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ENSO


jaxjagman
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Normally La Nina is bullish the entire severe weather season from Dixie early to Plains late. However this year features trouble from a southern Plains drought and possible transition toward El Nino. 

23 hours ago, rolltide_130 said:

What significance would Nina lasting in May have for the plains? Increased rainfall for March/April? I have a trip out there this May as well but I've more or less written off any hope of much action west of the I-35 corridor and I'm more prepped for an E OK/KS year this year. 

CFS keeps La Nina but it is horrible predicting spring/summer during winter. More likely Nina fades which makes severe wx fade. Drought would indeed favor east of I-35 in the jungle. Still May is by far the climo peak out there.

Last year we posted some papers about all four phases (Nina, Nino, and TNI both directions). After years of skepticism, research is revealing some correlations. 

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Passing of the KW was causing up-welling recently east of the IDL in the thermocline  showing colder waters mixing in and further east shows down-welling where warmer waters are mixing in the thermocline on the Pentad.Today's ENSO shows Nina holding rather strong with all regions with the exception of region 4 in a moderate Nina state,per Tropical Tidbits

 

CPC   Climate Weather Linkage  El Niño Southern Oscillation.png

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IRI ENSO Forecast

CPC/IRI ENSO Update

Published: Februrary 08, 2018

El Niño/Southern Oscillation (ENSO) Diagnostic Discussion issued jointly by the Climate Prediction Center/NCEP/NWS and the International Research Institute for Climate and Society

ENSO Alert System Status: La Niña Advisory

Synopsis: A transition from La Niña to ENSO-neutral is most likely during the Northern Hemisphere spring (~55% chance of ENSO-neutral during the March-May season). 

During January 2018, La Niña was evident in the pattern of below-average sea surface temperatures (SSTs) across the central and eastern equatorial Pacific Ocean (Fig. 1). The latest weekly index values were close to -1.0°C in the Niño-1+2, Niño-3, and Niño-3.4 regions, while the western-most Niño-4 region was -0.5°C (Fig. 2). While negative anomalies were maintained near the surface, the sub-surface temperatures in the eastern Pacific Ocean returned to near average during the last month (Fig. 3). This was due to the eastward propagation of above-average temperatures in association with a downwelling equatorial oceanic Kelvin wave, which undercut the below-average temperatures near the surface (Fig. 4). The atmospheric conditions over the tropical Pacific Ocean also reflected La Niña, with suppressed convection near and east of the International Date Line and enhanced convection around Indonesia (Fig. 5). Also, the low-level trade winds remained stronger than average over the western and central Pacific, while upper-level winds were anomalously westerly.  Overall, the ocean and atmosphere system remained consistent with La Niña.

Most models in the IRI/CPC plume predict La Niña will decay and return to ENSO-Neutral during the Northern Hemisphere spring 2018 (Fig. 6). The forecast consensus also favors a transition during the spring with a continuation of ENSO-neutral conditions thereafter.  In summary, a transition from La Niña to ENSO-neutral is most likely during the Northern Hemisphere spring (~55% chance of ENSO-neutral during the March-May season) (click CPC/IRI consensus forecast for the chance of each outcome for each 3-month period).

La Niña is anticipated to continue affecting temperature and precipitation across the United States during the next few months (the 3-month seasonal temperature and precipitation outlooks will be updated on Thursday February 15th). The outlooks generally favor above-average temperatures and below-median precipitation across the southern tier of the United States, and below-average temperatures and above-median precipitation across the northern tier of the United States

This discussion is a consolidated effort of the National Oceanic and Atmospheric Administration (NOAA), NOAA’s National Weather Service, and their funded institutions. Oceanic and atmospheric conditions are updated weekly on the Climate Prediction Center web site (El Niño/La Niña Current Conditions and Expert Discussions). Forecasts are also updated monthly in the Forecast Forum section of CPC’s Climate Diagnostics Bulletin. Additional perspectives and analysis are also available in an ENSO blog.

The next ENSO Diagnostics Discussion is scheduled for 8 March 2018. To receive an e-mail notification when the monthly ENSO Diagnostic Discussions are released, please send an e-mail message to: [email protected].

Climate Prediction Center
National Centers for Environmental Prediction
NOAA/National Weather Service
College Park, MD 20740

CPC/IRI Early-Month Official ENSO Forecast Probabilities

Season La Niña Neutral El Niño
JFM 2018 87% 13% 0%
FMA 2018 60% 40% 0%
MAM 2018 43% 54% 3%
AMJ 2018 32% 61% 7%
MJJ 2018 27% 56% 17%
JJA 2018 25% 54% 21%
JAS 2018 25% 50% 25%
ASO 2018 26% 46% 28%
SON 2018 27% 40% 33%
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Discussion and comparison of recent conditions with historic El Niño conditions

 

Click to enlarge
comp.png

In the context of yet another aborted El Niño event less than one year ago, this section features a comparison figure with six other short-lived events during the MEI period of record. Only one of them occurred before 1980, while 2017 joins both 2014 and 2012 in a recent clustering of events that lasted five bimonthly seasons or less, with all of them ending before September-October.

Compared to last month, the updated (December-January) MEI dropped just a bit further to reach -0.62, confirming its weak La Niña ranking.

