2nd Annual Snow Thread for the Mountains

[franklin NCwx]

Looks like the mountains won't be relying on nearly as much on CAD to get our cold air with this next potential winter storm. Columns look to be much cooler then the last storm with not much of a warm nose showing up so far.

cad doesn't work in the mountains, except the far eastern slopes. Weak offshore lows dont help very much either. Bring on the piedmont runners!

[EmersonGA]

Parts of Roan Mtn are likely the snowiest for TN/NC. Some recent weather research instruments up there seems to support this. For Virginia it is Mt. Rogers although far Western Highland County along the WV border might be close. Not sure about Georgia.

For Georgia it is likely Brasstown Bald since it is the tallest. However, the Cohuttas are not much shorter and sit northwest of the main line which may give them better upslope position since there is nothing taller to steal moisture.

[nchighcountrywx]

From GSP Morning AFD for early next week:

MODELS ARE IN AGREEMENT ON MONDAY THAT HIGH PRESSURE TO THE NORTH

WOULD SUPPRESS FRONTAL PRECIP TO THE SOUTH OF THE NC MTNS AND

FOOTHILLS BUT SLIGHT CHANCE POPS REMAIN FOR NE GA AND PARTS OF THE

UPSTATE. A MORE DOMINANT LOW SHOULD EMERGE ALONG THE FRONT MONDAY

NIGHT...ON THE GULF COAST IN THE ECMWF OR OVER THE FLORIDA PENINSULA

IN THE GFS. COLDER AIR WILL BE MOVING IN FROM THE NW AS THE LOW

MOVES EAST NEAR NORTHERN FLORIDA. THIS WILL HAVE TO BE WATCHED

CLOSELY TOWARD THE POSSIBILITY OF A WINTRY PRECIP EVENT FOR OUR

FORECAST AREA LATE MONDAY NIGHT INTO TUESDAY. UNTIL WE HAVE GREATER

CONFIDENCE TOWARD AN OUTCOME AND SINCE THIS IS NEARLY A WEEK

AWAY...WE WILL START LEANING IN THE DIRECTION OF COLDER TEMPS AND

MORE PRECIP.

[nrgjeff]

Models will zig zag a lot on exact track until the weekend, but one thing is clear: Confidence is good that it will be cold enough for snow in the mountains - if the precip falls. Models are trying to resolve 2-3 shortwaves in a row.

 

Regarding CAD posts above, yeah it might help the Blue Ridge but not anything west of it. Monday was almost laughable how most of Avery County was 5 degrees warmer than the east facing Blue Ridge.

 

While CAD does not do the mountains much good, the mountain bonus is that with cold air aloft it will snow at 546 thickness, and sometimes as high as 552 with a bowling ball upper low.

[Met1985]

Models will zig zag a lot on exact track until the weekend, but one thing is clear: Confidence is good that it will be cold enough for snow in the mountains - if the precip falls. Models are trying to resolve 2-3 shortwaves in a row.

 

Regarding CAD posts above, yeah it might help the Blue Ridge but not anything west of it. Monday was almost laughable how most of Avery County was 5 degrees warmer than the east facing Blue Ridge.

 

While CAD does not do the mountains much good, the mountain bonus is that with cold air aloft it will snow at 546 thickness, and sometimes as high as 552 with a bowling ball upper low.

Thanks for the post. The future looks good for cold at least. Euro has been impressive for the upcoming pattern for this late in the season. Could be nothing to see snow in April around here.

[Hvward]

Models will zig zag a lot on exact track until the weekend, but one thing is clear: Confidence is good that it will be cold enough for snow in the mountains - if the precip falls. Models are trying to resolve 2-3 shortwaves in a row.

 

Regarding CAD posts above, yeah it might help the Blue Ridge but not anything west of it. Monday was almost laughable how most of Avery County was 5 degrees warmer than the east facing Blue Ridge.

