2018/2019 Mountains and Foothills Fall/Winter Thread

[HurricaneTracker]

1 minute ago, BretWheatley said:

I’m torn between believing watching history unfold (weenie, I know) and still being extremely skeptical. Cheers! 

Don’t need to be skeptical.  It’s all there.  All the cards are on the table.  If anything, we may get constructive interference from the northern stream wave (ala 18Z FV3).  Everything looks good to me for the moment.  It’s OK to geek out on this one - you may never see anything on the magnitude and scale like this again!

[Carvers Gap]

40 minutes ago, HurricaneTracker said:

Hi all.  I hear some folks have asked for my take on the current winter storm.  Happy to help and participate here when I can and when I think my posts will be informative (rather than just banter or MBY endless posts).  So here goes.  AND do note - this is for the mountains of WNC only.  Sorry other readers.

I think most, if not all, of you have the general idea that a big winter storm is on tap.  That storm system is currently entering Southern California (which is a great thing for them!).  They are in serious drought out that way and every storm system helps.  The southern position of the upper level low moving onshore in associated with a strong subtropical jet are two very common characteristics of El Niño.  So you will see some folks in the main thread refer to this as an El Niño wave.  In El Niño years, the subtropical jet (STJ) flows fast from west to east from SoCal through southern Texas and into the Gulf Coast states.  That is exactly what we have here.   By Saturday, this jet buckles tremendously as our low gets carved out, with wind speeds greater than 180 knots (almost 200 mph)!  This is very intense and only seen with the biggest storm systems in the mid-latitudes.  The southeastern states will be under the right entrance region of the jet (a proxy for upward vertical motion).

Then we have the full wave at 500mb moving in across the ArkLaTex region at 18Z Saturday.  Meanwhile, a strong northern stream wave is forecast to be located over central North Dakota.  Over time, the GFS model does not ever phase (I.e., merge) these two waves into one.  Instead, the primary wave that comes into California scoots across the Deep South and induces a surface low pressure system near Houston, TX basically first thing Saturday morning.  This low draws upon rich and deep gulf moisture (characterized by precipitable water values in excess of 1.40” - incredibly deep for December and sourced from the STJ and eastern Pacific!  Wow!  By Saturday night and into Sunday morning, this deep moisture is pointed straight at the southern Apps, much like a fire hose but with deep tropical connections.  Meanwhile, as the surface cyclone moves into southern Georgia, we have southwest winds aloft but locally we have southeast winds circulating around our low.  This in turn brings in a secondary layer of moisture at the surface, combined with deep tropical moisture aloft.  I just cannot emphasize how big a deal this tropical fire hose is.  Even in spring this would be a big deal (for severe weather/flooding reasons).

The surface low however has other things to work with.  A seasonally-strong cold cP (continental-polar) airmass, will be building into the Midwest on Friday and Saturday.  In winter, anything over 1040mb is a very cold airmass.  This high pressure is basically squeezed east as the STJ buckles and mass evacuation (I.e., air parcels being ejected from the center of the low pressure in Texas), act to strengthen the squeeze (confluence) in the Midwest.  Let’s not forget this high will be moving over some snow cover, which acts like a refrigerator.  Some models handle the intensity of such highs differently.  Regardless, all models take the high into New England and then the cold oozes southwest, hugging the entire Apps Chain all the way to western NC.  Enter the wedge.  This wedge is sourced from cold air in New England.  Wedging is reinforced (I.e., positive feedback loop) by dynamical cooling from precipitation and ageostophic adjustment due to barrier winds.  We have all those ingredients here.   Southeast winds around the low act to also serve as an “upslope” mechanism, inducing upward vertical motion and enhancing any existing synoptic-scale vertical motions.  Oof.  

Score one for the NAM here.  GFS has been very bad so far this year with wedging air masses (too warm).  It has always played catch up while the CMC and RGEM greatly (and I do mean greatly!) overdoes the cold wedge.  NAM seems to be the sweet spot (did I just type that?).  It has a 1038mb high moving into position during the day Saturday. So, the question is, how cold?  Ignoring surface temperatures for the time being, the 850mb temperatures (~5000’) stay below freezing the entire time!  The cold is REINFORCED by precipitation and 35 knot southeasterly winds above the surface.  Surface temperatures are also below freezing, as a stready wind vector from the NE funnels cool and dry cP air into the storm system, and the forecast soundings (thermal profiles) remain ALL SNOW on the GFS model.

