December 2017 Mid-Long Range Disco 2

[Ralph Wiggum]

Understatement of the century. the Ocean gets more snowfall than we get in an entire year. I imagine the odds of getting 1' of snow from both of those events is something like 1/1000000000, but I'm hopeful with that GFS run 

GFS op shows how we can fail in 2 different ways with 2 potential MECS within 3 days of each other......first a hair West, second a hair East. Ultimate tease run.

[Cobalt]

2 minutes ago, Ralph Wiggum said:

6 minutes ago, Cobalt said:

Understatement of the century. the Ocean gets more snowfall than we get in an entire year. I imagine the odds of getting 1' of snow from both of those events is something like 1/1000000000, but I'm hopeful with that GFS run 

GFS op shows how we can fail in 2 different ways with 2 potential MECS within 3 days of each other......first a hair West, second a hair East. Ultimate tease run.

I imagine we cash in on at least 1 snow event before the year ends

[Bob Chill]

Nice to see the gfs speed things up but till not a good upper level pattern for snow. It did work a few times with similar setups in 2014. That's a strong ridge in the atl on the run though. Prob becuase of the big cutoff pumping heights in front. Weird run for sure. 

[Cobalt]

Just now, Bob Chill said:

Nice to see the gfs speed things up but till not a good upper level pattern for snow. It did work a few times with similar setups in 2014. That's a strong ridge in the atl on the run though. Prob becuase of the big cutoff pumping heights in front. Weird run for sure. 

Weirder than the run that had 70s for Christmas?

[Bob Chill]

Just now, Cobalt said:

Weirder than the run that had 70s for Christmas?

Nah, cmc covered that again tonight. Consensus. 

[Cobalt]

Much weaker signal for the SE ridge's extent on the 0z GEFS. Again, I can't post since I can't post image files larger than 0.03MB

[Cobalt]

Snow mean upped for potential Wednesday event as per GEFS. 3/20 members show 1.5" of snow or more for DC. There's hope

[BuffaloWeather]

Buf NWS says get excited, the cold is coming again. If it gets to Ohio Valley it should hit Mid Atlantic shortly after. 

Quote

A closed low over Siberia is forecast to break down in the coming days with a chunk of its energy being ejected out across the Kamchatka Peninsula and northern reaches of the Pacific ocean. Eventually...this very robust bundle of mid level energy is forecast to help carve out a full latitude trough over the heart of North America. While highly anomalous ridging off the West coast would extend from 20N all the way to the Pole...a large portion 0f the polar vortex would settle south to northern Ontario. This newly phased pattern would not only include a cross polar flow...but more importantly would allow H85 temps of <-30c within the vortex to make their way across the northern plains. While this long range forecast would place the coldest air of this outbreak over the plains states...the air would eventually make its way to the Ohio Valley.

 

[Cobalt]

1 minute ago, BuffaloWeather said:

Buf NWS says get excited, the cold is coming again. If it gets to Ohio Valley it should hit Mid Atlantic shortly after. 

 

Hype is (hopefully) real!

[Cobalt]

GEFS shows a slight ridge from during Christmas, but judging by the snow mean upping during that time, it must be just a few member skewing the mean. Def not as bad as the 18z, and while the 18z had the ridge still there on the 26th, the 0z GEFS has the ridge broken down

[Cobalt]

I'm so bummed that I can't post images due to the bogus Max total file size limit. Good GFS/GEFS run

[Birds~69]

27 minutes ago, Cobalt said:

I'm so bummed that I can't post images due to the bogus Max total file size limit. Good GFS/GEFS run

You need to delete some old attachments. Your probably a shade below the max which I think is 40MB...

[Chris78]

When comparing the gefs 18z to the 0z there' a bigger difference  during the 7 to 10 day time frame than what there is later in the run. I think that really shows how much uncertainty there is over the holiday weekend. The models are having a really hard time with the strength of the war. 

