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Pattern December to Remember

I bet the unusually warm gulf of Mexico (for this time of year) is not helping our storm track and thermals so far this winter. Also led to the deadly tornadoes west of us I saw from multiple sources.
 
IMHO, I think the models are finally starting to focus in on where the cold air is going to be. The west. Basically like any other year. Will it eventually move east? Maybe. It’s been quite difficult for that to happen the last several years. DE104F94-011B-42E5-B244-0DC0C2C2B1C1.png
 
NorthDFWwx said:
It is quite the pattern squeeze play though.

-NAO / MJO Phase 7

vs.

-PNA / -EPO
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And with the pattern looking even more volatile the 2nd half of the month, hopefully we won't have to deal with yet another (3rd) severe weather outbreak...
 
How were the EURO/EPS at 00z? Didn’t see many posts about it
 
Not surprisingly, the GEFS breaks down the ridge at the end of the run. 85E0AE7C-2208-4BC2-95A4-D975DC30E166.png
 
BirdManDoomW said:
I bet the unusually warm gulf of Mexico (for this time of year) is not helping our storm track and thermals so far this winter. Also led to the deadly tornadoes west of us I saw from multiple sources.
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The GOM temps have nothing to do with our thermals or storm track if the upper flow is oriented correctly. We simply need a cold air source and a pattern that doesn't feature a bubble ridge in the center of the country.
 
With the wave train moving across the US out of the trough in the pacific starting this weekend and lasting through at least Christmas and maybe after I'm still not entirely sure I'd get too attached to warm/cold. One mis step in model amplification/non amplification makes the difference in a clogged up SE Canada and an ever digging trough in the east or a flat slightly ridged SE. Chances are we land in the middle with a more variable day to day pattern but the potential is certainly there for a really warm/fairly chilly change
 
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I'm still a believer that we will need the MJO to push into phase 8 to change things up. It's unclear if it will make it there.
EMON_phase_MANOM_51m_small.gif


diagram_40days_forecast_GEFS_member.gif
 
From: LC

The Gulf Of Alaska Low. The Grand Banks Vortex. The Subtropical Jet Stream. Pray they never meet!

You cannot help but notice the vigorous southern branch wind field, which is riding over the big subtropical high in Florida. This feature has its origins in the equatorial Pacific Basin below Hawaii (it is not tied to the Madden-Julian Oscillation, the convective response of which is located much further west). We have seen in the past (you remember last February, right?) that when the STJ phases with polar and Arctic streams, the results can be cold, cruel, and damaging.

There is a -chance- for a triple phase over the eastern third of the USA around December 23 - 26, possibly giving rise to a huge mAk Grand Banks vortex (below Newfoundland). And perhaps again December 31 - January 3 just a bit further south and east. I am following the usually mild, progressive GGEM series for the next 16 days, which has the blocking signatures in the Gulf of Alaska and Greenland. And brings cold air the farthest south into the lower 48 states, at times touching the Tennessee Valley and the Carolinas.

Now if you live in the south central states or Dixie (sorry, Texas...) you will be bypassed by the winter weather. The Midwest and Northeast stand to see the best chance for snow and ice (not a sure thing, but at least better odds than the southern and central tier. The Intermountain Region should see plenty of frozen precipitation, largely west of the Continental Divide. Alberta and Saskatchewan may have to endure routine bitter cold, with snow and wind events, until the January Thaw shows up around 1-10-2022.

The good news is January Thaw starts on 10th! Lol


Sent from my iPhone using Tapatalk
 
GaWx said:
These 5 periods are the only two week plus long cold periods at ATL since 1950 that were during a -PNA:

- 12/29/1967-1/13/1968: 0.2” + 2 Ts of SN
- 12/1/1968-1/16/1969: 3 Ts of SN
- 12/27/1978-1/9/1979: 2 Ts of SN
- 1/24/1979- 2/21/1979: major ZR & 4.4” of sleet from different storms
- 11/27/2010-12/25/2010: 1.3” Christmas snow (only measurable one on record?) plus 3 other trace to 0.1” wintry events.

So, what did these rare five periods have in common to be able to get that longlasting cold during a -PNA? A -AO and a -NAO were both present every time with them being quite strong during most of these 5 periods. A -EPO was present only during 3 of the 5 periods….so, not crucial. ENSO wasn’t crucial. The key is the strong -AO and -NAO. Furthermore, note the multiple wintry precip events during all 5 periods.
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This is great info! My area in the mid-south had significant snowfall during four out of five of those periods and unusually long periods with snowcover on a couple as well. Glad to know there is at least some hope without much help from the Pacific.
 
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Poimen said:
I'm still a believer that we will need the MJO to push into phase 8 to change things up. It's unclear if it will make it there.
EMON_phase_MANOM_51m_small.gif


diagram_40days_forecast_GEFS_member.gif
Click to expand...
I think we collectively put too much weight on the MJO. It's just not that simple, IMO. Don't get me wrong, I'd like to see it move into the colder phases too. But there are plenty of other things that can screw things up.

We need to just prepare for variability, with a warm bias, this winter. But ill bet the stars align a couple/few times for us to track some winter weather.
 
Blue_Ridge_Escarpment said:
Only to fold as it gets closer to date night.
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I personally don’t get this talk. I understand with a -NAO it backs down but we haven’t seen that this season yet . We are having a very warm December . Sure doesn’t seem like the SER has folded . Greenville sc broke their all time December high. Show me where it’s folded outside of model land .
 
Rain Cold said:
I think we collectively put too much weight on the MJO. It's just not that simple, IMO. Don't get me wrong, I'd like to see it move into the colder phases too. But there are plenty of other things that can screw things up.

We need to just prepare for variability, with a warm bias, this winter. But ill bet the stars align a couple/few times for us to track some winter weather.
Click to expand...
I’m not upset about the MJO, I would be satisfied with it stalling in phase 7, as it is a colder phase for January.
 
Rain Cold said:
I think we collectively put too much weight on the MJO. It's just not that simple, IMO. Don't get me wrong, I'd like to see it move into the colder phases too. But there are plenty of other things that can screw things up.

We need to just prepare for variability, with a warm bias, this winter. But ill bet the stars align a couple/few times for us to track some winter weather.
Click to expand...
I'm with you. But something needs to change somewhere to reconfigure the N Pac.
 
Ryan Maue,



https://twitter.com/RyanMaue
Today, I'm going complain more about the ensemble mean of a weather model forecast. Ensemble: same forecast model is run 50 more times but w/tiny perturbations introduced at time = zero. These tiny changes can result in wildly different solutions, even in a few days. Day 10:


Image

Image
 
This clear explanation tells you everything you need to know.

MJO is hung up in 6 and there is nothing favorable for NC until it rotates into 8/1

Winter chances appear dim through January 15 and may not work into our favor until late winter after February 1

Only the gracious Lord knows for sure

 
Poimen said:
I'm still a believer that we will need the MJO to push into phase 8 to change things up. It's unclear if it will make it there.
EMON_phase_MANOM_51m_small.gif


diagram_40days_forecast_GEFS_member.gif
Click to expand...

Agreed. The pattern is not changing for a reason. Definition of insanity, doing the same thing and expecting a different result. 7 is likely not going to do it IMO.
 
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