December 2023 Mid/Long Term Pattern Discussion: Let it Snow!

[Daniel Boone]

2 hours ago, Carvers Gap said:

MRX mentioned snow above 3k' I "think."

The 12z Euro also is picking up on an active (mostly rainy) wx pattern during the next ten days.  That storm around 170-180hr probably is going to have to be watched for frozen possibilities either with wrap around or with the storm itself.  There may be some minor upslope potential following it.  Still way out there, so lots of possibilities...but generally a slp tracking to our SE w/ marginal surface temps.

Yeah, checked their Twitter and they finally did mention possibly ending as a mix in the Mountains Monday morning last night. Of course they were referencing higher elevations. So, still late and also the elevation and precip type part. With the setup and model output I'd worded flurries in the lower eles Monday morning with snow shower's in higher elevations ending late morning.

    Depending on how long and strong blocking holds, could be cooler than indicated during projected mild period. 

 

[fountainguy97]

Some pretty surprising confidence in models for some NW action on the back side of the next big system December 6-8th.  GFS has a secondary low take a clipper-like path.
 

this EPS blend is showing you where precip is falling below 33 degrees or likely snow. (Brown) pretty much every model and ensemble member has some NW snow occurring at this time frame. 
 

let's see if we trend to a more significant event or away from one in the next few days.
 

[Carvers Gap]

No idea if the Euro Weeklies are correct, but generally when an ensemble is that cold at range, reality is much colder...if it verifies.  Bullseye is around NYE to the first week of January.  Transition begins well before then.   

[Itryatgolf70]

3 hours ago, Carvers Gap said:

No idea if the Euro Weeklies are correct, but generally when an ensemble is that cold at range, reality is much colder...if it verifies.  Bullseye is around NYE to the first week of January.  Transition begins well before then.   

I know the weeklies used to run twice a week, but now every day I think. Excitement every day in some form or fashion

[Carvers Gap]

51 minutes ago, Itryatgolf70 said:

I know the weeklies used to run twice a week, but now every day I think. Excitement every day in some form or fashion

The weeklies which run daily.  

[Carvers Gap]

The 938 SLP at 378 on the 18z GFS is worth your time.  LOL!!!

[Daniel Boone]

Radiance wx posted on main forum enso thread how CFS v2 was showing a warm December referencing the eastern states as he's been forecasting. He showed how his analogues have outperformed guidance this Fall. He's been forecasting another cold /snowy Winter in New Mexico where he lives. 

He actually does pretty good over all but, he kinda stuck his foot in his mouth as the CFS 2 is showing the entire country mild for December, even New Mexico. 

     I thought it kind of funny, lol

[Carvers Gap]

Interesting overnight developments in regards to Weeklies output.  The transition week looks to be the week of Christmas.  That could leave us with a seasonal or warm Christmas.  It is after that that the longwave pattern is quite cold.  Now, I must caution...modeling has (likely) already erroneously signaled that cold transition this winter for the Dec 14th time frame - technically, it could end up being correct.  But that was shoulder season modeling, and maybe even it was an example of the cart getting in front of the horse - meaning sometimes modeling flips too quickly by a week or two.  So, the expected turn to colder was pushed back.  However, the transition begins about 7-10 days after LR extended modeling originally had it.  Is it right? I am very cautiously optimistic.  The actual pattern transition to an eastern trough sits in the 21-28 day range(with hints of the transition even prior to that as rains are now returning it appears - reference LC).  So, there is some skill there, but models will often bust in that range.  What is the biggest concern?  The cold dumps West and holds and/or a strat warm is just creating havoc in LR modeling.  I don't think that happens but the residual PDO (does anyone have the current, daily output?) and Nino climatology could do exactly that.  I just don't think it holds in the West this time.  The MJO would likely kick it out as it is primed for decent phases by mid winter.   So we might be looking at our first cold shot of the winter.  It might work something like this:

Weeks 1-2 of December: warm

Week 3: transitional phase

Week 4:  seasonably cold

Weeks 1-2 of January: cold

But all of that said, it would absolutely not surprise me to see all of that shifted back two weeks.  I seems like it really wants to be warm IMBY during the New Year, and the second or third week of Jan is when the colder part of Nino winters hit.  But the above is what modeling is generally showing right now.  Is it right?  I don't know, but I think it is a bit quick and maybe a bit extreme.  And it is odd to see modeling so cold at this range.  Time will tell.

