December 2017 Long Range Disco

[BristowWx]

36 minutes ago, losetoa6 said:

Check out this crazy  ridge bridge on the 6z. That's a 1064 high poised to come down into the conus.

I don't think I have ever seen anything like that screen saver shot.  Almost feel like its fake as in something a weenie would great and then say LOL!

[showmethesnow]

EPS was a very interesting run to say the least.

We see a continuation of the weakening and shifting eastward of the western blocking (-NAO) in the extended from prior runs. But that may not matter and is probably a direct result of what the EPS wants to do with the N American half of the pv split at lower levels. As we have seen over the last few runs the EPS has been driving that pv south into extreme N Canada and strengthening it. The latest run though is even more aggressive in sending it southward. Now the pv in this location can act as an effective replacement for the NAO and favors cold if not potentially extreme cold in our local as it sets up a trough in the eastern half of the US . Now depending on its location at any given time (pv normally will not stay stationary as it will wobble and rotate as energy revolves around) will determine what we could possibly expect. To far south with the pv and we will see suppression of systems. To far east and we are on the back side of the trough in a NW flow hoping for small time events as NS energy rotates around (Always a chance of a Miller B but as we all know that favors to our north). What we would prefer to see (if you are looking for a moderate to strong storm) is it to be located above roughly the Central to Eastern lakes region as this typically places us on the front side of the trough where systems then can move up from our south and west and amplify. If the EPS is correct with the pv in the extended the question then becomes is it just paying a short visit or is setting up shop there. This question is the difference between an extended period of above normal chances of cold and snow (if it's planted) or a relaxing of the pattern late December into January (if it leaves).

Another thing we see with the EPS is that it is once again being progressive in pulling out the SW trough and energy and driving it east and is in fact part of the reason I believe we are now seeing a signal (roughly centered around day 8/9) for a storm in the eastern US. I hesitated to even bring this up because this signal is showing up on the means alone and not supported by the individual members themselves which are all over the place. 

All I can say after looking over the overnight runs is that it looks to be a fun time to be tracking.

[psuhoffman]

6 minutes ago, mitchnick said:

Pretty good from what I've seen.  The recurving typhoon translates into a trough in the east in 7-10 days.  Since there's already one present,  it should result in a stable east coast trough. A bit of confirmation of the weeklies. 

Good catch. Another good indicator right now is the second significant dive in the AO back to back right now. That's usually indicative of a long term phase change setting in. 

[showmethesnow]

1 minute ago, psuhoffman said:

Good catch. Another good indicator right now is the second significant dive in the AO back to back right now. That's usually indicative of a long term phase change setting in. 

Liking what you are seeing? Sure beats what we had to deal with the whole of last year. And the season is just beginning. Here's hoping this is what we can expect through the whole winter.

[mappy]

I'm hugging this like whoa

Quote

Forecasters with Washington Post's Capital Weather Gang blog also raised the red flag on the upcoming weather pattern change on Monday, saying it "screams winter weather potential." Two time periods experts there cited as analogs to the upcoming weather pattern include December 1989, which set cold temperature records, and December 2009, which featured a blizzard known as "Snowpocalypse." 

https://www.washingtonpost.com/news/capital-weather-gang/wp/2017/11/27/extreme-weather-pattern-change-may-mean-cold-and-stormy-mid-december-in-eastern-u-s/?utm_term=.3633769cf87e

[Ralph Wiggum]

Check out this crazy  ridge bridge on the 6z. That's a 1064 high poised to come down into the conus.

Learning every day here so I need some clarification. Clearly with this look the PV is forced into the conus with a blocking ridge over most of the arctic region. That part I understand. But what would keep the cold air source from rebuilding in those favored regions up North? When I see that type of ridging at high latitude I generally relate that to AN temps at the surface under the ridge (NAO usually means Greenland is 'warm' etc). Guess what Im asking is can this look sustain the cold in the USA with cold source regions cut off or am I misreading this? Does the displaced PV eventually moderate and the pattern eventually roll over on itself a few days after this range? I know Im way ahead of the LR progs but just curious if this sort of look can sustain the cold. Maybe Im overthinking it. Im just not used to seeing such an extreme look. One would certainly think when this look relaxes/reloads/rolls over it could spell an Archambeault type of big ticket event for some part of the East.

[Eskimo Joe]

Another good sign for us...really hope this holds.

 

[mitchnick]

37 minutes ago, Ralph Wiggum said:

2 hours ago, losetoa6 said:

Check out this crazy  ridge bridge on the 6z. That's a 1064 high poised to come down into the conus.


 

Learning every day here so I need some clarification. Clearly with this look the PV is forced into the conus with a blocking ridge over most of the arctic region. That part I understand. But what would keep the cold air source from rebuilding in those favored regions up North? When I see that type of ridging at high latitude I generally relate that to AN temps at the surface under the ridge (NAO usually means Greenland is 'warm' etc). Guess what Im asking is can this look sustain the cold in the USA with cold source regions cut off or am I misreading this? Does the displaced PV eventually moderate and the pattern eventually roll over on itself a few days after this range? I know Im way ahead of the LR progs but just curious if this sort of look can sustain the cold. Maybe Im overthinking it. Im just not used to seeing such an extreme look. One would certainly think when this look relaxes/reloads/rolls over it could spell an Archambeault type of big ticket event for some part of the East.

