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Wintry Jan 15-16 Winter Storm Discussion & Obs

Wow, this thing is trending I see. Putting those of us back to the west in play. Lots of options on the table, but I love where we are headed. Definitely gives me the 12/7/17 vibes as well.
 
The Tennessee snow events this year were never nailed down until the last 24-36 hours or so, then the 3K NAM and 12k NAM pretty much sniffed out the zones that were misses. The globals never caught on and just plowed ahead with heavy snow in areas that ended up getting next to nothing. Different kind of storm here and some of the issues here were caused by downsloping that shouldn't affect the areas getting big hits tonight. , I've found over the last few years that the RGEM does really well with northern stream systems like how this one begins.
 
GSP

LONG TERM /FRIDAY THROUGH MONDAY/...
As of 300 am EST Tuesday: Friday will provide a brief lull between
systems as a shallow ridge sets up between a departing shortwave
trough and the next major system amplifying over the northern
Plains. We are trying to keep our excitement in check for the
weekend system given the spread evident in the operational models
and ensembles. Uncertainty remains high, but there are trends toward
greater confidence in at least some wintry weather affecting much of
our region over the weekend.

The setup will include a zonally-oriented 850 mb baroclinic zone
atop our region just north of the old frontal zone Friday night.
This could well provide a focus for moist upglide redeveloping
quickly across the area Friday night into Saturday. Subfreezing 850
mb temps would permit wintry ptypes at onset in most areas, with
mainly snow in the northern tier and possibly a light wintry mix
farther south as profiles wet bulb down. Meanwhile, the deepening
upstream system will dive southeast through the central CONUS the
first half of the weekend and amplify west of the Appalachians. Run-
to-run and model-to-model consistency issues abound, with the
operational GFS now much deeper with an H5 low tracking across the
Deep South Saturday night. The ECMWF and Canadian camps depict more
of a positively-tilted open wave crossing the forecast area. The
common factors include fairly cold profiles already in place and
decent potential for moisture return ahead of the amplifying system.
The main difference is that the ECMWF/CMC solutions would be a
quicker hit/shorter duration, which would limit wintry accumulations
a bit more.

The GFS, on the other hand, exhibits a far more dynamic southern
closed low position, bringing the heart of its moisture and forcing
over the cold air in place Saturday night through Sunday. In fact,
the 850 mb low center track on the GFS is perfect for record setting
snowfalls across our region. This solution has the surface low
tracking through southern AL/GA along the frontal zone Saturday
night and deepening over the SC coastal waters on Sunday. In
addition, frontogenesis would be robust atop our area in this case,
and a lobe of negative EPV crossing the region would even suggest
some potential for thundersnow. However, it`s important to note the
recent consistency issues with the GFS runs, and the fact that the
GEFS plumes have plenty of spread. Still, the prudent course is to
to start featuring the system in the HWO given the potential for
accumulating snowfall.

The upper system will depart late Sunday, but with lingering
northwest flow snowfall quite possible along the spine of the
southern Appalachians. Additional height falls may occur back to the
west over the Ohio River Valley on Monday. This early week system
appears a bit more moisture starved, and it seems the better
dynamics will pass north of our forecast area. However, additional
scattered snow showers will be possible in the mountains following
the wave passage late Monday given the northwest flow upslope
moisture in the residual cold air.
 
Shaggy said:
Raleigh, Wilmington, and morehead city all introducing snow into their forecast for the weekend
Click to expand...
Yes and GSP seems a bit more bullish in their discussion this morning. Another thing I’m noticing is just how much the temperatures have come down on my local forecast from TWC… they now have my highs both Saturday and Sunday down in the 30s with now 2-6 inches of snow Saturday night and Sunday
 
Tornado and high wind most of north-eastern NC with interior HECS blizzard 12”+ interior regions Raleigh to Maine
 
Let’s not get too crazy with the low or we’ll just be talking about a lot of disappointed folks in the triangle.
 
From RAH:

Then the weekend arrives. On Saturday morning an upper low will be
over the central Plains and it will push southeast towards the Gulf
Coast by Sunday morning. The upper low will cause a surface low to
form to the southeast, which will eventually move offshore of the
Carolinas and deepen as it heads out to sea. There is still a lot of
run-to-run variability with the storm, and a major part of this is
because the system is currently over the Pacific Ocean in a relative
data-void area for model information. The upper level system will
finally move over North America Wednesday night, and once it is
better sampled, perhaps the models will come into better agreement.
Nevertheless, the Canadian high pressure should allow for a cold-air
damming event to develop in advance of precipitation, and the newest
NBM has come in with much colder air for Saturday, Saturday night,
and Sunday. This should allow for most precipitation that falls
Saturday night to fall as snow, and it also appears that any mixed
precipitation regions would be narrow. The 00Z GFS/GEFS show
widespread precipitation over the area, while the 00Z European keeps
the bulk of the precipitation south and east of the forecast area.
Considering the major differences in where the models are showing
precipitation, essentially maintained the chance pops that were
previously inherited, but with the colder temperatures, greatly
reduced the amount of rain/snow coverage in favor of all snow.
******************************************************************************

So we may see big swings until after Wednesday night.
 
IMO the Gfs OP is way too amped. I do not think we will see that strong of a storm. A mix between the GFS/EURO seems reasonable. Did not like to see the shift northwest in the latest GFS run though.


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Loganelliott99 said:
IMO the Gfs OP is way too amped. I do not think we will see that strong of a storm. A mix between the GFS/EURO seems reasonable. Did not like to see the shift northwest in the latest GFS run though.


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Click to expand...
6z GEFS is much further south and less amped than both the 0z run and the 6z GFS.
 
Loganelliott99 said:
IMO the Gfs OP is way too amped. I do not think we will see that strong of a storm. A mix between the GFS/EURO seems reasonable. Did not like to see the shift northwest in the latest GFS run though.


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I guess the GFS is another option at this point. But like you said the euro is south so maybe the final outcome is something in between. One thing is certain, we're going to be seeing many different options with each model run during the next couple of days.
 
packfan98 said:
6z GEFS is much further south and less amped than both the 0z run and the 6z GFS.
Click to expand...

Yeah I just saw that. The GEFS really doesn’t even have a member like the GFS OP. Maybe one. I still think a mix between the EURO/GFS could happen. Regardless, it’s going to be a major winter storm whether it’s ice/snow


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FallsLake said:
I guess the GFS is another option at this point. But like you said the euro is south so maybe the final outcome is something in between. One thing is certain, we're going to be seeing many different options with each model run during the next couple of days.
Click to expand...
Until the 6z GFS, there had been non stop southward shifts by all models. 12z suite will be interesting to see if Ukie and Euro continue shifts south or start to show a more amped system. Looks fun and very plausible we are dealing with a major SE snowstorm, either huge totals (somewhere lol) with an amped up system coming up the coast or a weaker but deep south slider. I'd say Larry isn't completely out of the game just yet
 
I'm speechless this morning. Good things happen when the jet buckles lol Love seeing upstate and midlands possibly getting in on the action. Good stuff
 
Loganelliott99 said:
IMO the Gfs OP is way too amped. I do not think we will see that strong of a storm. A mix between the GFS/EURO seems reasonable. Did not like to see the shift northwest in the latest GFS run though.


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Click to expand...
Yeah it’s really hard to buy into these last 2 amped GFS runs. I would expect once the low hits the ocean to see some quick strengthening with the warm SST’s, but these last two runs have had pressures as low as a category 1 hurricane
 
The hell ? The 06s gfs track seems Bit extreme to south side . Time will tell
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