Carvers Gap

0z GFS rolls the AH into Alaska and forms a mega block. Should set the stage for a strong Arctic outbreak around just after that storm comes on board at 264. Just another iteration of the possibilities once the pattern begins to shake-up.

2-4" over portions of E TN as well....perfect tract for snow here. Was reading the thread for the Midwest...one of the forecast NWS discos there talked about a storm working from the GOM northward being a possibility next weekend.

0z GFS commentary(will update this post as it runs): @162 winter storm incoming/underway definitely can see the GFS is working off a different MJO scenario despite a great winter storm track GFS does get there...still think it is dealing with some severe feed back issues with the system that doesn't come on board. Pretty obvious the MJO for the GEFS is a bit different than the CMC's Stay tuned for 6z...should be more model mayhem.

And it should be noted that modeling is going to be all over the place with cold on the move.....again, the 18z GEFS looks fantastic. Just trying to get the pattern right for now.

Nice cold front rolls through 3-5th. Takes a little longer to reload. The 18z GEFS holds to a quicker reload after the first front. Again, take a look at what @Holston_River_Ramblerhas posted above. Nice, stable quad groupings. Then, roll that forward into the 300s and the GFS is juggling 7-8. I think cold is on the table. Models just don't know which piece of energy or amplification to jump on. Likely will be some HUGE swings in actual reality. Model mayhem may be on the way - which I like!!!

18z GEFS through 300 looks really good.

And roll that forward into the 300s and all of that just scatters. Crazy what is in the LR right now. Not sure modeling is equipped for where it goes after that map above. It is a beauty though.

