February 2023 Obs/Discussion

[radarman]

At any rate these guys aren't calling for a -AO in the next two weeks, they're calling for a new SSW if I read the tweets correctly, and the forcing for such isn't obvious to me.  If others have insight on that part of it, I'd welcome it certainly.

[78Blizzard]

1 hour ago, metagraphica said:

Swing and a miss.  Might not have been snow but might have been interesting in it's own right.

About as close as we'll get to this photo from Feb 7 45 years ago:

[ORH_wxman]

30 minutes ago, Typhoon Tip said:

If an SSW happens now ... and proves to be a downward propagating phenomenon/mass ... through the vertical coordinates of the stratospheric column, the tropopausal interaction times for early March... If said evolutionary arc begins in a week, it times for mid March... and so on. There is no -AO correlation prior to that time lagged offset.

That's awfully late in the solar calendar.  The mid latitude flow may be breaking down?  That's the climate for that time of year March --> ... hense 'bowling season'  Cut offs that if timed right, can produce like April '97, but far more commonly they ruin 10 days with 39 F light rain. That is the total circuiting manifold of the AO beginning to disconnect as that month moves on.  In a La Nina year with a history of actually being better coupled (more so than the last year and prior..>)... mm.   La Nina notoriously favor warmer springs.  It's like we are running out of time for SSWs, made even worse by the latter climo suggestion.  

We could actually fit mid month's warm up...followed by a would-be attempt at a 2 week recovery... then fade, nicely prior to any influence at mid latitudes by an SSW ... mid March.   When they are that late... I just wouldn't put much hope in that if I were the crew.

 

The 2nd week of March can sometimes break down into a more bowling ball “spring” type pattern but we’ve also seen it behave like mid-winter too (2014 or 2017 come to mind with these massive longwave deep troughs over the east with upstream ridging in the west)….2018 was maybe a hybrid…massive NAO/AO blocking and a lot of cutoffs but there was a thermal gradient to tap into that is often not there in, say, early to mid April, so we got those epic snow bombs in March ‘18. 

Either way…I don’t have much to add on the SSW front for you and radarman’s discussion but I don’t put much stock in them from a LR perspective since they are so hit or miss on the effects…usually by the time we can figure out if it’s going to cause favorable blocking, that said blocking is already seen by mid-range ensemble guidance and there’s no need to try and read the tea leaves at 10mb or 50mb. 

 

[CoastalWx]

I’m no strat guru,  but I do like looking at the 50mb temp anomalies from a northern hemi perspective. I’m not a fan of those charts showing graphs/ trends….I need to see the motions for myself. 
 

It does look to get disturbed a bit. The 50mb vortex gets pushed into Siberia with a trough extending into the CONUS and eastern US. Sometimes that can result in a split. Note this is only through day 16.  Anyways, we’ve seen that already this winter, and nothing it’s also split this winter with little to show for it. 
 

Bottom line, nothing exciting imminent. 

[Ginx snewx]

1 hour ago, brooklynwx99 said:

I think the main reason for that is the major SSW event that the weeklies are predicting. pretty much every member flips zonal winds negative, and some do for a prolonged period of time. this would be a serious reason to believe in a shake-up

this is also getting to within a medium range timeframe for this kind of stuff... this isn't 2-3 weeks out as it's been all winter. the initial disruption occurs in a few days, and the strong dipole over Greenland is a classic way to get strong heat fluxes into the stratosphere. in other words, I don't believe that this is voodoo, so to speak. the pattern that's causing the house of cards to collapse is currently ongoing

the mean has 10 m/s easterlies between the 13-17th... taking into account a lag of about three weeks, this takes us to the first week of March, which is when the Weeklies and extended GEFS both develop pretty legit blocking given the lead time. there's an actual 50/50 signal with a trough into Europe. both the AO and NAO flip solidly negative, which makes sense given an obliterated SPV

it's also peculiar that blocking hasn't returned since the spell in December... almost invariably, blocking returns at some point in the winter after coming on that strong in December. I don't have the stats here, but the correlation between highly anomalous Dec blocking and returning blocking in Jan-Mar is very high

either way, I'm honestly intrigued about March now, and I know that @40/70 Benchmark has been for a while, too. obviously, the standard caveats apply with the SSW stuff... the effects still need to couple to the troposphere, after all, but this is a legitimate pattern driver that can deliver some anomalous blocking. at least it's something to think about while the blinds are closed from like the 13th until the last week of the month. it's also worth noting that Feb 2018 also absolutely roasted before March happened

 

3 hours ago, Ginx snewx said:

Nice vortex split. Figure 3 weeks to see.

 

[dendrite]

1 hour ago, Damage In Tolland said:

The next 10 days of Napril from Hammer on NBC 30.

That will be way nicer than April

[SouthCoastMA]

3 minutes ago, dendrite said:

That will be way nicer than April

Yeah that looks like early May here

[Lava Rock]

That will be way nicer than April

That's brutal. Sorry

Sent from my SM-G981U1 using Tapatalk

[SnoSki14]

Important to note that a SSW event doesn't guarantee cold/snow even if it were to occur

[powderfreak]

1 hour ago, Damage In Tolland said:

The next 10 days of Napril from Hammer on NBC 30.

