Winter 2020-21 Discussion

[BristowWx]

Just got the new Farmers Almanac...”sheets of sleet” for LWX.  Curious use of words.  Chuckle worthy but traditional. 

[StormchaserChuck!]

More of this stuff guys (ridge in the West)

[Maestrobjwa]

3 hours ago, BristowWx said:

Just got the new Farmers Almanac...”sheets of sleet” for LWX.  Curious use of words.  Chuckle worthy but traditional. 

What I found interesting about them last year was...not even THEY forecasted in big storms for last winter like they usually tend to do! That shoulda warned us of last winter's drudgery, lol

[BristowWx]

2 hours ago, Maestrobjwa said:

What I found interesting about them last year was...not even THEY forecasted in big storms for last winter like they usually tend to do! That shoulda warned us of last winter's drudgery, lol

Agree.  They do mention the solar minimum but offset by continued warming.  They are spitballing like the rest of us.  Anything would be better than last winter.  

[StormchaserChuck!]

Looks like another +NAO Winter.. just horrible.

Arctic ice melt pattern. 

[CAPE]

September edition of the CanSIPS is out. My glass half full overview-

Overall it looks less torchy for the winter months than the previous run. For December, not a half bad look, and verbatim just about average temps. At h5 the positive heights in the EPAC are such that the mean ridge is decently placed..close enough for perhaps a +PNA at times. Beyond that the heights shift westward in Jan, but still not a terrible look for the east coast- maybe a gradient type pattern. By Feb the EPAC ridge is a monster, max +height anomalies south of the Aleutians, and whatever winter there was would be over. Up top, December looks like a neutral AO/NAO, Jan a somewhat +AO/NAO,  Feb ++AO/NAO. So not much help in the high latitudes.

[snowman19]

3 hours ago, CAPE said:

September edition of the CanSIPS is out. My glass half full overview-

Overall it looks less torchy for the winter months than the previous run. For December, not a half bad look, and verbatim just about average temps. At h5 the positive heights in the EPAC are such that the mean ridge is decently placed..close enough for perhaps a +PNA at times. Beyond that the heights shift westward in Jan, but still not a terrible look for the east coast- maybe a gradient type pattern. By Feb the EPAC ridge is a monster, and whatever winter there was would be over. Up top, December looks like a neutral AO/NAO, Jan a somewhat +AO/NAO,  Feb ++AO/NAO. So not much help in the high latitudes.

It honestly looks like a typical La Niña “front end loaded” (Dec - mid January) winter. It’s truly amazing that the models continue to advertise +NAO/+AO, just amazingly persistent for years now. December does look more neutral like you said

[Scarlet Pimpernel]

On 8/20/2020 at 6:25 PM, nw baltimore wx said:

I’d enjoy seeing some 2-4” clippers with cold, blustery winds behind them. It’s been awhile. 

Something like Feb. 14, 2015 would be kinda cool!!  That wasn't really 2-4" area-wide, but I got like 2" in an hour or so followed by gusty winds and temperatures plummeted into the teens for the next day or so, as an Arctic front went through.  One of the coolest "mini events" I can remember.

[Scarlet Pimpernel]

11 pages for a Winter 2020-21 thread, and we're barely into September...oy gevalt!!  Either desperation or hope, I'm not sure which.

I didn't read the whole thing, but has Ji canceled this upcoming winter yet?  And how many times?   Do we have Panic Room previews??  @WxWatcher007 promised so many new amenities this upcoming season for the wayward weenies!!

[CAPE]

On 8/20/2020 at 5:15 AM, CAPE said:

CFS is on one of its better "runs" lately, 

Big picture h5 for Dec and Jan look pretty decent, and is a 'believable' look for a typical weak Nina. Feb doesn't look bad either, but with the massive +height anomalies it has in the EPAC, there would probably be more of a ridge in the east, although it also suggests a -NAO lol.

The latest CFS runs now have a torch for December lol, but then a pretty good look for January- similar to above but better- deeper trough and hints of a bit of HL help. Looks pretty similar to h5 back in Jan of 2018 when we had the cold period(and the bomb cyclone). February doesn't look terrible either. All just for fun ofc at this juncture with these climate models.

