NOAA Updates its ENSO Alert on July 11, 2024 – We are Now in La Nina Watch but the Expected Arrival Date has Been Delayed. – Published July 13, 2024

July 13, 2024Posted inweather2 Comments

“Synopsis:  ENSO-neutral is expected to continue for the next several months, with La Niña favored to emerge during August-October (70% chance) and persist into the Northern Hemisphere winter 2024-25 (79% chance during November-January).”

So we are really in ENSO Neutral but NOAA may not want to admit their forecast was wrong so they present it this way. It is correct that we are in La Nina Watch but it is also correct that we currently remain in ENSO Neutral..

On the second Thursday of every month, NOAA (really their Climate Prediction Center CPC) issues its analysis of the status of ENSO. This includes determining the Alert System Status.  NOAA now describes their conclusion as “ENSO Alert System Status: La Nino Watch”

The exact timing of the transition is now less clear which should decrease the reliability of the Seasonal Outlook to be issued next Thursday.

We have included an ENSO Blog article by Emily Becker.

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CLIMATE PREDICTION CENTER ENSO DISCUSSION

The second paragraph is what is important:

“Compared to the previous month, the most recent IRI plume delayed the emergence of La Niña to September-November 2024, with La Niña then persisting through the Northern Hemisphere winter.  The forecast team is also favoring a delayed development of La Niña this month, but is anticipating the transition to occur earlier (August-October).  This is, in part, supported by the continuation of below-average subsurface ocean temperatures and near-term forecasts suggesting a resurgence of easterly wind anomalies in July.  In summary, ENSO-neutral is expected to continue for the next several months, with La Niña favored to emerge during August-October (70% chance) and persist into the Northern Hemisphere winter 2024-25 (79% chance during November-January).”

Below is the middle paragraph from the discussion last month.

“The most recent IRI plume indicates La Niña may develop during July-September 2024 and then persist through the Northern Hemisphere winter. The forecast team is also favoring the development of La Niña during July-September because the rate of cooling has slowed since last month. The team still favors La Niña to emerge sometime during the summer months, given the persistent below-average subsurface ocean temperatures and changes in the tropical atmospheric circulation. In summary, ENSO-neutral conditions are present. La Niña is favored to develop during July-September (65% chance) and persist into the Northern Hemisphere winter 2024-25 (85% chance during November-January; “

We now provide additional details.

CPC Probability Distribution

Here are the new forecast probabilities. The probabilities are for three-month periods e.g. JJA stands for June/July/August.

Here is the current release of the probabilities:

This chart shows the forecast progression of the evolution of ENSO from the current El Nino State to Neutral and by the summer to La Nina.  This kind of bar chart is not very good at showing uncertainty.

Here is the forecast from last month.

The analysis this month and last month are a bit different with again the transition to La Nina being slower than thought last month. This seems to be a trend. I am not sure that we will actually have a La Nina.

Some will need to click on “Read More” to read the rest of this article.

NOAA Updates its ENSO Alert on April 11, 2024 – The El Nino Advisory/La Nina Watch Continues. Not Much Change on the Timing – Published April 11, 2024

April 12, 2024Posted inweatherNo Comments

On the second Thursday of every month, NOAA (really their Climate Prediction Center CPC) issues its analysis of the status of ENSO. This includes determining the Alert System Status.  NOAA again describes their conclusion as “ENSO Alert System Status: El Nino Advisory La Nino Watch”

The exact timing of the transition is not very clear which will impact the reliability of the Seasonal Outlook to be issued next Thursday.

We have included an ENSO Blog article by Emily Becker that includes two very interesting animations. .

 

CLIMATE PREDICTION CENTER ENSO DISCUSSION

The second paragraph is what is important:

“The most recent IRI plume indicates a transition to ENSO-neutral during spring 2024, with La Niña potentially developing during late summer 2024.  The forecast team continues to favor the dynamical model guidance, which is slightly more accurate than statistical models during this time of year.  La Niña tends to follow strong El Niño events, which also provides added confidence in the model guidance favoring La Niña.  In summary, a transition from El Niño to ENSO-neutral is likely by April-June 2024 (85% chance), with the odds of La Niña developing by June-August 2024 (60% chance).”

Below is the middle paragraph from the discussion last month.

