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Wintry January 8-9 Wintery Weather Potential!

Gone to ---- just as we get closer nevee fails lol
 
HORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
As of 300 AM Tuesday: Sharp upper ridging will begin to move over
the region Wednesday as sfc high follows underneath. Expect both to
quickly push offshore Wednesday night, which will introduce a return
flow at the sfc. Behind the ridge, a potent upper low will be
approaching the area from the west. As of now, model guidance
continues to track the upper low from the central CONUS at 12Z
Wednesday and sinks it into the lower MS Valley through the Deep
South and setting up shop right over the cwa around 12Z Friday. With
SW flow aloft and a return flow making its way into the region, deep
moisture advection will be equipped with the system as the ample
moisture source from the Gulf of Mexico and Atlantic pushes QPF
trends up for the event. The QPF amounts are still in question as
model guidance still spreads a wide variety of numbers for this
system, but is slowly upticking with time. The sfc low is shown
sliding over southern GA, near the GA-FL line Thursday night into
Friday, which allows the cold conveyor belt associated with the sfc
low to work into the cwa as the moisture wraps around the backside
of it. The upper low settling over the cwa will produce enough cold
air aloft to subtract the potential warm nose in the ~850 mb level,
which makes this more of a rain/snow event than additional wintry p-
types being included. The mountains should remain all snow through
the event as the isothermal layer remains below 0 degrees C at
roughly ~2000 ft in elevation, with that layer being shown making it
to the surface in soundings east of the mountains as well. Most of
the precip should start out as liquid outside of the mountains, but
the transition zone should begin to work its way over the I-40
Corridor during the early morning hours Friday as the sfc low pushes
east. Where the transition zone ends up is still the big question.
Model guidance indicates a frontogenesis zone around the 700 mb -
800 mb level near the NC/SC state, which would support heavier
precip and could help make a transition to heavy wet snow with
somewhere between I-40 and I-85 as a possible deformation band
forms. With the dendrite snow growth zone exceeding -12 degree C and
the isothermal layer remaining below freezing all the way through
vertical profile right up to the top of a very shallow boundary
layer, heavy snow rates could possibly organize somewhere outside of
the mountains. With the event still 3-4 days out, there will be
uncertainty to where that band actually sits and whether enough cold
air will allow for this scenario to play out. The onset of precip
will start overnight Thursday and should continue through of good
portion of Friday. Where the heavy precip rates occur is likely
where the actual rain/snow line develops. As of now, confidence is
growing for winter storm warning criteria snow for the mountains
with a watch for the higher elevations expected over the next 18-30
hours. Confidence begins to lower the farther outside of the
mountains you go. Current runs and temperature profiles would
suggest the transition zone to occur along or near the I-85
corridor. This will depend on the track of the sfc low, which will
determine how much cold air actually works into the cwa and the
location of the transition zone. One thing working into our favor is
the timing of the event as it is expected to enter the region during
the coldest part of the day (~06Z - 12Z Friday). Most of the global
models have the precip exiting the region by 00Z Saturday with
gradual height rises and an incoming sfc high expected to filter in
drier air into the region Friday night, with backside NW flow snow
lingering in the northern mountains and along the TN Border. Wishful
thinking could get you in trouble with this setup as the cold air is
not fully in place before the precip starts falling over the area. A
lot more questions than answers at this time, but an active pattern
is on the horizon. It`s still to be determined if all of the
ingredients play out for a favorable environment to support snow
east of the mountains. Based on the current guidance, there could be
wintry precip in store for areas that have not witnessed winter
weather yet this season. Our office will take baby steps before
issuing out any products. Confidence will either grow or lessen
based on the next couple of model runs, which will help determine
what kind and where any winter products will be issued for the GSP
cwa. Temperatures will be near normal for much of the short term
with the exception of Friday, which is trending cooler with each
model run.

&&

.LONG TERM /SATURDAY THROUGH MONDAY/...
As of 330 AM EST Tuesday: With the upper low exiting offshore by
12Z Saturday, sfc high builds in behind it with gradual height
rises. Expect this pattern to settle in through the upcoming
weekend as drier air filters in with temperatures at or slightly
below normal expected. Going into the early part of next week,
model guidance are keying in on a digging trough that drops over
the central CONUS over the weekend as it dips over the Southern
Plains. A sfc low begins to develop over the western Gulf Coast and
strengthens fairly quickly as it rides along the Gulf Coastline
over the weekend. The upper trough is shown swinging across the
lower MS Valley and Deep South before reaching the cwa Monday
into Tuesday of next week. As of now, the global models keep the
sfc low further south than the initial system, which could lead
to the area missing out on the event completely, according to the
ECMWF. With enough cold air aloft and yet another favorable track,
winter weather potential could wander back into the forecast during
the early part of the new work week. This system is still 6-7 days
out and a lot of changes will be made between now and then. This
will be another system worth monitoring since a shift to the north
can put portions of the cwa in the honey hole for decent QPF
response. The overall progression of this system is quick hitting
and would need for the variables to set up just right for this to
work in our favor and based on the current trends, that is not the
case. Due to the uncertainty of this event, 20 PoPs have been
stashed in the forecast for now to cover the variety of possible
outcomes this far out from late Sunday through next Tuesday. The one
thing that`s slightly different and a little more favorable than the
system expected later this week is that the cold air won`t chase any
precip that does develop as much as this week`s storm. Temperatures
will remain slightly below normal through much of the extended
period.
 