Take a moment and examine the thermal profile I shared here for 7pm Saturday night.  Note that very deep isothermal layer (layer of equal temperature...below freezing) from the surface to 700mb.  This is a classic WNC heavy duty, paper machete, snow sounding.  And I can tell you our thermal profiles stay this way for a while.  Oof.

So, let’s review. We have 1) cold high pressure wedging down...check.  2) source of upward vertical motion (double check).  3) moisture?  Oh heck yea.  CHECK.  And this is just the southern stream wave!  The northern stream eventually comes down to reinforce the growing trough over the east coast giving us our second punch in the gut.

OK.. now here is where I lay down my personal thoughts having digested and explained it all here.  <takes off the gloves>

I want to impart a few things on you guys.  Stop looking at the snow maps.  They are assuming 10:1 ratios....and just by looking at those soundings, you can absolutely tell it won’t be 10:1 (I am thinking 7:1, based solely on experience).  You should be looking at trends in the QPF.  And you should NOT look at the QPF from the GFS - why?  Because it has been wrong by a factor of 2, and even 3, most of the fall season in western North Carolina!  (Not saying it could be right elsewhere, but for now, WNC has been missed badly by the GFS).  Here the Euro and NAM models have performed very well in this department.  And you gotta think...BIG source of tropical moisture.  Plus Atlantic moisture.  Plus vertical motion.  Plus jet dynamics.  When the dynamics are there the moisture will find a way.  We are not lacking dynamics.  Euro was around 3.00” of liquid equivalent.  NAM isn’t out this far yet.  GFS was 1.40” (multiply by a factor of 2 and you get 2.80”).  Dang!  That’s a LOT of liquid.  Thermal profiles support snow, and maybe some sleet far southern escarpment as the warm nose tries to invade (briefly).

10:1 ratio gives you 28-30” of snow.  Bwa ha ha ha.  I can’t do it.  Just can’t do it.  What did GSP say, “generational” event?  You bet.

7:1 ratio still gives 15-18” of cement snow.  Oof.  Who in their right mind feels good about issuing a forecast like that around here?  It’s unheard of.  Can it happen?  It could.  Would I go with these values at day 4 (looking at you WYFF)....no.  Why not?  Because the atmosphere is always in motion.  Things flow like saltwater taffy being pulled from two ends.

And we still have time to watch this.  BUT BUT BUT...we have been watching this since Saturday, Dec 1.  It is equally mind-boggling to me to think that the large scale pattern and such has been so incredibly consistent for so long!  The Weather Prediction Center now has the mountains 70-90% chance of a major winter storm at DAY 4!  Wow. 

The Euro has a 96% chance of 6” or more from this system.  The GEFS mean is creeping up (on QPF...more snow, less sleet/ZR as the wedge is better reflected).

Oh and start time?  BANK ON EARLIER rather than later.  I have seen this time and time again.  These systems break out precipitation along the warm fronts and into the cold dome earlier than most systems.  GFS might have this right.  Another trend to watch next 2-3 days.

Alright, enough rambling.  Hope it’s helpful.  TL;DR - get ready.  Prepare now for a big snow event with potential for prolonged power outages. This is as big a deal since December 2009.  if you live anywhere in the cold air damming favored areas of WNC (sorry Franklin), this storm has your number.

 

 

 

Hey, snuck across the "hill" to read this. Heard rumors of a great write-up and was not disappointed.  What a great and informative post.  Stellar.  Thanks for taking the time to write this.

[NavarreDon]

Great write up HT, very detailed and appreciated. I just want to piggy back on the fire hose part of the write up. This is the disco from MOB for our area. It will give you some insight into the downstream part of the storm.


SHORT TERM /Thursday night Through Saturday night/...A mid to
upper level zonal flow pattern will persist across the central
Gulf Coast region Thursday night through Friday, while surface
high pressure continues to ridge over the southeastern U.S. Cloud
cover will be on the increase across our forecast area through
Friday, but the forecast looks to remain dry as deeper moisture
remains to our west and northwest through Friday afternoon. Cool
temperatures continue with lows Thursday night in the 30s over the
interior, with lower to mid 40s near the immediate coast. Highs
Thursday should moderate into the upper 50s to the lower 60s.