Below are two contrasting months. By no means am I saying this is what happens. However, sometimes to illustrate something, an exaggerated example is often helpful. La Nina winter with incredibly warm temps followed by a very cold January. Yes, this pattern is rare. It was rare then, and it is rare now. 71 degrees to start January. If we hadn't had that 26 degree AN departure to start the month....So, this is why I have learned not to quite on winter while in December. Lots of lesser examples exist. Click column heading to sort ascending, click again to sort descending. Date Temperature HDD CDD Precipitation New Snow Snow Depth Maximum Minimum Average Departure Sum 1758 1061 - - 599 0 1.76 0.3 - Average 56.7 34.2 45.5 6.2 - - - - 0.0 Normal 49.5 29.2 39.3 - 795 0 3.76 1.7 - 1984-12-01 51 31 41.0 -1.1 24 0 0.00 0.0 0 1984-12-02 59 27 43.0 1.1 22 0 0.08 0.0 0 1984-12-03 53 33 43.0 1.3 22 0 T 0.0 0 1984-12-04 38 23 30.5 -11.0 34 0 0.00 0.0 0 1984-12-05 42 35 38.5 -2.8 26 0 0.28 0.0 0 1984-12-06 40 12 26.0 -15.1 39 0 0.13 0.3 0 1984-12-07 30 10 20.0 -20.9 45 0 T T T 1984-12-08 49 16 32.5 -8.2 32 0 0.00 0.0 T 1984-12-09 55 22 38.5 -2.0 26 0 0.00 0.0 0 1984-12-10 45 32 38.5 -1.8 26 0 0.03 0.0 0 1984-12-11 57 37 47.0 6.9 18 0 0.00 0.0 0 1984-12-12 62 31 46.5 6.6 18 0 0.00 0.0 0 1984-12-13 67 45 56.0 16.3 9 0 0.00 0.0 0 1984-12-14 69 36 52.5 12.9 12 0 0.00 0.0 0 1984-12-15 71 38 54.5 15.1 10 0 0.00 0.0 0 1984-12-16 65 39 52.0 12.8 13 0 0.00 0.0 0 1984-12-17 64 44 54.0 14.9 11 0 T 0.0 0 1984-12-18 60 42 51.0 12.1 14 0 0.01 0.0 0 1984-12-19 62 51 56.5 17.8 8 0 0.08 0.0 0 1984-12-20 59 51 55.0 16.4 10 0 0.08 0.0 0 1984-12-21 64 51 57.5 19.1 7 0 0.04 0.0 0 1984-12-22 60 35 47.5 9.2 17 0 0.26 0.0 0 1984-12-23 51 27 39.0 0.9 26 0 0.00 0.0 0 1984-12-24 48 25 36.5 -1.5 28 0 0.23 0.0 0 1984-12-25 50 28 39.0 1.2 26 0 0.22 0.0 0 1984-12-26 59 25 42.0 4.3 23 0 0.00 0.0 0 1984-12-27 59 38 48.5 10.9 16 0 0.00 0.0 0 1984-12-28 69 39 54.0 16.6 11 0 0.00 0.0 0 1984-12-29 69 41 55.0 17.7 10 0 0.00 0.0 0 1984-12-30 64 46 55.0 17.8 10 0 0.08 0.0 0 1984-12-31 67 51 59.0 21.9 6 0 0.24 0.0 0 Click column heading to sort ascending, click again to sort descending. Date Temperature HDD CDD Precipitation New Snow Snow Depth Maximum Minimum Average Departure Sum 1112 598 - - 1153 0 3.21 9.7 - Average 35.9 19.3 27.6 -8.8 - - - - 0.8 Normal 46.5 26.3 36.4 - 886 0 3.65 3.0 - 1985-01-01 71 56 63.5 26.5 1 0 0.33 0.0 0 1985-01-02 57 38 47.5 10.7 17 0 0.71 0.0 0 1985-01-03 44 38 41.0 4.3 24 0 0.34 0.0 0 1985-01-04 42 31 36.5 -0.1 28 0 0.32 T 0 1985-01-05 31 26 28.5 -8.1 36 0 T T T 1985-01-06 46 20 33.0 -3.5 32 0 0.00 0.0 T 1985-01-07 39 29 34.0 -2.4 31 0 T T 0 1985-01-08 38 31 34.5 -1.8 30 0 T 0.0 0 1985-01-09 43 20 31.5 -4.8 33 0 0.00 0.0 0 1985-01-10 38 32 35.0 -1.2 30 0 0.02 T 0 1985-01-11 37 23 30.0 -6.2 35 0 0.06 T 0 1985-01-12 29 17 23.0 -13.1 42 0 0.01 0.1 T 1985-01-13 36 13 24.5 -11.6 40 0 0.00 0.0 0 1985-01-14 41 15 28.0 -8.1 37 0 T T 0 1985-01-15 29 16 22.5 -13.5 42 0 T T 0 1985-01-16 42 11 26.5 -9.5 38 0 0.11 1.1 0 1985-01-17 35 29 32.0 -4.0 33 0 0.21 2.1 2 1985-01-18 36 26 31.0 -5.1 34 0 T T 2 1985-01-19 35 25 30.0 -6.1 35 0 0.10 0.9 T 1985-01-20 25 -16 4.5 -31.6 60 0 0.21 2.1 3 1985-01-21 2 -21 -9.5 -45.7 74 0 0.00 0.0 3 1985-01-22 20 2 11.0 -25.2 54 0 0.02 0.3 3 1985-01-23 24 11 17.5 -18.8 47 0 T T 3 1985-01-24 39 4 21.5 -14.8 43 0 0.00 0.0 2 1985-01-25 37 15 26.0 -10.4 39 0 0.01 0.1 1 1985-01-26 22 10 16.0 -20.5 49 0 T T 1 1985-01-27 27 5 16.0 -20.6 49 0 0.10 1.0 T 1985-01-28 32 24 28.0 -8.7 37 0 0.13 1.8 2 1985-01-29 31 15 23.0 -13.8 42 0 0.00 0.0 3 1985-01-30 40 15 27.5 -9.5 37 0 0.02 0.2 1 1985-01-31 44 38 41.0 3.9 24 0 0.51 0.0 T

If you really want to see how complex the pattern is about to get, go to the NH view of the 18z GFS and look at it at 500. Once the Aleutian high(edit) is dislodged, chaos ensues. Model mayhem is likely on the table at this point. To me, I would suggest the potential for a progressive(but slow) pattern. Versus things getting locked in, we may well see things move...but slowly until things shake out. What is on modeling is a major disruption to the atmospheric circulation. I think we are about to see an amplified, short wavelength pattern. It is almost like the big Aleutian high was a cotter pin - kind of held things in place.

