January Mid/Long Range Disco 2

[Heisy]

Ridge bridge tonight

Looking ahead to keep my sanity. At least ensembles show this may be for real


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[Heisy]

If the -EPO PNA does form as advertised it may take a couple NS disturbances to usher in the cold. Then we wait and see if we can time a shortwave because there doesn’t seem to be any Atlantic blocking to facilitate anything


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[jayyy]

YAWN

[ravensrule]

SUCH A BRUTAL THREAD. It’s worse than being a kindergarten teacher 

[CAPE]

Glad I was super busy yesterday lol.

The means continue to advertise a more favorable longwave pattern to be in place beyond month, with an Aleutian low, slightly +PNA, -EPO, -AO. The North Atlantic looks at least serviceable. Realistically our next chance for a trackable threat is 10 days away. The CMC ens has had the coldest look with hints of a southward displaced TPV, and the GEFS is now suggesting that.

The period around the 23rd is an interesting look, suggestive of NS waves riding overtop of the ridge/spinning off the TPV, along with energy ejecting eastward from the Baja region.

[CAPE]

The EPS has a pretty nice look at h5 here, but not very cold at the surface. The primary difference compared to the GEFS/CMC ens at this point is less amplified EPO ridge and a weaker ridge towards the Kara sea. The TPV over northern Canada remains more poleward and associated with (stretched towards) the stronger vortex towards the Aleutians- this keeps the polar air largely contained. The bridging of those ridges helps displace the TPV more southward on the other guidance. The EPS does get colder air into the US a few days later with a weaker, more consolidated Aleutian vortex and more amplified EPO ridge.

[North Balti Zen]

8 hours ago, WesternFringe said:

Okay, we can go back to hearing from preferred posters why it can’t snow in the MA after it just did.  My bad.  I will stop being so optimistic for snow chances.

I’m in northern maryland on 0.0 and have had literally just two minutes of light flurries this entire season in a forum where people are acting like we have Memphis, Tennessee's annual chances at snow.
 

So fuck off with all this. just…discuss weather. But take the climate warming change shit elsewhere. You clearly have a weird agenda to pretend it isn’t warming. Take it elsewhere. 

[Ralph Wiggum]

Period centered near the 23rd is finally reflecting the less hostile curremt PAC transition and dropping BN 850s across a good chunk of the US. As I often say, I prefer a more broad-based colder look as opposed to the PV dropping right on top of our regions. All 3 major global ens systems are supporting this look as we pass mid January. So the head fakes wrt the pattern progression were in fact not head fakes and reemerged on the globals after disappearing for a few days. The lag time to get things In place may have just been a couple days longer to get there at worst:

And fwiw, the CFS is not only still on board for a February redemption but has actually strengthened the colder looks in a broad regime across the country:

H5 maps show some decent signals but obviously nothing discrete at this range. First ingredient is always the colder air, and my post was to show we are finally going to have that in place it appears. Will begin looking at H5 for longwave stuff as we head forward. 

[mappy]

10 minutes ago, North Balti Zen said:

I’m in northern maryland on 0.0 in a forum where people are acting like we have memphis’ chances at snow.
 

So fuck off with all this. just…discuss weather. But take the climate warming change shit elsewhere. You clearly have a weird agenda to pretend it isn’t warming. Take it elsewhere. 

Agreed

We have a climate change forum, friends. If you really gotta scratch that itch to discuss whether we are warming or not, please do so here:

https://www.americanwx.com/bb/forum/18-climate-change/

 

Thanks!

Management

[Weather Will]

WB 6Z EURO…less of a sting for the late week fiasco when even Northern Maine is fringed…hopefully something to track in a couple of weeks.  Fingers crossed wave to track in a week or so….

[Rtd208]

19 minutes ago, Weather Will said:

WB 6Z EURO…less of a sting for the late week fiasco when even Northern Maine is fringed…hopefully something to track in a couple of weeks.  Fingers crossed wave to track in a week or so….

[Terpeast]

2 hours ago, CAPE said:

The EPS has a pretty nice look at h5 here, but not very cold at the surface. The primary difference compared to the GEFS/CMC ens at this point is less amplified EPO ridge and a weaker ridge towards the Kara sea. The TPV over northern Canada remains more poleward and associated with (stretched towards) the stronger vortex towards the Aleutians- this keeps the polar air largely contained. The bridging of those ridges helps displace the TPV more southward on the other guidance. The EPS does get colder air into the US a few days later with a weaker, more consolidated Aleutian vortex and more amplified EPO ridge.

I’ve been seeing these advertised pattern changes starting around Jan 23 on the big 3 models. 

Question is:

- Will it stick? Or get can kicked

- Is it real? Or another head fake

- Will we get enough cold air far enough east? Doesn’t have to be arctic, just cold enough

The nina appears to be weakening. In December it was 0.9-1.0, and now it is 0.7-0.8. Maybe we get to cold enso neutral by Feb?

That would be good in that the pac jet retracts just enough to give us a pattern that might work. 