[Cobalt]

0z Euro pretty similar to 12z, if not faster in delivering the cold air, but not by much. I like seeing that consistency there

[Cobalt]

Euro actually has temps not topping freezing the day after Christmas. All we need is precip and a dash of good luck, and we're golden from the 24th to past New Year's

 

 

[AfewUniversesBelowNormal]

The 12/23 storm will probably be far enough south to give us snow.

 

[Cobalt]

3 minutes ago, AfewUniversesBelowNormal said:

The 12/23 storm will probably be far enough south to give us snow.

 

I agree with you there. 0z runs may not be a fluke, especially since the EPS/Euro have said the same thing for the past 24 hours, and the GFS and sort of  GEFS have joined the idea of the cold air getting here before Christmas. Only time will tell

[Cobalt]

0z EPS is warmer, but I just think that's due to the fact that if it were to be warm on Christmas, it would be a torch. Looked at individual members. 13/26 show near-below normal temperatures, but 10/26 show torch for Christmas. Not too far off the GEFS, but a bit cooler

[mitchnick]

6z GFS=boring

[MillvilleWx]

Just now, mitchnick said:

6z GFS=boring

The natural gas market would be everything but lol As for here, it would be incredibly meh. I'm sure EJ just mehed in his sleep after feeling the disturbance in the force

[BristowWx]

1 hour ago, MillvilleWx said:

The natural gas market would be everything but lol As for here, it would be incredibly meh. I'm sure EJ just mehed in his sleep after feeling the disturbance in the force

Still no real consensus about the 23-26 but still better than 18z yesterday.  I think the Euro just had it cold on the 25th.  Maybe today something new and exciting.  

[showmethesnow]

Thought I would go over a little of what's in play for around Christmas (Christmas eve/Christmas/Day after). As I have mentioned quite often it will probably come down to what type of interaction we see with the SW trough/energy and any trough surges southward out of Canada. Picked several runs from the EPS centered on Sun 00Z to give you some of the different scenarios.

Below we see the latest run of the EPS. This is very shortly after we see the SW trough/energy get slowly ejected eastward. What we are seeing is that the influence of that trough/energy is strong enough that the upper trough surge is throwing most of its energy in diving into it. Thus we see with the trough/energy's slow ejection the energy is getting dumped towards the SW US. If you follow the pressure anomalies it gives you a good idea where. Now what this dump into the southwest is also doing is pumping up and reinforcing War (Western Atlantic Ridging). So what we are seeing with this setup is... A) The cold is getting dumped farther west (more distance to travel) B ) the eastward movement of the cold has been dampened (much of the energy is being dumped southward not eastward) C) WAR is coming in stronger (makes it more difficult for the cold to break it down). This is probably not the look you want to pin your hopes on for a cold or even possibly snowy/icy period around Christmas.

 

Now below we see yesterdays 12Z run. This features a quicker ejection of the SW trough/energy so it is farther east when we see the upper trough surge southwards. Again the ejected SW trough/energy is strong enough that we are seeing the energy is mostly being dumped southward into it in the central portion of the country instead of into the southwest as the previous case. Again we see this pumping up the WAR but notice where the stronger height anomalies are occurring. They are now farther north then the previous map. So what we see compared to the map above is A) The cold is being dumped further east (less distance to travel). B ) A more easterly component to the dump (A little more oomph pushing eastward) C) Higher heights through our latitude are weaker (Less resistance to the cold pushing in). This setup could work for getting cold in for the Christmas period but as far as frozen I would think the odds are of the lower order (discounting flurries). 

 

 

Now below we have a run from two days ago. The difference we are seeing is that the SW trough/energy is not getting ejected. We are also seeing it farther south extended all the way off of the Baja. So while it is influencing the upper trough surge southward that influence is muted a good deal by it's farther south positioning and generally weaker overall look. So what we are seeing is that the upper trough surge isn't getting sucked whole hog into the southwest but instead bleeding a small portion into it while the majority of the energy is allowed to escape eastward. Now what does this mean downstream through our region for the Christmas period? Well we see A) Much less energy being pumped into the SW trough which in turn means weaker ridging off the east coast (less resistance to the cold pushing eastward). B ) Most of the energy from the upper trough surge is invested in an easterly component and not being spent moving southward (more oomph and quicker progression of the cold eastward). C) Much better setup leading into Christmas period for possible froze which I will explain in detail below.

