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ENSO Discussion

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#1601
Black Hole

Posted 10 November 2018 - 10:51 AM

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Atmospheric equatorial rossby waves are typically formed (like most convectively coupled waves) from deep convection and they radiate westward from their heating source, often exhibiting a pronounced axisymmetric equatorial structure with gyres of the same sign (cyclonic or anticyclonic) straddling the equator, the speed of these waves is a function of distance from the equator, with faster westerly propagation closer to the equator and vis versa and on average they travel at about a third of the speed of a Kelvin Wave. In the case where twin cyclones are axissymmetric wrt the equator and propagating westward as an equatorial Rossby Wave, they produced westerly wind anomalies at the surface which disrupts the wind-gravity balance in the equatorial Pacific, ultimately producing a Kelvin Wave in order to restore this balance because the eastward wind is slower. Zonal advective feedbacks, those related to convection, and the underlying "elasticity" of the thermocline (in our current climate) all contribute to non-linearities in the system wherein the contribution from anomalous westerly wind of the same magnitude and duration as a corresponding easterly wind anomaly will actually push the equatorial Pacific slightly towards El Nino instead of being dead-on neutral. It's one major reason why even in years like 2014 which had one pronounced westerly wind burst over a period of several months which were actually dominated by easterlies still ended up w/ net +SSTAs in the Eq Pacific. In a warmer climate where the static stability of the upper ocean increases due to disproportionate warming rates in the upper vs middle-deep oceans actually stiffen the thermocline and dampen non-linearities that currently exist in the system, such that the strongest El Ninos will actually be as strong as the largest La Ninas instead of today where we find "Super" Ninos like 1877-78, 1982-83, & 1997-98 having greater amplitude over monster La Nina events like 1973-74, 1916-17, etc

Thanks for the explanation. Which charts do you find best to track these equatorial rossby waves? I know the kelvin waves can be seen with the anomalously warm ocean temperatures propagating eastwards. 


BS Atmospheric Science University of Utah May 2015

PhD Candidate Atmospheric Sciences

 

--Emphasis on: Forecasting, Mountain Weather, Numerical Weather Prediction, Data Assimilation

 

Winter 2017/2018

Dec 4: 3.2", 16: 0.9", 20: 2.1", 23: 1.5", 25: 4.6"

Jan 6: 1.5", 20: 10.8", 25: 1.5"

Feb 19: 8.6", 20: 2.4", 23: 7.1", 25: .5"

Mar 4: 13", 15: 1.8", 17: 5.3", 25: 4.2"

April 12: 1", 17: 1.3"

Total: 69.3"

 

 

Winter 2016/17 Snow:
Nov 17: 3.2", 23: 1.6", 28: 9.2" (14)

Dec 1: .5", 16: 2.5", 25: 13" (16)

Jan 2: 5", 3: 2.4", 4: 7.7", 12: 1", 19: 1.2", 21: 13", 23: 6", 24: 1", 25: 3.7", 26: 2.5" (43.5) 

Feb 11: .5", 23: 6.5", 27: 4.5" (13.5)

Mar 5: 5.5" (5.5)

Apr 8: 2", 9: 1.8" (3.8)

May 17: 1" (1)
Total: 96.3"

Lowest Temp: 2F


#1602
OKwx2k4

Posted 10 November 2018 - 11:17 AM

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Thank you guys all for writing that stuff out. I can usually tell you what something is going to do or show and explain(atmosphere,ENSO,etc...), but I can't touch an explanation like that for the "how?". Thank you.

#1603
Geos

Posted 10 November 2018 - 02:43 PM

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Hard drop in the 3.4 index. el Nino throwing in the towel?...

 

nino34.png


Finn Hill, elevation: 460 ft

2018 moisture: 33.99", 11/12
Lowest Temp of Autumn 2018: 29°, 11/11

2018-2019 winter snowfall total: 0.00"2017-2018: 9.0", 2016-2017: 14.0"

Weather station/wx cam: http://map.bloomsky....qBxp6apnJSnqqm2
https://www.wundergr...OTHE144#history


#1604
Webberweather53

Posted 11 November 2018 - 12:14 PM

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Thanks for the explanation. Which charts do you find best to track these equatorial rossby waves? I know the kelvin waves can be seen with the anomalously warm ocean temperatures propagating eastwards. 

 

Carl Shreck and Mike Ventrice's sites are my two favorite places to go to monitor eq Rossby Waves in real-time!

 

http://mikeventrice....hovmollers.html

 

 

https://ncics.org/po...io/monitor/mjo/



#1605
Black Hole

Posted 11 November 2018 - 02:34 PM

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Carl Shreck and Mike Ventrice's sites are my two favorite places to go to monitor eq Rossby Waves in real-time!

 

http://mikeventrice....hovmollers.html

 

 

https://ncics.org/po...io/monitor/mjo/

Thanks! Appreciate the help. Trying to become much more well versed in this stuff.