My recent experience w/ 10mb strat warms is that models will erroneously dump cold into the East, but revert to the West(that could be Nina climatology doing that during the past three years).  But the general defaults of strat warming cold displacement are: 1. Eurasia 2. western US 3. EC in that order.

New CANSIPS out in a couple of days....

[Itryatgolf70]

6 hours ago, Carvers Gap said:

Interesting overnight developments in regards to Weeklies output.  The transition week looks to be the week of Christmas.  That could leave us with a seasonal or warm Christmas.  It is after that that the longwave pattern is quite cold.  Now, I must caution...modeling has (likely) already erroneously signaled that cold transition this winter for the Dec 14th time frame - technically, it could end up being correct.  But that was shoulder season modeling, and maybe even it was an example of the cart getting in front of the horse - meaning sometimes modeling flips too quickly by a week or two.  So, the expected turn to colder was pushed back.  However, the transition begins about 7-10 days after LR extended modeling originally had it.  Is it right? I am very cautiously optimistic.  The actual pattern transition to an eastern trough sits in the 21-28 day range(with hints of the transition even prior to that as rains are now returning it appears - reference LC).  So, there is some skill there, but models will often bust in that range.  What is the biggest concern?  The cold dumps West and holds and/or a strat warm is just creating havoc in LR modeling.  I don't think that happens but the residual PDO (does anyone have the current, daily output?) and Nino climatology could do exactly that.  I just don't think it holds in the West this time.  The MJO would likely kick it out as it is primed for decent phases by mid winter.   So we might be looking at our first cold shot of the winter.  It might work something like this:

Weeks 1-2 of December: warm

Week 3: transitional phase

Week 4:  seasonably cold

Weeks 1-2 of January: cold

But all of that said, it would absolutely not surprise me to see all of that shifted back two weeks.  I seems like it really wants to be warm IMBY during the New Year, and the second or third week of Jan is when the colder part of Nino winters hit.  But the above is what modeling is generally showing right now.  Is it right?  I don't know, but I think it is a bit quick and maybe a bit extreme.  And it is odd to see modeling so cold at this range.  Time will tell.

My recent experience w/ 10mb strat warms is that models will erroneously dump cold into the East, but revert to the West(that could be Nina climatology doing that during the past three years).  But the general defaults of strat warming cold displacement are: 1. Eurasia 2. western US 3. EC in that order.

New CANSIPS out in a couple of days....

I think it's about the mjo progression if it means anything into the colder phases. Hopefully sooner rather than later. The weeklies coming out every day now causes alot of emotional rollacosters. 

[Carvers Gap]

5 minutes ago, Itryatgolf70 said:

I think it's about the mjo progression if it means anything into the colder phases. Hopefully sooner rather than later. The weeklies coming out every day now causes alot of emotional rollacosters. 

Nah, this is a pretty good sub-forum for not having emotional roller coasters.  Or maybe we all have just ridden this roller coaster enough...that we know that fluctuations in extended LR are just normal.

Yes, the MJO almost always has a say.  I think it was Flash who noted that when we are talking about the MJO...the weather pattern is usually not conducive for snow.  LOL. So, I don't talk about it as much.

Truly, I don't think winter has shown its hand quite yet.  We are kind of in that transitional timeframe for a few weeks.  I do like how the Weeklies look, but we will see if it is legit.