Or it would be bad that this nina weakening may alter IOD forcing to give us a warm Feb (as I predicted in my winter outlook).

It could go either way, or both ways in the same month. 

March, as always, is a wildcard. 

[Mikeymac5306]

Another two weeks we wait...

 

[FPizz]

10 hours ago, pazzo83 said:

It's even more pronounced for cities closer to the coast.  I feel like NYC has barely gotten below freezing at all this season (aside from the brief Christmas cold snap).

The city can be 32, and all areas within 10 miles of it, N, SW, E and W are 19.  It's not even worth using their temps anymore.

[psuhoffman]

10 hours ago, WesternFringe said:

‘Shenandoah Valley Area’ is a large area to generalize.  I live at 1550’ nnw of Staunton and we have had many nights below average temps this year.  It has been plenty cold, just no precip to match.  

Let's avoid the climate change angle here and just focus on the real argument you made which is "right now cold isn't the problem".  I don't agree with the attacks but I think everyone is just beyond frustrated.  But here is why your claim is problamatic.

1) night time lows during radiational cooling is a horrible way to judge the true nature of an airmass.  The cold can be a very shallow surface layer.  What is way more important to the chances for snow is the depth and scope of the airmass.  

2) There is an issue with probabilities.  Cold is only 1/2 of the equation for getting snow.  Precip is the other.  So saying, it was cold enough to snow during these 10 days this winter and it didn't so cold is the problem is completely ignoring 50% of the equation.  Getting snow is about timing up both the cold and the moisture.  So if we only get precip on 20% of days in winter and its only cold enough on 20%...well math starts to become a real problem!  

3) Additionally due to our latitude and the way waves work we are most likely to be on the warm side of the equation right before and during precipitation because of the fact that any approaching wave is likely to have a southerly flow ahead of it.  This gets back to the depth issue.  If you are cold but its a shallow cold in a marginal airmass its not going to be enough to resist the warm air advection that comes ahead of any storm.  And this is critical because that is also what creates the vast majority of our winter precipitation.  So if the airmass is not sufficient to resist WAA we are left with the only way we can get snow is to get super lucky with some crazy perfect cutoff h5 pass and bombing cyclone that dynamically cools the airmass over us.  It happens...but its not a good way to roll if you want snow regularly. 

4) Putting all that together...yes right now cold is your biggest problem because while you do have a shallow cold layer due to it being the coldest week of the year and good radiational cooling conditions in one of the colder locations in the mid atlantic...the depth of the airmass right now is not enough to win in the equation I laid out above.  

[pazzo83]

51 minutes ago, FPizz said:

The city can be 32, and all areas within 10 miles of it, N, SW, E and W are 19.  It's not even worth using their temps anymore.

yeah except for the millions of people who live there, of course.

[psuhoffman]

@CAPE

The EPS look is more favorable to us getting snow imo. Before I even get into the details it’s possible it’s not really warmer just less wrong. Both the others have a more pronounced cold bias. 
 

That factor aside, the gefs might be a colder look because it has a deeper trough but again cold is only 1/2 the equation. That gefs look is not good for snow. Any strong wave will cut. Any weak wave will get shunted in a progressive flow. We’d be left rooting for a perfectly timed perfectly amplified progressive boundary wave. 

 

The eoro has a way more favorable longwave configuration to get an amplified wave under us.  It’s not as cold but we have to hope it “cold enough”  Its not a pac puke torch like now at least.  But it doesn’t have as much straight arctic fetch as the gefs but again for the millionth time a straight arctic fetch pattern isn’t a good one for snow.  The vast majority of our snowstorms come with temps near freezing in marginal cold because the longwave pattern that’s best to get amplified systems off the mid Atlantic coast isn’t an arctic cold pattern.  

I think some are getting fooled into rooting for that gefs kinda pattern because those progressive boundary waves are literally the only snow events we’ve been getting for 7 years now. But that’s also why its been the worst 7 years in history. That’s never going to be a winning game plan. We might luck into one of those waves once in a while but it’s gonna be more of the same crap with way more Ls than Ws. 
 

I would way rather run a test case on if what should be our best snow pattern can still work.  The eps isn’t a pac puke pattern.  It’s a domestic CP regime.  There are no excuses if what the EPS is indicating doesn’t work other than the obvious one.  But Imo we should roll with that and if we get that EPS look And we still get a couple good track rain events then we know…you know!  

 

[SomeguyfromTakomaPark]

On 1/9/2023 at 8:51 AM, psuhoffman said:

Ok I’ve been leading the Deb brigade but this is just a flat lie.
 

Temp anomalies at the end of the EPS run

 

And it’s trending colder.  It may not be super cold but that’s a workable profile. And frankly the days of being really cold without some anomalous TPV displacement or direct arctic discharge (which isn’t even great for snow see Dec 23 ) are becoming rare.  Plus even the new 30 year means are skewed too cold since yes warming.  But we’re talking is it cold enough to snow. Compare that to now 

that profile now is unworkable. There is a huge difference between +10 and +3 temps in our source regions.  Look at the actual 850 temps day 15 on EPS

That’s not arctic cold no but it’s a very workable profile.  The issue is will it actually happen.  Guidance head faked a colder pattern for right now 15 days ago but that’s a different argument.  

