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Pattern January 2020 - Operation Thaw Alaska

Folks,
We are about to experience what is almost definitely going to end up being a once in a lifetime bad for cold weather index trifecta during 1/12-14:

- MJO phase 5 peak near the high 3s around 1/12. That would easily be the 2nd strongest on record in winter back to 1975! The only phase 4/5 winter peak higher than the low 3s since 1975 was the low 4s that was way back in Feb of 1985!

- +AO peak near +4.4 on ~1/13. A +4.4 has been exceeded in only 12 winters since 1950. There have only been two winters since 2008-9 having this including the last time having occurred 12/21-2/2016.

- -PNA of ~-2: a sub -2 has occurred in only 8 winters since 1950 with only 3 winters of the last 50 and only 1 winter of the last 25. The last time was way back on 12/20-1/2010!

- No entire winter since the MJO data started in 1975 had all of these 3 happen, much less within only a 3 day period

- SouthernWx will offer free emotional support during 1/12-14 for anyone who feels they can’t handle this historic combo
 
"Thoughts On The 11-15 Day Period And The MJO

Models are in agreement with the presence of a strong stratospheric polar vortex (SPV) over the next 15+ days, and this discussion on the tropical forcing has this consideration. The MJO is a wave of clouds, storms, wind and pressure that traverses the global tropics. It is influential in the warm pattern forecast in the next 5-7 Days across the South and East in its propagation through phase 5. By the 11-15 Day period, the models show diverging solutions, with the GFS EN projecting a strong push into phase 7 while the Euro projects a less coherent signal going to neutral. The maps on left illustrate how this difference in the MJO is contributing to the diverging model solutions with the pattern evolution during the period.In past seasons, the GFS EN has shown a bias to be too strong through Pacific phases, while the Euro EN has carried the opposite risk in being too weak. As such, the forecast assumes the MJO will remain a coherent signal as it propagates into phase 7 during the 11-15 Day period. The maps below (Green & Furtado, 2019) are temperature composites for cases reflected in the models during the 11-15 Day period. The forecast most closely resembles the case when the MJO moves into phase 7, with aboves in the South and belows confined to the northern tier. The second case is similar to the Euro, with a weaker MJO supporting a colder forecast risk in the East." from Maxar this morning
 
GaWx said:
Folks,
We are about to experience what is almost definitely going to end up being a once in a lifetime bad for cold weather index trifecta during 1/12-14:

- MJO phase 5 peak near the high 3s around 1/12. That would easily be the 2nd strongest on record in winter back to 1975! The only phase 4/5 winter peak higher than the low 3s since 1975 was the low 4s that was way back in Feb of 1985!

- +AO peak near +4.4 on ~1/13. A +4.4 has been exceeded in only 12 winters since 1950. There have only been two winters since 2008-9 having this including the last time having occurred 12/21-2/2016.

- -PNA of ~-2: a sub -2 has occurred in only 8 winters since 1950 with only 3 winters of the last 50 and only 1 winter of the last 25. The last time was way back on 12/20-1/2010!

- No entire winter since the MJO data started in 1975 had all of these 3 happen, much less within only a 3 day period

- SouthernWx will offer free emotional support during 1/12-14 for anyone who feels they can’t handle this historic combo
Click to expand...

At least the rain will keep it from feeling like 85°


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The weaker Euro MJO would be more favorable for SE cold than the strong phase 7 forecast of the GEFS per Maxar, which matches my own analysis: per biases, it will likely end up in between:

GEFS:
1578673949436.png

EPS:
1578674021649.png
 
GaWx said:
The weaker Euro MJO would be more favorable for SE cold than the strong phase 7 forecast of the GEFS per Maxar, which matches my own analysis: per biases, it will likely end up in between:

GEFS:
View attachment 30149

EPS:
View attachment 30150
Click to expand...
Euro ensembles looks very widspread and do have a lot of members deep into phase 7 and a lot even propelling into 8-1
 
GaWx said:
Folks,
We are about to experience what is almost definitely going to end up being a once in a lifetime bad for cold weather index trifecta during 1/12-14:

- MJO phase 5 peak near the high 3s around 1/12. That would easily be the 2nd strongest on record in winter back to 1975! The only phase 4/5 winter peak higher than the low 3s since 1975 was the low 4s that was way back in Feb of 1985!

