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Morch Madness Negative NAO Long Range discussion


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1 minute ago, stormtracker said:

And also, when did we merge with the NYC forum?

He is annoying AF because he doesn't lie or fabricate anything. It's always the truth. But he is only around to revel in delivering bad news. 

In 2016 all up until mid January he was popping in to say how awful it was. Then the entire 10 days around the HECS he disappears. Then that first fail in February that year he pops in during the 0z run the night before that was the final nail in the coffin for D.C. snow to "inform" us it wasn't gonna snow. He is a jack wagon. 

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1 minute ago, psuhoffman said:

He is annoying AF because he doesn't lie or fabricate anything. It's always the truth. But he is only around to revel in delivering bad news. 

In 2016 all up until mid January he was popping in to say how awful it was. Then the entire 10 days around the HECS he disappears. Then that first fail in February that year he pops in during the 0z run the night before that was the final nail in the coffin for D.C. snow to "inform" us it wasn't gonna snow. He is a jack wagon. 

Oh man...if you only knew...

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1 minute ago, Interstate said:

What a mess

Remember the post about the "full latitude ridge" being our fail scenario. Well it's universal across all guidance now. It may be transient and not kill the whole threat window but it's gonna kill what was supposed to be the best look and first half of it. After that who knows. But very disappointing. 

So much wrong with this...

IMG_4275.thumb.PNG.91a0566e398e102bd247d014a464ef33.PNG

The first wave usually sets the table by amplifying into the 50/50 region and getting stuck under the block. That then prevents ridging into the northeast and encourages confluence. But this time perhaps it's too much blocking. Not many -4 std blsocks to test that but the storm gets stuck at our latitude instead which allows ridging to slide over the top and link up creating a full latitude ridge. That then let's the next system slide across instead of digging. All the dominoes fall wrong after that. 

Could this evolve into a threat. Yes if the next wave gets up into 50:50 space and the high latitude ridging holds and the guidance shows that BUT they showed that for the march 4-8 period 36 hours ago and lost it so I'm not gonna pretend to not see that troubling trend. 

We're still looking way out so this isn't over but bad trends the last 24 hours imo. 

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52 minutes ago, psuhoffman said:

Remember the post about the "full latitude ridge" being our fail scenario. Well it's universal across all guidance now. It may be transient and not kill the whole threat window but it's gonna kill what was supposed to be the best look and first half of it. After that who knows. But very disappointing. 

So much wrong with this...

The first wave usually sets the table by amplifying into the 50/50 region and getting stuck under the block. That then prevents ridging into the northeast and encourages confluence. But this time perhaps it's too much blocking. Not many -4 std blsocks to test that but the storm gets stuck at our latitude instead which allows ridging to slide over the top and link up creating a full latitude ridge. That then let's the next system slide across instead of digging. All the dominoes fall wrong after that. 

Could this evolve into a threat. Yes if the next wave gets up into 50:50 space and the high latitude ridging holds and the guidance shows that BUT they showed that for the march 4-8 period 36 hours ago and lost it so I'm not gonna pretend to not see that troubling trend. 

We're still looking way out so this isn't over but bad trends the last 24 hours imo. 

Am I the only one who finds this humorous, in the "laugh until you cry" way?  The first legitimate -NAO episode in what, the last 5 or 6 years, and its going to be too strong?

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1 hour ago, losetoa6 said:

Interesting write up from NWS  up in Mass.

National Weather Service Taunton MA
648 AM EST Sun Feb 25 2018

Overview...

Blocky N Atlantic pattern associated with an anomalous -NAO of 4 to
5 standard deviations (SD) below average
, associated +3 SD H5 high
retrograding W into SE Canada, parent 1040+ surface high, pressing
the thermal wind axis S thru which N/S stream impulses merge having
dug through a prevailing W CONUS H5 trof before ejecting, stretching
E. Energy piling up, slowed, pressed S by high pressure building N,
favorable storm development emerges off the E CONUS coast. Airmass
juxtaposition key as to outcomes towards the end of the week after a
quiet start. Only confidence is persistent NE winds of significant
duration during high astro-tides, coastal flooding concerns. Lower
confidence otherwise, consensus forecast guidance heavily weighted
with ensemble means continues. Hit targets of opportunity below.

Thursday into the weekend...

Battle of airmasses between an ejecting low out of the Central CONUS
up against building high pressure into Canada. Slowed pattern
, each
building their own weight, juxtaposition between the two ultimately
determining outcomes. 


Strong -NAO, -4 to -5 SD, would expect a cool,
dry setup for NE CONUS, storm track lying further S per block. Mid-
Atlantic getting crushed
. Interrogating Washington DC top 10 snows
versus the NAO time series after 1948, 5 out of 7 storms, 3 prior to
1948, were associated with a -NAO around -3. Recall February 2010?
Washington DC "snowmageddon" blink.gif of 17.8"? Monthly NAO averaged near -2.
Cherry picking data? Perhaps. CIPS analogs? Interrogating where NAO
indices <= -1, noting trend of sliding low S of New England, further
so with a stronger -NAO.