 

While CAD does not do the mountains much good, the mountain bonus is that with cold air aloft it will snow at 546 thickness, and sometimes as high as 552 with a bowling ball upper low.

 

Thanks for the info, good stuff right there.  When looking at the column data typically what particular level(s) would you say are best for the snow growth area to set up?  Also I saw you post the other day noting that if the 700mb level is -4c that it would allow snow to fall to the surface, am I interpreting that correctly?  If not what would you consider to be the minimum height in the atmosphere where temps can be above freezing but snow will still reach the surface in dendrite form?

[MikeGold]

Models will zig zag a lot on exact track until the weekend, but one thing is clear: Confidence is good that it will be cold enough for snow in the mountains - if the precip falls. Models are trying to resolve 2-3 shortwaves in a row.

 

Regarding CAD posts above, yeah it might help the Blue Ridge but not anything west of it. Monday was almost laughable how most of Avery County was 5 degrees warmer than the east facing Blue Ridge.

 

While CAD does not do the mountains much good, the mountain bonus is that with cold air aloft it will snow at 546 thickness, and sometimes as high as 552 with a bowling ball upper low.

 

 

The CAD can help the mtns West of the Blue Ridge. Depends on the strength/depth of the CAD and the exact direction of the winds.  In strong situations..the CAD penetrates into the French Broad river valley SW to the Balsams mtns in the vicinity of Waynesville/Balsam Gap with a depth as high or higher than the ridge tops. Further SW penetration is blocked by the Balsams and by the downsloping. 

[nrgjeff]

Mike provides more detail above on CAD. Living there is the best way to discern the microclimates. Thank you!

 

Thanks for the info, good stuff right there.  When looking at the column data typically what particular level(s) would you say are best for the snow growth area to set up?  Also I saw you post the other day noting that if the 700mb level is -4c that it would allow snow to fall to the surface, am I interpreting that correctly?  If not what would you consider to be the minimum height in the atmosphere where temps can be above freezing but snow will still reach the surface in dendrite form?

 

As for cold air aloft, the opposite situation, yes -4C at 700mb gets the job done for mountains above 3,500 FT but only with multi-layer clouds. Low clouds all >0C of course bring nothing but drizzle. You need 0C within about 1,500 FT AGL, the lower the better. The 700mb -4 is quick and dirty because it is still 4,500+ FT AGL (mountains). Sounding forecasts can be used to locate the forecast 0C level.

 

Best case for snow growth would be closer to -6 to -8C at 700mb and the -23C at 500mb still holds. Basically I'm shifting the surface snow forecasting rules up 3,000 FT. At surface it is 850mb at -3 to -5C; 700mb at -10 to -12C; and, 500mb at -23C.

 

Finally some thickness guidelines. At 546, vs 540 sfc, mountains should get snow. It can even snow (wet snow) at 552 in the higher mountains (4,000 FT) with a cold upper low and great UUL, but one needs to check for a lot of issues with the 552 forecast. Thickness should fall during the event. The 850mb low must still go to the south. Warm air at mid-levels will kill it. One can check for that with 700mb forecasts, sounding forecasts, or partial thickness forecasts. Beware of the 850-700mb layer; it can't be too warm. With a cold upper low, if everything else checks out, thickness can start at 552 and it will still be all snow at mountain peaks.

 

Asheville is lower so the more standard guidelines apply. However I assume living in Asheville allows visits to the higher mountains and/or skiing or riding when snow is forecast there. Some of the towns at higher elevations represented on the board are high enough for the mountain rules.

[MikeGold]

Mike provides more detail above on CAD. Living there is the best way to discern the microclimates. Thank you!

 

 

As for cold air aloft, the opposite situation, yes -4C at 700mb gets the job done for mountains above 3,500 FT but only with multi-layer clouds. Low clouds all >0C of course bring nothing but drizzle. You need 0C within about 1,500 FT AGL, the lower the better. The 700mb -4 is quick and dirty because it is still 4,500+ FT AGL (mountains). Sounding forecasts can be used to locate the forecast 0C level.

