NOAA Updates its ENSO Alert on December 14, 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. Some of the other Weather Advisory Organizations are predicting a higher probability for a “Historically Strong” El Nino. I personally believe that this El Nino will be somewhat of an underachiever. We will be finding out over the next two months.
We have included a link to an interesting ENSO Blog article by Emily Becker.
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 winter 2023-24. Based on the latest forecasts, there is now a 54% chance of a “historically strong” El Niño during the November-January season (³ 2.0°C in Niño-3.4). An event of this strength would potentially be in the top 5 of El Niño events since 1950. While stronger El Niño events increase the likelihood of El Niño-related climate anomalies, it does not imply expected impacts will emerge in all locations or be of strong intensity (see CPC seasonal outlooks for probabilities of temperature and precipitation). In summary, El Niño is expected to continue through the Northern Hemisphere winter, with a transition to ENSO-neutral favored during April-June 2024 (60% chance;).” Below is the middle paragraph from the discussion last month. We see that this month there is an increased chance of a “historically strong” event. “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.” |
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 JAS 2024 and one does see a tail-off in the probabilities for El Nino conditions in the Eastern Pacific after the winter season. Is a return to La Nina in our future? |
Here is the forecast from late last month.
| The analysis this month and last month are pretty similar. |