Ensemble members clustering off the Delmarva Peninsula while model
deterministic solutions are hugging further N close to Long Island.
Believe S trend is emerging per 25.0z EC. Echoing prior forecaster,
strong -NAO, subsequent block, storms forced E, slowed, evolving
into coastal storms, but storms could get suppressed S. It is all
about timing. Simply wait and see with later forecasts. But per
climatology, prefer ensemble clustering / 25.0z EC which are further
S compared to all other guidance.

Warm-core system, absent Arctic air, precip-type issues
mainly as rain / snow first glance. Confident of persistent NE winds
during high astro-tides, coastal flooding concerns.

 

Wow!

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20 minutes ago, cbmclean said:

Am I the only one who finds this humorous, in the "laugh until you cry" way?  The first legitimate -NAO episode in what, the last 5 or 6 years, and its going to be too strong?

I really dont think its a case of it being too strong. The PAC is just so hostile that even a NA block of this magnitude wont be able to mitigate it- at least not initially. Take away that damn deep trough out west, and there wouldn't be an amped conus ridge for the retrograding NA ridge to merge with. Earlier runs had the trough out west weakening/ retrograding much sooner, with quickly lowering h5 heights developing underneath the block over the east. If you recall it looked as though suppression might be the biggest problem, not a ridge bridge with nearly a complete absence of cold. Either way, the pattern still does look to become more stable and favorable towards the 7th, and in the meantime with all the chaos there is no reason to write off any possible threat preceding that.

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20 minutes ago, C.A.P.E. said:

I really dont think its a case of it being too strong. The PAC is just so hostile that even a NA block of this magnitude wont be able to mitigate it- at least not initially. Take away that damn deep trough out west, and there wouldn't be an amped conus ridge for the retrograding NA ridge to merge with. Earlier runs had the trough out west weakening/ retrograding much sooner, with quickly lowering h5 heights developing underneath the block over the east. If you recall it looked as though suppression might be the biggest problem, not a ridge bridge with nearly a complete absence of cold. Either way, the pattern still does look to become more stable and favorable towards the 7th, and in the meantime with all the chaos there is no reason to write off any possible threat preceding that.

Good post. We'll probably get our best setup as the neg nao breaks down. That's usually how it works. Can't write anything off either way. Even with a big neg nao, all storms are still northern stream. That puts us at a bit of a disadvantage but we've had plenty in the past that have worked. I doubt we get through mid March without seeing snow fall at some point. I'll worry about details if we can get something legit inside of 5 days. 

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2 minutes ago, Bob Chill said:

Good post. We'll probably get our best setup as the neg nao breaks down. That's usually how it works. Can't write anything off either way. Even with a big neg nao, all storms are still northern stream. That puts us at a bit of a disadvantage but we've had plenty in the past that have worked. I doubt we get through mid March without seeing snow fall at some point. I'll worry about details if we can get something legit inside of 5 days. 

Yeah that tends to be how it plays out. Of course climo will quickly become more hostile as we approach mid month. This isn't like March of 14/15 where we had a mechanism for big cold. Its going to be challenge in the lowlands the further into March we go. I am still hopeful we get some positive trends for the day 8-9 deal.

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3 minutes ago, Chris78 said:

My take away is the day 5-6 thing forgetaboutit.

After that who knows. A lot of moving pieces now and I just hope something lines up for us correctly.

Yeah thats pretty much where I am. I will be teaching a 60 hour class over the next 2 weeks so its probably a good thing I wont have much time to super analyze every run, lol. Maybe I'll be "surprised".

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1 hour ago, C.A.P.E. said:

I really dont think its a case of it being too strong. The PAC is just so hostile that even a NA block of this magnitude wont be able to mitigate it- at least not initially. Take away that damn deep trough out west, and there wouldn't be an amped conus ridge for the retrograding NA ridge to merge with. Earlier runs had the trough out west weakening/ retrograding much sooner, with quickly lowering h5 heights developing underneath the block over the east. If you recall it looked as though suppression might be the biggest problem, not a ridge bridge with nearly a complete absence of cold. Either way, the pattern still does look to become more stable and favorable towards the 7th, and in the meantime with all the chaos there is no reason to write off any possible threat preceding that.

It's a combo. Everything is a series of interactions. But the block being so strong does cause the Atlantic low to get stuck too far south. Now with a better Pacific that would be ok if there was a mean pna ridge.  But in this specific case we might have been better off with a more standard block of -2.5 std located a bit further north then this first wave might move up into 50/50 and offset the Pacific trying to pop ridging. Remember some of our best march patterns had a -pna. But they had a 50/50 to offset and the blocking wasn't -5 Std. Lol. But it's not one thing. Your right with a better PAC we would be ok. I was just assuming a crap PAC as a given so was focused on the rest of the factors. 

