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
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. |