Carvers Gap

Globals are not warm for next Thursday. I agree w/ @tnweathernut and others that this is a time to watch. It is very rare to get that type of cold without precip on the front edge of that type of front. It happens, but about 90% of the time there is high ratio stuff when this rolls in. Real feels. Again, with some snow under that...some locals may make a run at record lows which I thought were pretty safe. The GEM is the "warm model." Now let that sink in.

I am expecting ice. Anything else is bonus! But right....the GFS is gonna need some company. It is just a conspiracy to make us all stay up late again? About one mile into my run each of the last two days, I am asking myself why I am so tired.

Yeppers. Yeppers. @Met1985said the GFS did ok w/ a recent snow event in W NC that the Euro didn't even have I don't think. I think the Euro has better physics, and I will need it on board. But...there have been trends southward today. Also, models are cooling off the earlier part of the run....tells me there is still some adjusting occurring. Eventually, that adjusting gets here. Maybe it is hurricane hunter data. Might be a one off run. But other models are only about 50-100 miles of going east of the Apps at times.

Nah. Nobody is worried about it. You are one of us, man. Get in there and sling it. Just be yourself. You aren't saying anything that the rest of us aren't thinking!!!!

Maybe we need to talk about mountain waves more often. The GFS got bored and was like, "Ok. Ok. Here ya go. Just please don't make me look at another wind map from Carvers Gap."

Just one more lap, GFS! You can do it!!! So is this a headfake of a headfake...kind of like a double reverse. If it flips back north, this is like a double reverse w/ a halfback pass???

Paging @TellicoWx...the 18z GFS says, "There ya go." Inland runner. Man, if it wasn't the GFS I would be excited. But...I have seen it pull off a stunner at this range...just enough not to ignore it. I mean we have seen that energy get right to the far edge of the eastern valley and run west of the Apps. We have seen Apps runners. So, it makes sense to have a solution or two with runs east of the Apps....I have NO IDEA if that run is right. However, we have been seeing baby steps today which are south of some modeling - not all.

I am here for more mountain wave talk and the GFS girlfriend who just can't walk away without breaking up ten times first.

@Math/Metis the legit expert on mountain wave events. Any time I read MRX talking about mountain waves...I am like, I recognize this verbiage! Something to think about. Not saying those dots connect. Not saying they don't. I think he is from that area as well. Guru on this and interesting. The wind can be howling in Camp Creek...and barely a breeze here. That weather station there was built to collect mountain wave data. One year, the wave was so strong...it knocked over the tower anemometer. They get like 80mph gusts with high end stuff. @Holston_River_Rambleryou are correct that the river valleys are a component of this...but I couldn't explain it in 5 pages. @Rebback to our normally scheduled programming of ice, heartbreak, and 8-9 day storm discussions. Haha! Here are some sources. If one of you all wants to start a thread on it, I would be more than happy to participate. It pretty fun to track. One day, I am going up there to see the MWE for myself. Interestingly, this weekend's setup is ideal for mountain wave events - cold air damming on the east slopes, slp cutting from MS through TN. https://www.weather.gov/mrx/arealextent Also, weaker cold-air damming on the eastern side of the southern Appalachian Mountains appeared to allow warning-level winds at the Coker Creek and Shady Valley sites, with the weakest cold-air damming observed during the warning-level wind dates at Shady Valley. https://www.weather.gov/mrx/mtnwavewinds The composite maps of surface isobars (Figure 19) revealed a low pressure system over the mid-Mississippi River Valley (northwest of the southern Appalachian Mountains) with an area of high pressure centered off the mid-Atlantic coast during both warning-level and advisory-level wind events. A deeper low pressure area was observed with the warning-level wind events (compared to the advisory-level events), which resulted in a stronger pressure gradient across the southern Appalachian Mountains. In both the warning-level and advisory-level composite maps, the surface temperatures revealed that cold air damming was occurring across the eastern side of the Appalachian Mountains. This cold air damming was a little stronger with the advisory-level events (compared to the warning-level events), while warmer temperatures were further north on the western side of the southern Appalachian Mountains with the warning-level events. The combination of a weaker low pressure system over the mid-Mississippi River Valley and stronger cold air damming (a blocked boundary layer) on the eastern side (upwind) of the southern Appalachian Mountains likely caused the wind flow below 700 hPa to be weaker during the advisory-level events.

I honestly don't know where the other "streamer" is coming from". It may well be catching the Indian Creek drainage from near Sams Gap. You really want to look at the mountain on the NC side. It has to sit perpendicular to the SE winds. Could be Unaka. As much downslope as Johson City gets(and I am on the terminus of that I26 streamers). But yeah, that almost has to be Roan Mountain causing that other warming area - sits perfectly upstream for that warming to happen. That Roan Mtn warming comes right around the end of Buffalo(could be using Buffalo as well). And honestly, JC could be catching the Indian Creek funnel which connects to the Roan stream. Crazy physics in the mountains. Just another great example of why it is so difficult to forecast here. And the win can howl on Roan Mountain.

The bottom purple arrow is almost exactly where Camp Creek is....almost perfectly. And that may have been your intention.

So mountain waves are not really seeking corridors like gaps. @Math/Met - bat signal for an explanation. My understanding has always been that these are places where the winds out of the SE hit the mountains almost at a 90 degree angle, are forced to compress on the ridges which speeds them up at the top - like a wave coming into the beach. There probably is a component where they are hitting the lower points on high ridges. Basically works like a compressor. The ridge has to be the right slope for this to work on both sides of the mountain in order to allow the winds to come across smoothly and race down the other side. If the beach is too steep...not great waves. Needs to move from deep to shallow water at a certain rate(sharp but smooth) in order to create big waves. The only thing with this...the wave rushes down the other side of a mountain. Just a few places in the world which can do what Camp Creek does.

I think technically the warm areas are actually the mountain wave downslope. The colder places in between are areas not hit by the downslope. But I can't say that for sure.

I would say 95% chance it is the mountain wave event. You can see the winds and direction on the second image.

For sure...but likely wind. I looked this AM when I saw those warmer temps streaking across Tenn. The general correlate to winds I think.