Carvers Gap

For an industrial plant to cause this, it would take something like a massive settlement pond from a paper plant to cause the life and the moisture - like lake effect. There is nothing to the northwest of Gray that fits that bill - not even a lake. That little snow line is really similar to the gap in the mountains west of Knoxville which allows Knoxville to get more snow...not quite the same setup, but similar. FWIW...BAE and Eastman are due north....and they would actually deter dendrite formation - you can trust me on that one! Hahah. Those plants affect weather, but I have never seen those plants add snow to anyone's back yard. Lots There is a notch in Bays Mountain near Laurel Run park. There is another notch near Baileyton. Wind cuts through those places and also to the east where the mountain range terminates at the radio towers. Those wind flows converge back near Gray when NW winds run perpendicular to Bays. I think the orographic lift between the three area then combines to create convergence in the lee of Bays. Think of a sports car cutting through air in a wind tunnel. Air goes around each side and then over the top. It converges again behind the car. I think that is what happens. That band has been there a long time. @Holston_River_Rambler, I agree. a small glass manufacturer won't cause that. That industrial park over there is pretty much defunct. I don't even really count that as an industrial plant - very small w/ maybe one stack. If that line of thinking was used for Eastman, there should be a HUGE snow belt downwind from it. Hahah. It is 100% orographic life along w/ those gaps in the mountain. Your last graphic there is right on the money w/ ONP. There is another one of these in Alpine, Wy. Where there is a break in the mountain, these little bands set up. I used to live on Boone Lake and would drive to Kingsport when younger(every morning). I drove through that band so many times. Again, you all have done a great job with this. That area is just one of strong convergence. Even during summer thunderstorms...same. Always a lot of convergence there.

Out of Bristol.

I am on a roll this morning. I absolutely hate agendas. This came from a local met, and I am embarrassed for this person. "Possibly aided by an industrial plant in Hawkins Co." That just burns my biscuits. I have news for folks not from this area...we certainly have lots of industrial plants in Kingsport, and they do affect the weather. But there ain't jack crap upstream from that snow band. It is orographic lift from Bays Mountain which sets up in the lee of the mountain. We have studied and documented it here. I don't understand how a local met hasn't seen this about 1000x time already - and this person should know!!! 2" in Gray reported on the ground

Seeing MRX(almost gleefully) this morning say that their forecast area had a 40-60% of being AN...after looking at that statement it got me to thinking. It may well go warm, but what I am seeing is not a slam dunk. Why not mention the potential for at least a cold period that month? Big and honest question: When is the last time that weather office had forecast a BN month for winter? We certainly have had BN temp months, but when is the last time they have actually posted a BN forecast for a winter month, and how often has that occurred? We went like 20 straight days with BN temps from Thanksgiving to mid-Dec, and barely a peep. Christmas goes warm...and their site is flooded with warm graphics. So, I want to know this...when is the last time they have forecasted a BN month for temps during winter? I am rarely critical of that office, but let's see how they caption December which "should" be within a few tenths of normal either way. Are we going to see lots of red and oranges for a few tenths of within normal? Those folks are pros there, but I would sure like to see them at some point not carry the company water.

Man, the GEFS ensemble and deterministic after d8 are waaaaay out there on an island. The 18z GEFS going the deterministic run. The 18z GEFS ensemble has no support from any other ensemble run. The 18z AIGFS(which JB hates) is truly an awesome pattern by the end of its run. edit: Some halfway support from the 18z AIFS Euro. But the AIFS Euro looks pretty good. I think the cold will be centered back a bit further west than early December which is probably not a bad thing.

I also think the 8th is starting to be a trackable window. No guarantees, but it is showing up across modeling and at 500 on ensembles. With the NAO block likely in place, it is certainly a realistic option.

Kind of a minor event possible on NYD from the Plateau into SE KY, SW VA, and border areas of NE TN. Maybe we can cook something up per the 18z RGEM. I don't think anything more than a dusting or snow showers, but we have seen these trend south at the very last minute - as in the radar is the only thing that verified this far south.

The 18z GFS definitely trying to get in on the action. It has a storm which cuts into the forum area, but still manages to stay south. The good thing? It is the GFS at 10 days. The great thing? Good storm track.

