Winter 2020-21 Discussion

[CAPE]

24 minutes ago, WxUSAF said:

We’ve got “extreme weather bullseye” working in our favor 

Better than atmospheric memory. We really need it to forget.

[frd]

IRI update. Maybe some minor implications.  

 

 

[frd]

This is  interesting,  especially the what occurs after the first of the year, when the favored MJO phase(s) tends to change. This seems to be related to the Nina peaking in the OND period and then waning thereafter.

 

 

 

[40/70 Benchmark]

On 11/17/2020 at 3:34 PM, StormchaserChuck! said:

My Summer N. Atlantic SST = Winter NAO index, is 9-1-4 in the last 14 years. It was more than 1.5SD off last Winter, but the average SD is 0.55. It comes in at -0.15 for the Winter, about Neutral. (Warm upper box is negative, Cold lower box is negative). I would say that's -0.10 even. 

Most bombed the arctic last season....I think all of the smoke from the fires really augmented the PV.

[40/70 Benchmark]

On 11/17/2020 at 3:34 PM, StormchaserChuck! said:

My Summer N. Atlantic SST = Winter NAO index, is 9-1-4 in the last 14 years. It was more than 1.5SD off last Winter, but the average SD is 0.55. It comes in at -0.15 for the Winter, about Neutral. (Warm upper box is negative, Cold lower box is negative). I would say that's -0.10 even. 

I don't think that you will be too far off this season. I think I went with + .25 to .55 range...basically neutral-positive.

I think most would take a near neutral NAO and run, this year. lol

[psuhoffman]

8 hours ago, 40/70 Benchmark said:

I don't think that you will be too far off this season. I think I went with + .25 to .55 range...basically neutral-positive.

I think most would take a near neutral NAO and run, this year. lol

depends how we get that numerical average.  A neutral NAO with a crap pac doesn't really do us any good.  But if the average is derived from a mix of positive and negative periods...that would be just fine as the negative periods would present windows of opportunity for us.  Furthermore...there are times when the NAO can be negative but from an anomaly in a position that does us very little good...(extremely east based -NAO) and there are times we can get a bootleg block near the western edge of the NAO domain and the NAO numerical value is actually neutral yet the pattern is great for us.  The devil is in the details.  

[40/70 Benchmark]

13 hours ago, psuhoffman said:

depends how we get that numerical average.  A neutral NAO with a crap pac doesn't really do us any good.  But if the average is derived from a mix of positive and negative periods...that would be just fine as the negative periods would present windows of opportunity for us.  Furthermore...there are times when the NAO can be negative but from an anomaly in a position that does us very little good...(extremely east based -NAO) and there are times we can get a bootleg block near the western edge of the NAO domain and the NAO numerical value is actually neutral yet the pattern is great for us.  The devil is in the details.  

I think you read a bit too much into that....all I meant was a neutral NAO beats the hell out of the exotic positives that we have grown accustomed to. I never said its the entire story HAHA. I lived through 2009-2010 here in SNE, so trust that I know a negative NAO is not a panacea. lol

You are also correct that there is more to the NAO domain than the assigned numerical index value.

[psuhoffman]

3 hours ago, 40/70 Benchmark said:

I think you read a bit too much into that....all I meant was a neutral NAO beats the hell out of the exotic positives that we have grown accustomed to. I never said its the entire story HAHA. I lived through 2009-2010 here in SNE, so trust that I know a negative NAO is not a panacea. lol

You are also correct that there is more to the NAO domain than the assigned numerical index value.

Sorry I know you knew all that. My post was meant to add for some others who might be reading. I should be more clear about that when I post though. 

[StormchaserChuck!]

Horrible 3-month Winter by CPC, It proves they don't really know what's going on.      I'm kind of looking forward to a -0.10 DJFM NAO prediction. 

[StormchaserChuck!]

On 11/23/2020 at 11:33 AM, 40/70 Benchmark said:

Most bombed the arctic last season....I think all of the smoke from the fires really augmented the PV.