[North Balti Zen]

Sounds like a CFS CFS blend gets us three months of winter. Off to pitch my analysis to Bastardi...

[CAPE]

2 hours ago, North Balti Zen said:

Sounds like a CFS CFS blend gets us three months of winter. Off to pitch my analysis to Bastardi...

Yeah a CanSIPS Dec followed by a CFS Jan and Feb would be pretty decent.

A month from now we can reanalyze.This is fun.

[snowman19]

Looks like this is going to be a +QBO winter, August’s QBO number went up to +4.78

[CAPE]

3 hours ago, snowman19 said:

Looks like this is going to be a +QBO winter, August’s QBO number went up to +4.78

QBO won't make much difference. Its impacts are nebulous imo, and even more so in Nina. The AO/NAO is pretty much guaranteed to be positive for the winter months based on persistence and general correlation to Nina. Not to say we wont have a few periods where it is less positive or neutral. Maybe the solar minimum will save the day(winter).

[psuhoffman]

44 minutes ago, CAPE said:

QBO won't make much difference. Its impacts are nebulous imo, and even more so in Nina. The AO/NAO is pretty much guaranteed to be positive for the winter months based on persistence and general correlation to Nina. Not to say we wont have a few periods where it is less positive or neutral. Maybe the solar minimum will save the day(winter).

Keep this in mind though...going back 50 years DC hasn’t had a warning level snow during a Nina without some NAO blocking preceding the event. I went back and looked at EVERY Nina warning event a few years ago and found every one was set up by blocking. In some cases it was a bootleg block that didn’t necessarily tank the numerical NAO.  But when I examined the h5 it was there. So absent any blocking kiss any chances of more than minor events in DC goodbye. 

[StormchaserChuck!]

Nina/+QBO is strong 10mb PV, it will probably downwell given the weak atmospheric conditions. 

[CAPE]

11 hours ago, psuhoffman said:

Keep this in mind though...going back 50 years DC hasn’t had a warning level snow during a Nina without some NAO blocking preceding the event. I went back and looked at EVERY Nina warning event a few years ago and found every one was set up by blocking. In some cases it was a bootleg block that didn’t necessarily tank the numerical NAO.  But when I examined the h5 it was there. So absent any blocking kiss any chances of more than minor events in DC goodbye. 

Blocking would be lovely, but as we all know, its pretty rare during winter lately. We could see something transient ofc, but if this winter is to feature a colder period, I am inclined to think it will probably require a favorable EPAC for a time, something like Jan of 2018. No one in DC area should expect more than a low end warning event or 2 at best, and hopefully a few 1-2" deals. That would be a major win after the debacle of last winter.

[StormchaserChuck!]

It's like.. the pattern defaults, and the NAO is a sub-index at this point. It would be nice to see that change. I say that too about the 10mb PV, it just seems par for the course for the pattern of late and the Nina is weak around -0.7. 

[psuhoffman]

1 hour ago, CAPE said:

Blocking would be lovely, but as we all know, its pretty rare during winter lately. We could see something transient ofc, but if this winter is to feature a colder period, I am inclined to think it will probably require a favorable EPAC for a time, something like Jan of 2018. No one in DC area should expect more than a low end warming event or 2 at best, and hopefully a few 1-2" deals. That would be a major win after the debacle of last winter.

I don’t disagree, just pointing out the fact that in a Nina DC really needs some HL blocking to get a decent snow. It was shocking how much so. In all other enso conditions DC can luck their way to a warning event without blocking.  But in a Nina even cold periods absent blocking typically end up dry. No stj tends to be a big problem. Can’t luck into a progressive southern steam wave. Need a strong block to force the northern stream to dig under us and pick up some gulf moisture.   I’m not saying we get blocking.  And we don’t need long periods, we could cash in with transient blocking.  Just saying the Nina’s that featured a raging +NAO wall to wall like last year...well they ended up like last year.  We need to hope we get at least some favorable looks up top (even if only temporary) or the panic room will be very busy!

[psuhoffman]

@CAPE of course records are made to be broken. I’m sure there have been big snow in a Nina absent blocking if you go back far enough. I’m sure it’s possible. Just very unlikely. Kinda like 2010.  But maybe this year is the 1/100 fluke. But if you told me today the NAO behaves like last winter and is wall to wall positive I would bet DC ends up under 5” snowfall!  