I think the dry conditions(outright drought) in some areas of the forum is worth a continuing discussion. The southern edge of our forum is really dry as is west Tenn/eastern Arkansas. The southern Apps, as is typical w/ La Nina, are BN for rainfall. MBY is normal which has not been a usual occurrence of late. Thankfully, I think as we trend towards El Nino this summer....we will see a normal summer for temps, rain, and a reduced risk for endless summer next fall. If El Nino takes hold early enough, we could see cooler than normal temps later in spring.

That is a really good run of the Euro Weeklies(which are now dailies!). Ridge out west w/ it bridging across to Greenland. This is generally supported by some of the colder analogs. This pretty much holds throughout the run. Now, I have been doing this for a while....it likely won't hold for 6 weeks. The weeklies kind of just roll with week one and don't really move from that pattern sometimes. As @John1122notes, that storm track is a good one if it verifies. A word of caution: There has been no more fickle beast in wx modeling than LR modeling this winter. I wouldn't develop a long term attachment!!! I have 2x30day chunks at 500 posted. I mainly have done that, because each kind of tells a different story - both good for winter in the Tennessee Valley. I add two control images - you know I like the control. The temps map I think is a little bit less washed out, and it gets cold on that control run! The snow map is very similar to the ensemble, and that is likely a good sign. It is basically snow climatology, but I will take average vs none. But it gives us a good idea of the storm tracks possible - sliders, cutters, and inland runners. And if you need something to be concerned about if you like snow...I have that for you as well. Now, the good thing is that BN precip prob means it has been cold. I definitely am in the school of thought that we do a lot better when cold is in place. So, there is good and bad with this map. I don't have to explain the bad.

I use photobucket. @John1122mentioned a service he uses as well. I use photo bucket. I just upload the photo, and then grab a hosting link for it. Some hosting sites are free and some are maybe five bucks a month.

Also, ensembles are starting to honk that an Alaskan block is setting up. Now that....that would deliver cold.

The 12z AIFS Euro has three storms back-to-back-to-back. Easily the best suite of the year in terms of just synoptical setup.

5 day mean for the deterministic 12z Euro...~d6-11.

It is quiet in here to have such a good 12z suite. The 12z Euro looked loaded. Very nice run with plenty of chances and actual snow embedded in the run.

Winch chills here in Bristol are in the teens. Flurries are in the air. What a reversal in temps.

The 12z CMC has the EPO in place by Jan 6 with a nice pattern in place by the 8th - eastern trough.

I thought the 12z GFS was close with two storms on Jan 7 and Jan 11. Sure enough, the 12z CMC which doesn’t have a progressive bias…brought it. Good look. Big storm.

Really good example of a NA ridge retrograding at mid latitude w/ the HL ridge also doing the same. If that is stable, that is game on and very tough to break down. If it traps a piece of the TPV, even better for winter weather. Bottom up strat splits....do they affect the troposphere immediately? Good overall trends continuing on modeling overnight.

Met, how does that scoring system work? Blues, reds, yellow, points?

