Jan Medium/Long Range Disco 2: Total Obliteration is Coming

[psuhoffman]

43 minutes ago, Shad said:

I really like what we are seeing on the Euro and EPS......do we think that this continues to trend south a bit more before the inevitable northern trend the last 48 hrs

This one does not necessarily have to trend north.  There is a TPV sitting right on top of us.  Depending on how that wobbles it could even suppress the wave further.  It's a chaotic situation with a ton of energy pinwheeling around the vortex but it's one where its not as sure to correct north IMO.  Last time I was very confident in a north correction because there was marginal cold, no blocking, nothing to stop the mid level southerly flow, and the NS was way out of the way.  There was no mechanism to suppress anything.  This is a different setup.  

[psuhoffman]

47 minutes ago, WinterWxLuvr said:

The 19th is a burp away from being a big time event

I prefer cows fart but go ahead 

[psuhoffman]

46 minutes ago, wawarriors4 said:

@RIC Airport posted this in the Richmond/SEVA thread.....

They lit up like a christmas tree 

[psuhoffman]

42 minutes ago, Ralph Wiggum said:

But....do we/will we get a stj wave moving across which is the final piece?

There is one there, it's just too weak as of yet and gets dominated by the NS making for more of a miller b screw job setup.  BUT...that wave wasn't even picked up at all until recently.  We just need a SLIGHT adjustment there and boom.  The pattern has been screaming for that window.  The longwave setup is absolutely perfect in every way.  We just need a somewhat healthy STJ wave to come along during a 48-72 hour window and it will likely work out.  12z GFS/EURO were very close just not quite a strong enough wave to get it done.  But its so close.  

[Terpeast]

6 minutes ago, psuhoffman said:

There is one there, it's just too weak as of yet and gets dominated by the NS making for more of a miller b screw job setup.  BUT...that wave wasn't even picked up at all until recently.  We just need a SLIGHT adjustment there and boom.  The pattern has been screaming for that window.  The longwave setup is absolutely perfect in every way.  We just need a somewhat healthy STJ wave to come along during a 48-72 hour window and it will likely work out.  12z GFS/EURO were very close just not quite a strong enough wave to get it done.  But its so close.  

Let's see how clear the models get this after the next cutter. I think they'll start getting into better agreement on the final solution for the 19th to 22nd window once the cutter passes by on Friday. It would still be 7-10 days out at that point, but if the "big one" is going to get sniffed out early, we should start seeing that by then - around Friday/Saturday. Now? A bit too soon.

[psuhoffman]

45 minutes ago, brooklynwx99 said:

there are hints that there could be a vort traversing the southern US. I think this would be northern stream driven overall, but that can absolutely change. better to focus on the overall pattern right now, which is about as good as can be

Well be careful with that... because a NS dominant solution would likely not end well here.  Almost all of our big snowstorms need to be STJ dominant.  That is why there is such a huge difference in snow climo in la nina years between DC and NYC.  We are simply too far southwest for NS systems to work.  They develop to late for us 90% of the time.  I agree this time period has a LOT of potential, but if you want the mid atlanticn south of 40 to get in on it there will have to be a trend towards a stronger STJ component to the threat. 

[WesternFringe]

1 hour ago, WEATHER53 said:

Because, they are show every possible outcome 

I think I’m beginning to understand that models are for fun but not forecasting. This can help alleviate some of my angst and poor interactions at times.

When it shows snow and 28 at noon today for Tuesday and then shows rain and 60 at 18z then Neither was a Prediction of an actual high percentage outcome but rather an example of “if a,b,c, d” then such an outcome will follow and 6 hours later show “e,f,g,h” and just keep rotating every 6 hours.

im happy to finally get this through my thick head and perhaps I can just sit back and enjoy the myriad of examples that will be forthcoming. 

I think you are getting closer to the way most of us think about models, but they are tools for forecasting (meteorologists literally use them as tools to do so) and they don't show every possible outcome.  Without models, we would have no idea that it is going to get very cold next week, for example.  Now, we don't know exactly what each shortwave is going to do 5-10 days away, but we do know the major players at 500 and the overall synoptic set-up that will drive the weather during this timeframe.