 

 

[Daniel Boone]

9 hours ago, Carvers Gap said:

Interesting overnight developments in regards to Weeklies output.  The transition week looks to be the week of Christmas.  That could leave us with a seasonal or warm Christmas.  It is after that that the longwave pattern is quite cold.  Now, I must caution...modeling has (likely) already erroneously signaled that cold transition this winter for the Dec 14th time frame - technically, it could end up being correct.  But that was shoulder season modeling, and maybe even it was an example of the cart getting in front of the horse - meaning sometimes modeling flips too quickly by a week or two.  So, the expected turn to colder was pushed back.  However, the transition begins about 7-10 days after LR extended modeling originally had it.  Is it right? I am very cautiously optimistic.  The actual pattern transition to an eastern trough sits in the 21-28 day range(with hints of the transition even prior to that as rains are now returning it appears - reference LC).  So, there is some skill there, but models will often bust in that range.  What is the biggest concern?  The cold dumps West and holds and/or a strat warm is just creating havoc in LR modeling.  I don't think that happens but the residual PDO (does anyone have the current, daily output?) and Nino climatology could do exactly that.  I just don't think it holds in the West this time.  The MJO would likely kick it out as it is primed for decent phases by mid winter.   So we might be looking at our first cold shot of the winter.  It might work something like this:

Weeks 1-2 of December: warm

Week 3: transitional phase

Week 4:  seasonably cold

Weeks 1-2 of January: cold

But all of that said, it would absolutely not surprise me to see all of that shifted back two weeks.  I seems like it really wants to be warm IMBY during the New Year, and the second or third week of Jan is when the colder part of Nino winters hit.  But the above is what modeling is generally showing right now.  Is it right?  I don't know, but I think it is a bit quick and maybe a bit extreme.  And it is odd to see modeling so cold at this range.  Time will tell.

My recent experience w/ 10mb strat warms is that models will erroneously dump cold into the East, but revert to the West(that could be Nina climatology doing that during the past three years).  But the general defaults of strat warming cold displacement are: 1. Eurasia 2. western US 3. EC in that order.

New CANSIPS out in a couple of days....

Hopefully, the mild spell is shorter than forecasted. Block will squelch it some. MJO Amplitude in warm phase may be the determining factor in how much warming we get. That warm pool might amplify it's affects, however though. Hopefully, it will move along and get to cold phases. It should hit a decent Amp once there. 

[Carvers Gap]

5 minutes ago, Daniel Boone said:

Hopefully, the mild spell is shorter than forecasted. Block will squelch it some. MJO Amplitude in warm phase may be the determining factor in how much warming we get. That warm pool might amplify it's affects, however though. Hopefully, it will move along and get to cold phases. It should hit a decent Amp once there. 

I expect the warmup to be longer than expected.  The MJO will work against us until mid Jan I think, and then it flips in our favor.   I still think mid-Jan through Feb is our best shot.  Anything prior is just bonus for me.  Pretty active pattern though with poor temp source regions feeding it.  Good to see the pattern being modeled as an active one.

[Daniel Boone]

2 hours ago, Carvers Gap said:

I expect the warmup to be longer than expected.  The MJO will work against us until mid Jan I think, and then it flips in our favor.   I still think mid-Jan through Feb is our best shot.  Anything prior is just bonus for me.  Pretty active pattern though with poor temp source regions feeding it.  Good to see the pattern being modeled as an active one.

Yeah, wouldn't surprise me with Nino Climo and the basically basin wide strong Nino. The phase forcing should change favorably in January. So, you're probably right man. I still hold some hope for something to knock the typical canonical Nino December off kilter enough to give us a shot or two. 

[Carvers Gap]

The 0z and 6z GFS with some interesting solutions overnight....

[Carvers Gap]

Sometimes I read JB, and wonder...did we just talk about that on our sub-forum?  And yes, yes we did this time.  He has a nice post about the MJO this morning, and....how it is driving the pattern. @Daniel Boone, you called front seat on this one!  Anyway, I take a slightly different tangent than JB(I think) and use the GEFS ext(weeklies) as the GEFS has simply been kicking butt and taking names of late, and it usually does this during shoulder season.  Then, after shoulder season, the ECMWF suite returns the favor most years.  