 

That's weird, on TT it shows positive anamolies out to 360 for that same run, which is what I was looking at.

[CAPE]

1 hour ago, psuhoffman said:

@CAPE

The EPS look is more favorable to us getting snow imo. Before I even get into the details it’s possible it’s not really warmer just less wrong. Both the others have a more pronounced cold bias. 
 

That factor aside, the gefs might be a colder look because it has a deeper trough but again cold is only 1/2 the equation. That gefs look is not good for snow. Any strong wave will cut. Any weak wave will get shunted in a progressive flow. We’d be left rooting for a perfectly timed perfectly amplified progressive boundary wave. 

 

The eoro has a way more favorable longwave configuration to get an amplified wave under us.  It’s not as cold but we have to hope it “cold enough”  Its not a pac puke torch like now at least.  But it doesn’t have as much straight arctic fetch as the gefs but again for the millionth time a straight arctic fetch pattern isn’t a good one for snow.  The vast majority of our snowstorms come with temps near freezing in marginal cold because the longwave pattern that’s best to get amplified systems off the mid Atlantic coast isn’t an arctic cold pattern.  

I think some are getting fooled into rooting for that gefs kinda pattern because those progressive boundary waves are literally the only snow events we’ve been getting for 7 years now. But that’s also why its been the worst 7 years in history. That’s never going to be a winning game plan. We might luck into one of those waves once in a while but it’s gonna be more of the same crap with way more Ls than Ws. 
 

I would way rather run a test case on if what should be our best snow pattern can still work.  The eps isn’t a pac puke pattern.  It’s a domestic CP regime.  There are no excuses if what the EPS is indicating doesn’t work other than the obvious one.  But Imo we should roll with that and if we get that EPS look And we still get a couple good track rain events then we know…you know!  

 

I get it but I don't try to extract that level of detail on a course LR mean that we know will change anyway. I was mostly addressing previous posts about the advertised surface temps being 'too warm' and why there are differences wrt that across the guidance in the LR at this point. The current depiction in the NAO domain is certainly better on the EPS. Personally I would like to see some legit cold get involved in the pattern given my location and the outcomes that have occurred here recently with that type of setup.

[SnowenOutThere]

12z GFS shows how the upcoming pattern could easily disappoint with a cutter where the Epo goes negative and Pna goes positive causing a brief cooldown before southern Canada returns to torching. 

[psuhoffman]

13 minutes ago, SnowenOutThere said:

12z GFS shows how the upcoming pattern could easily disappoint with a cutter where the Epo goes negative and Pna goes positive causing a brief cooldown before southern Canada returns to torching. 

That’s why I said root for the EPS. The Gfs op gives us the pattern the gefs advertises. 

Ya this looks cold, and it is cold for a few days, but this is very unlikely to lead to a meaningful snowstorm. 

 

[Its a Breeze]

GFS loses the hurricane, but has four cutters in four days.

Can't wait for tomorrow...

 

 

[WxUSAF]

12z GEFS (and really the last few GEFS runs) looks more like the EPS in the D11+ range. 

[CAPE]

We can all root for what we want, and it changes nothing. These advertised patterns are going to morph into something at least somewhat different anyway, and we will live with whatever we get. I have rooted for the patterns that are historically 'more likely' to produce meaningful snow and even when it ends up close to advertised, lately it mostly just rains here. I can think of one instance since 2016 where a legit -NAO has yielded meaningful snow imy. I'll roll the dice on a pattern that brings the cold, and risk dry or an amped cutter. There are risks for failure regardless, and some amount of timing and luck is always required

[WxUSAF]

6 minutes ago, WxUSAF said:

12z GEFS (and really the last few GEFS runs) looks more like the EPS in the D11+ range. 

@psuhoffman…with a PNA/EPO ridge  unconnected to the ridging over the Atlantic side across Canada and a piece of the PV in between, central Canada cools down in only 48 hours after the ridge goes up. 

[Ralph Wiggum]

Here we go....gefs:

[brooklynwx99]

4 minutes ago, WxUSAF said:

@psuhoffman…with a PNA/EPO ridge  unconnected to the ridging over the Atlantic side across Canada and a piece of the PV in between, central Canada cools down in only 48 hours after the ridge goes up. 

yeah, there’s legit arctic flow here. would get everyone cold quickly. this is a great pattern verbatim

[BristowWx]

^I can see what you are looking at... a path looking at hr 342 on GEFS.  all of the sudden Canada is quite cold and the red had fled.  step one I suppose

[mattie g]

Good thing is that the upslope looks to crank after our cutter this weekend!

 

[Ralph Wiggum]

Just jumped on briefly....at work. What's this I missed we have to root for models verbatim now? Ffs let's get the cold air source reestablished then get it into the lower 48 first and foremost. Could care less if it has staying power, if it doesn't look perfect, etc. Ingredient 1....cold...the thing we've been lacking. LFG!