Warm season starting early… the Ryan on-air screen shots of forecasts. Usually reserved for May onward.

[NW_of_GYX]

1 hour ago, mahk_webstah said:

Depends on what happens in the week to 10 days following from my perspective. I want it to melt out if it’s going to get really warm next week. Then we can start over again for a little late season run. If it’s not going to get warm for long, but I would hope for a net gain from this week.

It’s early Feb. My winter is just starting. Only thing I don’t mind melting right now are SNE snow weenies. I can see why you’re ready for a melt though, just drove over the kanc and it’s a different world on the west side of the whites. Me to conway is still buried but Lincoln and campton will be melted out by early next week. Plenty of snow above 2000’ on the kanc though. 

 

 

[Damage In Tolland]

32 minutes ago, dendrite said:

That will be way nicer than April

I could see a lot of 70’s and 80’s this Napril 

[ORH_wxman]

34 minutes ago, NW_of_GYX said:

It’s early Feb. My winter is just starting. Only thing I don’t mind melting right now are SNE snow weenies. I can see why you’re ready for a melt though, just drove over the kanc and it’s a different world on the west side of the whites. Me to conway is still buried but Lincoln and campton will be melted out by early next week. Plenty of snow above 2000’ on the kanc though. 

 

 

Reminds me a bit of ‘96-97 (pre-March/April of course)…..mild winter but there was a ton of snow in the lakes region there in W ME. We went up skiing to Sunday river on Feb 16-18 that year and there about 2” of crust in ORH…zero pack east of ORH on 495 all the way up through southern Maine and then it went from 0 to about a 40” pack in Waterford ME in a span of 30 miles or so. They had a great snow year despite a lot of the region struggling to that point. 

[UnitedWx]

2 hours ago, WinterWolf said:

18z shananigans as usual. 

Like clockwork!

[STILL N OF PIKE]

1 hour ago, SnoSki14 said:

Important to note that a SSW event doesn't guarantee cold/snow even if it were to occur

It’s almost akin to a Hail Mary attempt to get something to shake something up , particularly for those south of the gradient  

[MJO812]

3 minutes ago, UnitedWx said:

Like clockwork!

Matches the euro

[Typhoon Tip]

1 hour ago, radarman said:

Dude the delayed propagation downward is ssw 101.  Enough with the condescension please.  And the 3 weeks delay isn't accurate.  It's shorter than that, and even then only a rule of thumb.  One could argue that the strong HP right over the pole that caused the recent PV displacement was the direct result.  And it shows up in the zonally averaged Z Anom GPH graph I posted even though it was  not a big portion of the total >65N space.  We understand and appreciate that you're into this stuff but turns out you're not the only one.

20 days. 
You put a ?… I was just answering your question OK there’s no condescension - if you know the information you know the information but it didn’t look like you did because the example you labeled is not a propagating SSW - which was my only  point. 
 

[UnitedWx]

1 hour ago, SouthCoastMA said:

Yeah that looks like early May here

I think he may mean we'll have back door cold, and a pattern we want now in April lol. At least I could see that happening 

[UnitedWx]

3 minutes ago, MJO812 said:

Matches the euro

Amazing, they match? Miracles never cease lol

[Snowcrazed71]

So with the GFS going way south, and the euro being where it was today, might we see it trend more towards a snowy or solution? Haven't had that happen at all this season as it's always trended the other way ( warmer and rainier ). It'd be cool to see how it plays out, but as usual like everything else, it has a lot going against it. 

[RUNNAWAYICEBERG]

1 hour ago, MJO812 said:

Matches the euro

I never bought the second piece of energy wrapping up and running inland, there’s just not enough spacing from the cutting lead vort unless it slows down and phases in, which the trend is for it to not to. It’s a precarious setup but progressive so it wasn’t worth dissecting until we’re inside d4, if the chance is still there. There’s room though to sneak in an event, but it’s tight. We’ll see.

[radarman]

1 hour ago, Typhoon Tip said:

20 days. 
You put a ?… I was just answering your question OK there’s no condescension - if you know the information you know the information but it didn’t look like you did because the example you labeled is not a propagating SSW - which was my only  point. 
 

No argumentative tone... honest question here... what is the basis for this 20 day rule for propagation down to the troposphere?   When I go back through past events I don't see it.  There may be examples of such, particularly 2003 which was used as a paradigm in a lot of the original literature, but over time it's my opinion that 03 has been proven to be largely a one off, and has not representative of a standard behavioral model.  There's plenty of other examples of the propagation downward occurring on shorter, even much shorter timescales too.  Or not propagating downward at all.  

