NOAA Updates its ENSO Alert on June 13, 2024 – The El Nino Advisory/La Nina Watch Continues but it is expected to be the Final El Nino Advisory – Published June 14, 2024
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: Final El Nino Advisory/ La Nino Watch”
The exact timing of the transition is now fairly clear which should increase the reliability of the Seasonal Outlook to be issued next Thursday.
We have included an ENSO Blog article by
>
CLIMATE PREDICTION CENTER ENSO DISCUSSION
| The second paragraph is what is important:
“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; ” Below is the middle paragraph from the discussion last month. “The most recent IRI plume favors an imminent transition to ENSO-neutral, with La Niña developing during July-September 2024 and then persisting through the Northern Hemisphere winter. The forecast team continues to favor the dynamical model guidance, which suggests La Niña could form as early as June-August 2024 [Author’s Note: slipped a month which is not a big surprise], with higher confidence of La Niña during the following seasons. La Niña generally 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 in the next month. La Niña may develop in June-August (49% chance) or July-September (69% chance).” |
We now provide additional details.
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 a bit different with again the transition to La Nina being slower than thought last month. |