Looking at the nearest 12 rankings (+6/-6) in this season, and excluding the five cases that showed a three-month rise of 0.5 or more, we end up with the following seven 'analogues': 1963, 68, 85, 96, 08, 09, and 12 (only 08 was flagged as an analogue last month, showing unusual volatility). Subsequently, four of these analogues indicated La Niña rankings three months later (March-April), but only one by June-July (1968) and another one by September-October (2008). On the other hand, the two most recent cases (2009 and '12) transitioned to El Niño by Jun-July, with the latter returning to ENSO-neutral later that year, and 1963 took a bit longer to reach weak El Niño status later that year. Thus, continued La Niña conditions are more likely than not for the next few months, but a transition to at least a short-lived El Niño is more likely than continued La Niña later this year, if not more likely than ENSO-neutral condiitons.

Negative SST anomalies can be found along the Equator from the dateline to South America, as seen in the latest weekly SST map. The coldest anomalies can be found east of 130W.

For an alternate interpretation of the current situation, I recommend reading the NOAA ENSO Advisory which represents the official and most recent Climate Prediction Center opinion on this subject. In its latest update (8 February 2018), weak La Niña conditions are diagnosed, and predicted to transition to ENSO-neutral during March-May with a 55% chance. This is perhaps a bit faster than I would phrase it, but then this is for Niño region 3.4.

There are a number of ENSO indices that are kept up-to-date on the web. Several of these are tracked at the NCEP website that is usually updated around the same time as the MEI, in time for this one. Note that I am referring to the OISST.v2 data, not ERSSTv5 (which are currently in sync). After a short-lived run of Niño region 3.4 SST anomalies near +0.5C in May and June 2017, this index dropped to -0.43C in September and -0.45C in October, just shy of the official La Niña threshold of -0.5C, but decreased dramatically in November (-0.86C), continued at -0.77C in December and -0.75C in January. For comparison, Niño region 3 SST nurtured +0.5C anomalies from February through May 2017, dropping to -0.2C in August, between -0.6C and -0.7C in September and October, followed by a similar dramatic drop in November (-1.05C), steadying around -1.1C in December and January.

For extended Tahiti-Darwin SOI data back to 1876, and timely monthly updates, check the Australian Bureau of Meteorology website. In 2017, this index oscillated around 0 through May, only to drop to -10 (-1 sigma) in June, corresponding to El Niño conditions for just one month, but rose to +8 in July, back down to +3 in August, +7 in September, +9 in October, +12 in November, the highest value since September 2016, only to yoyo back to -1 in December, and bouncing back to +9 in January. In other words, the SOI is back to wild fluctuations that do not really match any other ENSO index, although the longer- term average is clearly in weak La Niña territory.

The next update for the MEI is expected on or before March 10. Compared to last month, the odds for continued La Niña conditions in the MEI sense are about the same, at least through the next three months. Meanwhile, the PDO showed its lowest value since January 2014 in October (+0.05), followed by +0.15 in November and +0.50 in December. After four years of PDO-positive conditions, this index came very close to switching last fall, but seems to be stuck in the positive mode for now. Daily updates of the ENSO status can be found at the TAO/TRITON website, showing weakening La Niña conditions in early February over the equatorial Pacific, along with anomalous westerlies near the dateline. Perhaps the NOAA ENSO Advisory is correct about a quicker demise of La Niña than discussed above.

https://www.esrl.noaa.gov/psd/enso/mei/#discussion

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12 hours ago, AfewUniversesBelowNormal said:

It's strengthening a little bit, a lot versus climatology for this time of year. In El Nino transition, it's usually a little different right now meaning this probably goes until April.. that's all 

You know, I wonder how the -QBO is influenced during a transitional ENSO state.  Usually it is money for cold in this area and is closely tied to high latitude blocking.  I wonder if the -QBO is enhanced or muted during a transitional state?

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55 minutes ago, Carvers Gap said:

You know, I wonder how the -QBO is influenced during a transitional ENSO state.  Usually it is money for cold in this area and is closely tied to high latitude blocking.  I wonder if the -QBO is enhanced or muted during a transitional state?

I don't know much about the QBO. QBO, MJO, AAM sound like new age terms. It was so cool to see precip patterns change when the SOI went negative


Check out the NOI or SOI*

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2018 February Quick Look

Published: February 19, 2018

A monthly summary of the status of El Niño, La Niña, and the Southern Oscillation, or ENSO, based on the NINO3.4 index (120-170W, 5S-5N)

Use the navigation menu on the right to navigate to the different forecast sections

In mid-February 2018, the tropical Pacific reflected La Niña conditions, with SSTs in the east-central tropical Pacific in the range of weak to moderate La Niña and most key atmospheric variables showing patterns suggestive of La Niña conditions. The official CPC/IRI outlook calls for La Niña continuing through at least early spring, followed by a likely return to neutral conditions around mid-spring. Support for this scenario is provided by the latest forecasts of statistical and dynamical models.

 

 

111.png

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The SST movement changes direction next few weeks. This is when you'll see it change or not, some people say a Kelvin wave like we had is a preceding mark. Those +subsurface in the western regions are impressive. I think it's strengthening versus climo is a  strong signal for North Pacific -PNA, like we are seeing now. The whole pattern has shifted north 200 miles so you aren't going to see severe wx setups like early 2000s 

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