The 18z GFS may be right after Jan 5th, but that is a bizarre run with not a ton of support from other modeling. Looks like feedback problems to me yet again. Let's see if its ensemble supports that. I will say....the BIG problem is that we have 7-8 vortices rotating counter clockwise around those AN heights that was dislodged from the Aleutians. If you go to the northern hemisphere view, you can see them orbiting in what looks like drones just circling a mother ship. Models are not handling that well at all, and understandably so. Below is the Euro at 12z at hour 216. Amazing, but good luck to numerical model sorting this out any time soon!!!! ....To all the models at 0z, may the odds be ever in your favor.

I doubt it. Definitely on the sauce at 12z. LOL. I was getting ready to bust on it until I stumbled across this in my search. This is its look for Dec 29 to Jan 5. Yes, first part of that is going to be warm but the time from from Jan 3-5 could be very cold. But look at the date this was made....

@Holston_River_Rambler...always great photos Not sure I have ever seen something like this before. This is the 12z CFSv2 control. These are -20F departures for western portions of the forum area......for a 30 day time frame. LOL. The mean is 5-10 BN which is just insane in an of itself. This is why I don't share a foxhole with this model...but, man.

Jax, if the SST build in the western Pacific, that would likely allow more convection to occur in the MJO regions 8-1-2, right?

LOL. Check out these 24 hour temperature changes from Jan 2 to 3. First is the CMC and the next is the Euro. The CMC is at 6z on the 3rd and Euro is at 12z on the 3rd. GFS is a mere 25-30 degree temp change.

After the weather we are having right now, if we go BN for part of early January that is gonna hurt! Just sayin.........

We really need a "wow" like button for this site. That is crazy. Are we talking the GOA or Aleutians when talking eastern Pac? I would think a more traditional placement would be likely. EPS was playing with that late in its run...either that or zonal with some northwest flow.

The 12z EPS has the period of Jan 3-10 BN for temps, and that is with a warm-up embedded. Both the GEPS and GEFS reflect a similar depiction. Precip during that timeframe looks at or above normal if smoothed. Could be a warm-up and rain deal, could be over-running, could be a slider....lots on the table. Looks like we have a cold shot around the 3rd, cold relaxes, and another (maybe more significant) shot arrives around the 7th. The EPS tries to lift the BN heights at 500 northward, but the cold(mslp maps reference) is so extensive it almost has to burn itself out.

The 12z EPS is a pretty much a complete reversal of the current pattern at almost all latitudes of NA, just flip the reds and blues at 500. Oh the irony if we switch to a +PNA pattern. Most of those flips are good...but not all.

12z EPS looks good. Not sure what is going on with the GFS operational...but all three ensembles show a nice period of cold weather for early January. Whew - the CFSv2 is really cold. Probably is not right for a number of reasons(little to quick with the MJO and it is always cold anyway), but crazy in terms of eastern cold. The ensembles look like a scaled back version both in intensity and duration.

I like your ENSO thread, especially during the off-season. I think you should keep it. Both threads(severe/ENSO) are kind of unique to our subforum. Your call, but just my two cents.

Euro looks more like the CMC though not to that extreme for the Jan 3 front. Looks like a wave rides the front w/ some winter potential north of I40.

12z CMC and GEFS look similar to previous runs, including the cold shot on the 3rd.

Most modeling has been very solid with the Jan 3rd cold front - Jan 1-2 have been warm(just not record warm). There is a cool front that comes through on some modeling around NYE or NYD. Looks to me like the GFS still had a good run and a pattern flip. Just giving it a closer look, looks like both the CMC and GFS get to a cold pattern with the same mechanics which is to use a piece of energy to rotate cold in behind it. The GFS is jumping on the second piece of the split trough. CMC deepened the eastern trough with the first piece. So, not sure that was an MJO issue as much as it was with model jumped on which piece of energy to slam the cold home. For now, my money is on the CMC.

The difference in the 12z CMC and GFS on the 3rd is stark - stark. The CMC is single digits shortly after and the GFS seems to be struggling with feedback over the eastern PAC. It could be right, but it doesn’t have support to this point. Again, its MJO looks nothing like the others. The CMC has been super consistent. We will se what the Euro does at 12z.

MJO for the gfs looked off this AM. May be right and it may not. We are going to see some runs today which are likely vastly different between model suites. I take some comfort in that the GFS continually busted on going into 8. LOL. So it’s jog back towards 6 is an outlier among models at this time. CMC at 12z looks good. Gfs will get there but later in the run.