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1 minute ago, psuhoffman said:

It's a combo. Everything is a series of interactions. But the block being so strong does cause the Atlantic low to get stuck too far south. Now with a better Pacific that would be ok if there was a mean pna ridge.  But in this specific case we might have been better off with a more standard block of -2.5 std located a bit further north then this first wave might move up into 50/50 and offset the Pacific trying to pop ridging. Remember some of our best march patterns had a -pna. But they had a 50/50 to offset and the blocking wasn't -5 Std. Lol. But it's not one thing. Your right with a better PAC we would be ok. I was just assuming a crap PAC as a given so was focused on the rest of the factors. 

Absolutely. It's never one thing, lol. Large scale fluid mechanics is complex stuff. Just basing my thoughts on what the guidance was previously advertising, with the -3 SD NA block and how it could have unfolded with the hostile PAC relenting, and much sooner. Now admittedly, even the advertised look earlier in the week wasn't ideal because with the strong block, the 50-50 low was displaced further south, and we would have been fighting suppression/shredding of developing waves. But as it looks now, the big ass NA block wont be able to simply bully the crappy PAC into submission, so we end up with some merging of HL and ML ridging, and the "good" period gets delayed. So be it. We just have to roll with it and hope for the best.

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1 hour ago, C.A.P.E. said:

If you recall it looked as though suppression might be the biggest problem, not a ridge bridge with nearly a complete absence of cold.

Well, as a friendly visitor from the SE forum I was kind of hoping for a little suppression :) (Commence pummeling).

There is a continual debate in our forum regarding which teleconnection is most important for SE cold/snow.  Many people hold with the EPO; others advocate the AO/NAO combo or one or the other individually.  Curiously there isn't much mention of the PNA.  Anecdotally the last few years lurking on these forums, its seems that that the Pacific can overcome a hostile Atlantic more easily than the Atlantic (or AO) can overcome a hostile Pacific.

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29 minutes ago, WestminsterSnowCapitalMA said:

pics please. Im desperate for snow maps

Aren't we all.  But you're not going to get very far here asking people to post them for you, especially when there's not much to show. You'll see this board light up with snow maps when there's something more exciting on the models.  If you want to get your fix now, you can find snow maps for the Euro ensemble members here. 

https://weather.us/model-charts/euro/virginia/m0_snow-depth-in/20180310-0600z.html

Find the drop-down box labeled "members" and flip through it to see what the different ensemble members are showing.  You can also adjust the date and time for which the snow map is generated where it says "Valid for".

 

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5 minutes ago, cae said:

Aren't we all.  But you're not going to get very far here asking people to post them for you, especially when there's not much to show. You'll see this board light up with snow maps when there's something more exciting on the models.  If you want to get your fix now, you can find snow maps for the Euro ensemble members here. 

https://weather.us/model-charts/euro/virginia/m0_snow-depth-in/20180310-0600z.html

Find the drop-down box labeled "members" and flip through it to see what the different ensemble members are showing.  You can also adjust the date and time for which the snow map is generated where it says "Valid for".

 

awesome thanks man!

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Always 7-10 days away and misleading by models that don't predict the weather but rather display a wide array of it 

it's the season of the Nina, the pattern is almost a 1989-90 one, bitter cold then extreme warmth, winter is over. The pattern change chase has been in effect since mid Jan .  It's changed alright-got worse.

Matt, Ian, me, Huff, Midlo, Mike used to do all of this-follow the models every 6 hours and wear ourselves out with never ending hope, reinforced by models, that a beneficial change is forthcoming.  You can barely find any of those guys anymore.

theres more to Weather, locally nationally and globally than mathematical equations. There is the signs that have been given moving into the winter(analogs), the enso and the Nao and there are indexes that are en vogue but are dubious as to predictive qualities(stratosphere)

there is no push for a change as status quo is very well funded because when you show almost all the possible outcomes you can always point to one that did pan out and keep the money flowing thank you 

 

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1 minute ago, Thanatos_I_Am said:

Unreal how quickly the GFS lost that March 7th threat. 

Not unreal.  VERY real, and expected this year.   What makes this so irritating is that we were supposed to be entering in a great period of blocking, etc and everything that can go wrong is going wrong according to modeling.   

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1 minute ago, stormtracker said:

Not unreal.  VERY real, and expected this year.   What makes this so irritating is that we were supposed to be entering in a great period of blocking, etc and everything that can go wrong is going wrong according to modeling.   

Yeah, you're right. I guess I was falling victim to the idea that we could be sniffing out LR threats around now. Fool's gold. Heh. 

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