- +AO peak near +4.4 on ~1/13. A +4.4 has been exceeded in only 12 winters since 1950. There have only been two winters since 2008-9 having this including the last time having occurred 12/21-2/2016.

- -PNA of ~-2: a sub -2 has occurred in only 8 winters since 1950 with only 3 winters of the last 50 and only 1 winter of the last 25. The last time was way back on 12/20-1/2010!

- No entire winter since the MJO data started in 1975 had all of these 3 happen, much less within only a 3 day period

- SouthernWx will offer free emotional support during 1/12-14 for anyone who feels they can’t handle this historic combo
Click to expand...

If the forecast is right ( and it is cause it is for a torch ) my overnight low Sat night will be 15 warmer than my average high for that date and a staggering +33 above the average low.....in fact for the next week the NWS does not forecast a single period where the temp is lower than my average daily high for this week.....so if that is right MBY will spend a entire week without ever getting colder than what the average HIGH is for this time of year. However if the payoff is 2-4 weeks of legit winter with snow I say bring it.
 
Well not a weenie run by any means but that’s okay the potential is still there and again plenty of factors that can wiggle this far out that would still produce a big time storm hopefully GEFS holds serve
 
Jimmy Hypocracy said:
Ain’t that a kick in the nuts

my ensemble snow mean got above 5” three times last year and I saw nothing all three times. Ensemble snow means are generally ?
Click to expand...
That was last year let’s not reminisce in the past .. looking forward high snow means GENERALLY mean that it’s eyeing some mischief possibility coming our way that’s what we need to focus on .. hoping 12z gefs at least a has a good snow mean although I’m sure it won’t be as high
 
no crazy fantasy storm but the cold is still there which is all that matters right now. That reinforced shot looks quicker also.
 
There is not going to be a god-tier run with a mega fantasy storm every run. The cold is still there, stick to ensembles.. don't get caught up in run-to-run variability. Pretty much everyone here knows this but it has to be reminded so we don't get to into our emotions about ops lol....
 
Henry Margusity calls this the model cha cha cha. They’ll dance around but may ultimately go back to an earlier solution. Gonna have to watch it evolve.


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12z GEFS is pretty interesting on winter possibilities, although it's out in fantasy land. There are going to be some huge members that skew the mean though (especially if you include the ice).

Edit: As soon as I can I'll be interested in how the heights map looks.

Edit2: Lol at the member that places ice as far south as the middle of Florida.
 
GeorgiaGirl said:
12z GEFS is pretty interesting on winter possibilities, although it's out in fantasy land. There are going to be some huge members that skew the mean though (especially if you include the ice).

Edit: As soon as I can I'll be interested in how the heights map looks.

Edit2: Lol at the member that places ice as far south as the middle of Florida.
Click to expand...
Actually it looks like a decent amount of members showed a good ice or snow event skewing the mean would probably be if only 2 big ensembles had massive snow or ice storms but there was probably a good 10+ with fairly good events
 
My gefs ens says, look at me and forget the OP. Snowy/Icy solutions starting just after the 240ish and that is not way out in fantasy land
 
Storm5 said:
Too many folks worried about the snow mean expecting it to hold . We are still a good ways out .......


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Click to expand...
As long as it’s showing snow output you know the pattern for said time frame is likely conducive of frozen precipitation. That’s about all they’re good for as far as I’m concerned
 
Storm5 said:
Too many folks worried about the snow mean expecting it to hold . We are still a good ways out .......


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Click to expand...
Agree completely! Let's just figure out if we are actually going to verify this pattern flip to cold before even giving more than a thought on Winter weather.
 
Downeastnc said:
If the forecast is right ( and it is cause it is for a torch ) my overnight low Sat night will be 15 warmer than my average high for that date and a staggering +33 above the average low.....in fact for the next week the NWS does not forecast a single period where the temp is lower than my average daily high for this week.....so if that is right MBY will spend a entire week without ever getting colder than what the average HIGH is for this time of year. However if the payoff is 2-4 weeks of legit winter with snow I say bring it.
Click to expand...

