January 2019 Medium/Long Range Pattern Discussion

[Holston_River_Rambler]

Best looking 10 -15 day GEFS ensemble mean yet:

 

3'' mean line into N. Louisiana 

[AMZ8990]

36 minutes ago, Carvers Gap said:

I think right now I would not trust modeling on specifics due to the amount of cold air that is in play.  I do think cutters are definitely possible early on until the trough establishes itself.  What we need is a 1-2 punch during the early period of blocking.  First storm drags down the cold behind.  The second system overruns it.  Not a given, but that is one scenario that will work.  And agree, the warm-up and rain deal is always possible.

Actually, that is not the reason that I came on here to post this AM.  Wow, when I look at the GEFS and especially the EPS this AM...No idea if this is shown in the future, but the EPS, which has had a tendency all winter not to amplify troughs enough during d10-15, brings the PV into the Great Lakes late during the period.   During days 14-15, there are -8C departures over the upper Midwest(lower peninsula of Michigan).  That is very cold for an ensemble at that range.  Again, no idea if that is there on the next run, but given the configuration on the blocking that is certainly a higher probability now than during normal winters.  

Back to the cutter scenarios, there (as Jeff and I had kicked around) have been two storm tracks this winter ....There is the primary from KC to DC that Jeff had mentioned as the primary.  However, there have been some storms take the low road up the coast.  I think both of those continue.  Now, if the PV drops in...that completely changes all of that.  Heck, that might even change the duration of the cold as the cold would eventually be used-up and the pattern would end sooner.  But man, would it be really cold if that happened!  We are still about one week from this pattern really locking in.  I have a hunch that the storm track associated with the cold doesn't show itself until the cold is here.  Right now, the models are just now "figuring out the pattern" - meaning placement and evolution of the said trough.  So, I expect the details to be sketchy.  In my thinking, I sort of thought that we might not see a storm until the end of the month....but some models during the past couple of days hurried that look a bit and have since backed off which is not uncommon.  So, I suspect the storm pattern for the Upper South will arrive, but not as quickly as it looked a couple of days ago. I think a PV that is pressing southward will likely(highly likely) suppress the storm track, hopefully we will get a few shots before Mobile, AL, does!

 

  GEFS seems to really like the colder solution versus what the other models have been showing.   It’s been steady with that look for quite a while now too.  If it’s right then there will be some seriously cold air in our neighborhood to tap into.  Nice share from Holston in the above map as well, it’s gonna be an interesting couple of weeks for most of the lower 48 going forward I think in regards to wintry precip.  

[nrgjeff]

Confidence is pretty good on a somewhat sustained cold stretch. I think 2-3 weeks in a row temps will average BN but still some mild interludes between fronts. Pattern recognition north of I-40 and at higher elevations is favorable for snow at least once. Jury is out along US-72 until something can get within 36 hours. Hurry up and wait, lol!

MJO convection is noted in multiple zones, but none with dominant influence. Convection is forecast to lessen in the next 7-10 days. With less tropical forcing, the polar vortex should remain split. NWP is in good agreement on the cold. GFS clusters are all cold. EPS does have a SER minority cluster but it is only 25%. Other 75% are cold.

Deterministic models (both) tend to have semi-cutters through early next week. Ensembles are similar. I-40 north is in play for snow both times; but, I do not expect anything interesting in the HSV-CHA corridor. Just cold.

Quite possible the storm track continues to sink south into early February. Longer duration cold tends to intensify with time until it breaks. Such a scenario would leave the door open for everyone. For now I think I-40 north. Eagerly awaiting ECMWF weeklies tonight.

[Carvers Gap]

Like Jeff, really wanting to see where the Weeklies go after that wild run overnight.  At 12z, it was slightly less extreme.  It may very well be that the Weeklies are derived from an outlier(0z).  So, it should be interesting. 

...No change in my thinking after 12z.  I really don't trust any model with details until the trough sets up shop around the 20th.  Based on the multiple looks that were are seeing on operationals, I feel fairly confident that no model will do well until the cold is established - not really an earth shattering statement on my part.  I would be very surprised if we don't have 2-3 events(speaking of somewhere in the forum region) at least to track before mid-Feb.

[Mr Bob]

They are out and you don't need the groundhog....weeks 2-6 are all very cold...I am going to need a trip to Aruba by mid February. 

[Carvers Gap]

17 minutes ago, Mr Bob said:

They are out and you don't need the groundhog....weeks 2-6 are all very cold...I am going to need a trip to Aruba by mid February. 

Great news.  I wasn't sure whether to laugh, applaud, or just load the wood stove.  Thanks for the update!

[Mr Bob]

6 minutes ago, Carvers Gap said:

Great news.  I wasn't sure whether to laugh, applaud, or just load the wood stove.  Thanks for the update!

I love a great snow storm like everyone else here but 5+ weeks cold.....

