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Feb To Forget? - 2020 Discussion


TalcottWx
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29 minutes ago, weatherwiz said:

I agree...but I think we're talking about different aspects here...you're referring to long-term forecasting where I'm talking about medium-range signals. 

The PV has been quite strong all winter...and while perhaps from an evaluation of pre-season indicators you could assume weakening based on several factors (such as descending QBO as you mentioned)...we can also see models in the 10-15 day period just start to weaken the PV and then all of a sudden inside of D10 or D8 that signal vanishes...once it becomes apparent that there indeed be direct impacts on the PV the initial forecasts really mean nothing. 

My understanding is that one way to weaken it is to keep pelting it with Rossby wave after Rossby wave...and strong Rossby waves. Let's say you have a 4-5 week stretch of horrific winter weather...and you think it may never end...if there is a constant flux of Rossby waves pelting the PV...that can give you a very strong indication that within the next 3-4 weeks big changes will result. 

Anyways...perhaps through pre-season guidance you can put a wager on these changes happening...but until you actually spot those potential developments within guidance the preseason guidance doesn't hold a whole heck of alot of merit. 

Yea...at some point you have to decide whether it is time to abandon ship. It was about the first week of February for me last year.

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5 minutes ago, weatherwiz said:

This is a great site with stratosphere products

stratobserve.com 

You can see that the PV does look to elongate by around 228-hr...but then towards the end of the run it becomes more compact..I would assume though we would want it to become more displaced on our side of the hemisphere

gfs_nh-vort3d_20200124_f252_rot000.png

 

I'm glad I have that notion correct about the PV taking hits. 

One thing noticeable too (wish I could do this in animation) but around 228-hr there is a reversal of the zonal winds aloft...they become westerly 

gfs_nh-uzm-epfluxes_latprs-xsect_20200124_f276.png

 

Quite a bit of heat flux too

gfs_nh-ehf-hgt_lonprs-xsect_20200124_f252.png

 

Again though...seems like all of this is happening on the wrong side of the globe?

 

(Of course this is based off the GFS)

Scott mentioned yesterday that 2015 was mainly on the other side of the globe...I think there is more to it than that. 

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Just now, 40/70 Benchmark said:

Not worried yet.

I mean we can still have great snowstorms but all indicators on all Ens have a POS AO Pos NAO neutral if not negative PNA and a positive EPO. That warming at 50 mb is temporary. This is all on overnight runs. Things change but today any sustained deep winter for Feb is not shown

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Just now, 40/70 Benchmark said:

Scott mentioned yesterday that 2015 was mainly on the other side of the globe...I think there is more to it than that. 

Yeah I certainly agree there is definitely more to it than that.

The biggest weight overall I think is structure and placement of these anomalies and synoptic features. This is that extra piece which makes the seasonal forecasting challenging...sure we can have an idea of how NAO/AO may evolve based on QBO projection and how the stratosphere may evolve but we really don't know how they will be structured...and that's the key piece...I think anyways. 

Do you remember way back I think his name was Allan (Raleighwx) did something with breaking the NAO into regions (similar to ENSO) with east-based and west-based +/- NAO events...he even had an index to measure it...but never heard of anything since and there is very little about this online. but doing the correlations to patterns by breaking down (say a negative NAO) between east/west based increased the correlation significantly. 

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5 minutes ago, Ginx snewx said:

I mean we can still have great snowstorms but all indicators on all Ens have a POS AO Pos NAO neutral if not negative PNA and a positive EPO. That warming at 50 mb is temporary. This is all on overnight runs. Things change but today any sustained deep winter for Feb is not 

The crap Pacific is expected. It may take until March, but the polar domain should improve...nothing epic, but solid. 

Remember when I told you in November that we will need the atlantic for a good second half?

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4 minutes ago, weatherwiz said:

Yeah I certainly agree there is definitely more to it than that.

The biggest weight overall I think is structure and placement of these anomalies and synoptic features. This is that extra piece which makes the seasonal forecasting challenging...sure we can have an idea of how NAO/AO may evolve based on QBO projection and how the stratosphere may evolve but we really don't know how they will be structured...and that's the key piece...I think anyways. 

Do you remember way back I think his name was Allan (Raleighwx) did something with breaking the NAO into regions (similar to ENSO) with east-based and west-based +/- NAO events...he even had an index to measure it...but never heard of anything since and there is very little about this online. but doing the correlations to patterns by breaking down (say a negative NAO) between east/west based increased the correlation significantly. 

I know east based NAOs are not nearly as favorable, like ENSO events.

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Just now, 40/70 Benchmark said:

The crap Pacific is expected. It may take until March, but the polar domain should improve...nothing epic, but solid. 

We can get away with having a crappy PAC I think...although depending on what you're expectations are. If you're expecting a pattern that is going to consistently deliver well that's difficult with a crappy PAC but if we can get a favorable polar domain and get an active storm track...chances are something will deliver...perhaps more ratters than not but I'll take the chances

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Just now, 40/70 Benchmark said:

I know east based NAOs are not nearly as favorable, like ENSO events.

was it east-based? 

I thought the east-based events had the + height anomalies positioned east of Greenland which yielded a higher likelihood for -height anomalies across the east...while a west-based had the +height anomalies so far west (and during strong events) they even were displaced south and penetrated into our region?

I may have this reversed though...trying to picture in my head

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Just now, weatherwiz said:

We can get away with having a crappy PAC I think...although depending on what you're expectations are. If you're expecting a pattern that is going to consistently deliver well that's difficult with a crappy PAC but if we can get a favorable polar domain and get an active storm track...chances are something will deliver...perhaps more ratters than not but I'll take the chances

Both sides are crappy for the foreseeable futures, though the PAC is a little less crappy in the medium range....we get a PNA ridge while the EPO stays kind of meh but better than it has been.

Here's what it looks like in that D11-12 time range

 

Jan24_12zEPS276.png

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4 minutes ago, ORH_wxman said:

Both sides are crappy for the foreseeable futures, though the PAC is a little less crappy in the medium range....we get a PNA ridge while the EPO stays kind of meh but better than it has been.

Here's what it looks like in that D11-12 time range

 

Jan24_12zEPS276.png

I wish we could poke that ridging a bit more into the GoA...even with the crappy polar region perhaps that could displace some of the cold that's been in AK our way and at least we would have that nearby. 

That look isn't great...but would certainly take chances given the time of year

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Maybe bookend bombs for ASH this winter. 

Just don’t give me raIn every 3 days like last winter and brutal cold in between

today Is a pretty nice day, I’ll take AN and drier than normal If snow Ain’t happening . 

If anyone is punting pacific wouldn’t you  always lean below normal snow ...given how inconsistent blocking and a decent Atlantic is every year 

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4 minutes ago, SnowEMass said:

When was the last time we had a warm solution become cold as opposed to OTS coming back toward the coast closer to showtime.  Can’t think of any recent examples of the former. 

this year we've had a few close calls, otherwise, IDK.. I was mostly kidding.  I'm not too worried about what it shows 200+hr out.. just something to track I guess.

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8 minutes ago, Snow88 said:

Too many vorts along the flow . Models are going to show many solutions.

It's way out there in time...but as Ginxy said Tele's look like crap going forward.  Sure we can time something right(and sure hope we do), but after a lil good news/better look yesterday, it  looks to have kind of reverted back to a "not so good look" in the LR again.  

 

Certainly not trying to be a downer, but She ain't gonna let us out this year I fear.   I'm just hoping for One Major Storm out of this season(We missed out here on the Early Dec one for the most part)...even 06 gave us a bomb; I'd take that and run and let Spring come after that.  

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