GFS looked colder this run at the surface and was only a few degrees off for many more areas. Dew points were also very close. 850s were very borderline during precip onset but they dropped quickly. Good news is that WAA looked weaker this run as well.
 
Looking at the 6z NAM, it barely has any QPF for N.C at 18z Friday. That's probably the reason for the bad run imo
 
RAH biting more on the chances of mix rain and snow; and now even talking ending the storm with all snow. The limiting factor will still be the surface temps which shouldn't get below freezing until late in the event. **slushy car topper event

Although the period will start out with high pressure over North
Carolina, this will be shunted to the east as low pressure develops
over the southeastern United States and moves east. Forecast still
appears that the daytime hours on Thursday will be dry, with rain
moving in from southwest to northeast overnight. Throughout this
entire storm, atmospheric soundings appear to support a rain/snow
mix, especially considering daytime highs on Friday have come down a
couple more degrees - ranging from the upper 30s in the north to the
mid 40s in the south. Temperatures are not forecast to drop below
freezing Thursday night, which would likely make it difficult for
any snow to stick unless rates were very high. Have increased pops
to likely for rain, but also expanded the area in the forecast that
additionally has a chance of snow. The ECMWF remains slightly slower
than the GFS in the departure of the low Friday night, and think
that the storm could wrap up with snowflakes by themselves instead
of mixed with rain. While the track of the low is far enough south
to put the forecast area on the northern side of the low, and
northerly winds will be present much of Friday and Friday night to
supply some cold air, the amount of cold air moving into the region
still seems to be the limiting factor for snowfall potential
throughout the 36 hours.
 
SimeonNC said:
I don't know about everyone else but I feel pretty encouraged by the overnight runs.
Click to expand...
Same, some of the models actually trended much better and ensembles are loving this system and imo the reason some models trended bad last night was they are overcorrecting due to the sampling inputs. I think we could see the GFS correct back to a more favorable look. And from what I can see it looks like the GEFS could already be starting to do that with the 6z run.
 
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Ethan80963 said:
Same some of the models actually trended much better and ensembles are loving this system and imo the reason some models trended bad last night was they are overcorrecting due to the sampling inputs. I think we will see the GFS correct back to a more favorable look. And from what I can see it looks like the GEFS is already starting to do that with the 6z run.
Click to expand...
Can you post the mean when it's done?
 
Bad thing is soil temps will not be frozen, but they wont be warm either. And ground temps continue to cool each day leading up to the event. Forecast highs today and tomorrow (for central NC) look to be in the mid/upper 40s. Lows tonight and tomorrow night in the upper 20s to low 30s. We'll need all the help we can get to see accumulations.

Current soil temps:
aaaa.JPG
 
FallsLake said:
Bad thing is soil temps will not be frozen, but they wont be warm either. And ground temps continue to cool each day leading up to the event. Forecast highs today and tomorrow (for central NC) look to be in the mid/upper 40s. Lows tonight and tomorrow night in the upper 20s to low 30s. We'll need all the help we can get to see accumulations.

Current soil temps:
View attachment 62915
Click to expand...
Soil temps will be irrelevant for areas that will see the heaviest snow imo.
 
Ethan80963 said:
Same some of the models actually trended much better and ensembles are loving this system and imo the reason some models trended bad last night was they are overcorrecting due to the sampling inputs. I think we will see the GFS correct back to a more favorable look. And from what I can see it looks like the GEFS is already starting to do that with the 6z run.
Click to expand...
Idk man. I'm personally not feeling this for the upstate up to Clt metro. Remember these snow maps you're seeing are 10:1. We know that's not happening. So if you take the already small amounts of less than 2 inches its showing and cut in half you aren't left with much considering the surface will be above freezing. Plus always account for the inevitable nw jog withing 36 hrs. I think just seeing a brief changeover and seeing snow fall would be a win in this setup. I would love to be wrong but we better start seeing some colder solutions today. And to be honest the ensembles have burned me so many times that within 72 hrs like we are now the higher resolution ops should be used.
 
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