“The most recent IRI plume indicates a transition to ENSO-neutral during spring 2024, with La Niña potentially developing during summer 2024 .  While different types of models suggest La Niña will develop, the forecast team favors the dynamical model guidance, which is slightly more accurate for forecasts made during this time of year.  Even though forecasts made through the spring season tend to be less reliable, there is a historical tendency for La Niña to follow strong El Niño events.  In summary, a transition from El Niño to ENSO-neutral is likely by April-June 2024 (83% chance), with the odds of La Niña developing by June-August 2024 (62% chance).”

We now provide additional details.  The level of uncertainty with respect to how this El Nino will play out has changed a bit. NOAA is not quite as confident that we will have a LaNina. It is a slight change.

CPC Probability Distribution

Here are the new forecast probabilities. The probabilities are for three-month periods e.g. MAM stands for March/April/May.

Here is the current release of the probabilities:

This chart shows the forecasted progression of the evolution of ENSO from the current El Nino State to Neutral and by the summer to La Nina.  This kind of bar chart is not very good at showing uncertainty.

Here is the forecast from last month.

The analysis this month and last month are not very different.
Click on “Read More” to read the rest of this article.

NOAA Updates its ENSO Alert on March 14, 2024 – The El Nino Advisory/La Nina Watch Continues. Not Much Change on the Timing – Published March 15, 2024

March 15, 2024Posted inweatherNo Comments

On the second Thursday of every month, NOAA (really their Climate Prediction Center CPC) issues its analysis of the status of ENSO. This includes determining the Alert System Status.  NOAA again describes their conclusion as “ENSO Alert System Status: El Nino Advisory La Nino Watch”

The exact timing of the transition is not very clear which will impact the reliability of the Seasonal Outlook to be issued next Thursday.

We have included an ENSO Blog article by Emily Becker.

 

CLIMATE PREDICTION CENTER ENSO DISCUSSION

 

The second paragraph is what is important:

“The most recent IRI plume indicates a transition to ENSO-neutral during spring 2024, with La Niña potentially developing during summer 2024 .  While different types of models suggest La Niña will develop, the forecast team favors the dynamical model guidance, which is slightly more accurate for forecasts made during this time of year.  Even though forecasts made through the spring season tend to be less reliable, there is a historical tendency for La Niña to follow strong El Niño events.  In summary, a transition from El Niño to ENSO-neutral is likely by April-June 2024 (83% chance), with the odds of La Niña developing by June-August 2024 (62% chance).”

Below is the middle paragraph from the discussion last month.

“The most recent IRI plume indicates a transition to ENSO-neutral during spring 2024, with La Niña potentially developing during summer 2024.  Even though forecasts made through the spring season tend to be less reliable, there is a historical tendency for La Niña to follow strong El Niño events.  The forecast team is in agreement with the latest model guidance, with some uncertainty around the timing of transitions to ENSO-neutral and, following that, La Niña.  Even as the current El Niño weakens, impacts on the United States could persist through April 2024 (see CPC seasonal outlooks for probabilities of temperature and precipitation).  In summary, a transition from El Niño to ENSO-neutral is likely by April-June 2024 (79% chance), with increasing odds of La Niña developing in June-August 2024 (55% chance).”

We now provide additional details.  The level of uncertainty with respect to how this El Nino will play out has not changed very much.

CPC Probability Distribution

Here are the new forecast probabilities. The probabilities are for three-month periods e.g. FMA stands for February/March/April.

Here is the current release of the probabilities:

This chart shows the forecasted progression of the evolution of ENSO from the current El Nino State to Neutral and by the summer to La Nina.  This kind of bar chart is not very good at showing uncertainty.

Here is the forecast from last month.

The analysis this month and last month are not very different.
Click on “Read More” to read the rest of this article.

NOAA Updates its ENSO Alert on November 9, 2023 – The El Nino Advisory Continues. In a Week, NOAA Will Update us on how this Impacts U.S. Weather

November 10, 2023Posted inweatherNo Comments

On the second Thursday of every month, NOAA (really their Climate Prediction Center CPC) issues its analysis of the status of ENSO. This includes determining the Alert System Status.  NOAA again describes their conclusion as “ENSO Alert System Status: El Nino Advisory”

There is not much doubt that we have an El Nino. How long it lasts and its strength remains to be seen. NOAA may be more conservative compared to some other Weather Advisory Organizations. That is concerning as some of the other Weather Advisory Organizations are predicting a higher probability for a “Historically Strong” El Nino.

We have included a link to an interesting ENSO Blog article by Emily Becker and a link to a fairly comprehensive article we wrote on El Nino back in September.  We have included some of the key graphics from both the Emily Becker Blog Post and the earlier article that I wrote and for those who have a strong interest in this El Nino winter, I recommend that you utilize the links to read both articles.