Somewhat similarly but not as extreme, ATL is not forecasted for its lows to get below the average highs for the next 6 or so days with an average anomaly near +20 for the 6 days averaged out! This would place Jan 1-15 at a super torch of +11! And then 1/16-19 are expected to still be AN per model consensus and still leave ATL at about +10 for 1/1-19. Absent an historic cold snap late month, Jan will end up AN by at least several degrees. Maxar has them ending up at a whopping +8 (~51.3) as of now because they don't see cold making it down into the SE until at least the last few days of the month due to a +AO/+NAO/strong MJO phase 7 combo before then though they acknowledge the risk of a weaker MJO like the Euro bringing cold in earlier. They are taking a huge risk in fading the colder models in the SE but they realize there are cold biases that can be faded.
 
Jimmy Hypocracy said:
As long as it’s showing snow output you know the pattern for said time frame is likely conducive of frozen precipitation. That’s about all they’re good for as far as I’m concerned
Click to expand...
I learned the hard way last year not to take the ensembles at face value. If I had half the snow they modeled last year it would have been a historic season.
 
Can't worry about every run. Careless if it shows snow yet or not. Temps is as always the key and models have been every where this year. Next week was supposed to be cold now its next weekend. Still a ways out to believe either way or be concerned if snow or not. Pattern change is key and looks like models are on it so far
 
Unless there's consistent convergence across virtually all model/ensemble suites around a storm 5-7 days out, then it's a low probability event and there shouldn't be be a lot of angst around pretty snow maps that pop up and go away. Anything beyond D7 is complete speculation, in terms of specific storm details.

Overall, the ensemble pattern still looks good and supports winter returning. It's good that some of the models are actually showing winter weather. That's the first order of business. So, mission accomplished there.

As the pattern begins to change, that should pick up, and we should see bona fide individual threats emerge that have some consistency inside of the 5-7 day mark. That's the second item on the list, and right now, it carries a status of Pending.

After that, storm detail analysis can begin. Right now, that's in the queue. As long as the pattern change is not a mirage or one-hopper to the second baseman, we'll get there. Then we'll see what we've got. Sometimes we get a base hit. Sometimes we hit a tater.

ETA:

12z GEFS on 1/7, valid 12z 1/23. Crap as far as the eye could see 3 days ago:

gfs-ens_z500a_namer_65.png

12z GEFS today, valid 12z 1/23. Little bit of a difference:

gfs-ens_z500a_namer_53.png

And 384 GEFS today:

gfs-ens_z500a_namer_65 (1).png

Given where we were 3 days ago, I'll take it.
 
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Most of this is within the 10-15 day time frame, that period is looking amazing no doubt.... but it's 10+ days out and there will no doubt be some huge swings. But post, share, discuss all you want, heck I don't care if you get all chill running down your leg over it, not my place to tell you how to react, just sit back and enjoy the roller coaster ride

1578680472331.png
 
Ollie Williams said:
Mean is the highest I’ve seen the entire winter! Member 6 Lol.
ac224c7569c173b52fcfedced0bbaceb.jpg

f325ed3fbb8c6e89aa3daa1ff4f05b66.jpg
a2ba8e559e884fed66e637c60e04682b.jpg



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Click to expand...

Wow, that's an impressive ensemble mean. GEFS seems to be on board with the -EPO pattern change and so far it doesn't look like it dries up when the Alaskan ridge establishes. Still a good ways out, but very nice to see at least a colder change up ahead.
 
Nick_boynton_ said:
Well this should produce our thunder... that then means in 10 days we see snow .. let’s see how it verifies
Click to expand...

Not sure if you're serious, but according to -------------, that old wive's tale has been accurate (I'm going off memory) like 1 out of 8 times in the past decade. So, very little correlation, if any.
 
Brief warm-up after D10 on the eps, that wasn't there yesterday (I don't think) but looks like pattern reload after that.... delayed but not denied.
 
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