The next upper level trough is forecast to move from the Desert
Southwest Friday evening to the vicinity the Mid-Mississippi and
Tennessee Valley region by Saturday night. An associated area of
surface low pressure should track eastward along the coastal
portions of Louisiana, Mississippi, Alabama, and northwest Florida
along a frontal boundary Saturday into Saturday night. Deep layer
ascent will spread into western and northwestern portions of our
forecast area Friday night into Saturday morning, then across the
remainder of the CWA Saturday afternoon into Saturday night ahead
of the approaching trough axis and low pressure system. Widespread
rain showers will impact the region Saturday into Saturday night,
and will keep categorical POPs in the 80-90% range during this
time frame. The primary concern with this event will be heavy
rainfall, as the latest medium range guidance continues to
advertise widespread 2-3 inches of rain over much of the region,
but there could be some localized amounts of 4-6 inches near the
coast which will be within a region of stronger forcing and
higher precipitable water values. Localized flooding/flash
flooding may become a concern near the coast, where soils remain
relatively saturated from the rainfall event last weekend. The
severe weather potential still remains more uncertain and
primarily relegated to areas near the immediate coast. There will
be plentiful deep layer and low level shear with this system, but
instability remains highly uncertain. A severe threat could
eventually impact locations near the AL coast and portions of the
northwest Florida panhandle Saturday afternoon into Saturday
night, where there are still some signs of a weak warm sector and
associated weak instability penetrating inland over this portion
of the area ahead of the low pressure system, and will continue
to monitor this potential over the next 2-3 days.


.

[Boonelight]

58 minutes ago, HurricaneTracker said:

Hi all.  I hear some folks have asked for my take on the current winter storm.  Happy to help and participate here when I can and when I think my posts will be informative (rather than just banter or MBY endless posts).  So here goes.  AND do note - this is for the mountains of WNC only.  Sorry other readers.

I think most, if not all, of you have the general idea that a big winter storm is on tap.  That storm system is currently entering Southern California (which is a great thing for them!).  They are in serious drought out that way and every storm system helps.  The southern position of the upper level low moving onshore in associated with a strong subtropical jet are two very common characteristics of El Niño.  So you will see some folks in the main thread refer to this as an El Niño wave.  In El Niño years, the subtropical jet (STJ) flows fast from west to east from SoCal through southern Texas and into the Gulf Coast states.  That is exactly what we have here.   By Saturday, this jet buckles tremendously as our low gets carved out, with wind speeds greater than 180 knots (almost 200 mph)!  This is very intense and only seen with the biggest storm systems in the mid-latitudes.  The southeastern states will be under the right entrance region of the jet (a proxy for upward vertical motion).

Then we have the full wave at 500mb moving in across the ArkLaTex region at 18Z Saturday.  Meanwhile, a strong northern stream wave is forecast to be located over central North Dakota.  Over time, the GFS model does not ever phase (I.e., merge) these two waves into one.  Instead, the primary wave that comes into California scoots across the Deep South and induces a surface low pressure system near Houston, TX basically first thing Saturday morning.  This low draws upon rich and deep gulf moisture (characterized by precipitable water values in excess of 1.40” - incredibly deep for December and sourced from the STJ and eastern Pacific!  Wow!  By Saturday night and into Sunday morning, this deep moisture is pointed straight at the southern Apps, much like a fire hose but with deep tropical connections.  Meanwhile, as the surface cyclone moves into southern Georgia, we have southwest winds aloft but locally we have southeast winds circulating around our low.  This in turn brings in a secondary layer of moisture at the surface, combined with deep tropical moisture aloft.  I just cannot emphasize how big a deal this tropical fire hose is.  Even in spring this would be a big deal (for severe weather/flooding reasons).

The surface low however has other things to work with.  A seasonally-strong cold cP (continental-polar) airmass, will be building into the Midwest on Friday and Saturday.  In winter, anything over 1040mb is a very cold airmass.  This high pressure is basically squeezed east as the STJ buckles and mass evacuation (I.e., air parcels being ejected from the center of the low pressure in Texas), act to strengthen the squeeze (confluence) in the Midwest.  Let’s not forget this high will be moving over some snow cover, which acts like a refrigerator.  Some models handle the intensity of such highs differently.  Regardless, all models take the high into New England and then the cold oozes southwest, hugging the entire Apps Chain all the way to western NC.  Enter the wedge.  This wedge is sourced from cold air in New England.  Wedging is reinforced (I.e., positive feedback loop) by dynamical cooling from precipitation and ageostophic adjustment due to barrier winds.  We have all those ingredients here.   Southeast winds around the low act to also serve as an “upslope” mechanism, inducing upward vertical motion and enhancing any existing synoptic-scale vertical motions.  Oof.  

