Carvers Gap

3k NAM trended SE and expanded northern precip shield.

The wind in combinations with temps in the 30s has been very cold. I know some out and back runners who had it good on the way out, and then had an 18 degree WC headwind on the way back.

Advanced teleconnections.

That is awesome. Didn’t u also have the fully black wooly worm?

12z GFS is a glacier.

Again, for the eastern valley(MBY) these are the three or four models that I use in order from here on out: RGEM, HRRR, 3kNAM, RAP. I haven't looked at the ARW, but it can be good as well. Enjoy ya'll, I have to head out for a bit. Bring it on home.

This post is not for Holston or the veterans. Here are some tricks old timers use. It has been a while since we have tracked a decent storm for the eastern side of the state - maybe three or four years in the valleys? The biggest thing to watch right now are trends. If totals continue to go up with each run today, that means models are still likely playing catch-up. If modeling begins to reduce totals, same general idea...models are playing catch-up re: reducing totals. Trends, even small ones, in regards to precip axis placements matter a lot as a small move can have huge implications 300miles away. Think of it like this. If a hurricane is coming into the coast at a 30 degree angle, any change to its trajectory changes the landfall quite a bit. If it is coming in at a right angle to the coast, it doesn't change as much. Because this is flat, but turns over the eastern valley, entry points(into the eastern valley) for the system and the jet make a big difference in the eastern valley. Models are still moving some and that is expected as they get new data. This would appear to be moving around less which makes it easier. Miller A's are known to change even at the very last model run - and this is not a Miller A. So, hopefully this is a bit more predictable. Good trends overnight as totals went up. Let's see what 12z brings to the table.

In all seriousness, the 12z NAM(3k and 12k) does look like it is still on the juice to some extent as it is still trending SE in small steps. One thing to watch, at least one of them had a NW jog at one point - the 12k did later in the run but was south earlier in the same run. The Hi-Res 3k NAM took another jog SE. So, tough to know what NAM trends are when one goes one way and one goes the other during the same run. It could score a coup. But which one(hi-res or 12k) and which run? In the eastern valley, we do want the NAM on board at some point, because it is in coming into range where it can score a coup and has certainly done so in the past. It appears that MRX either tossed the NAM or didn't weight it heavily overnight. We will see what other mesoscale models show at 12z in relation to it. And this isn't about betting or winning or losing. Sure, have at it in re: to one's own backyard. However, our ultimate goal is to watch trends and to find out where it goes. We really have two model cycles left to get a decent idea: 12z and 18z for most and 0z overnight for eastern areas. One thing to watch, a lee side low is developing on models which hammer E TN the most. That is a good feature for E TN peeps. Keep an eye out for that one.

Nah, I meant it is a good run.

The 3k NAM is currently working its issues out.....

12z HRRR inbound..........might want to take a look.

I haven't looked closely to overnight trends. Is the 12z HRRR more or less than overnight runs?

Canada.

Check out the RGEM at 84. Yes, it is at range and probably way to cold, but wow. Real feel and actual.

What is starting to limit modeling trends is that the entry point into the forum area is northern MS to northern Alabama. Why? It is closer to the actual event, and less spread in modeling. That in turn, begins to limit how far the system can trend northwards. The RGEM is my "go to" from this point forward in the chase...for the eastern valley.

I've been telling ya'll that the jet max is the key for the eastern valley. It is what gives the lift to the system.

Great and helpful post. The nw jog has commenced. One more jog SE and that was gonna be bad. Good trend.

21z NBM...and likely has the lower 12z (further south) suite. I don't think it will have 18z until maybe 3-6 hours from now(1-2 runs). New is on the left.....

LOL. Truth, man! Truth! NBM is the way to go I think for now.

Unless there is a lee side slp in western NC which has been on some recent runs. Then there would be sinking air. However, sometimes a lee side isn't bad.........We have been known to develop lows over TRI during systems like this, and it enhances precip. So many moving parts at a micro level. I do agree that if the cold air gets over the Plateau, there is very little to stop it from quickly reaching the base of the Apps. I would guess most modeling is struggling with the strength of the cold air and under-doing how far it get into the SE. Tellico had a great explanation.

18z on left and 12z on right. The SE trend on modeling has stopped for the most part. That fits previous winter storm tracking. With 24-36 hours to go, that is pretty much normal. Remember that trends are what are important on deterministic runs as well. It is good to compare the current run to previous ones. Notice the eastern edge of precip has been curtailed. Again, I do suspect the jet is enhancing precip over the eastern valley. Some of the off runs(not 12z or 0z) are beefing up precip amounts. If a storm is gonna be a good one, precip will start to increase as modeling gets closer to the even, because they can't catch up. Time to watch for that trend.

Tellico, you really seem like you might have a red tag in your past(met).

What Tellico is mentioning is different IMO. I lived in JC for five years as well - love the upslope events! It isn't really a downslope. It is banking warm air up against the Apps as it gets pushed across the valley. Amazing modeling can even model that TBH.

So it banks the warmer air against the Apps? That is pretty rare. Good catch.

In addition, I read that they are concerned about precip issues along the length of the foothills as well is how I read it.