Carvers Gap

Tuesday set-up is not good - and I don't mean rain.

Thing is...the Para-GFS, UKMET, and CMC are even further SE with the cold boundary with the Euro still trending that way. This might be a case where the cold makes it to the Apps on Tuesday and banks right up against it. With a 1046 in that position, the cold would run down the spine of the Apps into the eastern valley unit it gets moved out of the way. IF, IF that looks is legit....eastern valley could be much colder if the precip gets out in front of the low. Again, I think this boundary keeps pushing eastward to at least the Apps before the SER beats it back.

The other thing is that it is very likely that more precip overruns that boundary earlier. If that happens, it would quite likely trap the cold in the valley from TYS to SW VA. It would scour over time, but that is ZR city right there for the eastern valley and way worse for middle TN.

Thing is the HP might get moved...but that is some really cold air that is going to likely get trapped north of I-40 if that is legit. That is nasty.

It is way more extreme than that. Let me see if I can grab a map and post it under CG2.

Wow. I am not sure the cold will get out of the way quickly enough with that. That is a bananan1046 high over an incoming storm. That is winter storm city there.

It moved 700 miles?

That is a significant move eastward of the boundary. In NE TN temps are almost 20F+ colder than the previous run...

12z Euro run has pushed the gradient further eastward on Tuesday through 123.

Pivotal looks good through 144. Looks like the entire state has 2+"...maybe almost the entire forum area.

Para-GFS, CMC, and UKMET at 12z all have something frozen in the eastern valley on Tuesday. GFS cuts further west.

Think E TN will get some looks eventually with this pattern. The pattern doesn't appear to be going anywhere. And this is not a pattern that is not producing for the forum area...it is just not producing for all backyards which is understandable given the size and microclimates of our region. However, this looks like west TN's pattern for now, and it is wild. I am not complaining. Yeah, I would like to see more snow IMBY(knee high to a giraffe always!). However, west TN has had to see the many of us talk about winter for years and years with few results, especially the Memphis area. Would really like to see Chattanooga sneak into this pattern as well at some point. West TN(especially Memphis) and Chattanooga have been in a snow/winter wx drought.

Disco from Memphis this morning....worth the entire read. DISCUSSION... A significant ice storm is expected to impact the Mid South later this afternoon through early Thursday afternoon. We are already seeing some icing and dangerous travel this morning across Arkansas. The Ice Storm Warning continues to be adjusted this morning as the push of colder air made it into the AR/MS delta regions. We have added Lee and Phillips Counties in AR to the warning, and we have also adjusted the Winter Storm Watch to include more areas in west Tennessee and north Mississippi. This will continue to be the case as we go through the event. Portions of the area will be upgraded to Ice Storm Warnings as the event unfolds. The freezing line this morning is draped across the forecast area and we will continue to watch the progress of this line as it will snake across the Mid South and serve as the delineation of ZR and rain. Taking a look at the range of possibilities for ice accumulation across the Mid South, we are generally seeing most of the guidance keep ice accumulations less than an inch of ice for the Mid South. The Worst Case Scenario (90th Percentile) shows a swath of 0.5 to 0.75 inch of ice along and north of I-40...just north of downtown Memphis, and a quarter inch of ice as far south as Clarksdale, MS. The most likely scenario (50th Percentile) has a swath of ice of 0.25-0.40 along and north of I-40 with little to no accumulation south of I-40. The official forecast sticks close to WPC guidance with is more in line with the 50th percentile. We will have to watch for trends in obs and rainfall to adjust the forecast as needed. Either way a significant ice storm will make travel very dangerous...cause power outages...and tree damage. The other thing to be said for this event is that this ice has the potential to be around for a while. Precipitation will move out and end on Thursday, but from Thursday night onward....portions of the forecast area will not get above freezing until late next week. Ice could be around into the weekend. This means the possibility of power outages with bitterly cold temperatures for several days. Wind chill readings Friday and Saturday will be quite cold, approaching single digits in some areas. A fast-moving trough will bring a chance for very light snow to portions of the area Saturday evening, but no impacts are anticipated. A reinforcing cold shot will arrive by Sunday, where wind chill values will fall below zero early next week. Beyond the cold...another system is expected to impact the Mid South Monday night into Tuesday. This could bring another shot of winter precipitation, but let`s get past this ice storm first before we dive into that system.

Tellico, that looks like a bit of a shift trend southeast on that run. Is that your take?

JB mentioned the same error. I have seen systems cut between just a sliver daylight between two big highs. I also have seen big highs exit quickly. But some of the stuff shown lately just seems so counterintuitive. A great example is how far south the ice line has trended. It was just north of the Ohio River. Now it is running though sought KY. My suspicion is that this cold finds its way to the Plateau and then banks west of the Apps. Might take several storms for this to occur, but I like that option. I like this pattern. Maybe I won't in the end...but truly being near the boundary between cold and precip is interesting to follow. Also, modeling is VERY prone to big shifts even in the medium range right now. So, I think any solution that appears locked-ed at d5...might not be. And yeah, sometimes it is like modeling doesn't see the NAO block and then it is like....whoa, better fix that solution once it finally "sees" it.

Like clockwork, when we begin to see even one model exit the MJO 6/7 loop...seems like we see the front press on all models. I know I sound like a broken record, but this boundary "should" press eastward with each piece of energy. Have to think the Tuesday system is looking like a significant event, but I am going to remain guarded with that. Also, beware of systems that cut directly into big highs. They may attack them as the enter or exit the area, but if they are over the Lakes, easter Plains, or central Plains....that system is likely to be forced southeast.

Seeing ice storm warnings hoisted for eastern Arkansas and a good portion of KY beginning tonight. Edit: and NW TN.

In for later...

Yeah, the thread doesn't mean anyone likes it! Totally agree. However, if they are talking ice storm warnings...it is newsworthy and worth discussing IMO.

Been a while since we have seen a 384 mean for the entire sub-forum that looked like this.

Just looking at the ensembles....looks like an outside thread at a light mixed precip event Sunday, a bigger event around the 16th, and then the overrunning pattern just holds. We are going to have to work for it in eastern areas, but man....middle and west TN are looking good. Honestly, if the 12z EPS is correct in the depiction of the gradient....it is going to be a wild couple of weeks. And we haven't really pushed back the pattern. The boundary for the cold air has been moved, but the overrunning pattern is still appears legit.

This is the 12z EPS. This is the look that brings winter wx to the forum area.

You all feel free to fire-up a thread. Been a while since that area of the forum has had a thread for an event.

12z suite is loaded for bear....Looks like 3-4 windows for winter weather. Pretty much every system is going to have to be watched as each one has a winter component on the west and NW side.

Just looking at the CMC, GFS and Euro for 12z...looks like this sub-forum is going to be an active place. Though details are not nailed down...sure seems like the intersection of precip and cold is in this area. Right now, I favor middle and west areas first with the threat gradually pushing east. The 12z Euro IMHO would be a massive ice storm for pretty much everyone. I know it had rain in the East, but doubt that cold is going to get scoured that quickly with two highs sitting over the top.