January 10/11 Winter Storm Potential - May the Odds be Ever in our Favor

[Brick Tamland]

RDPS looks like the NAM.

 

[strongwxnc]

I really want to take something to knock me out till maybe Thursday cause this is like hoping your team makes it through the playoffs to the championship game.  But, seriously, trying to temper things just in case.  On a scale of 1 to 10, what do we need to watch out for (those things like after a bust, we say the xyz got us).  I feel like most of these are zero or on the very low end, except maybe warm nose. 
1 no worry 10 worry
-----------------------------------------
1) Sun Angle (guessing zero)
2) Warm Nose - 6?, 7?
3) Gulf convection robbing moisture (haven't heard anything so I assume none)
4) Went too negative tilt
5) Too positive tilt
6) High was in the wrong position
7) Cold couldn't get past the mountains (cold already locked in place i think)
 

Right with ya! Wake me up in two days!


.

[WinstonSalemArlington]

[wncsnow]

Here are my reasons for optimism-

1. Snow pack to the north and cold in place

2. Cold (frozen) ground and sun angle are ideal for quick accumulation 

3. Majority of the precipitation falls at night. Easier to stick. 

4. Confluence should prevent it cutting too far north/west

5. The air is dry out ahead and will allow for evaporative cooling. 

 

[NGTim]

5 minutes ago, wncsnow said:

Here are my reasons for optimism-

1. Snow pack to the north and cold in place

2. Cold (frozen) ground and sun angle are ideal for quick accumulation 

3. Majority of the precipitation falls at night. Easier to stick. 

4. Confluence should prevent it cutting too far north/west

5. The air is dry out ahead and will allow for evaporative cooling. 

 

excellent.  didn't think about snow pack, cold ground, evap cooling, and Especially precip falling at night.  good stuff!

[Buddy1987]

2 minutes ago, wncsnow said:

Here are my reasons for optimism-

1. Snow pack to the north and cold in place

2. Cold (frozen) ground and sun angle are ideal for quick accumulation 

3. Majority of the precipitation falls at night. Easier to stick. 

4. Confluence should prevent it cutting too far north/west

5. The air is dry out ahead and will allow for evaporative cooling. 

 

THIS!!! On Sunday I was at 36 degrees with a 4 dew point. Once snow became moderate my temp dropped down to 28. Amazing what evap cooling can do. 

[Brick Tamland]

I noticed the ICON did move the higher totals further north compared to the previous run.

[marsman]

5 minutes ago, wncsnow said:

Here are my reasons for optimism-

1. Snow pack to the north and cold in place

2. Cold (frozen) ground and sun angle are ideal for quick accumulation 

3. Majority of the precipitation falls at night. Easier to stick. 

4. Confluence should prevent it cutting too far north/west

5. The air is dry out ahead and will allow for evaporative cooling. 

 

Cold ground for sure - air temps here in Cary right now are at 38-39 - ice is still on the roads and ground in the shaded areas and not melting (maybe sublimating though).

[eyewall]

Raleigh AFD:

 Cold high pressure will again build
into the region in the wake of the departing low Sat night. While
the exact track of the low remains uncertain, the overall character
and track of the system remains consistently a Miller A scenario,
which (as noted in the previous discussion) favors a p-type
distribution of mostly rain/snow with a narrow corridor of mixed p-
type separating the two regimes. With the cold air in place and
sufficient lift and saturation in the dendritic growth zone, latest
guidance suggests snow at the onset in most, if not all locations.
As the low approaches, a strengthening warm nose aloft could be
strong enough to melt the falling snow, which would result in either
sleet or freezing rain (where sfc temps are at or below 0 degrees C)
depending on whether it is able to refreeze before making it to the
ground. Some of the biggest questions continue to be where the
rain/snow line will set up and how much sleet will mix in and over
what area, both of which will impact total accumulations. There is
still too much uncertainty to answer those questions with much
confidence. Latest available guidance generally suggests the
rain/snow line should lift nnwwd through the area Fri night as the
low lifts along the Carolina coast, possibly making it as far as the
climatologically favored I-85 corridor, with mainly snow to the
north, a wintry mix along, and mainly rain to the south of the line.
Precipitation onset will likely be between 21Z Fri and 03Z Sat, with
the precipitation quickly exiting the area Sat late morning/early
aft.