The first slide is the MJO centered on NDJ.  Of note, if centered on OND, the southeast ridge presents itself in phases 8, 1, and 2.  The lesson?  The deeper that we get into December the more that regions 8 and 1 verify as colder.  The next three slides are the CPC indices re:  NAO, AO, and PNA.  The NAO in my opinion is just not overly important at this time of year.  It matters more during mid/later winter and spring.  And note to self, an -NAO during fall means scorching hot temps in the southeast(same for summer usually).  The AO and PNA are going to drive the bus this winter IMHO.  With the NAO going negative early, it probably will have a say later this winter as that often repeats.  However, when the PNA/AO are in tandem it gets cold here.  Just look at the last couple of days for evidence.

Now, onto the MJO....take a look at the GEFS ext.  This plot came out yesterday.  It rotates into phase 8 around the 17th.  Many weeklies model runs have been fairly stubborn in the regime changing around mid-month.   This has been true since the beginning of November.  And even more interesting, the pushing back of the pattern changes has been almost non-existent.  Maybe during the past month it has been pushed back 24-72 hours.  I think I had a post a couple of weeks ago about modeling switching up around the 14th.  It might be the 17th now.  But overall, the week of Christmas looks like a transition timeframe with decent potential afterwards.

And how do we know the MJO is in crap phases right now...well, because we are having to talk about it(Flash's rule #1).  The good news is that we should see it rotate on around instead of camping out inf 4-5-6.

Lastly, source regions matter.  Beware during El Nino years....

 

[fountainguy97]

Our clipper for next week just won't go away.  Ceiling is probably pretty low because it's positive tilt but if we can get it closed off could really be a nice little start to December. 

[Daniel Boone]

1 hour ago, Carvers Gap said:

Sometimes I read JB, and wonder...did we just talk about that on our sub-forum?  And yes, yes we did this time.  He has a nice post about the MJO this morning, and....how it is driving the pattern. @Daniel Boone, you called front seat on this one!  Anyway, I take a slightly different tangent than JB(I think) and use the GEFS ext(weeklies) as the GEFS has simply been kicking butt and taking names of late, and it usually does this during shoulder season.  Then, after shoulder season, the ECMWF suite returns the favor most years.  

The first slide is the MJO centered on NDJ.  Of note, if centered on OND, the southeast ridge presents itself in phases 8, 1, and 2.  The lesson?  The deeper that we get into December the more that regions 8 and 1 verify as colder.  The next three slides are the CPC indices re:  NAO, AO, and PNA.  The NAO in my opinion is just not overly important at this time of year.  It matters more during mid/later winter and spring.  And note to self, an -NAO during fall means scorching hot temps in the southeast(same for summer usually).  The AO and PNA are going to drive the bus this winter IMHO.  With the NAO going negative early, it probably will have a say later this winter as that often repeats.  However, when the PNA/AO are in tandem it gets cold here.  Just look at the last couple of days for evidence.

Now, onto the MJO....take a look at the GEFS ext.  This plot came out yesterday.  It rotates into phase 8 around the 17th.  Many weeklies model runs have been fairly stubborn in the regime changing around mid-month.   This has been true since the beginning of November.  And even more interesting, the pushing back of the pattern changes has been almost non-existent.  Maybe during the past month it has been pushed back 24-72 hours.  I think I had a post a couple of weeks ago about modeling switching up around the 14th.  It might be the 17th now.  But overall, the week of Christmas looks like a transition timeframe with decent potential afterwards.

And how do we know the MJO is in crap phases right now...well, because we are having to talk about it(Flash's rule #1).  The good news is that we should see it rotate on around instead of camping out inf 4-5-6.

Lastly, source regions matter.  Beware during El Nino years....

 

Excellent post brother ! As far as any credit to me, just seeing what's presented before us and giving my relic opinion, lol. Going to be alot of  luck with this one. Basin wide Nino going to make it tougher, really. Sure there's more favored forcing areas but ...you know what I'm saying. To pinpoint exactly when the MJO will reach the cold phases, your Post is right on. You're the best man ! 

[Itryatgolf70]

2 hours ago, Carvers Gap said:

Sometimes I read JB, and wonder...did we just talk about that on our sub-forum?  And yes, yes we did this time.  He has a nice post about the MJO this morning, and....how it is driving the pattern. @Daniel Boone, you called front seat on this one!  Anyway, I take a slightly different tangent than JB(I think) and use the GEFS ext(weeklies) as the GEFS has simply been kicking butt and taking names of late, and it usually does this during shoulder season.  Then, after shoulder season, the ECMWF suite returns the favor most years.  