CLIMATE PREDICTION CENTER ENSO DISCUSSION

The second paragraph is what is important:

” The most recent IRI plume favors El Niño to continue through the Northern Hemisphere spring 2024.  Based on latest forecasts, there is a greater than 55% chance of at least a “strong” El Niño (³ 1.5°C in Niño-3.4 for a seasonal average) persisting through January-March 2024.  There is a 35% chance of this event becoming “historically strong” (³ 2.0°C) for the November-January season.  Stronger El Niño events increase the likelihood of El Niño-related climate anomalies, but do not necessarily equate to strong impacts (see CPC seasonal outlooks for probabilities of temperature and precipitation).  In summary, El Niño is anticipated to continue through the Northern Hemisphere spring (with a 62% chance during April-June 2024.”

Below is the middle paragraph from the discussion last month. We see that this month there is a substantial chance of a “historically strong” event.

“The most recent IRI plume favors El Niño to continue through the Northern Hemisphere spring 2024.  Also considering recent observations and the NMME, the team favors at least a “strong” event with a 75-85% chance through November-January (≥1.5C for the seasonal average in Niño-3.4).  There is a 3 in 10 chance of a “historically strong” event that rivals 2015-16 and 1997-98 (seasonal average ≥ 2.0C).  Stronger El Niño events increase the likelihood of El Niño-related climate anomalies, but do not necessarily equate to strong impacts locally.  Consider consulting CPC seasonal outlooks for probabilities of temperature and precipitation in the coming seasons.  In summary, El Niño is anticipated to continue through the Northern Hemisphere spring (with an 80% chance during March-May 2024).”

We now provide additional detail but I am keeping this article shorter than usual because nothing much has changed since last month.

CPC Probability Distribution

Here are the new forecast probabilities. The probabilities are for three-month periods e.g. OND stands for October/November/December.

Here is the current release of the probabilities:

You can clearly see the forecast does not extend beyond MJJ 2024 and one does see a tail-off in the probabilities for El Nino conditions in the Eastern Pacific after the winter season.

Here is the forecast from late last month.

The analysis this month and last month are pretty similar.

NOAA Updates its ENSO Alert on September 14, 2023 – The El Nino Advisory Continues. In a Week, NOAA Will Update us on how this Impacts U.S. Weather

September 15, 2023Posted inClimate, weatherNo Comments

On the second Thursday of every month, NOAA (really their Climate Prediction Center CPC) issues its analysis of the status of ENSO. This includes determining the Alert System Status.  NOAA again describes their conclusion as “ENSO Alert System Status: El Nino Advisory”

There is not much doubt that we have an El Nino. How long it lasts and its strength remains to be seen. NOAA may be more conservative compared to some other Weather Advisory Organizations.

CLIMATE PREDICTION CENTER ENSO DISCUSSION

The second paragraph is what is important:

“The most recent IRI plume indicates El Niño will persist through the Northern Hemisphere winter 2023-24.  Despite nearly the same ensemble mean amplitude as last month, the shorter forecast horizon means that the odds of at least a “strong” El Niño (≥1.5C for the November-January seasonal average in Niño-3.4) have increased to 71%.  However, a strong El Niño does not necessarily equate to strong impacts locally, with the odds of related climate anomalies often lower than the chances of El Niño itself (e.g., CPC’s seasonal outlooks).  In summary, El Niño is anticipated to continue through the Northern Hemisphere winter (with greater than 95% chance through January – March 2024; ).”

We now provide additional detail but I am keeping this article shorter than usual because nothing much has changed since last month.

CPC Probability Distribution

Here are the new forecast probabilities. This information in the past has been released twice a month and the first release is based on a survey of Meteorologists, the second is based on model results. The probabilities are for three-month periods e.g. ASO stands for August/September/October. The approach may have changed as IRI (The International Research Institute for Climate and Society, Columbia University Climate School) may no longer be involved.  Their website has not been updated this month.

Here is the current release of the probabilities:

You can clearly see the forecast does not extend beyond AMJ 2024 and one does see a tail-off in the probabilities for El Nino conditions in the Eastern Pacific after the winter season.  Some Meteorological Agencies see El Nino lasting longer but JAMSTEC showed it ending sooner in the article I posted last night which you can access HERE.

Here is the forecast from late last month.

This showed a slower demise of the El Nino.