Score one for the NAM here.  GFS has been very bad so far this year with wedging air masses (too warm).  It has always played catch up while the CMC and RGEM greatly (and I do mean greatly!) overdoes the cold wedge.  NAM seems to be the sweet spot (did I just type that?).  It has a 1038mb high moving into position during the day Saturday. So, the question is, how cold?  Ignoring surface temperatures for the time being, the 850mb temperatures (~5000’) stay below freezing the entire time!  The cold is REINFORCED by precipitation and 35 knot southeasterly winds above the surface.  Surface temperatures are also below freezing, as a stready wind vector from the NE funnels cool and dry cP air into the storm system, and the forecast soundings (thermal profiles) remain ALL SNOW on the GFS model.

Take a moment and examine the thermal profile I shared here for 7pm Saturday night.  Note that very deep isothermal layer (layer of equal temperature...below freezing) from the surface to 700mb.  This is a classic WNC heavy duty, paper machete, snow sounding.  And I can tell you our thermal profiles stay this way for a while.  Oof.

So, let’s review. We have 1) cold high pressure wedging down...check.  2) source of upward vertical motion (double check).  3) moisture?  Oh heck yea.  CHECK.  And this is just the southern stream wave!  The northern stream eventually comes down to reinforce the growing trough over the east coast giving us our second punch in the gut.

OK.. now here is where I lay down my personal thoughts having digested and explained it all here.  <takes off the gloves>

I want to impart a few things on you guys.  Stop looking at the snow maps.  They are assuming 10:1 ratios....and just by looking at those soundings, you can absolutely tell it won’t be 10:1 (I am thinking 7:1, based solely on experience).  You should be looking at trends in the QPF.  And you should NOT look at the QPF from the GFS - why?  Because it has been wrong by a factor of 2, and even 3, most of the fall season in western North Carolina!  (Not saying it could be right elsewhere, but for now, WNC has been missed badly by the GFS).  Here the Euro and NAM models have performed very well in this department.  And you gotta think...BIG source of tropical moisture.  Plus Atlantic moisture.  Plus vertical motion.  Plus jet dynamics.  When the dynamics are there the moisture will find a way.  We are not lacking dynamics.  Euro was around 3.00” of liquid equivalent.  NAM isn’t out this far yet.  GFS was 1.40” (multiply by a factor of 2 and you get 2.80”).  Dang!  That’s a LOT of liquid.  Thermal profiles support snow, and maybe some sleet far southern escarpment as the warm nose tries to invade (briefly).

10:1 ratio gives you 28-30” of snow.  Bwa ha ha ha.  I can’t do it.  Just can’t do it.  What did GSP say, “generational” event?  You bet.

7:1 ratio still gives 15-18” of cement snow.  Oof.  Who in their right mind feels good about issuing a forecast like that around here?  It’s unheard of.  Can it happen?  It could.  Would I go with these values at day 4 (looking at you WYFF)....no.  Why not?  Because the atmosphere is always in motion.  Things flow like saltwater taffy being pulled from two ends.

And we still have time to watch this.  BUT BUT BUT...we have been watching this since Saturday, Dec 1.  It is equally mind-boggling to me to think that the large scale pattern and such has been so incredibly consistent for so long!  The Weather Prediction Center now has the mountains 70-90% chance of a major winter storm at DAY 4!  Wow. 

The Euro has a 96% chance of 6” or more from this system.  The GEFS mean is creeping up (on QPF...more snow, less sleet/ZR as the wedge is better reflected).

Oh and start time?  BANK ON EARLIER rather than later.  I have seen this time and time again.  These systems break out precipitation along the warm fronts and into the cold dome earlier than most systems.  GFS might have this right.  Another trend to watch next 2-3 days.

Alright, enough rambling.  Hope it’s helpful.  TL;DR - get ready.  Prepare now for a big snow event with potential for prolonged power outages. This is as big a deal since December 2009.  if you live anywhere in the cold air damming favored areas of WNC (sorry Franklin), this storm has your number.

 

 

 

Incredible write up man. I appreciate the time you took to give us this information! You made this pretty easy to follow, especially for someone like me who doesn’t understand all of the technical aspects of forecasting.