 

Best case for snow growth would be closer to -6 to -8C at 700mb and the -23C at 500mb still holds. Basically I'm shifting the surface snow forecasting rules up 3,000 FT. At surface it is 850mb at -3 to -5C; 700mb at -10 to -12C; and, 500mb at -23C.

 

Finally some thickness guidelines. At 546, vs 540 sfc, mountains should get snow. It can even snow (wet snow) at 552 in the higher mountains (4,000 FT) with a cold upper low and great UUL, but one needs to check for a lot of issues with the 552 forecast. Thickness should fall during the event. The 850mb low must still go to the south. Warm air at mid-levels will kill it. One can check for that with 700mb forecasts, sounding forecasts, or partial thickness forecasts. Beware of the 850-700mb layer; it can't be too warm. With a cold upper low, if everything else checks out, thickness can start at 552 and it will still be all snow at mountain peaks.

 

Asheville is lower so the more standard guidelines apply. However I assume living in Asheville allows visits to the higher mountains and/or skiing or riding when snow is forecast there. Some of the towns at higher elevations represented on the board are high enough for the mountain rules.

 

Thank you! I learned the hard away about CAD and the Balsam mtns last Winter when a miscalculation by the local weather forecasters and myself nearly left me nearly stranded at 6100 feet elevation on my mtn top!   The CAD's last gasp is often right at the Balsams. Probably should add that forced lift of CAD modified air enhances the effect locally just as it does near the Blue Ridge. 

 

To add to your answer to Hvward...a rule of thumb..you can generally get snow about 1000 feet below the free air freezing level...and as much as 2000 feet below it if the precip is convective/heavy in nature falling in otherwise steep lapse rate environment.

 

Probably also should mention wet bulb effects and an interesting rule of the thumb to use which can be found here:

http://www.theweatherprediction.com/habyhints/259/.  Thickness rules of thumb here: http://www.theweatherprediction.com/habyhints/97/

[Hvward]

Mike provides more detail above on CAD. Living there is the best way to discern the microclimates. Thank you!

 

 

As for cold air aloft, the opposite situation, yes -4C at 700mb gets the job done for mountains above 3,500 FT but only with multi-layer clouds. Low clouds all >0C of course bring nothing but drizzle. You need 0C within about 1,500 FT AGL, the lower the better. The 700mb -4 is quick and dirty because it is still 4,500+ FT AGL (mountains). Sounding forecasts can be used to locate the forecast 0C level.

 

Best case for snow growth would be closer to -6 to -8C at 700mb and the -23C at 500mb still holds. Basically I'm shifting the surface snow forecasting rules up 3,000 FT. At surface it is 850mb at -3 to -5C; 700mb at -10 to -12C; and, 500mb at -23C.

 

Finally some thickness guidelines. At 546, vs 540 sfc, mountains should get snow. It can even snow (wet snow) at 552 in the higher mountains (4,000 FT) with a cold upper low and great UUL, but one needs to check for a lot of issues with the 552 forecast. Thickness should fall during the event. The 850mb low must still go to the south. Warm air at mid-levels will kill it. One can check for that with 700mb forecasts, sounding forecasts, or partial thickness forecasts. Beware of the 850-700mb layer; it can't be too warm. With a cold upper low, if everything else checks out, thickness can start at 552 and it will still be all snow at mountain peaks.

 

Asheville is lower so the more standard guidelines apply. However I assume living in Asheville allows visits to the higher mountains and/or skiing or riding when snow is forecast there. Some of the towns at higher elevations represented on the board are high enough for the mountain rules.

 

 

Thank you! I learned the hard away about CAD and the Balsam mtns last Winter when a miscalculation by the local weather forecasters and myself nearly left me nearly stranded at 6100 feet elevation on my mtn top!   The CAD's last gasp is often right at the Balsams. Probably should add that forced lift of CAD modified air enhances the effect locally just as it does near the Blue Ridge. 

