December 2020 Medium/Long Term Pattern Discussion.

[Carvers Gap]

Yeah, modeling seems to be feeling the presence of the NAO for sure.  I am not ready to buy that feature quite yet as there has been a wicked bias towards that.  However, we are long over due for a -NAO.  Seems lately that the disruption of the SPV and -NAO go hand in hand...but seems like the NAO flashes and then disappears.   So, we will see what happens.  I was honestly surprised the Weeklies didn't look worse at 500.  If they had run from 12z, likely would have looked even better.  Again, lots of cutters and maybe some storms passing underneath if the block verifies.  Seems like when the NAO shows up, it is often a fixture for most of winter...but ready to see it verify for a week or two before really believing staying power.  IF(stress) that is a real feature, that should begin to create a feed(with the unfavorable PAC) into the norther Rockies which bleeds eastward at times.  Not an exceptional winter pattern, but probably has the potential to be better than the last few winters.  AN temps in January(provided they are slightly AN), can do the trick if timing is right.  The NAO would provide for more confluence along the EC.  Anyway, way out there...but worth a mention.  Hey, it is early Dec...most years(prior to the last five winters) I really wouldn't expect winter wx until later this month or Jan.  

[Carvers Gap]

Major changes on the GEFS extended for early January.  Fairly massive shift.  This is the daily run of the extended GEFS which rolls about this time each evening for the model suite I subscribe to.  @Holston_River_Rambler, do you have access to it?

Check that...shift begins Dec 28

[Daniel Boone]

3 minutes ago, Carvers Gap said:

Major changes on the GEFS extended for early January.  Fairly massive shift.  This is the daily run of the extended GEFS which rolls about this time each evening for the model suite I subscribe to.  @Holston_River_Rambler, do you have access to it?

Check that...shift begins Dec 28

If HLB can hold on while Niña rapidly weakens, we could really be in business, i.m.o... 

     Of course, the GW bunch that have so much to gain from it, may pay to have models hacked.  So, alot of folks would be caught of guard. Then we'd have fake Models or Forecasts, lol.

  All joking aside, wouldn't be too surprising actually, in light of all the proven fraudulence, lying and greed that's so prevalent nowadays. Sad, scary world.

[John1122]

I actually saw a story yesterday discussing ways to mitigate global warming via man made activities. One was reflecting sunlight via billions of floating pingpong balls. Others were releasing aerosolized sulfate high in the atmosphere at around 65000 feet, and using sea water to seed clouds. They said that each could lower global temps by .8 to 1.3c in the next decade. 

If if brings back winter, I say let it ride. 

[Stovepipe]

3 hours ago, John1122 said:

If it brings back winter, I say let it ride. 

[Holston_River_Rambler]

Sorry @Carvers Gap weathermodels doesn't have it. I can get it on Tropical Tidbits, but it is usually a day or two behind the most recent runs there. I thought Sunday's looked pretty good, but Monday's 0z went back to blah. I'm guessing Tuesday 0z was nice? 

Here is Sunday's:

 

If for nothing else, worth making one to see how it verifies, now that we have it running out to 800 hours. 

[Holston_River_Rambler]

Being playful and optimistic (no caffeine yet so I have to try harder, lol) one could look at the GEFS control's vision for tropical convection going into January:

 

One could also look at Raul Roundy's regressions:

 

 

Roundy had a fun exchange yesterday on twitter about Greenland blocking coming back in early January. FRD  told PSU on the MA forum about it and , strangely (at least to me) he was about as surly as Jeff after a Chiefs loss about it. 

 

Canada looked cold on 18z GFS yesterday too:

some nice -40s and even a few -50s

 

 

 

[Holston_River_Rambler]

I'll add one more thing since I've had half a cup of caffeine now. I am going to be very happy to see the cut off under the PNA ridge get out of there and clean up the flow. It was fun, but it's over. We made memories; we laughed and cried, but time to move on.

 

 

[Carvers Gap]

12z suite rolling.  Taking a quick break from the virtual school grind....  Looks like the GFS, ICON, and CMC have low-road storm threats.  The ICON(nice middle and west snow) and CMC both have something between 120-140h.  GFS looks slightly too progressive.  VERY active pattern - mostly rainers but some mix/snow stuff.