[Met1985]

58 minutes ago, HurricaneTracker said:

 

HT you know you are a freaking superstar here in the mountain forum! Never and I mean never hesitate to post here at all. I think I can speak for all in this forum but your opinion and posting in here is of great value to all of us. You know your stuff and you shoot us straight.  One hell of a write up and we all appreciate your input on this. Again never hesitate to post or put in your two cents. You are one of the best around here and I do mean that. Thank you.

[HKY_WX]

I've got the Escape filled w/ Water/blankets/flashlight/snow chains/etc... Ready to hunker down in Banner Elk starting Friday night. I haven't been this stoked about a storm in a long time.

[HurricaneTracker]

1 minute ago, HKY_WX said:

I've got the Escape filled w/ Water/blankets/flashlight/snow chains/etc... Ready to hunker down in Banner Elk starting Friday night. I haven't been this stoked about a storm in a long time.

Hard not to be stoked. Really seems everything is moving along as projected. Incredible consistency. I know folks in the main thread fear a last minute 180...could happen...but getting a sense we know all the players in the game and their modeled evolution matches fluid dynamics. No?  Or are you holding back just a bit?

[HKY_WX]

16 minutes ago, HurricaneTracker said:

Hard not to be stoked. Really seems everything is moving along as projected. Incredible consistency. I know folks in the main thread fear a last minute 180...could happen...but getting a sense we know all the players in the game and their modeled evolution matches fluid dynamics. No?  Or are you holding back just a bit?

For the northern Foothills/Mountains, I think it's all systems go... My only concern for the central/southern Mountains/Foothills is whether sleet/zr mixes in and reduces totals significantly. Need to wait until we get w/in NAM range to pinpoint that. As far as SLP track, I still see this as more of a A/B hybrid type track. Wouldn't surprise me to see a renegade SLP pop a little further north on the SW corner of the wedge (Central GA/AL area???), which often happens as the STJ vort pushes east. And then jump to the southeast coast. Overall, something to keep in mind as well is if this vort can continue to trend more cutoff. That could generate some T-SN possibilities and more enhanced banding. I continue to Harken back to Dec 2002 and Feb 2004.

[strongwxnc]

For the northern Foothills/Mountains, I think it's all systems go... My only concern for the central/southern Mountains/Foothills is whether sleet/zr mixes in and reduces totals significantly. Need to wait until we get w/in NAM range to pinpoint that. As far as SLP track, I still see this as more of a A/B hybrid type track. Wouldn't surprise me to see a renegade SLP pop a little further north on the SW corner of the wedge (Central GA/AL area???), which often happens as the STJ vort pushes east. And then jump to the southeast coast. Overall, something to keep in mind as well is if this vort can continue to trend more cutoff. That could generate some T-SN possibilities and more enhanced banding. I continue to Harken back to Dec 2002 and Feb 2004.

Could not agree more as I sit in the southern foothills. The track means everything for my area and east down the 74 corridor towards kclt.



.

[FlatLander48]

I'm not gonna quote anything to save space, but HT, I've been here for almost 4 years, and have never seen a write up anywhere near as great as what you posted. Obviously you are good at what you do, and a great asset to the forum and site in general. But that also leads me to think that regardless of the totals, we are in store for an amazing event and I am extremely excited for it. To everyone that contributes to this sub forum and site in general, you all have been a great influence in my pursuit of learning of the weather as a hobby and have enjoyed the time I have been here. I at this point am 100% in on this storm and am ready to go and excited to experience this with you guys.

[franklin NCwx]

Great write up HT!!!

[McDowell_Weather]

Here here great write up HT spot on as usual. Carry on 

[McDowell_Weather]

23 minutes ago, HKY_WX said:

For the northern Foothills/Mountains, I think it's all systems go... My only concern for the central/southern Mountains/Foothills is whether sleet/zr mixes in and reduces totals significantly. Need to wait until we get w/in NAM range to pinpoint that. As far as SLP track, I still see this as more of a A/B hybrid type track. Wouldn't surprise me to see a renegade SLP pop a little further north on the SW corner of the wedge (Central GA/AL area???), which often happens as the STJ vort pushes east. And then jump to the southeast coast. Overall, something to keep in mind as well is if this vort can continue to trend more cutoff. That could generate some T-SN possibilities and more enhanced banding. I continue to Harken back to Dec 2002 and Feb 2004.