[Holston_River_Rambler]

For your browsing pleasure (or pain):

 

[Carvers Gap]

Maybe I should put it in banter, but since we are in the quiet before the storm...someone did point out the 18z GFS.   Happy hour for all!

[Bango]

17 minutes ago, Carvers Gap said:

Maybe I should put it in banter, but since we are in the quiet before the storm...someone did point out the 18z GFS.   Happy hour for all!

Looked like happy hour to our north and south, but plenty to track

[Carvers Gap]

17 minutes ago, Bango said:

Looked like happy hour to our north and south, but plenty to track

h252 looked really good for this area as well.  Fairly strong winter storm for much of the forum.  Fantasy land stuff...Bango, you are in the TRI area aren't you?  Also, very cold temps.  Just one run, but interesting.  

[Carvers Gap]

26 minutes ago, Bango said:

Looked like happy hour to our north and south, but plenty to track

LOL.  I probably really should put this in banter.  I hadn't even seen the 16d snowfall map for the 18z GFS...plenty to track to the north, south, east, and west of TRI.  The snow hole over(we have a different name for it in town) Kingsport verifies...so this must be right.  If Chattanooga scored along with Knoxville...I can live with that.  Just one run...but definitely want to see loaded runs in the future.  That would be a good sign.

 

 

[BlunderStorm]

1 hour ago, Holston_River_Rambler said:

For your browsing pleasure (or pain):

 

Ahhh, that hits the spot. I've had enough of this holiday warmth.

[Carvers Gap]

FWIW, the 18z snow mean looks pretty good for most of the forum as well.

Another fun run, take a look at the 18z FV3 temps in southern Canada near the end of that run.  I saw -56F.  Wonder how long it will be until the Polar Vortex starts making headlines?  

[Bango]

16 minutes ago, Carvers Gap said:

LOL.  I probably really should put this in banter.  I hadn't even seen the 16d snowfall map for the 18z GFS...plenty to track to the north, south, east, and west of TRI.  The snow hole over(we have a different name for it in town) Kingsport verifies...so this must be right.  If Chattanooga scored along with Knoxville...I can live with that.  Just one run...but definitely want to see loaded runs in the future.  That would be a good sign.

 

 

Sorry, my snow output didnt show that, wow that is a healthy map for all

[Holston_River_Rambler]

Isotherm update for those interested. 

Mostly focused on northeast, but some good info for the pattern overall:

https://www.33andrain.com/topic/868-teleconnections-a-more-technical-discussion/?page=31&tab=comments#comment-121244  

Cherry-picked tidbit, for your perusal:

"Polar cap ozone reached record high levels recently, which is a pertinent proxy for BDC intensity and a strong precursor signal for anomalous high latitude blocking. Once the anomalous high latitude blocking accelerates in the troposphere, it should remain for a minimum of 30 days, potentially up to 45-50 days [which would take us into the first half of March]."

 

 

 

 

[Carvers Gap]

Just now, Bango said:

Sorry, my snow output didnt show that, wow that is a healthy map for all

Huge grain of salt since it is outside of d10.  I know you know that...just writing that for new folks looking in.  It may be an algorithm issue where I get mine.  Not sure.  I like that there are some nice storms in fantasy land though.  If we weren't seeing those, I would be pretty worried.  

[Carvers Gap]

1 minute ago, Holston_River_Rambler said:

Isotherm update for those interested. 

Mostly focused on northeast, but some good info for the pattern overall:

https://www.33andrain.com/topic/868-teleconnections-a-more-technical-discussion/?page=31&tab=comments#comment-121244  

 

 

 

 All I need to know....

The fruits of a felicitous pattern are almost always delayed from the point of initiation of favorability, and that particular adage will ring true this year as well.

and

Equatorward momentum transport will eventually result in split-flow structure and -AAM deposits in the high-latitudes, evidenced by aberrant -AO/-NAO blocking, set to accelerate significantly in the last week of January.

 

[beavis1729]

26 minutes ago, Carvers Gap said:

FWIW, the 18z snow mean looks pretty good for most of the forum as well.

Another fun run, take a look at the 18z FV3 temps in southern Canada near the end of that run.  I saw -56F.  Wonder how long it will be until the Polar Vortex starts making headlines?  

Yeah...FWIW, the incredible 462 dm thickness contour made an appearance at hour 306.  It's very rare to see even 474 dm...and 468 dm is almost unheard of.  462 dm almost seems impossible.  Sure, it's Day 13 on one run of an operational model...but this is noteworthy simply because, over the past 25 years of winter observing, I have never seen 462. 

Good times...and nice discussion in here too!

[Carvers Gap]

14 minutes ago, beavis1729 said:

Yeah...FWIW, the incredible 462 dm thickness contour made an appearance at hour 306.  It's very rare to see even 474 dm...and 468 dm is almost unheard of.  462 dm almost seems impossible.  Sure, it's Day 13 on one run of an operational model...but this is noteworthy simply because, over the past 25 years of winter observing, I have never seen 462. 