[Carvers Gap]

Biggest thing I notice is that it is a real pain to get it to snow in Tennessee prior to the 15th of December.  We have seen some early season, low-elevation snows during recent years...but really as a kid I never really expected it to snow until around or just after Christmas.   Getting some great tracks with marginal or no cold.  If we can keep that track(or have it re-develop) later this month or in early January, we would likely be in business.   I would not rule out accumulating snow north of I-40 during the next couple of weeks across the forum area.  Someone would have to thread the needle, but anytime a storm goes "under" us in terms of latitude during the winter months, it probably should be watched.

[John1122]

The Euro just bombed the mid-state. 

 

[John1122]

I just noticed how impressively it blanks Knox county on that run. 

[PowellVolz]

I just noticed how impressively it blanks Knox county on that run. 

.

[Carvers Gap]

The 12z GEFS and GEPS continue a very quick pivot of the pattern after d10.  The 12z GEFS(very late in the run so beware) has a ridge in the West and a block over Greenland.  GEPS has something similar with more ridging along the EC.  These are fairly significant changes compared to the what has been advertised for many days.  

[Carvers Gap]

1 minute ago, PowellVolz said:

.

MBY has zip as well.  Hey, it can only trend better.

[Carvers Gap]

33 minutes ago, John1122 said:

The Euro just bombed the mid-state. 

 

That threat is not too far into the future.  The 12z CMC and ICON especially have some threats.  ICON is super similar to the Euro.  Seems to be an wide range of solutions right after 120 with some of those begin wintry.

[Holston_River_Rambler]

UKMET had a less wound up piece of energy, but still a wave riding a front:

 

 

[Carvers Gap]

Just now, Holston_River_Rambler said:

UKMET had a less wound up piece of energy, but still a wave riding a front:

 

 

Man, I really despise lows in the GL regions when tracking storms...they really screw-up all kings to potential.  

[Holston_River_Rambler]

Not a bad signal for a trailing wave on the EPS, though not nearly as slap happy as the OP;

 

 

 

Some of the 12z GEFS members are like the Ukie:

[snowbird1230]

7 hours ago, John1122 said:

The Euro just bombed the mid-state. 

 

Not happening..Alabama getting more snow than the Smokies.lol

[John1122]

Not as extreme as the Euro, but the Icon laid down a solid 2-3 inch stripe from the Plateau to Nashville and a little southwest of there, also a dollop of 2 inch area in NE Mississippi in the same timeframe as the Euro storm.

[John1122]

At 500, the GFS looks great around the 15th all of a sudden. Nice -EPO bumping into Alaska with a near nationwide trough.

[Wurbus]

2 runs in a row for the Euro. What could go wrong a week out?! Seriously though, I think we mentioned this time frame as something to watch about a week ago, so pretty awesome something is still showing up to watch.

[John1122]

Major winter storm on the Canadian as well for the region later in the run.  Ice and snow on top of it. The teleconnections look much better. The Euro is getting towards a -EPO/-AO/-NAO look. 

[Holston_River_Rambler]

Man, I thought for sure that was an oddball Euro run yesterday, lol. Some EPS support though (no particular order and including the 0z Mean; sorry for the speed, but giphy limited me to 1.2 seconds per frame because of the image #):

[Holston_River_Rambler]

Oh Lawd, I forgot Knoxville:

 

The control looked a little more like yesterday's run, so that's why some of the eastern areas miss out on that member. 

[Holston_River_Rambler]

I think every model, except the GFS and GFS parallel, has some sort of wave riding the front laid down after this weekend's storm (even if they are no where near as amped as the Euro). 

Even the NAVGEM (God love it's little soul)

 

Isn't there some ancient lore about if the (supposedly) progressive NAVGEM has a storm...

 

[Carvers Gap]

Anything exciting happen with the overnight model runs?  

[Holston_River_Rambler]

I really like the conversational tone of the writer who does BNA's AFD (Not a jab at other AFDs, I like em all)

"

I think what will be of more interest to everyone is what`s on the
backside of Saturday`s system. As of right now, the white stuff is a
possibility Sunday night in both of our major models. However, the
euro is drastically different in evolution compared to the GFS. In
fact, if the euro verifies, portions of Middle TN could see plenty
of the white stuff. No, no, no. I`m not biting yet. The last
several euro runs have been much different from one another and
without a better sense of consistency, I`m just going to keep a
chance PoP in for Sunday night`s potential wintry stuff.

We`re cool and dry to start off next week, so for now, this weekend
system will be the only one to deal with over the next 7 days." 

[TellicoWx]

GFS/Euro usually are at odds with each other but this is par for 2020 I guess lol...6z GFS=Noah's Ark across the Mid south/TN valley..0z Euro= Winter wonderland..polar opposites