This is my biggest concern I'm still trying to recover from Feb 14.....

[Buckethead]

First, amazing post, HT.  Usually long post are exhausting to read.  You're an excellent write, too!  I'm curious to see if the warm nose reaches me up here at 4400', but honestly I'd be happy with another 4-5" event like today...and a little thundersnow.  

[BretWx]

1 hour ago, HurricaneTracker said:

Don’t need to be skeptical.  It’s all there.  All the cards are on the table.  If anything, we may get constructive interference from the northern stream wave (ala 18Z FV3).  Everything looks good to me for the moment.  It’s OK to geek out on this one - you may never see anything on the magnitude and scale like this again!

Phew. Tomorrow and Friday are going to be a RIDE. Gotta sleep now to prepare. 

[McDowell_Weather]

4 minutes ago, BretWheatley said:

Phew. Tomorrow and Friday are going to be a RIDE. Gotta sleep now to prepare. 

Sleep ahh yess something tells me I'll get very little and I can hear my wife now YESS HEATH it's still snowing quite opening the damn door every two seconds!!!!

[strongwxnc]

Sleep ahh yess something tells me I'll get very little and I can hear my wife now YESS HEATH it's still snowing quite opening the damn door every two seconds!!!!

Lol. Same here. I set up shop in the kitchen next to the back door. Light on, door open..


.

[wxduncan]

I feel pretty good where I set in Burke just hope the sleet stays away or very little at least.

[McDowell_Weather]

2 minutes ago, strongwxnc said:

Lol. Same here. I set up shop in the kitchen next to the back door. Light on, door open..


.

Me too so I don't wake anyone I can open the door to the carport to look at the street light good for those fine flakes lol I just got a generac generator from Lowe's with enough propane for two months7000 thousand dollars my moms on oxygen gotta keep it running I also bought a 95 toyota 4×4 this week so all I got to say is BRING IT scouts motto always prepared lol

[BlueRidgeFolklore]

1 hour ago, HKY_WX said:

For the northern Foothills/Mountains, I think it's all systems go... My only concern for the central/southern Mountains/Foothills is whether sleet/zr mixes in and reduces totals significantly. Need to wait until we get w/in NAM range to pinpoint that. As far as SLP track, I still see this as more of a A/B hybrid type track. Wouldn't surprise me to see a renegade SLP pop a little further north on the SW corner of the wedge (Central GA/AL area???), which often happens as the STJ vort pushes east. And then jump to the southeast coast. Overall, something to keep in mind as well is if this vort can continue to trend more cutoff. That could generate some T-SN possibilities and more enhanced banding. I continue to Harken back to Dec 2002 and Feb 2004.

I don't foresee it being an issue for the central mountains as much as it will be for southwestern mountains. This is usually a favorable setup for the AVL, HVL area. 

[franklin NCwx]

5 minutes ago, BlueRidgeFolklore said:

I don't foresee it being an issue for the central mountains as much as it will be for southwestern mountains. This is usually a favorable setup for the AVL, HVL area. 

Yeah, probably mixing southwest of the balsams.

[AirNelson39]

I've got the Escape filled w/ Water/blankets/flashlight/snow chains/etc... Ready to hunker down in Banner Elk starting Friday night. I haven't been this stoked about a storm in a long time.

Let me know if you need anything while you’re up here, I’m in Boone and plan to be out and about quite a bit throughout the storm.

[HKY_WX]

Let me know if you need anything while you’re up here, I’m in Boone and plan to be out and about quite a bit throughout the storm.

Will do man, I appreciate it!

[Hvward]

Love me a good HT write up! Thanks for all you do bud, looking forward to reeling this one in with you and everyone else here!

 

[strongwxnc]

Love me a good HT write up! Thanks for all you do bud, looking forward to reeling this one in with you and everyone else here!
 

Still a ways to go....


.

[SnoJoe]

2 minutes ago, strongwxnc said:

Still a ways to go....


.

I hear you Mark. It's so hard to get real excited about a Saturday night storm on a Wednesday. Meet me here Friday evening around 9pm and we'll have a toast together if it still looks good.

[Hvward]

Still a ways to go....


.

Yep, but with a Euro ensemble avg of +16” 3 days out.. I feel pretty good about this one and Asheville seeing at least 8”. Warm nose is going to play a factor, but even some mix during peak sunshine hours won’t cut totals that much.