[CAPE]

9 hours ago, psuhoffman said:

I don’t disagree, just pointing out the fact that in a Nina DC really needs some HL blocking to get a decent snow. It was shocking how much so. In all other enso conditions DC can luck their way to a warning event without blocking.  But in a Nina even cold periods absent blocking typically end up dry. No stj tends to be a big problem. Can’t luck into a progressive southern steam wave. Need a strong block to force the northern stream to dig under us and pick up some gulf moisture.   I’m not saying we get blocking.  And we don’t need long periods, we could cash in with transient blocking.  Just saying the Nina’s that featured a raging +NAO wall to wall like last year...well they ended up like last year.  We need to hope we get at least some favorable looks up top (even if only temporary) or the panic room will be very busy!

I know this is not DC- but I am basically on the same latitude and at low elevation- and I can think of 3 warning level events right off the top of my head in the last 2 Nina winters. The one in March I think did have some blocking, but the other 2 didn't. They were both coastal scrapers with 10" plus at the beaches, about 6 here, and little to nothing for DC. Just dumb luck I suppose.

eta- being further East/NE does help in  a Nina with catching the edge of a Miller B sometimes. Happened here in Dec 2010 (the storm never to be mentioned). Got 5" or so from that, and there was 10+ a few miles to my east, but that period did feature a -NAO IIRC.

[psuhoffman]

11 hours ago, CAPE said:

Odd how here- I know this is not DC, but basically on the same latitude and at low elevation- I can think of 3 warning level events right off the top of my head in the last 2 Nina winters. The one in March I think did have some blocking, but the other 2 didn't. They were both coastal scrapers with 10" plus at the beaches, about 6 here, and little to nothing for DC. Just dumb luck I suppose.

eta- being further East/NE does help in  a Nina with catching the edge of a Miller B sometimes. Happened here in Dec 2010 (the storm never to be mentioned). Got 5" or so from that, and that period did feature a -NAO IIRC.

You are actually in a better spot to try to luck into a warning level snow in a Nina without blocking. You can catch the west edge of some progressive late developing storms like are common in a Nina. DC is just too far west. Heck even with blocking they miss a lot but it at least gives them a chance. All the decent Nina snows in DC had blocking help.  March 18, January 2011, March 2009, February 2006, Jan 2000, March 99, and all the 96 storms featured at least some blocking leading up to them.  

 

 

[yoda]

it has begun

URGENT - WINTER WEATHER MESSAGE
National Weather Service Missoula MT
1235 PM MDT Fri Sep 4 2020

MTZ007-043-051845-
/O.NEW.KMSO.WS.A.0008.200907T1800Z-200908T0400Z/
Butte/Blackfoot Region-Potomac/Seeley Lake Region-
1235 PM MDT Fri Sep 4 2020

...WINTER STORM WATCH IN EFFECT FROM MONDAY AFTERNOON THROUGH
MONDAY EVENING ABOVE 6000 FEET...

* WHAT...Heavy snow possible above 6000 feet. Total snow
  accumulations of 2 to 4 inches with up to 6 inches above 7000
  feet possible.

* WHERE...Higher terrain of the Butte/Blackfoot Region and
  Potomac/Seeley Lake Region.

* WHEN...From Monday afternoon through Monday evening.

* IMPACTS...Persons with plans to be in the mountains or
  backcountry will experience very cold, wet and windy weather
  which will produce exceptionally raw and potentially dangerous
  conditions.

--------------------------------------------

URGENT - WINTER WEATHER MESSAGE
National Weather Service Missoula MT
1235 PM MDT Fri Sep 4 2020

MTZ002-051845-
/O.NEW.KMSO.WS.A.0008.200907T1500Z-200908T0400Z/
West Glacier Region-
1235 PM MDT Fri Sep 4 2020

...WINTER STORM WATCH IN EFFECT FROM MONDAY MORNING THROUGH
MONDAY EVENING ABOVE 6000 FEET...

