Carvers Gap

Worth saying about 1000x.

The 16 day run of the 6z GFS. It is going to be the zero or the hero. LOL. Of course the Euro had something similar as well just a few days ago. Of course, a lot of this is ice - so be sure to make that distinction. That would be a really big pattern for this entire subform. This is the potential for the pattern if the cold presses like the 6z GFS had.

Kind of an interesting test today....the NCEP/MJO plots show the MJO heading for 8 or COD just under the 8 plot(meaning background phases of MJO are cold). Let's see if modeling follows suit today.

That is no knock on the Euro BTW. It is a fantastic model, but it is shoulder season time, and that model is very mortal when seasons begin to change. All modeling is bouncing all over the place right now with this boundary and even with this current storm. I don't really have a "go to" model at this point. I think we are just going to have to rely on pattern recognition for a while. So, the real answer I am going to be looking for is the how strong the cold front will be later this week, its speed, and location. In other words, we needs its vector...victor.

I don't think the Euro is modeling this front well. I see some posts on other forums where Arctic air is often modeled too quickly and overdone. Indeed, that is often the case, and I don't disagree. However, there are times(because cold air is relatively low to the ground) that modeling misses the southerly extent of the cold air. Ditto to BNA above in saying that modeling is struggling with the Arctic front. When models can't reach consensus 12 hours from now, they don't have the late week pattern nailed down either IMO. The pattern has the potential to support a big overrunning event. I am just going with prior knowledge and not modeling...there should be an event. It is going to depend on whether the cold gets hung up on the Plateau(very plausible) OR seeps into the eastern valley and banks against the west slopes of the Apps. So, my guess is that western forum areas get hit with 1-2 ice/snow/mix systems(one significant) and then the from presses east towards the eastern valley. I think the 6z GFS may be on to something. Now the really question for me is whether a system remains to run the cold when it moves into the eastern valley. So for now, I am not swaying with model runs...just think this has a reasonable chance of occurring. We spotted this evening's system a couple of weeks ago by recognizing the pattern and knowing that a storm was possible. That doesn't mean we get snow tonight BTW, but it has been something to track and the NWS has issued winter weather products for various locations.

0z NAM (3k and 12K) have run...

12z GEFS still shows the potential for overrunning next week. Probably just need to lean on ensembles right now and not operationals....stuff is all over the place right now even inside of d3.

18z GEFS mean is very similar to the 18z Euro for system one.

Yeah, nice to have the Euro and RGEM singing the same song now. That is a good combo. Was just coming over to post that the Euro bumped up totals in general by about .5-1".

I don't think temps will be a big issue with the precip on the back side. I am just not sure that precip amounts are going to be high enough to get 2-4." With it being at night, that could help. Just seems like the overall system is less juicy. The mountains usually outperform valley locations here in terms of precip amounts - should have mentioned that earlier.

MRX indeed kicked the lower elevation call to the next shift...right thing to do with modeling still all over the place.

Agree, just not used to seeing it do that inside of 120.

MRX does have a snow map posted if someone wants to show it. I would probably shift heaviest amounts to the Plateau, but overall fits modeling.

Was mainly kidding. LOL. Great write-up this evening by MRX BTW. Also mentioned the potential in the LR as well. Sounds like they are using ensembles quite a bit which speaks to the inconsistency of operational and even short range modeling.

If I was MRX, I would kick valley location decisions to the next shift. LOL.

But one place the Euro is really susceptible is with getting hung-up in the southwest...but that normally happens at d+5.

Which looks like the CMC/GFS operational combo.

Definitely not just a Euro problem. The UKMET, GFS, and CMC all seem to be jumping around in unison which makes me thing there is a data ingest(or lack thereof) problem. The shift in unison away from the pattern a few days ago and then promptly back...makes me think we have a data issue. Ensembles, as MRX notes, are probably the way to go right now. They have been pretty steady.

I just think something is really off right now with modeling. I will say it makes since with the trough amplification to have a storm move sharply north - that makes sense. What doesn't make sense is why modeling took this long to get to this point. It has been obvious for weeks. We were dealing with out to see options just a few days ago. I really think we are entering a time frame where we need to see the cold driven to the Gulf Coast, and then have the boundary work back north...in order to have a shot.

The NAM is moving the snow axis about 150 miles a pop to the NW. Nice statewide run even it is less than favorable for MBY.

I am going to ride with @PowellVolz on this. I think something is out of whack right now. It is definitely not out of the ordinary for modeling to flip. Happens more than we like. That said, this flip flop stuff from one extreme to the other is odd within short time increments. Might see one flip, and that is it...but not the multiple extremes which we have seen for several days. Maybe it is just extreme cold which is in play. Maybe it is just shoulder season stuff since we are leaving our normal, winter long wave pattern. Maybe there is a computer or data problem. Something is off.

The 12z EPS actually looks very much like the CMC operational.

Regarding mid-late week overrunning event: The 12z EPS pushes the front through E TN at 174 which is later than 0z which was at 114. Everything is similar to 0z until the front hits west TN and then it CRAWLS across the state for nearly 60 hours. So, that creates an extended time opportunity for overrunning. The operational doesn't press the front through E TN until 222! It stalls the front in Missouri. So, there is some support to slow the front, but the actual operational is out of step with pretty much every model at this point....but I don't discount it. The EPS still has the overrunning window while the operational halts the cold in the Plains.

The 12z EPS provides some support for the operational. However, it is not to the extreme extent that it flips the pattern. Still has the overrunning event later next week. Something to keep an eye on for sure...big changes from the Euro should not be taken lightly.

12z Euro is much different than the 12z suite and much different than its other runs. It may be correct and it may not be. I think it is a combination of an error(getting hung up in the West for the umpteenth time this winter only to have it not verify nearly as strong) and a legit MJO trend not to go into phase 8 but the COD. It will be nearly 40-50 degrees warmer in some forum locations for later next week. At this point, I am not buying that extreme of a shift, but there is some trend to keep the cold west of the Apps - that I buy...just not West of the Apps as in Oregon.