Good times...and nice discussion in here too!

Thanks for those thickness values!  Impressive.  The 18z GEFS is also depicting -30 stuff in those areas.  With the blocking being depicted over Greenland and AK and increasing snowpack over the Midwest, there is certainly a path for some very cold air to head south into the Lower 48.  Stop by any time.

[Carvers Gap]

Let's see if this verifies.  This is the 18z GEFS....Normally, I would question that look except that the Weeklies and this AM's EPS basically have the same look.  

[ShawnEastTN]

It also seems like it's been quite a long time since I've seen the fantasy storms and cold being modeled relatively consistently. Maybe 3 or 4 years since I remember seeing multiple fantasy storms coming up on multiple runs. Of course getting them over the hump out of fantasy into closer range will be nice. I have to say I'm getting pretty excited, and I usually temper that quite a bit.

Sent from my SM-G965U using Tapatalk

[John1122]

Right now we have the EPS/GEFS/Weeklies showing winter in the heart of winter. We rarely ever manage to pull that look off. A few years ago we had a very snowy/cold stretch but even that one happened more from February 15th-March 10th or so.  Last year we had it in March and April. I was in 2 inches of snow here on April 18th. 

We are basically looking at the potential for those types of patterns but in prime time.  Hopefully we can cash it in.  I've not been looking at specific features today,  but David Aldrich showed a model run for next weekends system that spit out 2-4 inches in the area. No idea if it was the GFS/GEM/Euro. Either way it's the precursor to the first shot of Arctic air. After that we just get colder and colder.

These wild temps showed up in 2015 in the day 14-16 range while we were having a mild January. Seemed incredible at the time but we got big winter events and well below 0 cold with single digit afternoon temps during that stretch when it finally got here. 

[John1122]

GFS took its miller A monster from 18z, sped it up and warmed it up. Rainer that run even with a perfect Miller A track. Eventually the pattern/storm track will shake out but a storm with that track and plenty of cold on this  side of the country should not be a rain event up to the Ohio River. 

[John1122]

The Euro laughed at the GFS and pushed rain into Toronto, Canada that run. OP of the models are not in any form of agreement with their ensembles. I guess there's too much chaos going on right now for anything close to stable modeling.

[Bango]

32 minutes ago, John1122 said:

The Euro laughed at the GFS and pushed rain into Toronto, Canada that run. OP of the models are not in any form of agreement with their ensembles. I guess there's too much chaos going on right now for anything close to stable modeling.

Fv3 also showed the gfs solution, piss

[weathertree4u]

Are the guys at the NWS in Nashville looking at the same modeling as everyone else, the last of the morning discussion...

 will be some 40 to 50 degrees
colder than highs on Saturday. Thankfully, the Arctic cold blast
does not look like it will last long as models show temperatures
warming up quickly by the middle of next week ahead of our next
storm system.

 

[Carvers Gap]

Remember, there is brief warm-up after the weekend storm(has been there for some time) as the trough establishes itself in the East.  Cutters are also fairly normal early in this type of pattern.  

That said, the 6z GFS was a decent run w northwest flow.  Check out the GEFS snow mean for 6z.  Ensembles are the way to go until this trough dumps into the East.  Cold causes all kinds of wild swings after day 5 or 6.  Operational are just but one of the individuals for the most part.  The ensembles generally wash-out the wild swings.  The graphic below is not a certainty, but speaks to potential.  I highly doubt we this on every run, but it is impressive nonetheless.  

[Carvers Gap]

Also, I think that we will see brief warm-ups.  A couple of our mets mentioned that.  As these pieces of cold pinwheel down, there is room for brief but warm air masses to squeeze into the space in between cold air masses.  Now, after next weekend's warmup, there is very little "let-up." That could always change, but there is very little that says otherwise.  

[AMZ8990]

23 minutes ago, Carvers Gap said:

Remember, there is brief warm-up after the weekend storm(has been there for some time) as the trough establishes itself in the East.  Cutters are also fairly normal early in this type of pattern.  

That said, the 6z GFS was a decent run w northwest flow.  Check out the GEFS snow mean for 6z.  Ensembles are the way to go until this trough dumps into the East.  Cold causes all kinds of wild swings after day 5 or 6.  Operational are just but one of the individuals for the most part.  The ensembles generally wash-out the wild swings.  The graphic below is not a certainty, but speaks to potential.  I highly doubt we this on every run, but it is impressive nonetheless.  

I commend you on sticking with your forecast buddy,  you’ve been saying for months that more than likely this would be a back loaded winter and that we would have to be patient with the cold air.  I know we aren’t quite there yet but as it sits now your prediction looks pretty spot on.  Your getting pretty good at this hobby as you call it!!