I should note that no records have been broken at TRI that I know of. Anyway, this is for posterity and future use. What a temp change to go from near record temps on Sunday to single digit wind chills tomorrow night and below zero winch chills in the mountains! National Weather Service Morristown TN 140 PM EST Sun Dec 28 2025 ...New DISCUSSION... .KEY MESSAGES... Updated at 1233 PM EST Sun Dec 28 2025 - Very warm this afternoon with possible record highs being broken again. - Showers and a strong cold front cross the area tonight and early Monday morning. - Strong gusty winds expected area-wide this afternoon through Monday, especially across the higher elevations tonight. Either Wind Advisories or a Special Weather Statement is in effect. - Much colder air moves in behind the front. Wind chills near zero are expected across the higher elevations Monday night, and highs in the 30s on Tuesday. && .DISCUSSION... Issued at 1233 PM EST Sun Dec 28 2025 One more day of well above average temperatures before a big pattern change beginning tonight. Low 70s are currently being reported across parts of the valley this afternoon already. Will include climate stats below. Daily Record High Maximum Temperatures: Date Chattanooga Knoxville Tri-Cities Oak Ridge 12-28 73(2015) 76(2015) 73(2021) 72(2021) Southerly to southwesterly winds are also occurring. Expect these to increase throughout the day and overnight tonight. A low center currently over Iowa and Illinois, will deepen through the day as it tracks towards the Great Lakes. A cold front will then develop and trail it to the southwest. Damming to the east under high pressure will kick-start the winds over the Southern Appalachians likely earlier than anywhere else because of increasing pressure gradient. This will not be a true mountain wave set-up for the Southern Appalachians given the flow direction with the frontal passage, but there will still be gusts to near 50 mph, as indicated by the Wind Advisory in place there. Wind Advisories were also added for the plateau and southwest Virginia counties. Upon looking at the latest guidance from HREF, RRFS, and others, winds appear they will generally remain below advisory level for the rest of the forecast area - valley and SW NC. A Special Weather Statement through Monday morning was issued there mentioning gusts up to 35 mph, with possible pockets of near 40 mph. After 7 am or so, winds will slowly decrease from west to east, but will hang on for the most part for the eastern higher terrain. The primary direction following the front will be from the west. The warmest temperatures tomorrow will likely occur near midnight for the forecast area, as the front makes its mark during the overnight hours. A line of showers will accompany the front, but the most we can expect are gusts translated down to the surface from aloft with any gusty showers. The strongest of any storms or severe weather threat, will remain close to the low`s center south of Michigan. It appears any influence of return- flow/northwesterly flow behind the low will remain to our north. With lows in the 20s and teens for the higher terrain forecast Tuesday morning and some winds persisting for the higher terrain as well, wind chills near 0 will be possible. Weather turns dry later tomorrow through Wednesday. High temperatures will rebound 10 degrees or so from Tuesday into Wednesday. A weak system will approach from the north Thursday into Friday, bringing a chance of light precipitation, with best chances across the northern part of the forecast area. By next weekend, precipitation chances increase from the south as the front stalls to our south. Where this sets up may determine how much precipitation we see. The southern valley and SW NC could sure use some beneficial rain to remove some of the moderate drought.

This front tonight and tomorrow is going to be powerful. Real feel temps will differ almost 40 degrees from one end of the forum to another. According to the 18z 3kNAM, wind gusts could reach 40mph as the front passes through. The 18z HRRR, has gusts up to 50mph on the Plateau. Behind the front, on Monday and Tuesday wind chills very well could be in the single digits. Actual temps tomorrow night and Tuesday night should be in the mid teens to upper 20s. Winter is about to come back with a roar. The 3k Nam is picking up on some light snow bands as this passes in eastern areas. It doesn't have much accumulation, but it wouldn't surprise me to see the usual places at higher elevations get some light amounts.

Sign me up for this. Keep your fingers crossed. BN heights east or north of Hawaii(maybe a Kona Loa low???), ridge out west, trough in the east -NAO hooked into the EPO ridge, storm signal on the EC. If you were to design a winter pattern for our area...that is it. Most modeling has some iteration of this, but this is by far the best look. Notice the four quadrants in the northern hemisphere of cold and warm - 4 blues and 4 yellow/orange. Notice the HL blocking over North America.? Notice that Europe is also cold? That map teleconnects well. I don't really trust modeling right now, but this map doesn't have the craziness. The ridge over the EC today retrogrades into the West.

Seems like a much cooler suite. It could just be ebb and flow, but a lot of cold is present(even if AN at times) in Canada when compared to earlier runs. If the BN temps remain in Canada w/ an EPO/NAO couplet....it should come SE. Remember that 84-85 analog map(should be in the December thread) of the December warm-up in 84? While I don't think we see that type of flip, we could certainly see a lot of cold air headed south if trends continue. When I was growing up and spent some time on a farm, we generally enjoyed warm-ups at this time of year...but we knew what was likely coming next. Maybe the thing which is most encouraging is that ensembles are catching up now. If they are under playing the pattern(as they have for most of the season regarding cold), this could be a very cold pattern upcoming. I still want a 3-4 more days of model runs for things to get dialed-in though.

AMAZINGLY(and I use that word sparingly), models kind of settled down today after 300. Check out the 12z Euro and GFS at 360. That is a really great pattern. The good thing is the Euro gets there pretty quickly. With the Jan 2 trough, the Euro never really lets the ridge come back East. It simply retrogrades the ridge further west with each passing vortex -> that is probably the most likely scenario. Simply put the map in motion at 500, and watch the ridge keep popping up further west. If we can manage an EPO ridge which couples w/ the NAO block(and traps cold under it....better than 70/30 chance in my mind)...we might like where the surface pattern goes.