing some heavy hitters in NC thru 12/29.

Take it for what it's worth, I guess.

 

[Stormsfury]

17 minutes ago, Jonathan said:

DT posting the German and Swiss models in which he says contain "cutting edge technology" showing some heavy hitters in NC thru 12/29.

Take it for what it's worth, I guess.

 

FWIW, the 18z GERMAN (DVD-ICON) also cut totals on QPF considerably across lower SC/East Central GA on this run.  I have been following both for days and this is a case study going on to see how these models verify with all the mayhem ongoing with the usual guidance.   The SWISS VIRGINIA grid is pretty amazing on how it actually picks up on urban heat islands in its temperature schemes. 

[broken024]

Can that even be taken seriously? All other models show nothing CLT to rdu.

[Cold Rain]

34 minutes ago, Stormsfury said:

FWIW, the 18z GERMAN (DVD-ICON) also cut totals on QPF considerably across lower SC/East Central GA on this run.  I have been following both for days and this is a case study going on to see how these models verify with all the mayhem ongoing with the usual guidance.   The SWISS VIRGINIA grid is pretty amazing on how it actually picks up on urban heat islands in its temperature schemes. 

Both of these are about to take a major credibility hit with whatever credibility they had to begin with.  I think the Ironic got one right a year or two ago, and I’ve never seen the Swiss Miss in action.  But it’s going to be hard to believe anything they have to say going forward, when they both finally throw in the towel in a couple of hours.

[snowlover91]

Just now, Cold Rain said:

Both of these are about to take a major credibility hit with whatever credibility they had to begin with.  I think the Ironic got one right a year or two ago, and I’ve never seen the Swiss Miss in action, but it’s going to be hard to believe anything they have to say when both finally throw in the towel in a couple of hours.

FWIW the Swiss one backed down a lot on the 18z run. The Friday system looks just about done but there might be a nice little surprise in Eastern NC tomorrow morning if it’s cold enough for snow. 

[BullCityWx]

On the super analog page, the 96 blizzard was the #2 analog with the pattern given by the GFS, along with the 1988 storm in the top 10

[Stormsfury]

1 hour ago, snowlover91 said:

FWIW the Swiss one backed down a lot on the 18z run. The Friday system looks just about done but there might be a nice little surprise in Eastern NC tomorrow morning if it’s cold enough for snow. 

So did the 18z ICON with amounts especially across lower SC.  The SWISS model is pretty cool with its resolution and picking up urban heat islands but time will tell in a couple of days how right or wrong these are.  

[Rankin5150]

10 hours ago, griteater said:

To go along with what Widre said, processes that produce precipitation mostly occur aloft, above the surface.  The movement of surface highs and lows are also dictated by the flow configuration above the surface.  In a simple view for this 'storm', just look at the direction of the flow at 500mb over the southeast.  If you want to see precip get back into the upstate, you want to see more of a SW to NE orientation to the height lines over the southeast instead of the predominant west to east (see 2 images on the left at 500mb and 700mb) - that would lead to an increase in both the moisture transport and rising motion for precip generation.

 

GRIT, 

I am glad you posted this, so I could add in some commentary. Speaking of moisture transport and especially during CAD situations in the Carolina's, I have always studied the storms that have BUSTED IN OUR FAVOR. I can distinctly remember seeing forecasts for 1"-2" of snow and under a WWA, only to see the storm produce MUCH MORE snow and we end up with 6"-8" and under a WSW, hence, we all need to pay attention to how much confluence there is, as well as the strength of the HP's, as well as timing of the short waves. There is plenty of pieces available, to where a ULL can create havoc and the total dynamics are changed. If I am not mistaken, based on RECENT DATA, we have seen QPF overperform time and time again. I guess the case in point here is we have the main ingredients for a significant winter storm and it will all collude sooner, rather than later. 

Thanks for all your input and PBP with all of these "potentials"! 

Best regards, 

Jason 

[mackerel_sky]

GFS a little N for tomorrow's event

[DopplerWx]

for the event friday just keep in mind the jump nw in precip with the gfs in the last 24 hrs.  

last night's run:

00z tonight:

[J.C.]

HRRR

I'm sitting at 35F with a dewpoint of 25F.

[snowlover91]

I think we can scratch off the 29th storm. The German model finally dropped it and no model really supports anything outside of the NAM for some areas of SC and GA.