[brooklynwx99]

12 minutes ago, psuhoffman said:

Well be careful with that... because a NS dominant solution would likely not end well here.  Almost all of our big snowstorms need to be STJ dominant.  That is why there is such a huge difference in snow climo in la nina years between DC and NYC.  We are simply too far southwest for NS systems to work.  They develop to late for us 90% of the time.  I agree this time period has a LOT of potential, but if you want the mid atlanticn south of 40 to get in on it there will have to be a trend towards a stronger STJ component to the threat. 

i agree there. it's also possible that the trough buckles enough to make the whole point moot. but yes, there is certainly the potential for more southern stream influence between now and the next 10 days

[TSSN+]

Someone get Jobu some rum and a cigar and get this show started. Cerrano is bound to hit a curveball eventually. 

[Shad]

please no threads til Sunday, lets not jinx this one

[psuhoffman]

Any pattern breakdown continues to look brief if at all.  By the time it hits we might already be tracking a threat on the other side.  

Day 15

5 days later

Next 30 days 

That's how I drew it up in my mind.  I couldn't have created a better pattern if you handed me the magic crayons.  If this pattern doesn't work, during prime climo, during a nino... well it just better.  We aren't going to get a better chance than this to break out of our snow funk.  

[Stormchaserchuck1]

Initial trough is further SW on 18z NAM 84hr vs 12z GFS 90hr

https://ibb.co/6bV088Y

[Stormchaserchuck1]

4 minutes ago, psuhoffman said:

[15-30 days]

We aren't going to be a better chance than this to break out of this snow funk.  

Stratosphere warming should hit be hitting a favorable -NAO correlation time around then, too. It's like +80-120dm on the mean at +20-25 days. 

[brooklynwx99]

3 minutes ago, psuhoffman said:

Any pattern breakdown continues to look brief if at all.  By the time it hits we might already be tracking a threat on the other side.  

Day 15

5 days later

Next 30 days 

That's how I drew it up in my mind.  I couldn't have created a better pattern if you handed me the magic crayons.  If this pattern doesn't work, during prime climo, during a nino... well it just better.  We aren't going to be a better chance than this to break out of this snow funk.  

the nice part is that even if we don't get anything over the next 10-15 days, which is possible, this is what we're likely walking into... sign me up

[WEATHER53]

1 hour ago, wawarriors4 said:

@RIC Airport posted this in the Richmond/SEVA thread.....

15 out of 70 a huge hit for DC.

isn’t that higher than usually seen?

[psuhoffman]

The key is this.... 

As soon as that canonical pacific configuration sets up any ridge and warmth in the east is living on extremely borrowed time.  By the time it warms up the cold is coming again.  And this time the continent isn't a blow torch so we don't have to waste weeks trying to slowly develop a cold enough profile.  The next pattern reboot should come quick imo.  The MJO is flying in and out of the MC.  This isn't going to be a big problem imo.  

[psuhoffman]

6 minutes ago, Stormchaserchuck1 said:

Stratosphere warming should hit be hitting a favorable -NAO correlation time around then, too. 

Ok who kidnapped Chuck and replaced him with his less evil twin? 

[Ralph Wiggum]

1 hour ago, brooklynwx99 said:

there is no way in hell that ensemble modeling will pick such a feature out at 10 days 

My question was rhetorical of course. Most here should be aware a smoothed mean won't pick up on those most of the time at that range.

[Stormchaserchuck1]

2 minutes ago, psuhoffman said:

Ok who kidnapped Chuck and replaced him with is less evil twin? 

I am interested to see if +PNA holds if we go back to -NAO past 15D.. 

[WEATHER53]

1 hour ago, Kevin Reilly said:

Yea but that event had no "real" cold air locked in and it just vanished as the high way up north quickly left this is a different scene now.

Yes and ifs are useless but if that low could have moved in Friday at 10am then I think that air mass at that time would  have snowed us

[Stormchaserchuck1]

2 minutes ago, Ralph Wiggum said:

My question was rhetorical of course. Most here should be aware a smoothed mean won't pick up on those most of the time at that range.

CPC is going with below average precip right now

https://ibb.co/Zg7hQs7

[WEATHER53]

51 minutes ago, WesternFringe said:

I think you are getting closer to the way most of us think about models, but they are tools for forecasting (meteorologists literally use them as tools to do so) and they don't show every possible outcome.  Without models, we would have no idea that it is going to get very cold next week, for example.  Now, we don't know exactly what each shortwave is going to do 5-10 days away, but we do know the major players at 500 and the overall synoptic set-up that will drive the weather during this timeframe.