I think someone bought up all the cold Winter derivatives lol. 

[frd]

 

Interesting 

 

 

[Maestrobjwa]

1 hour ago, frd said:

 

Interesting 

 

 

Well now...gotta that possible connection!  

[Eskimo Joe]

This is a good advance, IMO. Here's a link to the full release which shows that RAOB and commercial aircraft data will be added as well:  https://www.weather.gov/media/notification/pdf2/scn20-46rapv5_hrrr_v4aab.pdf

[psuhoffman]

On 12/1/2020 at 1:11 PM, frd said:

 

Interesting 

 

 

2013/14 is interesting because if you ignore the central equatorial pacific (raging Nina right now) the rest of the global SST anomaly patterns are very similar.  

2013

Now

[Weather Will]

WB 6Z GFS Day 10.

[Maestrobjwa]

13 hours ago, psuhoffman said:

2013/14 is interesting because if you ignore the central equatorial pacific (raging Nina right now) the rest of the global SST anomaly patterns are very similar.  

2013

Now

Huh...wonder what 2013-14 would've looked like with a nina? Lol

[Prestige Worldwide]

Embrace the torch 

[Ji]

17 hours ago, Prestige Worldwide said:

Embrace the torch 

bamwx has no idea how to run a business. who would post warm models during winter

[Roger Smith]

Here's my speculation ... not much will happen in December, until possibly late in the month, January will be quite variable and will bring one or two decent winter storm scenarios, February will continue that trend for about the first half then turn very warm, March will be a warmish month too, perhaps one late snowfall event even into early April. Overall, a fairly average winter but some good spells for winter enthusiasts, some not so great. 

Persistent west coast ridge development can be expected, downstream from that, two different patterns may oscillate, one would be highly amped flow favoring inland storm track and mild temperatures in your region, the other would be a broad trough with the polar vortex dropping into Hudson Bay and Quebec, possible snowfall events might come then as storm track would be something like the current event only with more cold air around in mid-winter. 

Best analogue would be 1975-76. Did you get much snow that winter? I was living in Ontario then, we had a lot of lake effect and some transient low pressure snowfalls and an early end to winter with record highs around Feb 25 to 29. The March 1976 storm track must have been through PA and NY because we had very heavy mixed falls for a few days, sleet and ice pellets, it all turned to rain and there was a severe flood when the heavy winter snow pack melted. From what I recall there were not a lot of coastal lows that winter. 

[psuhoffman]

37 minutes ago, Roger Smith said:

Here's my speculation ... not much will happen in December, until possibly late in the month, January will be quite variable and will bring one or two decent winter storm scenarios, February will continue that trend for about the first half then turn very warm, March will be a warmish month too, perhaps one late snowfall event even into early April. Overall, a fairly average winter but some good spells for winter enthusiasts, some not so great. 

Persistent west coast ridge development can be expected, downstream from that, two different patterns may oscillate, one would be highly amped flow favoring inland storm track and mild temperatures in your region, the other would be a broad trough with the polar vortex dropping into Hudson Bay and Quebec, possible snowfall events might come then as storm track would be something like the current event only with more cold air around in mid-winter. 

Best analogue would be 1975-76. Did you get much snow that winter? I was living in Ontario then, we had a lot of lake effect and some transient low pressure snowfalls and an early end to winter with record highs around Feb 25 to 29. The March 1976 storm track must have been through PA and NY because we had very heavy mixed falls for a few days, sleet and ice pellets, it all turned to rain and there was a severe flood when the heavy winter snow pack melted. From what I recall there were not a lot of coastal lows that winter. 

You are kidding right?  Hopefully this is you just having a dark sense of humor.  1976 was one of the absolute worst Nina winters in our area ever.  It was virtually snowless in much of our region.  DC finished with 2" for the whole season from a few very minor cartoppers...didn't even get 1" from a single storm all winter.   The northern 1/3 of our region got a moderate snowstorm very late that winter in mid March...the rest of the region pretty much had no snow all winter except a few 1/2" naissance events.  That year is a nina nightmare cautionary tale here.  