AN heights and resulting AN temps (for that region) in the high latitudes is still plenty cold temps for our region and BN. So it's not a problem for us except at the beginning of the period sometimes when we need a few days for temps in that region to cool. But that happens fast naturally as long as Canada is not being flooded by Pacific air.

EDIT:I should add that it is NOT brutal cold in our area, but cold enough for snow ala 09/10.

[BristowWx]

just looking at the OP 12z...500mb is a beaut through 210...just straight up wow...lets see where it goes

[Cobalt]

Flurry watch at hours 200-240

[Cobalt]

I've gotta say, the GFS is really what we want to see.

[showmethesnow]

Most likely Suppression city on the GFS. PV drops to far south into the Lakes.

[BristowWx]

1 minute ago, Cobalt said:

I've gotta say, the GFS is really what we want to see.

it's straight up gangster look through 240 at 500mb...yeah I said it. 

[Cobalt]

Just now, BristowWx said:

it's straight up gangster look through 240 at 500mb...yeah I said it. 

Gangster is the perfect word to describe the 12z GFS

[Bob Chill]

4 minutes ago, Cobalt said:

I've gotta say, the GFS is really what we want to see.

For cold yea but not for good storm chances. When the pv drops that far south it acts like a sledgehammer and mashes everything. Good thing is the lr ops have been overdoing it quite a bit. We want to walk the line on the edge. 

[Ralph Wiggum]

10 minutes ago, BristowWx said:

just looking at the OP 12z...500mb is a beaut through 210...just straight up wow...lets see where it goes

cold/dry is my guess

[showmethesnow]

GFS is again making an attempt to pull out SW trough/energy. Looks as if it may partially be successful. Until we know how the trough dropping down into the central US around day 6 is going to handle the SW trough (pick up or leave behind) it is basically going to be guesswork as to what follows. Probably see some widely varying solutions on the op runs of the models.

[Cobalt]

Just now, Ralph Wiggum said:

cold/dry is my guess

I mean, that's a start I guess! Most of our snow events don't really happen in the meat of the cold anyways. They either usher in the cold, or keep the cold in for a bit before flipping the pattern.

[Ralph Wiggum]

Just now, Cobalt said:

I mean, that's a start I guess! Most of our snow events don't really happen in the meat of the cold anyways. They either usher in the cold, or keep the cold in for a bit before flipping the pattern.

Establish the cold then develop the storm chances....yes.

[Cobalt]

Just now, Ralph Wiggum said:

Establish the cold then develop the storm chances....yes.

The perfect snow chances happen when the ground is cold. The blizzard of 2016, for example, was perfect when it came to this. It hadn't topped freezing for at least 3 days before the storm, so we were set. If I do recall, the blizzard of 2009 was pretty good at this following that December 5th snow

[Interstate]

2 minutes ago, Cobalt said:

The perfect snow chances happen when the ground is cold. The blizzard of 2016, for example, was perfect when it came to this. It hadn't topped freezing for at least 3 days before the storm, so we were set. If I do recall, the blizzard of 2009 was pretty good at this following that December 5th snow

Well if you want Cold... you got it at the end of the run

[showmethesnow]

8 minutes ago, Cobalt said:

I mean, that's a start I guess! Most of our snow events don't really happen in the meat of the cold anyways. They either usher in the cold, or keep the cold in for a bit before flipping the pattern.

That pv placement would set us up for some possible quick hitting 1 or 2 inch type deals as energy rotates around the pv but it for the most part takes any moderate or big ticket items off the table. As it rotates out though you always have the possibility of something popping.

[WxUSAF]

Late next week is worth watching, especially since nothing else is happening. If the northern stream can get through quick enough while the southern stream hangs together, maybe we could get a narrow stripe of snow out of it. It’s a long shot but probably the only way to get snow at the very beginning of the pattern change.

[showmethesnow]

GFS really goes to the extreme in the longer range. That ridging over Alaska at the end of the run is something to behold. Not to mention the coast to coast cold that sets up.

[mappy]

[showmethesnow]

9 minutes ago, losetoa6 said:

Good point...A piece of energy could pull away from the core  and dig as the pv  lifts north. Perfect if we can score an 1-2" appetizer then get something to amplify soon after.

Run was definitely fun to look at if you like extremes. But I am not sure I would put much stock in it nor any other op run of the GFS for the foreseeable future. Mentioned it before but I guess it is worth mentioning again. Until the GFS resolves what it wants to do with the trough and energy in the southwest it will pretty much be guesswork as to what we can expect roughly day 7 and onwards. We will most likely see some widely varying solutions being spit out until then. Euro is also having the same problem resolving the SW trough as well though it's op runs have shown better consistency then the GFS. Doesn't mean that the Euro is right though.

[mitchnick]

I'll repeat what I said the other day, 12/17-12/21 is when we get hit by a snowstorm.  Probably from the energy in the SW, but I could be wrong on that point. Wouldn't turn down anything before it, but I don't see anything of consequence imho.

[Eskimo Joe]

GFS tries to pop a 576 ridge in Alaska.  Toasty for them, cool for us.

[showmethesnow]

Looks as if the GEFS is following the EPS's lead. Looks as if it may be keying on roughly day 8/9 for a storm somewhere in the east as well.

[mappy]

4 minutes ago, mitchnick said:

I'll repeat what I said the other day, 12/17-12/21 is when we get hit by a snowstorm.  Probably from the energy in the SW, but I could be wrong on that point. Wouldn't turn down anything before it, but I don't see anything of consequence imho.

Where can I buy my ticket to ride this hype train?