I just looked at a model pack with 70 differing solutions for DC. From 0 to 15”. That’s A Lot of Examples.  How many more would you need to call it “every possible outcome” ??

[winter_warlock]

17 minutes ago, TSSN+ said:

Someone get Jobu some rum and a cigar and get this show started. Cerrano is bound to hit a curveball eventually. 

In my best pedro cerrano voice.... " it is VERY BAD to steal Jobu's rum.. very bad!!" 

 

[Terrapinwx]

Initial trough is further SW on 18z NAM 84hr vs 12z GFS 90hr
https://ibb.co/6bV088Y

Nam at 84 looks very similar to the Euro, hopefully the start of something for the 18z runs


.

[Solution Man]

Where’s @stormtracker, getting near happy hour

[NorthArlington101]

Nam at 84 looks very similar to the Euro, hopefully the start of something for the 18z runs


.

The NAM at this range is probably about as good as the Mark Model

https://x.com/meteomark/status/1745163993893765438?s=46&t=YRAxGyE8QLsoshMtJniktg

[RevWarReenactor]

25 minutes ago, psuhoffman said:

Any pattern breakdown continues to look brief if at all.  By the time it hits we might already be tracking a threat on the other side.  

Day 15

5 days later

Next 30 days 

That's how I drew it up in my mind.  I couldn't have created a better pattern if you handed me the magic crayons.  If this pattern doesn't work, during prime climo, during a nino... well it just better.  We aren't going to get a better chance than this to break out of our snow funk.  

First time, in 6+ years I've seen you say that a LR pattern looks perfect for snow.

Exciting.

[psuhoffman]

5 minutes ago, WEATHER53 said:

I just looked at a model pack with 70 differing solutions for DC. From 0 to 15”. That’s A Lot of Examples.  How many more would you need to call it “every possible outcome” ??

You're thinking about it wrong imo.  We don't have the skill to be able to make a "this many inches" forecast from 6 days out!   That's why we call them "clown maps".   But if you look at the mean SLP, H5, surface and 850 temps you get the picture that the guidance is indicating there is a pretty decent chance of a wave sliding along the boundary just to our south next Tuesday.  

A responsible and reasonable forecast right now would be "there is a chance of a storm along the east coast affecting us early next week, and there could be enough cold air for it to be snow.  It could also still slide out to sea.  We will keep an eye on it and know a lot more in a few days"  

You can try to give a more specific forecast but the truth is we don't have the ability to with any accuracy, you would just be guessing which of the possible solutions within the typical margin of error from this range is going to happen.  But the guidance isn't showing EVERY solution.  There is absolutely no chance of a snowstorm tomorrow, or Saturday.  Not much of one Next Wednesday.  95% of the time there is NO chance of snow on a given day!  So narrowing the scope to one where there is a reasonable chance of a storm that COULD be snow in our area next Tuesday is good enough for this range and the guidance does that.  If you know what is important, what is just noise, and what are reasonable assumptions to make from them.  

[WesternFringe]

34 minutes ago, WEATHER53 said:

I just looked at a model pack with 70 differing solutions for DC. From 0 to 15”. That’s A Lot of Examples.  How many more would you need to call it “every possible outcome” ??

Did you see any 70 degree days in there? No?  

I bet you saw the vast majority of members showing a storm on or around the 16th.  That isn’t every possible outcome.  That is a specific outcome of a shortwave passing by.

Were some solutions warmer and some further north or further south?  Sure, because the models don’t have it pinned down from 6 days out.  But because of models, we know it is going to be cold and that a shortwave will be passing by the mid-atlantic.  Which is why we are all in here and talking about the 16th and the 20th.

How would you know that without models? And how would we know that if models were showing every possible outcome?

Furthermore, the individually perturbed members are meant to be taken in aggregate, not as 70 different models.

eta: I recall you saying that the cold would stay in place for the last storm and the mesos showing mixing and cold rain were wrong.  Were they wrong?  Or did the southerly winds at the midlevels cause mixing and rain for most?

[psuhoffman]

1 minute ago, RevWarReenactor said:

First time, in 6+ years I've seen you say that a LR pattern looks perfect for snow.

Exciting.

I thought Jan/Feb 2021 was pretty good and it was so close to a big period just not quite cold enough.  The last time I was this excited for a pattern was March 2018, which kind of underperformed here.  There were 4 legit threats and only 1 worked out.  We were also fighting the end of our realistic snow climo towards the end of that period too.