[psuhoffman]

@Roger Smith 1976 was similar to last year around here...in that it was what we get when you have a raging +NAM and a crap PAC and ATL at the same time... no hope.  The temps were colder that year due to a colder base state in general...but no way to get a frozen event and a favorable storm track in that setup.  

[Roger Smith]

Oh okay, I thought it might have been closer to average because with all that cold air around where I was (northeast of Toronto, we had a week where it never got above zero F) I figured the storm track must have been quite a bit to the south, I suppose it was just bad timing with the jet stream depressed but no energy. 

So maybe it will work out somewhat similar but with better timed energy. 

I do think the analogue will work out on a large scale but details like timing of energy can make a fairly substantial difference in a few places. 

Where I was, there was never all that much snow on the ground, wrong lake effect wind pattern (mostly NW, we did better with WNW) but some placed got absolutely buried in lake effect snow, for example, London ON. They had to go around and mark the positions of fire hydrants with 15 ft poles so the snowplows wouldn't shear them off. And all that was completely gone in about a week when it turned warm in mid to late February. 

[psuhoffman]

2 hours ago, Roger Smith said:

Oh okay, I thought it might have been closer to average because with all that cold air around where I was (northeast of Toronto, we had a week where it never got above zero F) I figured the storm track must have been quite a bit to the south, I suppose it was just bad timing with the jet stream depressed but no energy. 

So maybe it will work out somewhat similar but with better timed energy. 

I do think the analogue will work out on a large scale but details like timing of energy can make a fairly substantial difference in a few places. 

Where I was, there was never all that much snow on the ground, wrong lake effect wind pattern (mostly NW, we did better with WNW) but some placed got absolutely buried in lake effect snow, for example, London ON. They had to go around and mark the positions of fire hydrants with 15 ft poles so the snowplows wouldn't shear them off. And all that was completely gone in about a week when it turned warm in mid to late February. 

Looking at the h5 I don’t think that winter was bad luck. We rarely get much snow with a longwave pattern that features a raging +EPO/AO/NAO and WAR. That combo is a shut out the lights no hope don’t bother even paying attention pattern here. Even if we do get cold (and there were some chilly periods in 76) anything that amplified would cut in that pattern. 

[Snowy Hibbo]

In my winter forecast, I have found for an average to slightly above average winter in terms of snowfall for the Mid Atlantic.

Based upon the possibility for a SSW, some positive analogs for ENSO and QBO, decent pre-season snow cover, etc.

https://longrangesnowcenter.net/2020/12/06/north-america-winter-outlook-2020-21/

[WxUSAF]

Lol not sure what the analog is for this QBO pattern 

 

[psuhoffman]

3 hours ago, WxUSAF said:

Lol not sure what the analog is for this QBO pattern 

 

That was just one of the factors contributing to my extreme lack of confidence in seasonal forecasting lately.  Or at least my own ability to make a seasonal forecast.  I am sure there are those with a better grasp of things then me.  But between the QBO acting erratically, a lower solar minimum then we are used too, an overall warmer profile then we have ever had, and some very unusual SST configurations we have never seen before...I don't feel confident in anything.  

[StormchaserChuck!]

How about that ~ -2.00 NAO for mid-late Dec/early Jan on 12z models! I wonder if that means it will be +NAO Jan 10-March because the N. Atlantic NAO index was -0.1 for the Winter. 

[Ji]

On 7/12/2020 at 6:42 AM, CAPE said:

CFS has been on a "good" run lately with looks like these. No qualifiers necessary. We all know the deal with long range climate models.

 

cfs nailed it lol?

[CAPE]

LOL it "nailed" that and about 10 different advertised longwave patterns since then. Multiple times.

[StormchaserChuck!]

It looks like no El Nino above +0.7 will form next year, so I would go with this as my Winter forecast for 21-22..