Not going to post pics but essentially what we are seeing play out with this setup is that the cold will be pressing in more so from the north as opposed to the other two setups where we see it press in from the west. What this means is that the boundary through our region will have a more west to east component through our region vs. the other two that have a strong north to south component. This different configuration of the boundary and what it represents is key. What it represents is that we have blocking being created by the pv to the north which any amplifying system will have a hard time fighting to gain latitude. This boundary also offers the hope of multiple waves of energy riding along it as well through the Christmas period. Now compare this to the other two with their N to S configured boundaries. Their setups argue for pretty much a one shot deal with any possible storm and with a fairly high likelihood of them cutting west (especially the first one).

Now at this point I still think all options are on the table and I really favor none. The one thing I do possibly favor though is the cold will probably get in a little later through the Christmas period (day after?)

 

 

[BristowWx]

Another great write up Showme....perfect read for morning coffee.  6z did look rather uneventful once the front passes.  Still far out but a dry cold look for sure after 25th.  Still it avoids all out torch that run. Best we can hope for perhaps.  

[RDM]

Another excellent write-up showme...  Your balance of technical depth presented in plain ole English is a benchmark to shoot for.  Not sure what you do daily for a living, but you've clearly honed some impressive presentation skills.  Well done...

As a cursed engineer, I try to visualize the fluid dynamics of what's going on in the atmosphere.  That said, visualizing it is one thing, being able to eloquently present it is another.  And, you've done that with aplomb. 

Am hoping the more progressive influx of the PV keeps the WAR far enough off the coast to keep us on the colder side of the boundary.  Would be great to see several waves come through and give us a nice ride into 18. 

[Buddy1987]

25 minutes ago, showmethesnow said:

Thought I would go over a little of what's in play for around Christmas (Christmas eve/Christmas/Day after). As I have mentioned quite often it will probably come down to what type of interaction we see with the SW trough/energy and any trough surges southward out of Canada. Picked several runs from the EPS centered on Sun 00Z to give you some of the different scenarios.

Below we see the latest run of the EPS. This is very shortly after we see the SW trough/energy get slowly ejected eastward. What we are seeing is that the influence of that trough/energy is strong enough that the upper trough surge is throwing most of its energy in diving into it. Thus we see with the trough/energy's slow ejection the energy is getting dumped towards the SW US. If you follow the pressure anomalies it gives you a good idea where. Now what this dump into the southwest is also doing is pumping up and reinforcing War (Western Atlantic Ridging). So what we are seeing with this setup is... A) The cold is getting dumped farther west (more distance to travel) B ) the eastward movement of the cold has been dampened (much of the energy is being dumped southward not eastward) C) WAR is coming in stronger (makes it more difficult for the cold to break it down). This is probably not the look you want to pin your hopes on for a cold or even possibly snowy/icy period around Christmas.

 

Now below we see yesterdays 12Z run. This features a quicker ejection of the SW trough/energy so it is farther east when we see the upper trough surge southwards. Again the ejected SW trough/energy is strong enough that we are seeing the energy is mostly being dumped southward into it in the central portion of the country instead of into the southwest as the previous case. Again we see this pumping up the WAR but notice where the stronger height anomalies are occurring. They are now farther north then the previous map. So what we see compared to the map above is A) The cold is being dumped further east (less distance to travel). B ) A more easterly component to the dump (A little more oomph pushing eastward) C) Higher heights through our latitude are weaker (Less resistance to the cold pushing in). This setup could work for getting cold in for the Christmas period but as far as frozen I would think the odds are of the lower order (discounting flurries). 