 

To add to your answer to Hvward...a rule of thumb..you can generally get snow about 1000 feet below the free air freezing level...and as much as 2000 feet below it if the precip is convective/heavy in nature falling in otherwise steep lapse rate environment.

 

Probably also should mention wet bulb effects and an interesting rule of the thumb to use which can be found here:

http://www.theweatherprediction.com/habyhints/259/.  Thickness rules of thumb here: http://www.theweatherprediction.com/habyhints/97/

 

 

Wow Thanks guys awesome answers and very much appreciated!  Now I hope to apply these thoughts and contribute a little more!

[Met1985]

Wow Thanks guys awesome answers and very much appreciated!  Now I hope to apply these thoughts and contribute a little more!

I second this. Great insight on CAD and the mountains guys. Very interesting and unique. Talk about microclimate here in Haywood county and CADS sometimes the further west you are the warmer you can be from the eastern part of the county. Shoot sometimes it is as much as 20 degrees difference within the county. Also the cold air is just very impressive for this time of the year on the Euro. Not sure about snow but wow is it going to be getting cold around the 24th and looks like some good staying power with the strong negative EPO setting up again this year. The 850 0 degree like is almost all the way down to Florida on the 26th. Just very impressive for this time of the year.

[Blue_Ridge_Escarpment]

CAD still holding strong here on the Blue Ridge. Here just north of Marion at 5PM it is 46 degrees while Asheville sits at 59 degress.

[FLweather]

CAD still holding strong here on the Blue Ridge. Here just north of Marion at 5PM it is 46 degrees while Asheville sits at 59 degress.

 

Yeah I can't believe how long its holding. Its been roughly 72 hours and longer since the NE winds started to develop and really kick start the CAD.

[Blue_Ridge_Escarpment]

Yeah I can't believe how long its holding. Its been roughly 72 hours and longer since the NE winds started to develop and really kick start the CAD.

 

Like something you'd see in Jan/Feb, not mid-March.  

[Met1985]

CAD still holding strong here on the Blue Ridge. Here just north of Marion at 5PM it is 46 degrees while Asheville sits at 59 degress.

Ya been very nice here today. High clouds and a stiff breeze. Temp is 59 degrees. We are dropping fast though when the sun goes down. This mornings low was a cool 29 degrees.

[davenc]

For Georgia it is likely Brasstown Bald since it is the tallest. However, the Cohuttas are not much shorter and sit northwest of the main line which may give them better upslope position since there is nothing taller to steal moisture.

Thanks Mike and NW for the info. Just from the month I've been in the mts I'm realizing my weather so far as snow goes will be much different then folks in WNC for the obvious reason, I'm farther south. With that said, as long as the cold air is in place I can do pretty well with moisture coming up from the south. With systems like last weeks high winds, I will definitely get the winds and temperature drop and if I'm lucky some snow showers

Correct me if I'm wrong.. Ill take it, but as much as I love snow I figure WNC or VA might be in my longterm future. I'm still kinda ready for spring but excited at next wks winter weather prospects.

[Hvward]

Thanks Mike and NW for the info. Just from the month I've been in the mts I'm realizing my weather so far as snow goes will be much different then folks in WNC for the obvious reason, I'm farther south. With that said, as long as the cold air is in place I can do pretty well with moisture coming up from the south. With systems like last weeks high winds, I will definitely get the winds and temperature drop and if I'm lucky some snow showers

Correct me if I'm wrong.. Ill take it, but as much as I love snow I figure WNC or VA might be in my longterm future. I'm still kinda ready for spring but excited at next wks winter weather prospects.

 

Yeah Dave WNC is great for snow lovers but don't sell yourself short.  If you can, live as close to the Tennessee border as you can and get above 3500'.  No doubt you will be disappointed as a snow lover if you live in a valley behind the Apps.  Sure you may have a farther drive to work, but I bet most of the guys on here wouldn't trade there location for many others.

