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Btw ICYMI, I recently updated my reanalysis of 19th-21st century ENSO behavior via the "Ensemble Oceanic Nino Index (ENS ONI)" I've been running in near real-time for the past year or so. The biggest changes in this update of the index include the addition of ECMWF's newest reanalysis dataset, (ECMWF's Coupled Ocean-Atmosphere Reanalysis of the 20th Century), removal the very high resolution OISSTv2 (1/4th deg) & GHRSST OSTIA (1/20th) due to appreciable cold biases I found in these datasets (relative to others) that can be attributable to their disparate resolutions, as well as detection of an error in all December ONI data (which may have arisen in the previous version from an bug in my code used to calculate the monthly ONI) 

 


In the following text file, I've outlined my methodology and have kept a record of various changes/additions to the ENS ONI over the past year or so & I also provided standardized data, rankings, a "confidence index", raw monthly SST data (rounded to the nearest .01), and Inter-dataset Variance to provide first guess uncertainty estimates. The forthcoming release of Extended Reconstructed Sea Surface Temperature Version 5 (ERSSTv5), NOAA's 20th Century Reanalysis Version 3 (NOAA 20CRv3), and Hadley Centre Sea Ice and Sea Surface Temperature Version 2 (HADISST2) within the next several months-year or so will warrant yet another reanalysis of the ENS ONI w/ more improved ONI estimates through the mid-19th century in addition to possible extension of the ENS ONI to 1860.

http://weatheradvance.com/home/weat...c-NINO-Index-ENS-ONI-Raw-Data-1865-522017.txt

When I get a chance here in the next week or two, I will also update and release an ensemble Southern Oscillation Index (ENS SOI) that I've been working on for the past several months.

Here are the updated ONI tables color coded according to the Trenberth (1997) definition, which differs slightly from the one used at the CPC. This definition designates ENSO events when the NINO 3.4 region sea surface temperature anomalies are greater than +/- ~ 0.4C for 6 successive tri-monthly periods as opposed to +/- 0.5C for 5 successive tri-monthlies.

 

http://weatheradvance.com/home/weather/weatheradvance.com/wp-content/uploads/2017/05/Screen-Shot-2017-05-02-at-7.20.13-PM-750x1024.png

http://weatheradvance.com/home/weather/weatheradvance.com/wp-content/uploads/2017/05/Screen-Shot-2017-05-02-at-7.20.53-PM-755x1024.png

http://weatheradvance.com/home/weather/weatheradvance.com/wp-content/uploads/2017/05/Screen-Shot-2017-05-02-at-7.21.58-PM-748x1024.png

http://weatheradvance.com/home/weather/weatheradvance.com/wp-content/uploads/2017/05/Screen-Shot-2017-05-02-at-7.22.53-PM-755x1024.png

http://weatheradvance.com/home/weather/weatheradvance.com/wp-content/uploads/2017/05/Screen-Shot-2017-05-02-at-7.23.44-PM.png

http://weatheradvance.com/home/weather/weatheradvance.com/wp-content/uploads/2017/05/Screen-Shot-2017-05-02-at-7.24.22-PM.png

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Hopefully, w/ this 2nd year El Nino, we'll be able to eradicate the current -EPO/+TNH dominated configuration & the Hudson Bay-Greenland Vortex because it is one of (if not the) primary reason why

If nothing else, it will be interesting to see what effect this MJO cycle has on the current global pattern.

Yeah, I've certainly noticed, there have also been substantial low frequency changes in the EP zonal SST gradient that are contributing... The overall forcing & SST distribution in this NINO is ce

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Btw ICYMI, I recently updated my reanalysis of 19th-21st century ENSO behavior via the "Ensemble Oceanic Nino Index (ENS ONI)" I've been running in near real-time for the past year or so. The biggest changes in this update of the index include the addition of ECMWF's newest reanalysis dataset, (ECMWF's Coupled Ocean-Atmosphere Reanalysis of the 20th Century), removal the very high resolution OISSTv2 (1/4th deg) & GHRSST OSTIA (1/20th) due to appreciable cold biases I found in these datasets (relative to others) that can be attributable to their disparate resolutions, as well as detection of an error in all December ONI data (which may have arisen in the previous version from an bug in my code used to calculate the monthly ONI) 

 

In the following text file, I've outlined my methodology and have kept a record of various changes/additions to the ENS ONI over the past year or so & I also provided standardized data, rankings, a "confidence index", raw monthly SST data (rounded to the nearest .01), and Inter-dataset Variance to provide first guess uncertainty estimates. The forthcoming release of Extended Reconstructed Sea Surface Temperature Version 5 (ERSSTv5), NOAA's 20th Century Reanalysis Version 3 (NOAA 20CRv3), and Hadley Centre Sea Ice and Sea Surface Temperature Version 2 (HADISST2) within the next several months-year or so will warrant yet another reanalysis of the ENS ONI w/ more improved ONI estimates through the mid-19th century in addition to possible extension of the ENS ONI to 1860.