 

 

Now below we have a run from two days ago. The difference we are seeing is that the SW trough/energy is not getting ejected. We are also seeing it farther south extended all the way off of the Baja. So while it is influencing the upper trough surge southward that influence is muted a good deal by it's farther south positioning and generally weaker overall look. So what we are seeing is that the upper trough surge isn't getting sucked whole hog into the southwest but instead bleeding a small portion into it while the majority of the energy is allowed to escape eastward. Now what does this mean downstream through our region for the Christmas period? Well we see A) Much less energy being pumped into the SW trough which in turn means weaker ridging off the east coast (less resistance to the cold pushing eastward). B ) Most of the energy from the upper trough surge is invested in an easterly component and not being spent moving southward (more oomph and quicker progression of the cold eastward). C) Much better setup leading into Christmas period for possible froze which I will explain in detail below.

Not going to post pics but essentially what we are seeing play out with this setup is that the cold will be pressing in more so from the north as opposed to the other two setups where we see it press in from the west. What this means is that the boundary through our region will have a more west to east component through our region vs. the other two that have a strong north to south component. This different configuration of the boundary and what it represents is key. What it represents is that we have blocking being created by the pv to the north which any amplifying system will have a hard time fighting to gain latitude. This boundary also offers the hope of multiple waves of energy riding along it as well through the Christmas period. Now compare this to the other two with their N to S configured boundaries. Their setups argue for pretty much a one shot deal with any possible storm and with a fairly high likelihood of them cutting west (especially the first one).

Now at this point I still think all options are on the table and I really favor none. The one thing I do possibly favor though is the cold will probably get in a little later through the Christmas period (day after?)

 

 

Really the one thing I am looking for is to see if the Euro has its typical bias of holding the s/w energy back  in the Southwest too long, as it normally has a tendency to do this. The GFS is off it’s rocker right now and literally almost spits out a different solution every 6 hours. 

[eurojosh]

.

[aldie 22]

Just now, eurojosh said:

.

I agree

[Ralph Wiggum]

Thought I would go over a little of what's in play for around Christmas (Christmas eve/Christmas/Day after). As I have mentioned quite often it will probably come down to what type of interaction we see with the SW trough/energy and any trough surges southward out of Canada. Picked several runs from the EPS centered on Sun 00Z to give you some of the different scenarios.

Below we see the latest run of the EPS. This is very shortly after we see the SW trough/energy get slowly ejected eastward. What we are seeing is that the influence of that trough/energy is strong enough that the upper trough surge is throwing most of its energy in diving into it. Thus we see with the trough/energy's slow ejection the energy is getting dumped towards the SW US. If you follow the pressure anomalies it gives you a good idea where. Now what this dump into the southwest is also doing is pumping up and reinforcing War (Western Atlantic Ridging). So what we are seeing with this setup is... A) The cold is getting dumped farther west (more distance to travel) B ) the eastward movement of the cold has been dampened (much of the energy is being dumped southward not eastward) C) WAR is coming in stronger (makes it more difficult for the cold to break it down). This is probably not the look you want to pin your hopes on for a cold or even possibly snowy/icy period around Christmas.

 

Now below we see yesterdays 12Z run. This features a quicker ejection of the SW trough/energy so it is farther east when we see the upper trough surge southwards. Again the ejected SW trough/energy is strong enough that we are seeing the energy is mostly being dumped southward into it in the central portion of the country instead of into the southwest as the previous case. Again we see this pumping up the WAR but notice where the stronger height anomalies are occurring. They are now farther north then the previous map. So what we see compared to the map above is A) The cold is being dumped further east (less distance to travel). B ) A more easterly component to the dump (A little more oomph pushing eastward) C) Higher heights through our latitude are weaker (Less resistance to the cold pushing in). This setup could work for getting cold in for the Christmas period but as far as frozen I would think the odds are of the lower order (discounting flurries). 

 

 

Now below we have a run from two days ago. The difference we are seeing is that the SW trough/energy is not getting ejected. We are also seeing it farther south extended all the way off of the Baja. So while it is influencing the upper trough surge southward that influence is muted a good deal by it's farther south positioning and generally weaker overall look. So what we are seeing is that the upper trough surge isn't getting sucked whole hog into the southwest but instead bleeding a small portion into it while the majority of the energy is allowed to escape eastward. Now what does this mean downstream through our region for the Christmas period? Well we see A) Much less energy being pumped into the SW trough which in turn means weaker ridging off the east coast (less resistance to the cold pushing eastward). B ) Most of the energy from the upper trough surge is invested in an easterly component and not being spent moving southward (more oomph and quicker progression of the cold eastward). C) Much better setup leading into Christmas period for possible froze which I will explain in detail below.