[WeatherHawk]

1 hour ago, AirNelson39 said:

Let me know if you need anything while you’re up here, I’m in Boone and plan to be out and about quite a bit throughout the storm.

Same here...we'll be on the North side up 194...lots of wrecks today...two flips, one clipped a power pole, and one car clipped the rails heading down the hill near Wendy's beside BB&T

 

[BretWx]

Mean up once again for KAVL... 

[NavarreDon]

And now the Disco has entered the ST, it just gets better & better. I even see the B word! Hold your socks fellas cuz this one may knock your shoes off!!!

.SHORT TERM /FRIDAY NIGHT THROUGH MONDAY/...
As of 355 AM EST Thursday: High confidence that a nearly ideal
synoptic set up for widespread and significant winter weather will
commence across the forecast area this weekend and possibly continue
into early next week. The highest in significant winter weather is
placed across the mountains foothills and NC Piedmont along and
north of I-40 where snow is expected to be the dominant
precipitation type, although periods of sleet and freezing rain are
also likely, especially outside of the mountains. Moderate
confidence for significant winter weather exists in the SC/NC
Piedmont along and north of I-85 and south of I-40 mainly east of I-
25. South of I-85 is not out of the woods with periods of moderate
to heavy ice and/or snow possible, but rain is expected to mix in
most often here, likely limiting ice/snow accumulations and related
impacts.

The expected overall synoptic setup has not really changed much for
several days, although model guidance has fairly uniformly tracked
track of the winter storm a bit further south and therefore leading
to snow and mixed precip types becoming more likely a bit further
south. A key to the upcoming winter storm is that cold air will be
locked in place across the region as confluence aloft ahead of the
system maintains a 1030+ mb W-E elongated sfc high pressure system
to our north with cold air damming (CAD) persisting through most of
the event. Good model consensus shows sfc low pressure riding along
the fringe of the strong high, initially along the Gulf Coast
Saturday before riding along or just off the Southeast Coastline
while intensifying Sunday. This setup will bring light to moderate
precip overspreading much of the sometime Saturday afternoon or
evening before becoming heavy at times overnight into Sunday. The
latest NAM indicates very dry air courtesy of the CAD possibly
delaying precip onset, especially across NC foothills, Piedmont and
northern mountains. A strong low level jet of 40+ kt is expected to
push through the region Sunday bring breezy conditions to many
location and gusty winds to the mountains above 3K or 4K feet where
wind gusts in excess of 40 mph are likely. This combined with period
of heavy snow may support at least brief blizzard conditions,
especially across east facing mountains. The strong low level jet
will also support an elevated (700-800mb), but now somewhat cooler
warm nose which will likely increase the icing threat which model
guidance and climatology would suggest would change somewhere
between the I-85 and I-40 corridors, lasting at least 3-6 hours. The
timing of the change over is likely sometime late Sunday night
though early evening and would like be limited across the mountains,
although sleet and freezing rain may mix in at times during this
period, especially south of I-40.

The CAD will likely gradually dissipate late Sunday into Monday but be
replaced by cold air filtering in behind the storm. Any ice should be
large over during this time with snow the predominate type area-wide,
except during the afternoon when rain may mix in at times outside of
the mountains mainly into the Upstate of SC and northeast GA. A
deformation zone with banding precip is possible during this time,
but there is still some uncertainly where exactly sets up and how
much precipitation we may see. The bottom line is the additional
snow is possible just about anywhere during this time.

Melted snow/ice or liquid precip storm total amounts continue to be
around 2 inches across most of the forecast area with local amounts
approaching 3 inches possible south of I-85 and across higher east
facing mountains due to upslope enhancement. Early estimates
continue to place snow amounts between 10 and 20 inches across the
mountains, foothills Piedmont northwest of I-85. Local 20+ amounts
are possible across higher east facing mountain and foothill
locations. Dangerous freezing rain and sleet accumulations in excess
of one half an inch continue to be possible with the high totals and
therefore impacts between I-85 and I-40 outside of the mountains.
Although latest model trends suggest areas closer to I-85 might have
the most cause for concern.

the bottom line is that a potentially very dangerous winter storm
looms for much of the forecast area this weekend. And as the day
shift yesterday put it, this could be a once-in-a-generation event
for areas that experience mostly snow and ice. Now is the time to
prepare. Finish preparations by Friday as if this storm speeds up
Saturday may be too late, especially for the Upstate of SC into
northeast GA.