The first slide is the MJO centered on NDJ.  Of note, if centered on OND, the southeast ridge presents itself in phases 8, 1, and 2.  The lesson?  The deeper that we get into December the more that regions 8 and 1 verify as colder.  The next three slides are the CPC indices re:  NAO, AO, and PNA.  The NAO in my opinion is just not overly important at this time of year.  It matters more during mid/later winter and spring.  And note to self, an -NAO during fall means scorching hot temps in the southeast(same for summer usually).  The AO and PNA are going to drive the bus this winter IMHO.  With the NAO going negative early, it probably will have a say later this winter as that often repeats.  However, when the PNA/AO are in tandem it gets cold here.  Just look at the last couple of days for evidence.

Now, onto the MJO....take a look at the GEFS ext.  This plot came out yesterday.  It rotates into phase 8 around the 17th.  Many weeklies model runs have been fairly stubborn in the regime changing around mid-month.   This has been true since the beginning of November.  And even more interesting, the pushing back of the pattern changes has been almost non-existent.  Maybe during the past month it has been pushed back 24-72 hours.  I think I had a post a couple of weeks ago about modeling switching up around the 14th.  It might be the 17th now.  But overall, the week of Christmas looks like a transition timeframe with decent potential afterwards.

And how do we know the MJO is in crap phases right now...well, because we are having to talk about it(Flash's rule #1).  The good news is that we should see it rotate on around instead of camping out inf 4-5-6.

Lastly, source regions matter.  Beware during El Nino years....

 

Carver, not sure if you know about this website, but it has alot of stuff for people to look at: daculaweather.com. if it don't take you straight to mjo page, just put in: dacula weather mjo. Very informative stuff

[Carvers Gap]

27 minutes ago, Itryatgolf70 said:

Carver, not sure if you know about this website, but it has alot of stuff for people to look at: daculaweather.com. if it don't take you straight to mjo page, just put in: dacula weather mjo. Very informative stuff

He used to post in the SE forum. Great poster and site.

[Carvers Gap]

The 12z GFS and CMC both have the northern stream energy now.  I think that would be good for the northern Plateau.  Both are colder than earlier ensembles.

[Daniel Boone]

5 hours ago, Itryatgolf70 said:

Carver, not sure if you know about this website, but it has alot of stuff for people to look at: daculaweather.com. if it don't take you straight to mjo page, just put in: dacula weather mjo. Very informative stuff

Larry's website. 

[Carvers Gap]

Just looking at what I like to think are the final seasonal model runs for winter.  The CFSv2 run today is really good, and the CANSIPS is really not.  Both do feature varying degrees of beneficial HL blocking.  The low in the eastern Pacific is just shredding modeling right now(and the placement thereof).  LC mentions this in a post on social media today.  

[Daniel Boone]

Yeah, been hoping trend would be westward with that feature. 

[Carvers Gap]

Both the 12z GFS and CMC look decently December-ish.  They at least have my passing interest.

[jaxjagman]

1 hour ago, Carvers Gap said:

Both the 12z GFS and CMC look decently December-ish.  They at least have my passing interest.

Thats a decent trough going through East Asia Wednesday,you higher elevation people seemingly this time of year could get winter around the 14th give or take IMO.probably just cool rain for us

[Carvers Gap]

The Euro Weeklies are something to behold this evening.  Same sequence as share before, but man.

[Itryatgolf70]

8 minutes ago, Carvers Gap said:

The Euro Weeklies are something to behold this evening.  Same sequence as share before, but man.

Carver, can you elaborate some? Lol

[Carvers Gap]

The 18z GFS....what a way to run a warm-up.

[Carvers Gap]

The clown map is gonna be fun.  LOL.

[Daniel Boone]

54 minutes ago, Carvers Gap said:

The clown map is gonna be fun.  LOL.

Yeah, has one Storm(18th) dumping 14" here.