Not going to post pics but essentially what we are seeing play out with this setup is that the cold will be pressing in more so from the north as opposed to the other two setups where we see it press in from the west. What this means is that the boundary through our region will have a more west to east component through our region vs. the other two that have a strong north to south component. This different configuration of the boundary and what it represents is key. What it represents is that we have blocking being created by the pv to the north which any amplifying system will have a hard time fighting to gain latitude. This boundary also offers the hope of multiple waves of energy riding along it as well through the Christmas period. Now compare this to the other two with their N to S configured boundaries. Their setups argue for pretty much a one shot deal with any possible storm and with a fairly high likelihood of them cutting west (especially the first one).

Now at this point I still think all options are on the table and I really favor none. The one thing I do possibly favor though is the cold will probably get in a little later through the Christmas period (day after?)

 

 

Nice writeup. I was looking closely at the EPS mean and seeing some interesting discrepancies, so clearly things are getting skewed around based on some anomalous members. Looking solely at the 25th (since this is a date alot of folks have their eyes on), the mean slp maps show sprawled out HP from British Columbia all the way stretched across the Canadian Border extending into the Plains with the Eastern lobe into SE Canada over towards Nova Scotia. Looking again at the mean surface, still some weakish CAD signals from late on the 24th thru very early Christmas morning BUT the mean shows the CAD fading with the front hung up over the Gulf Stream and at least 2 waves nearby the coast giving precip to the region based on surface and precip means centered on the 25th. Here comes the discrepancies because so for this all looks OK as the front/boundary has cleared us and moved SE. When you look at 2m temps, they are actually AN for that day yet the surface and 500mb maps say CAA should have already occurred and temps should be much colder at the surface than the mean EPS shows.

 

Imo, this a reflection of the tight gradient setting up between arctic cold and SER influenced 'warmth'. There will clearly be some anomalous AN+ temps nearby right to the S and E of that boundary. The individuals pumping the ridge or being slower with the frontal boundary are skewing surface temps in the mean to the warm side. I think this date and the period in general from Dec 25-Dec 30ish needs to be watched for something coming N along the old frontal boundary. If the scenario played out perfectly there would be a heck of a slug of overunning with the SER forcing precip over the dome of HP settling East. I will gladly accept a weaker coastal boundary wave or two tho as these have proven to work for parts of the region thus far.

 

[Ralph Wiggum]

A couple maps to go with my post above. Note HP lobe and N NE flow into the region on backside of surface wave over Gulf Stream. Either CAA didnt happen yet, the lobe of HP over SE Canada is extremely modified, or something is getting skewed whether that be some members having stronger coastal wave(s) or some members have more warmth N and W with the boundary being also farther N and W. Interesting look on the mean in any event.

[showmethesnow]

4 minutes ago, Buddy1987 said:

Really the one thing I am looking for is to see if the Euro has its typical bias of holding the s/w energy back  in the Southwest too long, as it normally has a tendency to do this. The GFS is off it’s rocker right now and literally almost spits out a different solution every 6 hours. 

The GFS has a tendency to be all over the board when you get out in time. If you are going to follow an op in the extended the Euro is probably the better one, much better consistency.

As far as the GEFS though that has actually been pretty good with the representation of the SW trough for the lead into Christmas whereas the EPS has been a little jumpy. Think the EPS is conflicted on whether to pull the SW trough/energy out or hold it back. Now the bias you stated would obviously favor a quicker ejection but seeing the GEFS be steadfast on no ejection and would argue otherwise. So flip a coin. But at this point I think things argue for a SW trough so I would not be surprised if the final solution will involve a partial ejection of energy out of the southwest with a weaker trough/energy left behind.