[Crapper Jim]

Yeah Dave WNC is great for snow lovers but don't sell yourself short.  If you can, live as close to the Tennessee border as you can and get above 3500'.  No doubt you will be disappointed as a snow lover if you live in a valley behind the Apps.  Sure you may have a farther drive to work, but I bet most of the guys on here wouldn't trade there location for many others.

Asheville is a horrible place to live if you like snow.... my memory of living in the Blue Ridge (Asheville, not a part).  It's a valley-bowl-shaped place.  Protected by elevations all-around.

Annual precip is low - from my recollection of surrounding areas.

 

Best areas, as stated, are the "tops" of NW NC Blue Ridge - Jefferson, a few miles west of Boone (best snow I ever saw - right before the elevation drop into Tenn.), into Banner Elk (Grandfather Mountain, Beech Mountain), and various ridge tops before Mount Mitchell. Generally, 4,000 ft. or more.  Don't know about the Smokies. You can live on Beech, GF... if you're rich.  You can't live on Mt. Mitchell - State Park.

 

It's all an easy drive... even from Asheville.

[Met1985]

Well the 00z GFS is something to behold. Just wow at what could come down the pike for us next week. Looks like We get a system that comes in perfect then we get a huge push of arctic air coming in with upslope snow for the end of March. I mean record setting cold. Lows in the teens and highs in the twentys.Wow!

[MikeGold]

Asheville is a horrible place to live if you like snow.... my memory of living in the Blue Ridge (Asheville, not a part).  It's a valley-bowl-shaped place.  Protected by elevations all-around.

Annual precip is low - from my recollection of surrounding areas.

 

Best areas, as stated, are the "tops" of NW NC Blue Ridge - Jefferson, a few miles west of Boone (best snow I ever saw - right before the elevation drop into Tenn.), into Banner Elk (Grandfather Mountain, Beech Mountain), and various ridge tops before Mount Mitchell. Generally, 4,000 ft. or more.  Don't know about the Smokies. You can live on Beech, GF... if you're rich.  You can't live on Mt. Mitchell - State Park.

 

It's all an easy drive... even from Asheville.

 

Interesting topic-I think we had a similar discussion earlier in the season but worth repeating.

 

A few places to add/refine. (Places that one can actually buy a home there.) See snow map.

 

Soco Gap at the West end of Maggie Valley.  This is a well known hotspot for snow. Elevations generally 4000 to 5000 feet. 

 

Max Patch area on the TN/NC line around 4400 feet elevation. Definitely a few houses on the ridge near there.

 

The ridge that is North of the Wolf Laurel Ski Resort(near Mars Hill) right on the TN line..elevations extend to a mile up. Lots of homes. 

 

Homes on Roan Mt which extend up to 5000 feet. Also the valley areas to the West of Roan Mtn down to 3000 feet elevation in the vicinity of Route 226.  And Yellow Mtn to East of Roan to 5000 feet.

 

Ogle Meadows area which is SW of Pensacola with elevations to 5400 feet. A few homes. There are few locations near Mt. Mitchell to consider just because of the possibility of being able to observe the crazy weather that occurs on the mtn top although the snow that reaches the lower elevations is rather modest.  Unfortunately, the access the road to Mt. Mitchell is closed almost the entire Winter so one would have to hike/ski in to experience it. (Same goes for the Blue Ridge Parkway. The section near my place has been closed continuously for months. My location is basically the only location in NC above 6000 feet that has Winter access most of the time.) 

 

Oz area on Beech Mtn to 5500 feet.

 

Just along the TN border in general anywhere where a highway happens to cross the divide as there are quite a few mtn homes scattered along the border. 

 

Sugar Mtn to 5200 feet. (And nearby Seven Devils)

 

Sunalei Snake Mtn to 4800 feet.

 

And last but not least Hi-Mountain Subdivision near Balsam with elevations to a oxygen starved 6200 feet. 

 

Of course, if one is selecting a home in NC for snow-there are few additional things to consider.  