 

http://weatheradvance.com/home/weat...c-NINO-Index-ENS-ONI-Raw-Data-1865-522017.txt

 

When I get a chance here in the next week or two, I will also update and release an ensemble Southern Oscillation Index (ENS SOI) that I've been working on for the past several months.

 

Here are the updated ONI tables color coded according to the Trenberth (1997) definition, which differs slightly from the one used at the CPC. This definition designates ENSO events when the NINO 3.4 region sea surface temperature anomalies are greater than +/- ~ 0.4C for 6 successive tri-monthly periods as opposed to +/- 0.5C for 5 successive tri-monthlies.

 

 

In retrospect, I probably could have added 1897-98 to the list of weak La Nina years w/ a corresponding question mark, this event is certainly well within striking distance of being classified under the Trenberth definition if the new data from ERSSTv5, HADISST2, and NOAA 20CRv3 are supportive. 

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I've created a new Extended MEI (MEI.ext) time series using the 10 ensemble members from ECMWF's 20th Century Reanalysis Model (ERA-20CM) and experimented with several PC weighting adjustments I plan to implement in the Ensemble Extended MEI (ENS-MEI.ext). I also provided rankings and a time series w/ the original MEI.ext definition without any PC weighting (although 30-year sliding base periods and the EOF region remained the same as the new definition. Any comments, questions, feedback, etc. would be greatly appreciated! 

http://weatheradvance.com/home/weather/weatheradvance.com/wp-content/uploads/2017/05/ERA-20CM-MEI-1900-Nov-2010.txt

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Hard to deny the astounding interannual ENSO behavior similarities between 1929-1932 and the last 3 years. Cool Neutral >>> Borderline weak NINO >>> Strong-Super El Nino >>> Weak -ENSO event >>> Failed +ENSO event (but warmer than the preceding year)

http://weatheradvance.com/home/weather/weatheradvance.com/wp-content/uploads/2017/05/Screen-Shot-2017-05-22-at-3.06.02-PM-1024x185.png

 

http://weatheradvance.com/home/weather/weatheradvance.com/wp-content/uploads/2017/05/Screen-Shot-2017-05-22-at-3.06.20-PM-1024x186.png

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Hard to deny the astounding interannual ENSO behavior similarities between 1929-1932 and the last 3 years. Cool Neutral >>> Borderline weak NINO >>> Strong-Super El Nino >>> Weak -ENSO event >>> Failed +ENSO event (but warmer than the preceding year)

http://weatheradvance.com/home/weather/weatheradvance.com/wp-content/uploads/2017/05/Screen-Shot-2017-05-22-at-3.06.02-PM-1024x185.png

 

http://weatheradvance.com/home/weather/weatheradvance.com/wp-content/uploads/2017/05/Screen-Shot-2017-05-22-at-3.06.20-PM-1024x186.png

Interesting! Haven't looked back that far for analogs, but I'm definitely going to now. :lol:

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  • 3 weeks later...

All of those years sucked for Philly snow.

Well hey, verbatim we're on the tail end of that stretch. ;)

 

I think 2017/18 will be the grand finale in this ongoing stretch of mild winters, or will feature a mid-winter regime flip to blocking. With the QBO finally cycling negative for the first time since 2014/15 and the solar minimum approaching, I like the chances for some blocking this year, even if we end up with +EPO dominance in the long run.

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  • 2 years later...

Nino 3.4 just had a pretty sharp drop back down to zero.  Looks like Nino 4 dropped also.  The subsurface mean is just a little bit above normal.  Going to be a neutral winter as expected.

 

I will say the SOI continues to be a puzzle.  To look just at that you would think we are in a pretty major Nino.  Now with the MJO in octant 2 the low SOI is really weird.

Death To Warm Anomalies!

 

Winter 2020-21 stats

 

Total Snowfall = 7.0"

Day with 1" or more snow depth = 5

Total Hail = 0.0"

Coldest Low = 23

Lows 32 or below = 52

Highs 32 or below = 2

Lows 20 or below = 0

Highs 40 or below = 5

 

 

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