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BS Atmospheric Science University of Utah May 2015

PhD Candidate Atmospheric Sciences

 

--Emphasis on: Forecasting, Mountain Weather, Numerical Weather Prediction, Data Assimilation

 

Winter 2017/2018

Dec 4: 3.2", 16: 0.9", 20: 2.1", 23: 1.5", 25: 4.6"

Jan 6: 1.5", 20: 10.8", 25: 1.5"

Feb 19: 8.6", 20: 2.4", 23: 7.1", 25: .5"

Mar 4: 13", 15: 1.8", 17: 5.3", 25: 4.2"

April 12: 1", 17: 1.3"

Total: 69.3"

 

 

Winter 2016/17 Snow:
Nov 17: 3.2", 23: 1.6", 28: 9.2" (14)

Dec 1: .5", 16: 2.5", 25: 13" (16)

Jan 2: 5", 3: 2.4", 4: 7.7", 12: 1", 19: 1.2", 21: 13", 23: 6", 24: 1", 25: 3.7", 26: 2.5" (43.5) 

Feb 11: .5", 23: 6.5", 27: 4.5" (13.5)

Mar 5: 5.5" (5.5)

Apr 8: 2", 9: 1.8" (3.8)

May 17: 1" (1)
Total: 96.3"

Lowest Temp: 2F


#1606
Geos

Posted 11 November 2018 - 02:48 PM

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Cooling very evident now.

 

cdas-sflux_ssta7diff_global_1.png

 

Not particularly impressive looking!

 

cdas-sflux_ssta_global_1.png


  • OKwx2k4 likes this

Finn Hill, elevation: 460 ft

2018 moisture: 33.99", 11/12
Lowest Temp of Autumn 2018: 29°, 11/11

2018-2019 winter snowfall total: 0.00"2017-2018: 9.0", 2016-2017: 14.0"

Weather station/wx cam: http://map.bloomsky....qBxp6apnJSnqqm2
https://www.wundergr...OTHE144#history


#1607
snow_wizard

Posted 11 November 2018 - 04:53 PM

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Cooling very evident now.

 

cdas-sflux_ssta7diff_global_1.png

 

Not particularly impressive looking!

 

cdas-sflux_ssta_global_1.png

 

Yup...the atmosphere simply isn't on board.  The 30 day SOI is decently positive right now and the current MJO position favors further rises.


Death To Warm Anomalies!

 

Winter 2018-19 stats

 

Total Snowfall = 0.0"

Coldest Low = 27

Lows 32 or below = 4

Highs 32 or below = 0

Lows Below 20 = 0

Highs 40 or below = 0

 

 


#1608
Front Ranger

Posted 12 November 2018 - 08:18 AM

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    Forum Fantastic

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I disagree. I think there's a good shot at a major cold wave into the U.S. in mid November, and another one by late December.

 

So far, so good.


Cool anomalies soothe the soul.


#1609
SilverFallsAndrew

Posted 12 November 2018 - 08:24 AM

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So far, so good.

 

Really impressive shots of cold air into the middle and eastern part of the country so far this month. A lot of record lows on the Southern Plains the other day and probably more in the next few days. Widespread snow across Kansas and Oklahoma with this system this morning which is very unusual for this early in the season. 


Snowfall

2017-18: 30.3"

2016-17: 49.2"

2015-16: 11.75"

2014-15: 3.5"
2013-14: 11.75"
2012-13: 16.75"
2011-12: 98.5"

 

It's always sunny at Winters Hill! 

 


#1610
TT-SEA

Posted 12 November 2018 - 08:30 AM

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Any analogs for warmish neutral ENSO and low solar with significant cold air in the middle of the country in November?



#1611
Front Ranger

Posted 12 November 2018 - 08:35 AM

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Really impressive shots of cold air into the middle and eastern part of the country so far this month. A lot of record lows on the Southern Plains the other day and probably more in the next few days. Widespread snow across Kansas and Oklahoma with this system this morning which is very unusual for this early in the season. 

 

Currently 26 with snow and northerly winds gusting to 35 mph in Amarillo, TX.  :)


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Cool anomalies soothe the soul.


#1612
SilverFallsAndrew

Posted 12 November 2018 - 08:38 AM

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Currently 26 with snow and northerly winds gusting to 35 mph in Amarillo, TX.  :)

 

It's probably a little more common this time of year out in Amarillo as opposed to Tulsa. 


Snowfall

2017-18: 30.3"

2016-17: 49.2"

2015-16: 11.75"

2014-15: 3.5"
2013-14: 11.75"
2012-13: 16.75"
2011-12: 98.5"

 

It's always sunny at Winters Hill! 

 


#1613
Front Ranger

Posted 12 November 2018 - 09:27 AM

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Any analogs for warmish neutral ENSO and low solar with significant cold air in the middle of the country in November?

 

1986

1976

 

That's about it. Solar is lower this year, though. And +ENSO was more established in 1986.

 

Also, both those years had raging +PDO, while we're currently in a neutral PDO regime.


Cool anomalies soothe the soul.


#1614
Phil

Posted 12 November 2018 - 12:10 PM

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1986
1976

That's about it. Solar is lower this year, though. And +ENSO was more established in 1986.

Also, both those years had raging +PDO, while we're currently in a neutral PDO regime.


Eh, looks like a +PDO to me (albeit weaker) and both of those were solar minimum years.