* WHAT...Heavy snow possible above 6000 feet. Total snow
  accumulations of 2 to 4 inches possible at Logan Pass. Up to 7
  inches are possible above 7000 feet.

* WHERE...Higher terrain of the West Glacier Region.

* WHEN...From Monday morning through Monday evening.

* IMPACTS...Persons with plans to be in the mountains or
  backcountry will experience very cold, wet and windy weather
  which will produce exceptionally raw and potentially dangerous
  conditions.

[snowman19]

This is a pretty healthy looking La Niña at the moment. It’s really becoming more of a basin-wide event....region 4 hasn’t stayed this consistently cool for quite a long time:  

[frd]

8 minutes ago, snowman19 said:

This is a pretty healthy looking La Niña at the moment. It’s really becoming more of a basin-wide event....region 4 hasn’t stayed this consistently cool for quite

Might get a glimpse into the boreal winter pattern and outcomes during the end of Sept and early October according tho Ben.  

 

[Maestrobjwa]

http://www.arrl.org/news/solar-minimum-most-likely-occurred-in-december-2019

So according to this...they think it's possible that we did indeed hit the bottom back in December. So I'd imagine...if the "lag" in the benefit of previous solar minimums is true, then if we are to benefit from this one at all, we'd probably have to see it this winter. But if we don't...seems to me like we might have to consider that not even the solar min works anymore, smh

BUT...on the other hand...hey, if we hit the magic 18" mark or go above in a nina, we might be able to say it still works, haha

[psuhoffman]

3 hours ago, Maestrobjwa said:

http://www.arrl.org/news/solar-minimum-most-likely-occurred-in-december-2019

So according to this...they think it's possible that we did indeed hit the bottom back in December. So I'd imagine...if the "lag" in the benefit of previous solar minimums is true, then if we are to benefit from this one at all, we'd probably have to see it this winter. But if we don't...seems to me like we might have to consider that not even the solar min works anymore, smh

BUT...on the other hand...hey, if we hit the magic 18" mark or go above in a nina, we might be able to say it still works, haha

But did it ever really work. It was too small a sample to really show true statistically significant causality correlation. Consider historically we tend to get a big winter every 3-5 years anyways. And I’ve seen winters on either side of past minimums attributed to that. So that’s like a 3 year window. Could easily have been only a very minor weak correlation and as much to do with random chance as a true strong causality. That said hope this year proves that wrong. It’s all we got. 

[Maestrobjwa]

19 minutes ago, psuhoffman said:

But did it ever really work. It was too small a sample to really show true statistically significant causality correlation. Consider historically we tend to get a big winter every 3-5 years anyways. And I’ve seen winters on either side of past minimums attributed to that. So that’s like a 3 year window. Could easily have been only a very minor weak correlation and as much to do with random chance as a true strong causality. That said hope this year proves that wrong. It’s all we got. 

Now I've contemplated that argument about the strength (or lack thereof) of correlation...So you're better with statistics, so I'll just reiterate what I posted several months ago: I counted 11 solar minimums since 1902. Now...is 11 times still too small of a sample size? And if so...is the reason because there could've been some coincidences mixed in?

I made a post of the listed minimums and matched them up with the two winters that followed them. And each time...at least one of the two were above average except for the ones following the 1996 "bottom" (but that was the one time where the benefit came just before). Now is there something else to look at where we could gain more insight?

[Maestrobjwa]

55 minutes ago, psuhoffman said:

Consider historically we tend to get a big winter every 3-5 years anyways.

And dude...we might be about to test that a bit...gonna be five years this year, lol Man I hope stuff ain't broke in such a way that we gotta start waiting even longer for big winters! Life on this side is too short to have to wait 6+ years for an above average winter, lol My biggest fear is that stuff is so broke big winters are gonna be even harder to come by, smh

[CAPE]

3 hours ago, Maestrobjwa said:

And dude...we might be about to test that a bit...gonna be five years this year, lol Man I hope stuff ain't broke in such a way that we gotta start waiting even longer for big winters! Life on this side is too short to have to wait 6+ years for an above average winter, lol My biggest fear is that stuff is so broke big winters are gonna be even harder to come by, smh

You should get used to this possibility unless you plan to relocate. Or be more realistic with expectations and use median instead of mean.