I don't think there is anything inherent in a SSW that determines if it will propagate downward and eventually weaken the PV, just that other signals are dominant and ultimately determine the fate of it.  Also my opinion that the +GPH anomaly over the pole that drove down the record airmass may well have been associated with the U wind reversal that occurred in late jan, at 10 or so day lag.  Or maybe it's just coincidence.  Funny we didn't hear anything from the experts about an impending SSW (that did actually occur) when the wave2 and wave 3 signals spiked in mid Jan, now they're crowing for some unknown reason... hopefully the models are indeed onto something that I don't understand if that's the basis for the excitement.

[Typhoon Tip]

2 hours ago, ORH_wxman said:

The 2nd week of March can sometimes break down into a more bowling ball “spring” type pattern but we’ve also seen it behave like mid-winter too (2014 or 2017 come to mind with these massive longwave deep troughs over the east with upstream ridging in the west)….2018 was maybe a hybrid…massive NAO/AO blocking and a lot of cutoffs but there was a thermal gradient to tap into that is often not there in, say, early to mid April, so we got those epic snow bombs in March ‘18. 

Either way…I don’t have much to add on the SSW front for you and radarman’s discussion but I don’t put much stock in them from a LR perspective since they are so hit or miss on the effects…usually by the time we can figure out if it’s going to cause favorable blocking, that said blocking is already seen by mid-range ensemble guidance and there’s no need to try and read the tea leaves at 10mb or 50mb. 

 

You’re right… But I kind of nested a point in there that if we map what you’re saying over the top of Lanina climo …that kind of changes the landscape a little. I mean we’re just talking early prognostic measures here …it can certainly break either way.  

After having studied those sudden stratosphere warming events going back to 1979 very intently over the years I’ve just come to find those that happen in February are less representative in forcing the negative AO in spring also not as much realization of negative temperature departures at mid latitude. 

I also agree that the application of SSW is - at least for me - come under question for the usefulness frankly. Because I’ve seen the AO meander quite negative in years where there’s a SSW and subsequent propagation took place … you couldn’t parse out what was being caused by the SSW what was just there because of other planetary mechanisms

[Typhoon Tip]

18 minutes ago, radarman said:

No argumentative tone... honest question here... what is the basis for this 20 day rule for propagation down to the troposphere?   When I go back through past events I don't see it.  There may be examples of such, particularly 2003 which was used as a paradigm in a lot of the original literature, but over time it's my opinion that 03 has been proven to be largely a one off, and has not proven representative of a standard behavioral model.  There's plenty of other examples of the propagation downward occurring on shorter, even much shorter timescales too.  Or not propagating downward at all.  

I don't think there is anything inherent in a SSW that determines if it will propagate downward and eventually weaken the PV, just that other signals are dominant and ultimately determine the fate of it.  Also my opinion that the +GPH anomaly over the pole that drove down the record airmass may well have been associated with the U wind reversal that occurred in late jan, at 10 or so day lag.  Or maybe it's just coincidence.  Funny we didn't hear anything from the experts about an impending SSW (that did actually occur) when the wave2 and wave 3 signals spiked in mid Jan, now they're crowing for some unknown reason... hopefully the models are indeed onto something that I don't understand if that's the basis for the excitement.

Yeah good question but after studying the graphs of the propagators (I can’t pick it up right now I’ll do it tomorrow night if anyone’s interested) …

The propagation is a logarithmic decay in a downward progression gradually increasing the x-coordinate until it finally breaches the tropopause. So that curvature and trajectory typically takes 20 days. The AO, it doesn’t start interacting with the tropopause that’s when the index goes negative because that’s when the stabilization inversion starts breaking down the vortex; blocking nodes erupt and the annular structure of the polar region buckled around them.   

[ineedsnow]

HRRR and NAM with a little snow and sleet here tomorrow  night

[UnitedWx]

2 hours ago, Snowcrazed71 said:

So with the GFS going way south, and the euro being where it was today, might we see it trend more towards a snowy or solution? Haven't had that happen at all this season as it's always trended the other way ( warmer and rainier ). It'd be cool to see how it plays out, but as usual like everything else, it has a lot going against it. 

The biggest issue is there's not a lot of cold around...again 

[MJO812]

Everyone starting to hype up the strat warming event .

Maybe a wild March just like 2018?

[George001]

The SSW is trending stronger on the models. This is actually starting to get really interesting, yes there is a lag but in New England March is a winter month. There are no guarantees the SSW will be favorable for us, but a shake up of the current pattern is welcome. Id rather roll the dice and hope for the best with an SSW than just be stuck in our current (awful) pattern. If things do pan out with the SSW, I disagree that it will be too late. Early March is just in time for a potential 3 week run of storm after storm. 3 weeks isn’t a super long time, but in a favorable pattern nearly an entire seasons worth of snow or even more in 3 weeks can happen (especially areas closer to the coast).

[Torch Tiger]

8 minutes ago, MJO812 said:

Everyone starting to hype up the strat warming event .

Maybe a wild March just like 2018?

DId you hit 80 that month?

[George001]

2 minutes ago, Torch Tiger said:

DId you hit 80 that month?

You excited about the weather the next week or 2? A run at 70 isn’t out of the question, might be able to get some golfing in.