Headline: Weak La Nina Hanging On
Discussion: Strong warming stretched across the subsurface equatorial Pacific is stretching eastward well into the eastern half of the Pacific. Interestingly, a cool pool just off the northwest coast of South America has also strengthened and is preventing the approaching warmth from reaching the northwest coast of South America to kill off the La Nina. So a weak La Nina climate continues as identified by the March multivariate ENSO index (MEI) which was -0.57.
Fig. 1: Subsurface equatorial Pacific Ocean temperature anomalies indicate dramatic warming except off the northwest coast of South America.
Note that the resurgent cooling off the northwest coast of South America subsurface has also caused the Nino12 SSTA zone (purple) to cool this past week. Nino34 remains marginal La Nina.
Fig. 2: 12-week Nino SSTA observations indicate a steady weak La Nina. Note the cooler Nino12 region (caused by the resurgent subsurface cooling off the northwest coast of South America).