 

Visibility...if you can't see the snow/snow clouds-what fun is that? Fairly easy to get a mtn side home but likely you will only be able to see in one direction. Mtn top homes where you can see in all directions are rare..and often expensive. For homes above 5000 feet-fog is a big concern. At my own location-fog is so prevalent that it makes the location nearly uninhabitable. Endless days of fog is enough to drive many people bonkers!  

 

Wind...wind adds to the fun but in Western NC..windy areas are few and far between.  Most wind is related to NW flow and is found where there is a sudden drop off from the mtns to the piedmont in the vicinity of the Blue Ridge.  Grandfather mtn is the best example of this. Unfortunately, the best wind areas are usually separate from the best NW flow snow areas that are mostly found just to the NW of there or otherwise simply not experienced due to trees. One other type of big wind is the SW low level jet. It is usually only found only at the highest elevations in the SW mtns and mostly at night. My own mtn top is probably the best example of this. Rarely is snow associated with it. (See attached wind map.)

 

The weather the rest of the year...there are long down times between snows in NC!  If you like all types of weather-a few more things to consider. Many of the NW upslope areas area are also some of the driest/most boring areas the rest of the year. Areas near Grandfather Mtn, Sunalei Snake Mtn, Soco Gap, and Hi-Mountain are quite wet and snowy making them more interesting than the locations right on the TN line. Due to cooler temps..low CAPE..the mtns as a whole are rather meager in the thunderstorm department.  As a rule-the best area for storms is separate from the best area for snow in NC. (SMNP area that has no homes does get a lot of storms.) One side note to that-the Balsams mtns along the Transylvania Co line/Blue Ridge parkway is a very active thunderstorm initiation location which is fun to watch in the Summer. Transylvania Co in general is a great weather location but it gets ripped off in the snow department. See rainfall map. See lightning map. Enjoy!

[WNC_Fort]

Wow this threat next week actually bears watching? I am all in!

[WxBlue]

I'll absolutely take 3 inches on 00z GFS, but 00z Euro isn't as good as yesterday's 12z Euro (wowzer on that run). Ensemble for Euro isn't as confident about snow as it was back in February when we got 8 inches. Right now, I think the best case for Asheville is 4-5 inches, worst a trace. However, it's March and crazier things had happened

[MikeGold]

I'll absolutely take 3 inches on 00z GFS, but 00z Euro isn't as good as yesterday's 12z Euro (wowzer on that run). Ensemble for Euro isn't as confident about snow as it was back in February when we got 8 inches. Right now, I think the best case for Asheville is 4-5 inches, worst a trace. However, it's March and crazier things had happened

 

Unfortunately, it looks to me more of a coastal variety along with a NW upslope backside component translating into the usual goose egg for the Asheville area.  Still time for the models to come up with a better solution. 

[WxBlue]

Unfortunately, it looks to me more of a coastal variety along with a NW upslope backside component translating into the usual goose egg for the Asheville area.  Still time for the models to come up with a better solution. 

 

Yeah, the low isn't tracking close to land. I'm not all in for this storm here at bottom of this dumb valley

[Blue_Ridge_Escarpment]

Yeah, the low isn't tracking close to land. I'm not all in for this storm here at bottom of this dumb valley

 

I wouldn't be so quick to write that off yet.  Climo suggests this thing hugs the coast or even rides up I-95.  WPC likes this to be a coastal hugger.

[WxBlue]

12z Euro look pretty good for WNC. Waiting on ensemble from that model at any minute. Meanwhile, 12z GFS is sloppy...

[jacobr57]

12z Euro look pretty good for WNC. Waiting on ensemble from that model at any minute. Meanwhile, 12z GFS is sloppy...

 

How much precip for WNC based on the euro?

[Met1985]

Going to be a cold night tonight. Temp is at 48 degrees and the wind has a bite to it.

[WNC_Fort]

Jason Boyer from WLOS just posted this

[franklin NCwx]

Still looks like the usual weak crap we have seen all winter.