2025-2026 Fall/Winter Mountain Thread

[cold air aloft]

55 minutes ago, Moonhowl said:

Not what I wanted to see in the NWS GSP forecast discussion this morning:

 

While the system moves into the area, the colder air
appears to get a slight delay in arrival, thanks in part to a
developing shortwave moving over the southeast. This could create a
brief period of isentropic ascent with moisture lagging, ahead of
the colder air. What this does is help to create a warm nose sooner
than originally expected. A warm nose means more ice/sleet than
snow.

I can tell you how this will play out where I am. It will be in the 20's with sleet/ZR in Buncombe County and rain with temps in the mid 40's  IMBY with roaring SW winds a few hundred feet above me sounding like a 747. Having a warm nose take a way your winter storm is bad enough, but listening to it just adds to the misery lol.

[Hvward]

Nam3km has a smaller warm nose at hr 60 compared the NAM. I think we are going to have to rely on short range models to see if we get a few hours on Saturday of snow before the warm nose interferes. 

[BretWx]

12Z NAM ZR totals are pretty high considering. Especially down here IMBY.

[Maggie Valley Steve]

I had a sheet of ice on my asphalt driveway this morning and almost slipped on my backside. Not expected or forecasted. 

Hunter is right about the short-term guidance. We've been monitoring the Globals for a week now. Attention turns to the shorter range high resolution guidance for more nuanced possibilities.

[BretWx]

12Z ICON is just... nasty w/ ZR. 

[BretWx]

Just an example/reminder of what even .30in of ZR looks like. 

[Met1985]

What an absolute freaking mess.

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[BretWx]

12Z GFS starts precip HR54 through HR90. All ice, an hour or so of rain at the end. 

[Met1985]

Very heavy precipitation coming in as ice or a severe mix.

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[BretWx]

 

[Met1985]

Then back side flow snow.

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[BretWx]

ZR FRAM .90IN IMBY. 

YIKES.

[Met1985]

Crushed. Bye bye power.

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[Met1985]

Long duration flow snow.

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[Hvward]

Just now, Met1985 said:

Long duration flow snow.

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Yep came to post the same thing Met.  With the Great Lakes connection and the very cold temps this is a good setup for NWFS.  Kind of seeing a deformation feature developing on the backside, that could help as well.  Nonetheless this is looking to be a solid 48 hour event that will have major impacts.  I am hoping that the rain comes in Sunday afternoon and melts some ice that develops.  That could be a big saving grace especially for the SW mountains.  Tough forecast here for sure.

[Maggie Valley Steve]

This sure is looking like 48 to possibly a near 60 hour event for precipitation for the Mountains. Ugly ugly ugly. There is nothing good about this. Major Winter Storm approaching catastrophic if these trends continue.

[BretWx]

3 minutes ago, Hvward said:

Yep came to post the same thing Met.  With the Great Lakes connection and the very cold temps this is a good setup for NWFS.  Kind of seeing a deformation feature developing on the backside, that could help as well.  Nonetheless this is looking to be a solid 48 hour event that will have major impacts.  I am hoping that the rain comes in Sunday afternoon and melts some ice that develops.  That could be a big saving grace especially for the SW mountains.  Tough forecast here for sure.

Single digit lows in the next days after are not going to help. At all.

[calculus1]

Looking at the ZR totals posted above on the 12Z GFS, the northern foothills from Burke, Caldwell, and Catawba northeastward seem to hold on to the coldest upper levels the longest. This results in epic IP accumulations and much less ZR. We are in the primo position for CAD, and it may save us on the ZR, in this instance, keeping us IP much longer.

[BretWx]

FWIW - SREF PLUMES MEAN for KAVL went from .85in this morning to 4.83in SNO.

https://www.spc.noaa.gov/exper/sref/srefplumes/

[Rainforrest]

Looks pretty bad for Transylvania Jackson and Macon counties. That’s a lot of freezing rain. 

[BretWx]

Also: 

[BretWx]

Looking to next weekend. GFS is trying to throw something beautiful our way. So, we'll have something to track again next week! At least. 

 

[franklin NCwx]

16 minutes ago, Rainforrest said:

Looks pretty bad for Transylvania Jackson and Macon counties. That’s a lot of freezing rain. 

Unfortunately, it does.  Really pulling for the warm nose on this one