[CentralNC]

Both discussions out of GSP and RAH mention a true Miller A and if that is the case, it usually becomes a case of a smaller transition zone of ice between all snow and plain rain.  This feels like an I-85 special as someone mentioned earlier.  The further north you are of I-85 the more time you will spend in all snow.

[WinstonSalemArlington]

The Triad, Roanoke Valley, and Northwest NC/Tri-Cities tend to do best with Miller As.

[GaWx]

9 minutes ago, Brick Tamland said:

I noticed the ICON did move the higher totals further north compared to the previous run.

Yep. For example, ATL moved from 3.5” of snow on 12Z to 0.5” on 18Z.

[Buddy1987]

Wanted to get an idea why or how 18z Nam and GFS are differing with evolution etc. Found that by hour 36 the orientation of the energy out west is taller. This is what allowed the system to gain some latitude with Nam at 18z. GFS thus far is flatter. We will see how it translates down stream. 

[Brick Tamland]

10 minutes ago, eyewall said:

Raleigh AFD:

 Cold high pressure will again build
into the region in the wake of the departing low Sat night. While
the exact track of the low remains uncertain, the overall character
and track of the system remains consistently a Miller A scenario,
which (as noted in the previous discussion) favors a p-type
distribution of mostly rain/snow with a narrow corridor of mixed p-
type separating the two regimes. With the cold air in place and
sufficient lift and saturation in the dendritic growth zone, latest
guidance suggests snow at the onset in most, if not all locations.
As the low approaches, a strengthening warm nose aloft could be
strong enough to melt the falling snow, which would result in either
sleet or freezing rain (where sfc temps are at or below 0 degrees C)
depending on whether it is able to refreeze before making it to the
ground. Some of the biggest questions continue to be where the
rain/snow line will set up and how much sleet will mix in and over
what area, both of which will impact total accumulations. There is
still too much uncertainty to answer those questions with much
confidence. Latest available guidance generally suggests the
rain/snow line should lift nnwwd through the area Fri night as the
low lifts along the Carolina coast, possibly making it as far as the
climatologically favored I-85 corridor, with mainly snow to the
north, a wintry mix along, and mainly rain to the south of the line.
Precipitation onset will likely be between 21Z Fri and 03Z Sat, with
the precipitation quickly exiting the area Sat late morning/early
aft.

Seems like a typical winter storm for NC where we know something is going to happen but exactly who gets what and how much is hard to predict ahead of time. 

[Brick Tamland]

GFS at 69.

 

[Brick Tamland]

[Brick Tamland]

[NorthHillsWx]

Icon went way west with SLP

[Cheeznado]

GFS colder with more snow here than the NAM, although it still shows a lot of mix.

[WinstonSalemArlington]

[franklin NCwx]

Juiced!

[Brick Tamland]

GFS turns to ice at the end but mostly snow until then for NC.

[Brick Tamland]

[Buddy1987]

18z GFS is a beat down for WNC foothills/mountains and up into SVA.

[Brick Tamland]

GFS increased the totals a bit for the Triangle.

[NorthHillsWx]

GFS minimal changes

[NorthHillsWx]

GFS is 1-2” snow then ice for RDU. Stays below freezing for duration

[PackGrad05]

Classic storm with a tight gradient over wake. Rdu could be a lot different than fuquay/garner.


.

[GaWx]

18Z GFS much IP/ZR ATL vs 12Z with still heavy (~4.5”) snow (vs 5.5” 12Z). About same qpf. Precip types vs 1000/500 mb thicknesses still suspect (though not quite as off). So, I’m still thinking too heavy snow in southern part of snow accum.

ZR: increased from 0.1” to 0.25” ATL; ip also increased from near 0 to 0.10”

[NorthHillsWx]

1 minute ago, PackGrad05 said:

Classic storm with a tight gradient over wake. Rdu could be a lot different than fuquay/garner.


.

Kinda exactly what we expect to get from most miller A’s. Don’t think this is ironed out until Thursday