Biggest difference is ENSO, ironically. Niño 3.4 has dropped back below 0.5C again. Lots of intraseasonal variability this year.

nino34.png
Personal Weather Station, Live Stream on Wunderground: https://www.wundergr...pwsdash#history

#1615
Front Ranger

Posted 12 November 2018 - 12:37 PM

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+PDO was in full control both of those years, not so this year. I think that is key for the state of the North Pacific citculation this time of year.

And yes, both those years were solar min or just after, but overall activity was higher. Especially 1986.


Cool anomalies soothe the soul.


#1616
Black Hole

Posted 12 November 2018 - 12:48 PM

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+PDO was in full control both of those years, not so this year. I think that is key for the state of the North Pacific citculation this time of year.

And yes, both those years were solar min or just after, but overall activity was higher. Especially 1986.

Will you put out a winter outlook this year?


BS Atmospheric Science University of Utah May 2015

PhD Candidate Atmospheric Sciences

 

--Emphasis on: Forecasting, Mountain Weather, Numerical Weather Prediction, Data Assimilation

 

Winter 2017/2018

Dec 4: 3.2", 16: 0.9", 20: 2.1", 23: 1.5", 25: 4.6"

Jan 6: 1.5", 20: 10.8", 25: 1.5"

Feb 19: 8.6", 20: 2.4", 23: 7.1", 25: .5"

Mar 4: 13", 15: 1.8", 17: 5.3", 25: 4.2"

April 12: 1", 17: 1.3"

Total: 69.3"

 

 

Winter 2016/17 Snow:
Nov 17: 3.2", 23: 1.6", 28: 9.2" (14)

Dec 1: .5", 16: 2.5", 25: 13" (16)

Jan 2: 5", 3: 2.4", 4: 7.7", 12: 1", 19: 1.2", 21: 13", 23: 6", 24: 1", 25: 3.7", 26: 2.5" (43.5) 

Feb 11: .5", 23: 6.5", 27: 4.5" (13.5)

Mar 5: 5.5" (5.5)

Apr 8: 2", 9: 1.8" (3.8)

May 17: 1" (1)
Total: 96.3"

Lowest Temp: 2F


#1617
Front Ranger

Posted 12 November 2018 - 12:59 PM

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Will you put out a winter outlook this year?

 

Been meaning to. It's a difficult year, but feel like we have enough info now...hopefully I'll have time to throw something together this week.


Cool anomalies soothe the soul.


#1618
Black Hole

Posted 12 November 2018 - 01:12 PM

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Been meaning to. It's a difficult year, but feel like we have enough info now...hopefully I'll have time to throw something together this week.

I will if I have time as well. Not feeling too excited about prospects this winter but I don't think it will be as terrible as say 2014/15 was. Less of an extreme +PDO should help. 


BS Atmospheric Science University of Utah May 2015

PhD Candidate Atmospheric Sciences

 

--Emphasis on: Forecasting, Mountain Weather, Numerical Weather Prediction, Data Assimilation

 

Winter 2017/2018

Dec 4: 3.2", 16: 0.9", 20: 2.1", 23: 1.5", 25: 4.6"

Jan 6: 1.5", 20: 10.8", 25: 1.5"

Feb 19: 8.6", 20: 2.4", 23: 7.1", 25: .5"

Mar 4: 13", 15: 1.8", 17: 5.3", 25: 4.2"

April 12: 1", 17: 1.3"

Total: 69.3"

 

 

Winter 2016/17 Snow:
Nov 17: 3.2", 23: 1.6", 28: 9.2" (14)

Dec 1: .5", 16: 2.5", 25: 13" (16)

Jan 2: 5", 3: 2.4", 4: 7.7", 12: 1", 19: 1.2", 21: 13", 23: 6", 24: 1", 25: 3.7", 26: 2.5" (43.5) 

Feb 11: .5", 23: 6.5", 27: 4.5" (13.5)

Mar 5: 5.5" (5.5)

Apr 8: 2", 9: 1.8" (3.8)

May 17: 1" (1)
Total: 96.3"

Lowest Temp: 2F


#1619
Webberweather53

Posted 13 November 2018 - 06:26 AM

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As I alluded to a while back, I thought the atmosphere was clearly behaving like an El Nino and further put forward that +AAM in the subtropics wasn't just a temporary poleward propagating anomaly attributable to subseasonal variability because it persisted through multiple bouts of Indian Ocean/eastern hemisphere forcing. It should be pretty obvious to everyone now it's ENSO related and here to stay, the atmosphere clearly looks like what you'd expect in an El Nino. 

 

glaam.sig.90day.gif


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#1620
Phil

Posted 13 November 2018 - 01:00 PM

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How is poleward +AAM propagation (or any meridional transfer of AAM) an ENSO descriptor?

I consider it to be a budgetary function related to instabilities triggered by the seasonal cycle, QBO, and extratropical mechanics/MTs. Meridional transfer of AAM happens every year, even if it’s initial structure is state dependent (IE: ENSO related).
Personal Weather Station, Live Stream on Wunderground: https://www.wundergr...pwsdash#history